MSD ignition LEts see some

[dzolcali]

I want to see some peoples MSD ignition set ups.

What exactly does it improve on your jeep, or what can it do for your Jeep.

[Beej]

I don't have pics, but:

MSD stands for Multiple Spark Discharge. As the name says, they allow multiple sparks to ensure that the compressed fuel/air mixture in the chamber fully ignites. It is also a hotter spark and the plugs can be gapped further providing a larger spark as well. In some cases, this can increase horsepower since it increases efficiency, but some debate this. In a two-stroke engine, there is no doubt that they help enormously. They are also bombproof. Running an MSD ignition can increase RF noise which can be heard through your audio and in some cases disrupt computer function among other electronic things. So its also a very good idea to get the best plugs and plug wires you can find. 8.5mm plug wires and some kind of split-fire or other high-tech plug.

I don't have one on my Jeep, but I've had them on other vehicles. I like the simplicity and reliability of them. I've never really noticed any performance enhancements with them, except on a two-stroke engine. It really boosted the HP...

HTH

[dzolcali]

So, if I were to do a msd set up, it wouldn't smooth out the rpms and give the jeep a rougher sounding idle, or more growl or something. Just wondering, my friend had put an msd on his datsun truck a long time ago and that thing sounded beasty when he was done with it. Had some sorta rev limiter thing on it to?
arghh

[Beej]

So, if I were to do a msd set up, it wouldn't smooth out the rpms and give the jeep a rougher sounding idle, or more growl or something. Just wondering, my friend had put an msd on his datsun truck a long time ago and that thing sounded beasty when he was done with it. Had some sorta rev limiter thing on it to?
arghh I've never noticed a change like that with the MSD mod. Are you sure he didn't also put on a free flow exhaust and open intake? Those would account for the growl. The rougher sounding idle could just be advanced timing...

Others may have different thoughts...

[OT]

I wouldn't put one on a stock 4.0.
Hell, I wouldn't put one on a souped up 4.0, for that matter.
You'd be money ahead with just a hotter coil and a Tornado.

[dzolcali]

whats a tornado?

[OT]

whats a tornado?
http://www.improve-gas-mileage.net/images/tornadotv.gif


Seriously, not really.
:roflmao:

[dzolcali]

Ok umm I don't want that gimmick in my jeep. I want a way to like fine tune my engine so it sounds beefy, I got a flow master on it now....but I want even more growl but a smooth tone you know. Nvm just thought the msd would help

[BBeach]

If you've ever tried Rusty's air tube with with the 9" filter it sounds really good on my jeep imo. http://rustysoffroad.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=XJAT-1&Category_Code=PER_AIR There are people on here that make them themselves for very cheap. Basically an intake and exhaust would make it sound good.

[lighthouse jim]

I wouldn't put one on a stock 4.0.
Hell, I wouldn't put one on a souped up 4.0, for that matter.
You'd be money ahead with just a hotter coil and a Tornado.


Any suggestions on a" hotter coil"? I'm running a bit rich in my 91and have been thinking about an ignition upgrade of some sort, but don't know what I want, yet. I like the Rusty's intake kit--the price is reasonable. thanks.

[MudDawg]

Find the reason for the rich condition and fix it...the stock ignition is fine. I have run MSD on competition engines for years....they really help keep the fires burning in carbed motors with lots of cam duration, overlap and serious compression where the idle tends to be really rich...in the old days, stock ignitions were lacking somewhat in fire power...your ignition is fine on a stock motor unless there is something wrong with some ignition component....and stay away from "trick" spark plugs...they are a waste of $$ and may decrease your performance...

If you have use for a 2 step or a rev limiter...MSD is a good way to go..

[Bouncy]

Would an MSD get rid of the 5k rpm limit??

And which MSD coil/hotter coil should be put in?

I have a spare MSD 6al and thought about installing it also. Reading this, I may hold on to it instead.

[MudDawg]

It won't override the inherent rev limiter unless you changed to a stand alone ignition...then your efi won't work...unless there is a patch for that.
You can call MSD about it..they have excellent tech assistance.

[streetpirate]

then your efi won't work...unless there is a patch for that.


Thats easy, just set your IRQ to 62, make sure you are set up to recieve inbound host connections then flash the bios.

[Bouncy]

I emailed MSD about a week ago and haven't heard back on which coil to use.

StreetPirate...HUH?

Anywho, I had a spare MSD-6AL in the barn and was thinking of using it to get more/better spark. Wondered if it would screw up anything else. Also wondered if I could use a 6k chip in it like I have on my carbed V8.

Guess a hotter coil is all I can do without any major hassle.

[tealcherokee]

I emailed MSD about a week ago and haven't heard back on which coil to use.

StreetPirate...HUH?

Anywho, I had a spare MSD-6AL in the barn and was thinking of using it to get more/better spark. Wondered if it would screw up anything else. Also wondered if I could use a 6k chip in it like I have on my carbed V8.

Guess a hotter coil is all I can do without any major hassle.


WHY.... 4.0 makes peak power WAY before the 5250 rev limiter. and valves float around 5300-5400

[Bouncy]

WHY.... 4.0 makes peak power WAY before the 5250 rev limiter. and valves float around 5300-5400

Not sure if I am going overboard but...

4.7 stroker
Heavy valve springs
Better cam
Fully ported and polished head
Balanced assembly

May...Or at least should hit 6k rpm without to many problems.

I agree with you on the other info...But I am building this motor to run a little better than stock :D

[OT]

This is what I'm referring to, being better for a 4.0 application than an MSD.

http://www.4wd.com/newsite/shop/productdetail.asp?pid=9398&model=cherokee&cat=7&kid=502&catid=502&mid=n

I've installed two of these kits and there was a noticable difference.

http://www.4wd.com/catalog/products/large/9398.jpg

[dzolcali]

those look like nice plug wires...I already bought a rotor switch and distributor cap, whcih I have installed....I'm wondering, if I were to get msd 8.5mm wires would it help make things run smoother like that kit is claiming? Also i'm running performance truck plugs...can't remember who makes them but they are recommended by a few people on the boards. I have noticed significant improvement in rpm idle and rev after installing a new distributor cap alone.


off subject, how much are people paying to get qaulity window tinting jobs around here...I'm about to drop 250 for 15% on all the backs, and 45% on the front two does that sound reasonable.

[MudDawg]

Pop a 8k chip in it like i have on the mighty 2.5 mod-2.2

[MogifiedXJ]

This is what I'm referring to, being better for a 4.0 application than an MSD.

http://www.4wd.com/newsite/shop/productdetail.asp?pid=9398&model=cherokee&cat=7&kid=502&catid=502&mid=n

I've installed two of these kits and there was a noticable difference.

http://www.4wd.com/catalog/products/large/9398.jpg
I heard adding red spark plug wires adds like 25 rear wheel horsepower...just imagine if you added a red cap too. Oh, man!!!























































ahahahahah....for the love of God I'm only kidding. :D

[streetpirate]

off subject, how much are people paying to get qaulity window tinting jobs around here...I'm about to drop 250 for 15% on all the backs, and 45% on the front two does that sound reasonable.

I tinted my own, did 20 on all rears and 35 on doors, and its way to light on the doors. i would reccomend 20 all around.
tint shops wanted 300 and up to do my jeep, i did it myself for 60-70, and it all turned out great exept i got a little dust under the first one i did, and tore it a little in the corner.

it was relativaly easy, after doing my jeep, i would feel quite comfortable tinting any car that didnt have curvy glass.

and as far as the curves, the rear window has enough of a curve to it to be a PITA



CANT POST PICS BECAUSE MY FIREWALL AT WORK THINKS PHOTOBUCKET IS BAD!
stupid thing

[streetpirate]

MR. gasket exaust cut out, straight pipes at the pull of a cable for $50

[BBeach]

WHY.... 4.0 makes peak power WAY before the 5250 rev limiter. and valves float around 5300-5400
I agree with you on that, i tried holding it to redline by puttin it in the "1-2" gear in the auto at around 4900rpm and it'll keep going till prolly 5300 and it felt useless and i got worse elapsed times (done at track not doing all the time). I think if you look at the dyno graphs they cut out either because of them not going further or the engine not working best? Also, does this mean that the valves stay open or something floating and all? Is this why some cars sometimes put out blue or white smoke near redline through the exhaust like gas not being combusted properly or maybe oil seeping through the rings??

[Bouncy]

Blue smoke is oil
White smoke is coolant

Blue is rings going
White is head gasket.

As for 5250 rpms on a STOCK motor. On STOCK valves. On STOCK cam and on a STOCK head...yeah I can see the dyno curve and charts too.

On a 4.7 STROKER with a higher lift cam and a fully ported head with massive work on the runners and larger valves. With stiffer springs on the valves. With a fully balanced assembly and good bearings and a better harmonic balancer. blah blah blah...you get the idea....IT MAKES POWER.

Simple...take a V8 motor and it red lines at 5200rpms...Motor is done...FROM THE FACTORY. Take that same motor..remove all the casting flash and clean it up. Hop up the cam and get rid of the rev limiter and you get more power and higher RPMs.

Consider this...my 5.2 in my truck reds at 5200 rpms...thank you mr. epa. My 1973 cuda with a 340 4bbl red lined at 7K rpm. Pretty much same block, same stroke, little bigger pistons, same technology, and worse tolerances in 1973. 20 years newer for the 5.2 and they say it "CANT" do any better above 5200rpms...Horsesh1t

As for the question about valve float. float is the point were the spring isn't strong enough to close the valve as fast as the timing gear is moving. Thus the cam has rotated off the lobe, the push rod wants to follow the lifter down on the base of the cam...The rocker wants to follow the rocker...BUT the spring is strong enough/applying enough pressure to push the rocker against the push rod and keep pressure on it for a smooth flow of the parts.

What happens is, the spring kinda pops open and the head of the spring hits the rocker making a metal on metal noise like a machine gun....Read into this as a domino effect. Rocker HITs the push rod, push rod hits the lifter and so on...All that metal hitting eachother instead of riding smooth is called valve float and can lead to a blow motor pretty quickly.

Also with valve float, you have to worry about the valve staying open longer than it should....The piston may come up and hit the valve that is open...This is one of the reasons motors are timed. So the piston chases the intake valve as it comes up through the cylinder.

[tealcherokee]

BlaH blah blah.

on paper, you might think thats right, and for a v8 it is.

In realitly thats completly wrong for an I6





I just talk to the guys from clifford, all they do is straight 6 stuff. The stuff they know is amazing. John clifford beat a top fuel drag car in an AMC in the 1/8 mile.

anyway, w/ all the races they've won, never once have they shifted past 4300 rpm.

straight 6's dont make power, they make torque, and they make alot of it.

cliffords engines make 450 WHEEL torque at 3000 rpm!!!

[Bouncy]

on paper, you might think thats right, and for a v8 it is.

In realitly thats completly wrong for an I6





I just talk to the guys from clifford, all they do is straight 6 stuff. The stuff they know is amazing. John clifford beat a top fuel drag car in an AMC in the 1/8 mile.

anyway, w/ all the races they've won, never once have they shifted past 4300 rpm.

straight 6's dont make power, they make torque, and they make alot of it.

cliffords engines make 450 WHEEL torque at 3000 rpm!!!


I understand torque at low rpms...thus my ram running around 450hp and 1200 tq at the WHEELS. cummins 6 cylinder setup. It was enough to pull a fully loaded steel hauler out of the snow. And yes it makes the power and torque in the low rpms.

On the jeep, you can spin the motor to higher rpms and still make power. I'm not an electronics expert by any means but more fuel in more power out. I'm not building a race motor but with 4.10 gears or 4.56s, the red line comes up too fast and I'm not in the market for a 2nd gear when I'm climbing some sandy hills. Or even going through mud for that matter.

In the end, I've built far to many race motors and have a few ideas about how to do a 6 for wheelin. Its not that my ears are closed. Its more simple math. Fuel, Air, Lift of the cam, compression all equal power.

[BBeach]

on paper, you might think thats right, and for a v8 it is.

In realitly thats completly wrong for an I6





I just talk to the guys from clifford, all they do is straight 6 stuff. The stuff they know is amazing. John clifford beat a top fuel drag car in an AMC in the 1/8 mile.

anyway, w/ all the races they've won, never once have they shifted past 4300 rpm.

straight 6's dont make power, they make torque, and they make alot of it.

cliffords engines make 450 WHEEL torque at 3000 rpm!!!
Im not sure if you're being specific to jeep/truck applied inline 6s but the bmw m3's s54 inline 6 screams to 8000rpm, and there are plenty of nissan engines seen in the skyline and such that go much higher than 5k. However, they are DOHC for the most part not the OHV like us truck guys. It would be really cool if someone could make the 4.0 into a dohc setup. It would involve a new head and somehow doing away with the old camshaft. Timing chains would have to be changed and well, a lot of things, but imagine the possibilties. :roll:

[Beej]

On the jeep, you can spin the motor to higher rpms and still make power. I'm not an electronics expert by any means but more fuel in more power out. I'm not building a race motor but with 4.10 gears or 4.56s, the red line comes up too fast and I'm not in the market for a 2nd gear when I'm climbing some sandy hills. Or even going through mud for that matter.

In the end, I've built far to many race motors and have a few ideas about how to do a 6 for wheelin. Its not that my ears are closed. Its more simple math. Fuel, Air, Lift of the cam, compression all equal power. The high rpm harmonic that occurs in inline sixes is inherent to inline sixes. This is why a pushrod inline's limit is typically below 6000. As tealcherokee said, you can push the rpm limit higher, but why bother? Yes it will still produce power at higher rpm's but the peak power still occurs at lower rpm's. Your analogy about climbing a sandy hill is a good point, but can't you keep the motor in its powerband while climbing a hill without resorting to overreving?

When it comes to ICE's, rather than looking at more fuel in = more power out, think of it as more fuel+air in = more power out. The Jeep inline six's head is not the best for breathability and there's not much to work with in the head as far as re-porting for maximum high end rpm's. This is one of the reasons the Hesco head is desirable. In the regular head, you can jam in as much fuel as you want, if the head can't get enough air through, your power isn't going to increase, agreed?

Im not sure if you're being specific to jeep/truck applied inline 6s but the bmw m3's s54 inline 6 screams to 8000rpm, and there are plenty of nissan engines seen in the skyline and such that go much higher than 5k. However, they are DOHC for the most part not the OHV like us truck guys. It would be really cool if someone could make the 4.0 into a dohc setup. It would involve a new head and somehow doing away with the old camshaft. Timing chains would have to be changed and well, a lot of things, but imagine the possibilties. :roll: All of those high revvers are SOHC or DOHC without exception. I'm with you on the OHC idea for the 4.0. If it was doable in an efficient manner, the possibilities would be exciting...

[MudDawg]

Send a block and head to Cosworth...along with a train-car load of $50's.
Or maybe to Yamaha...they designed and built the heads for those nasty little dohc Toyota 1600's. Hell their own engines are approaching 175 hp per litre. A few years ago Honda had a 1.8 engine that produced more hp per litre than any other production car engine. Ford built an experimental version of the old 2.0 that used composite component technology to rev over 12k and make nearly 300 hp.

The reasons the 4.0 will never be a 10k rpm screamer are as Beej pointed out, it's inherent rpm limitations..the harmonic will eventually kill the crank. And the production head will not support (without forced induction) the CFM requirement for high rpm...the engine was designed for low production cost, ease of fitting external components (intake and exhaust), and to provide suitable power output for it's intended purpose (power a normal street vehicle).

HP is a theoretical figure...is is not measured directly...the torque (measurable) is used with a formula to determine how much work can be done (hp).

[tealcherokee]

and the simple fact, how the inline 6 works, youd need to go to a coil pack set up, a distributor physically cant keep up, youll either have it retarded too much or advanced too much for the high rpms, and in the low end youll have nothing

[BBeach]

and the simple fact, how the inline 6 works, youd need to go to a coil pack set up, a distributor physically cant keep up, youll either have it retarded too much or advanced too much for the high rpms, and in the low end youll have nothing
Is that because the rotor thing inside the distributor cant keep up? As in just no be able to spin fast enough (accurately at least)? After reading the last few posts, im seeing our poor 4.0's just cant handle what some of us want. Seems perfectly suited for offroading though.

[Bouncy]

The high rpm harmonic that occurs in inline sixes is inherent to inline sixes. This is why a pushrod inline's limit is typically below 6000. As tealcherokee said, you can push the rpm limit higher, but why bother? Yes it will still produce power at higher rpm's but the peak power still occurs at lower rpm's. Your analogy about climbing a sandy hill is a good point, but can't you keep the motor in its powerband while climbing a hill without resorting to overreving?

When it comes to ICE's, rather than looking at more fuel in = more power out, think of it as more fuel+air in = more power out. The Jeep inline six's head is not the best for breathability and there's not much to work with in the head as far as re-porting for maximum high end rpm's. This is one of the reasons the Hesco head is desirable. In the regular head, you can jam in as much fuel as you want, if the head can't get enough air through, your power isn't going to increase, agreed?

All of those high revvers are SOHC or DOHC without exception. I'm with you on the OHC idea for the 4.0. If it was doable in an efficient manner, the possibilities would be exciting...

On the head porting issue. Spent the last 5 nights out working on porting a 7120 head. The exhaust ports are terribly restrictive. The intake ports aren't too bad. Cut the short side a bit on the intakes and clean it up a bit. Exhaust, could cut half inch out of the short side and a good quarter of an inch out of the runner...And thats not even matching the gasket.

The bowls were left with a huge ridge on both intake and exhaust. Nearly a 90 degree turn. Also a cut ridge from the mill when they machined the valve seats and bowl.

After cleaning it up a LOT, the more fuel...AND air will equal more power. Not arguing that you hit max power at lower rpms...that seems logical from all the dyno charts I have been studying.

As for hitting the rev limiter...I kinda wheel in 1st gear. Two foot the jeep for complete control. After I mod the tranny to lock in 1st gear only and not worry about 2nd...Its a matter of either hitting the limiter or not. Its rare that I hit a limit but at 5k rpms, my speed isnt up high enough for my comfort level. My other jeep has a 6k chip and it runs great...When its together. (Read into that..suspensions are a pita in custom rigs.)

[streetpirate]

OK

so we dont need a msd 6 box to run our engines, what DO we need to make sure the electrical is up to par on built 4.0's that may see high rpm's?

[Dr. Dyno]

Im not sure if you're being specific to jeep/truck applied inline 6s but the bmw m3's s54 inline 6 screams to 8000rpm, and there are plenty of nissan engines seen in the skyline and such that go much higher than 5k. However, they are DOHC for the most part not the OHV like us truck guys. It would be really cool if someone could make the 4.0 into a dohc setup. It would involve a new head and somehow doing away with the old camshaft. Timing chains would have to be changed and well, a lot of things, but imagine the possibilties. :roll:

The BMW M3's inline six has a forged steel crank, forged steel rods, and forged aluminium pistons to achieve that 8000rpm redline as well as all the other high rev breathing trickery. Other high revving inline sixes also have forged bottom ends.
You could build a bottom end for the 4.0 that would survive 7000 rpm if you opted for a custom billet crank, Eagle forged rods, and custom forged pistons with full floating pins (all fully balanced). If you also add a solid lifter cam, a ported head with bigger valves, heavier valve springs, shaft-mounted roller rockers, chrome moly steel pushrods, and a timing gear drive, you'll have a valvetrain that'll also survive 7000rpm. All you need is a fat wallet.

[tealcherokee]

The BMW M3's inline six has a forged steel crank, forged steel rods, and forged aluminium pistons to achieve that 8000rpm redline as well as all the other high rev breathing trickery. Other high revving inline sixes also have forged bottom ends.
You could build a bottom end for the 4.0 that would survive 7000 rpm if you opted for a custom billet crank, Eagle forged rods, and custom forged pistons with full floating pins (all fully balanced). If you also add a solid lifter cam, a ported head with bigger valves, heavier valve springs, shaft-mounted roller rockers, chrome moly steel pushrods, and a timing gear drive, you'll have a valvetrain that'll also survive 7000rpm. All you need is a fat wallet.

its all well and good that you can build it to survive it, but, its never going to make power up there, not w/o a overhead cam set up

[dzolcali]

so, has anyone wondered why the put the intake manifold right under the exhaust manifold...heat rises, and the intake manifold should be cool not hot, so then you got this hot ass exhaust manifold right below it, I'm thinking get a new exhaust manifold wrap it in heat wrap, and then get a higherflow intake manifold and a big ported throttle body, will that help with gas milage and power?

[Beej]

Yes it will help, but its best not to think of mods as helping both gas mileage and power. They aren't mutually exclusive, but they don't necessarily go hand in hand either. Wrapping the manifold will help, but Dr. Dyno has a neat trick on his site regarding heat shielding too. The larger manifold on 2000+ 4.0's helps some breathing too and so will the larger throttle body, but you'll need some other performance enhancers to really see large gains with those two. See Dr. Dyno's site for more information. He's got the comprehensive list of information all in one place...

[Dr. Dyno]

Actually, the '99+ intake manifold has smaller runners than the earlier manifold so it's oriented to making more torque at lower revs, not higher rpm horsepower. To make it flow better at higher rpm, you'd need to extrude hone it and add dual throttle bodies like Hesco's "double trouble" prototype.
If you want a high revving, free-breathing 4.0, you'd have to select the longest duration Crane solid lifter cam that's available, bump the CR up to about 11:1, get the best porting job possible on the Patriot Performance aluminium head, use Clifford's dual outlet header, add the Clifford X-pipe, and run a dual 2.25" exhaust system. This is in addition to what I mentioned earlier.
You don't necessarily need to have an overhead cam and a crossflow head to make an engine breathe well at higher rpm but they certainly help. A good example of this is the 7.0L LS7 engine in the C6 Corvette. It's a pushrod engine yet it'll rev to 7000rpm.

[tealcherokee]

Actually, the '99+ intake manifold has smaller runners than the earlier manifold so it's oriented to making more torque at lower revs, not higher rpm horsepower. To make it flow better at higher rpm, you'd need to extrude hone it and add dual throttle bodies like Hesco's "double trouble" prototype.
If you want a high revving, free-breathing 4.0, you'd have to select the longest duration Crane solid lifter cam that's available, bump the CR up to about 11:1, get the best porting job possible on the Patriot Performance aluminium head, use Clifford's dual outlet header, add the Clifford X-pipe, and run a dual 2.25" exhaust system. This is in addition to what I mentioned earlier.
You don't necessarily need to have an overhead cam and a crossflow head to make an engine breathe well at higher rpm but they certainly help. A good example of this is the 7.0L LS7 engine in the C6 Corvette. It's a pushrod engine yet it'll rev to 7000rpm.

some one needs to do something like this, and no matter what, ill put money on it youll never get peak power to break 5000 rpm, and peak torque to break 4000. and theres no point at revving to 8000 if peak is at 5000 and 6000 makes the same power as 4000

[Dr. Dyno]

some one needs to do something like this, and no matter what, I'll put money on it youll never get peak power to break 5000 rpm, and peak torque to break 4000.

That's a brave statement to make. Considering Golen's 4.6 stroker made peak HP at 4900 and peak torque at 3900, it wouldn't take much to raise those rpm peaks and you'd lose your bet.

and theres no point at revving to 8000 if peak is at 5000 and 6000 makes the same power as 4000.

Who said anything about revving to 8000rpm? The redline on most engines is set at about 10% past peak HP rpm.

[MudDawg]

I don't follow the idea that a distributor ignition would be problematic...and i don't follow the idea that the engine will not make power above 5k without ohc...I do agree that the hp per litre numbers cannot match a high revving pent roof, multi valve combustion chamber engine...I will tell you that my 2.5 will rev well beyond 5k...and make usable power to boot...if an engine will flow enough air (good pumping efficiency), and is thermally and mechanically efficient, the only real limiting factor is the mechanical capability of the engine to endure the rpm...

[tealcherokee]

That's a brave statement to make. Considering Golen's 4.6 stroker made peak HP at 4900 and peak torque at 3900, it wouldn't take much to raise those rpm peaks and you'd lose your bet.



Who said anything about revving to 8000rpm? The redline on most engines is set at about 10% past peak HP rpm.


ok, what i should have said, is youll never get peak power up that high and have ANY low end at all, so its not optimal, but yes, a motor could be built to make power that high, but it would be useless. even golens

advertised as 260hp 295lbft, assume 20% drivetrain loss- 312hp 354hp

compared to your motor, 273hp 328lbft, torque is suffering in theyre motor.

just a comparison, theyre motor makes 1.2* the hp, but only 1.1* the torque, if your motor had the 312hp, it would be laying down about 393lbft, 40lbft more than golens.

[Dr. Dyno]

ok, what i should have said, is youll never get peak power up that high and have ANY low end at all, so its not optimal, but yes, a motor could be built to make power that high, but it would be useless. even golens

advertised as 260hp 295lbft, assume 20% drivetrain loss- 312hp 354hp

compared to your motor, 273hp 328lbft, torque is suffering in theyre motor.

just a comparison, theyre motor makes 1.2* the hp, but only 1.1* the torque, if your motor had the 312hp, it would be laying down about 393lbft, 40lbft more than golens.

Again you're mistaken. :) Golen's advertised 260hp@5000rpm and 295lbft@4000rpm is at the flywheel, NOT the rear wheels. In their JP magazine stroker build-up, the Golen 4.6 stroker actually made 268hp@4900rpm and 324lbft@3900rpm on an engine dyno so it was better than their advertised simulated numbers. It had a F&B 66mm TB, 24lb injectors, and a Hooker header for the dyno test.
I agree that if you get the peak HP rpm well above 5000 that low rpm torque will suffer, and indeed that IS a limitation in the pushrod OHV non-crossflow head design of the 4.0 engine. I built my stroker with the aim of making as much torque as possible over as wide a range as possible. Given that I've had to work with technology that's over 40 years old, I think I did a pretty decent job. It pulls hard from idle to redline so the whole 750-5250rpm range is useable.
Modern DOHC engines employ variable valve timing/lift and variable length intake manifolds to produce good low rpm torque and still have good high rpm breathing. The Chevy 4.2 I6 Vortec is a good example. It makes 291hp@6000rpm (70hp/liter) and 277lbft@4800rpm (67lbft/liter), but has a long stroke (4.02") to help it make at least 90% of maximum torque at less than 2000rpm.

[Beej]

I built my stroker with the aim of making as much torque as possible over as wide a range as possible. Given that I've had to work with technology that's over 40 years old, I think I did a pretty decent job. I think your 14 second quarter mile backs that up nicely... :D

[Michaelarchangelo]

Ive been following this thread for a while, and Im still trying to figure out why you would want to go through all the trouble to make the 4.0 a high revving motor? As have been stated, there are many factors that would limit such a thing. Pretty much the only stock component that would be used is the block.

[Dr. Dyno]

Not to mention the high cost of making the 4.0 a high revving motor.
I wanted the most bang for my buck and decided that building a 4.6L budget stroker made a lot more sense. Since it has more grunt than a herd of pigs, I don't need to rev the bejesus out of it but it's fun to occasionally wind it out to the rev limiter anyway.

[Michaelarchangelo]

I can understand the stroker motor, just not the high revving. If I wanted high revving motors, I would have kept my q45 or my SHO.

[JJacobs]

I just talk to the guys from clifford, all they do is straight 6 stuff. The stuff they know is amazing. John clifford beat a top fuel drag car in an AMC in the 1/8 mile.

cliffords engines make 450 WHEEL torque at 3000 rpm!!!

I'm calling BS on both of these statements. Proof please.

[Beej]

He's talking about 1/8 mile, not 1/4. Info on their page doesn't exactly back it up, but you can read between the lines. Its possible, if not probable...

[OT]

They were probably bracket racing and they probably broke out, so they said they beat a top fueler.

[JJacobs]

A TF dragster runs 270 in the eighth mile. Somehow I'm not seeing it..

[Beej]

It sounds like he did all his drag racing about 30 years ago and beyond, dunno if that makes a difference...
:dunno:

[Dr. Dyno]

I'm calling BS on both of these statements. Proof please.

It IS possible to make an easy 375hp/450lbft from a supercharged stroker, but that's at the flywheel.

[tealcherokee]

It IS possible to make an easy 375hp/450lbft from a supercharged stroker, but that's at the flywheel.

nope...... they do it naturally asperated.

custom intake, stand alone fuel injection system, extensive head work, custom exhaust header, and a correct cam, like no one on here uses, my self included

[Dr. Dyno]

You're saying Clifford got 450lbft from a naturally-aspirated I6 stroker? That's BS! The best anyone has managed to get from a naturally-aspirated stroker is 360lbft and that was Jakes Racing Engines from a displacement of 5.0L. Hesco's best dyno-verified effort was a naturally-aspirated 339lbft from 4.6L.
To get 450lbft, you definitely need some form of forced induction.

[MudDawg]

As far as i'm concerned, credibility at Clifford ended with the passing of Jack Clifford and the business being bought out by a former employee.

And I don't buy the idea of some double top secret camshaft...the Clifford catalog lists a cam that will make power to 7k+ rpm based on advertised lift, duration and overlap figures...the problem is the head cannot be easily "ported" to provide the VE required (and still use standard intake or exhaust)...the head would need to have radically revised port location...and that is if the valve shrouding issue can be effectively dealt with.

[tealcherokee]

You're saying Clifford got 450lbft from a naturally-aspirated I6 stroker? That's BS! The best anyone has managed to get from a naturally-aspirated stroker is 360lbft and that was Jakes Racing Engines from a displacement of 5.0L. Hesco's best dyno-verified effort was a naturally-aspirated 339lbft from 4.6L.
To get 450lbft, you definitely need some form of forced induction.


give them a call, the techs there will tell you everything theyre doing, he said they make these motors all the time

[j99xj]

Some of you will jump all over me by saying this, but the truth of the matter is that the overall horsepower is what determines acceleration and the rate at which work is performed, not torque.

Saying one engine is better than another because it makes more torque is ONLY valid when the gearing of both vehicles in question is the same.

If gearing becomes a variable then you open up a lot of different possibilites. Again, some of you will go crazy after I say this but it's true: A completely stock 4.0 with 4.88 gears will out torque a 4.6 stroker with 3.07 gears assuming the transmission and transfer case ratios are the same.

Some of you might ask "If the 4.0 makes more torque than the 4.6 stroker then why does it lose in a 1/4 mile or 0-60 race?" The answer is the difference in horsepower. The 4.6 stroker makes a lot more horsepower at all rpms.

Anyway I think 450 lb-ft out of a n/a Jeep straight 6 is not possible. I've read that you need at least 1 cubic inch for every lb-ft of engine torque you want. And unless you have a big block Chevy or Ford, you will find out rather quickly that you will need forced induction to get the torque you want.

[Beej]

I'm not going to jump all over you j99xj, but suffice it to say that what you stated above is an oversimplification of concepts. HP is a calculated function of torque and is calculated through this formula:
Horsepower = (torque x rpm)/5252.113

To say that torque is different due to gearing is not really accurate. You are colluding practice with theory. You are talking about perceived torque at the wheels which is not the same as actual torque at the flywheel. The 4.0 does not make "more torque than a 4.6", ever. I'm pretty sure that would be a mathematical impossibility in the same engine design.

The 4.6 makes "a lot more horsepower at all rpms", because it makes more torque at all rpms, and horsepower (which is not directly measurable), as shown above, is calculated from torque and rotational velocity, both of which are directly measurable. I'm not explaining it very well here, but others may be able to...

[Dr. Dyno]

If gearing becomes a variable then you open up a lot of different possibilites. Again, some of you will go crazy after I say this but it's true: A completely stock 4.0 with 4.88 gears will out torque a 4.6 stroker with 3.07 gears assuming the transmission and transfer case ratios are the same.

That's true but only because you're multiplying the lesser torque of a stock 4.0 by a greater amount. The resultant shorter gearing would result in a reduced maximum road speed in each gear and since the 4.0 makes less HP, it would also have a lower top speed.


I've read that you need at least 1 cubic inch for every lb-ft of engine torque you want. And unless you have a big block Chevy or Ford, you will find out rather quickly that you will need forced induction to get the torque you want.

The very best naturally-aspirated street engines make 1.4lbft/cu.in. so to make 450lbft from a naturally-aspirated engine, you need at least 320cu.in. or 5.3L. Now you see why I call BS on Clifford's claims.

[BBeach]

That's true but only because you're multiplying the lesser torque of a stock 4.0 by a greater amount. The resultant shorter gearing would result in a reduced maximum road speed in each gear and since the 4.0 makes less HP, it would also have a lower top speed.
Wouldnt that make it accelerate quicker because it would reach maximum power in a shorter time? Also, actual top speed could be increased if you were to gear it correctly. What i mean by this is that with my jeep with the aw4 4.0 3.55 gears, it hits limiter at around 116 or w/e and then its done because of limiter. Without the limiter, i dont think it would make it past 120 on flat ground with no wind merely because there isnt enough power at the 3500 or so rpm in the top gear. However, if you were to reduce the rear end gearing a certain amount, say 4.10 or 4.56, then your top gear (mine being .75:1 in tranny), would be better maximized. Im too lazy to do the math out, but i think if you were to have 4.10 gear, it would be x 4.10/3.55 so around ~4050 rpm at the same road speed in the top gear. But however, limiter exempt, the engine would have THAT much more power to overcome the drag, and all the other resistance against it. Basically, if you change the gearing properly, you would be able to make use of the higher end, while having a lower "theoretical top speed". With the gearing as is, it SHOULD be able to hit somewhere arond 150mph, but with the power available and the resistance against it, its not going to do it. I hope that makes sense/is right. :speepin:

[j99xj]

The 4.0 does not make "more torque than a 4.6", ever.

Very true....at the flywheel. But you can multiply torque to any amount you wish using gears.

Still not convinced?? Hook bumper to bumper with a tow strap to some other Jeeper and drive in opposite directions. One vehicle with the transfer case in 4 low, and the other in 4 high. Who do you think will win the tug of war? It has to be the guy in 4 low. Regardless of how many mods the guy in 4 high has done (including a stroker), he will lose. (Unless of course his engine is putting out 2.72 times as much torque at the flywheel, but that comes out to about 650 lb-ft flywheel torque, which is highly unrealistic for any n/a Jeep straight 6.)

Now if the gear ratios were the same for both vehicles in the tug of war, the stroker guy will whoop the other guys butt, thats a given.

Another useful example is that all cars produce faster acceleration in 1st gear than any other gear. Why is that? Because the torque multiplication is higher and the rpms are higher (thus more horsepower).

Take a little while to read this article, its a good read and makes perfect sense to me. http://personal.riverusers.com/~yawpower/tqvshp.html

[Beej]

So I read that page, and unless I'm mistaken, he's also proving that torque is still where its at, not horsepower, he's just using funky math and examples to come up with his results. He's factoring in variable rpms instead, the higher rpms are what yield the higher horses due to the fact that horsepower is a function of torque and rpms. His comparison seems a tad specious, but I'm no engineer and my math is still just grade 12, so I can't prove my statements the same way. It just strikes me that he's is comparing apples to oranges as he 'proves' hp is more important than torque...

Granted, you can alter measurable torque through gearing, that's beside the point though, as I was originally talking about flywheel torque...

Can somebody else educate us further here? I'm still not able to entirely wrap my head around this one...

[Dr. Dyno]

Let's compare two "engines" in the same vehicle (identical weight). Vehicle A has a 4.0L "revver" engine making 300hp@6000rpm and 300lbft@4500rpm with a 6600rpm redline, while vehicle B has a 6.0L "torquer" engine making 300hp@4000rpm and 450lbft@3000rpm with a 4400rpm redline.
If both were identically geared, vehicle B would have better in-gear acceleration but the maximum speed in each redline-limited gear would be reduced because this engine would have a lower redline rpm. Both should have the same theoretical top speed because they both have 300hp, provided vehicle B could reach that speed without hitting the rev limiter first.
In reality, these two vehicles would NOT be identially geared because their engines have different power delivery characteristics. If vehicle B had 50% taller gearing than vehicle A (let's say 5.13's for A and 3.42's for B), in-gear acceleration would be the same, the maximum speeds in each redline-limited gear would be the same (vehicle A would reach those speeds at 6600rpm whereas vehicle B would only need 4400rpm to reach the same speeds), and the 1/4 mile ET/trap speed would be the same. Both will have the same top speed but vehicle A might reach that speed at 6000rpm in top gear while vehicle B would only need 4000rpm to reach the same speed in top gear.
The low revving "torquer" engine can be built with cheap, cast components but the smaller "revver" engine will need expensive forged components to survive the higher redline rpm required to reach the same performance level of the higher displacement "torquer". Now you can see how that principle can be applied to the Jeep 4.0 and stroker engines.

[MudDawg]

That (the article)is an interesting discussion...but in essence it is a discussion about the effects of gear reduction. For all practical purposes torque (and horsepower) are the product of three things (at a given rpm)...Cylinder pressure, stroke lenght, and thermal efficiency...minus frictional losses.

A typical diesel engine produces massive torque because of the extreme cylinder pressure and the long stroke. But it cannot be revved very high...mechanical limitations due to the long stroke and the mass of the reciprocating assembly...

A top fuel engine...500 cu in...makes around 6k (theoretical..no dyno will handle one, and the engine will eat itself long before a stable reading can be taken) horsepower at 8.4k rpm. The cylinder pressures are staggering...the effects of the supercharger and the nitromethane.

Want a more powerful engine?? Make it as efficient volumetrically as possible (but you will need to choose at what rpm you want it to work at), use a fuel with high BTU per Lb..run it as lean as possible without detonation, contain as much heat as possible in the cylinders, and reduce frictional losses.

[j99xj]

In reality, these two vehicles would NOT be identially geared because their engines have different power delivery characteristics. If vehicle B had 50% taller gearing than vehicle A (let's say 5.13's for A and 3.42's for B), in-gear acceleration would be the same, the maximum speeds in each redline-limited gear would be the same (vehicle A would reach those speeds at 6600rpm whereas vehicle B would only need 4400rpm to reach the same speeds), and the 1/4 mile ET/trap speed would be the same. Both will have the same top speed but vehicle A might reach that speed at 6000rpm in top gear while vehicle B would only need 4000rpm to reach the same speed in top gear.


Exactly. As long as the engine with less torque is geared lower, (numerically higher) to "regain" the lost low end torque from a hot cam and highly ported cylinder head, performance will virtually be the same because the horsepower output is the same, just at different speeds.

Now I think we can also agree that the torquer engine will be far more reliable, cheaper to build, and cheaper to maintain. That's a given.

I think I'm going to run some simulations and see what happens. Maybe I'll upload some screenshots.

[JJacobs]

A typical diesel engine produces massive torque because of the extreme cylinder pressure and the long stroke. But it cannot be revved very high...mechanical limitations due to the long stroke and the mass of the reciprocating assembly...


Supposedly the torque of a diesel is not simply because of the long stroke, but that the power stroke is more of a long steady push rather than a quick bang. The fuel takes longer to burn in the chamber (dish in the piston) and voila, TQ.

I'm not a 4 litre hater by any means folks. I see some BS on here from time to time, like the spewing about Clifford. Also the lemming like mentality that an extra 12 percent displacement yields 70 percent power increases automatically is kind of annoying.

http://www.highperformancepontiac.com/tech/0410pon_most_powerful_pontiac_v8/

But how about that article? Makes you think huh? A friend of mine has a car with an inline 6, it's a chevy trailblazer 4.2, destroked to 4.0. It has two T-78 turbos and a Procharger F-3A, 70psi should get us about 2500 HP and hopefully the title 'quickest EFI car on the planet' at around 5.70's.

I don't see why a Jeep 4.0 couldn't get well over 1000 HP with custom bottom end parts, alcohol EFI and lots of boost- everyone else is doing it! I just don't want to try and pay that bill right now, though someone in here surely has the cash burning a hole in their wallet :)

[j99xj]

I don't see why a Jeep 4.0 couldn't get well over 1000 HP with custom bottom end parts, alcohol EFI and lots of boost- everyone else is doing it! I just don't want to try and pay that bill right now, though someone in here surely has the cash burning a hole in their wallet :)

Um......... I'm going to call BS. Formula 1 engines can barely make that, and thats at 20,000 rpms.

In order to produce high horsepower, you need high rpms, and that means you need a big bore and a short stroke. If the stroke is too long for the rpms the engine will break apart shooting pistons through your hood possibly hurting some innocent by stander. Not cool.

True high performance engines are engineered from the ground up to make the most horsepower possible. Reliability, fuel economy, and engine longevity are not at the top of the engine builders list.

The Jeep 4.0 was and is an excellent engine. The reasons for its success is the fact that it was/is a very reliable engine, gets decent fuel economy, and provides a wide powerband that is suited for all types of average driving, from off roading to highway passing. Making improvements to improve horsepower/torque are easy and cheap, and an easy route to better performance is as close as your local junkyard. (258 cranks etc)

But 1000 hp of it is just rediculous. Thats 250 horsepower per liter.

[Beej]

1000hp is doable in a turbo'd big block no problemo. They do it at under 6500 rpms pretty regularly. Check out http://www.nelsonracingengines.com and click on videos. Mind blowing, however there ain't no inline sixes in their stable...

[MudDawg]

Not me...I'm so poor I can't pay attention...I have plenty enough reliable, long lived power...If I get the need for speed...I hitch up the trailer and take my bike to the track and squeeze a few smurfs into those little blue bottles..

[MudDawg]

The cost for horsepower is inversely proportional. The first 50 or 60 is cheap..the last 2 cost mega bux..

If you want to see a truly kickass (street) jeep, check out the MJ "parts chaser" truck that Hesco has...

[JJacobs]

But 1000 hp of it is just rediculous. Thats 250 horsepower per liter.


Your point?

Get your head out of the sand for a while.. this stuff is out there. Did you even read the link I attached? Figure a 242 is 1/2 the displacement of that Pontiac, so 1000 is theoretically possible while the parts list may be huge. If you don't understand the potential of boost, please stay out of this conversation.

[j99xj]

Your point?

Get your head out of the sand for a while.. this stuff is out there. Did you even read the link I attached? Figure a 242 is 1/2 the displacement of that Pontiac, so 1000 is theoretically possible while the parts list may be huge. If you don't understand the potential of boost, please stay out of this conversation.

I thought we were talking n/a applications, geez you don't have to be rude. Boost will make a lot of power, no doubt, but I still believe 1000 hp out of a supercharged Jeep straight 6 is highly optimistic, even if the engine is a stroker.

[Beej]

I agree, I don't think you can get 1000hp out of a 4.0 inline six. A heavily blown DOHC inline six, yes, but I just don't see in a pushrod OHV inline six. 70lbs of boost is just campfire talk. Where would a realworld application be?

[JJacobs]

Rude's my middle name!
70psi is campfire talk? I have pictures of that car, but it won't be fired for a couple more weeks. On a Jeep 4.0 70 psi is a pipe dream, sure. I'd love to try a 1000hp 4.0/4.6 but only after winning the Lotto.. I bet it could be done.

[j99xj]

Rude's my middle name!
70psi is campfire talk? I have pictures of that car, but it won't be fired for a couple more weeks. On a Jeep 4.0 70 psi is a pipe dream, sure. I'd love to try a 1000hp 4.0/4.6 but only after winning the Lotto.. I bet it could be done.

Go for it. But if you won lotto and want absurd amounts of horsepower you need to omit reciprocating engines all together. Go for some gas turbines. http://en.wikipedia.org/wiki/Gas_turbine#Gas_turbine_for_mechanical_drive_appli cations

[Bouncy]

Damn...read the rest of this thread.

All this from a question about WHICH COIL FROM MSD for a Jeep 4.0L

Laughed at the 1000hp is 250 per cylinder...If it had 4 cylinders maybe :D

Boost is good to work with but the conversation started orginally about coils and wires...The NA motors. Now its about boost.

Each would seem to have the need for a separate thread.

All and all...power can be made and provided you have good equipment and good blancing, you can make power in upper RPMs. Can't say I am going through all the effort to bypass the 5k limit on the computer but if a simple fix comes out, I will most likely chip/change mine to 6k like my other jeep.

[dzolcali]

yeah I just quit this thread like four pages back cause it got way off topic LOL...oh well

[streetpirate]

in the true spirit of naxja, everything past the third page of the thread is people rambling off topic about ideas brought up by the original question.

and this is where most of the good stuff is

[gradon]

I already have 8.5KV's on the way, so would a MSD 8228 coil be worthwhile ($50) w/o the MSD-6, but with a better cap and plugs? By the way what plugs and cap are you guys using, would you recommend?

[Beej]

By the way what plugs and cap are you guys using, would you recommend? Mopar all the way...

[PapaPump]

I want to punch THIS thread