4.0 stroker crank

4.0 Stroker Crank

That is what i use in the advance search eng to learn all that i have so far!

OK my story first!....I won't to build a 4.5 or probable 4.6 stroker! the thing that's diff, then all that i have read so far, it that i what to build a stroker that pulls form.......well basically idle to 2500 maybe even as hi as 3500 rpm.
Torque is what is important to me, if i could make 300# torque and 100# horse power, that would be find with me!

If any one has a killer low end torque cam spec. that i can plug in to my dyno sim program, let me know.

My jeep is 89 Renix and is a stander with 3.07 gears and stock 27" tires(5th gear is useless)
Have a set of 3.55 housings, front and rear, that will be going in the jeep and 31/10.50/15 or maybe Even 32or 33/9.50/15.

Now, i know that if i am going to play in the rock, I will need much lower gear(higher numeral gear like 4.88) to be crawl over rocks with a stander tranny, let alone a lift kit!!!

I know, buying gears would be cheaper but not what i want to do.

Hoping also that 3.55 gears, instead of 4.88, should give me better gas mileage!?.:dunno:

OK now a couple of question to start with.

1. I will probably build the budget 4.6 but what would happen to the torque curve if i when with the much longer 6.125? 4.0 rods. would they make that much diff in low rpm. I know that the cost for piston would be High!

2. Quench, witch would be the best(most efficient) .020 or .100?

A. What is the minimal head to piston clearance?

B. With the focus on low rpm, could i run the stock fuel inj and pump?

3. Using the HO head be worth finding and using with the build. would it really have any that much advantage........and what about the newer equal length intake. sound like it would take some mods to do it any ways!

4. Pretty sure that i want the 12-258 crank, but the crank spacer that you can hack of from and old harmonic balancer or cutting 10mm of the crank don't make sense to me???? one way will move the HB towards the end and the ether way would move it toward the radiator?????

5. what vehicles have the 12-358 eng?.....80 and older AMC...right?
did ford ever us this eng and if so in what?

Flash.

No body from the night shift.........how about the day shift.

One more question allso

6. Could i get away with out a adj map sense or would it just be better to do so......is the adj map req. because of the bigger injectors or is the stroke a factor alls?


Flash.

Flash said:

4.0 Stroker Crank

That is what i use in the advance search eng to learn all that i have so far!

OK my story first!....I won't to build a 4.5 or probable 4.6 stroker! the thing that's diff, then all that i have read so far, it that i what to build a stroker that pulls form.......well basically idle to 2500 maybe even as hi as 3500 rpm.
Torque is what is important to me, if i could make 300# torque and 100# horse power, that would be find with me!

If any one has a killer low end torque cam spec. that i can plug in to my dyno sim program, let me know.

My jeep is 89 Renix and is a stander with 3.07 gears and stock 27" tires(5th gear is useless)
Have a set of 3.55 housings, front and rear, that will be going in the jeep and 31/10.50/15 or maybe Even 32or 33/9.50/15.

Now, i know that if i am going to play in the rock, I will need much lower gear(higher numeral gear like 4.88) to be crawl over rocks with a stander tranny, let alone a lift kit!!!

I know, buying gears would be cheaper but not what i want to do.

Hoping also that 3.55 gears, instead of 4.88, should give me better gas mileage!?.:dunno:

OK now a couple of question to start with.

1. I will probably build the budget 4.6 but what would happen to the torque curve if i when with the much longer 6.125? 4.0 rods. would they make that much diff in low rpm. I know that the cost for piston would be High!

2. Quench, witch would be the best(most efficient) .020 or .100?

A. What is the minimal head to piston clearance?

B. With the focus on low rpm, could i run the stock fuel inj and pump?

3. Using the HO head be worth finding and using with the build. would it really have any that much advantage........and what about the newer equal length intake. sound like it would take some mods to do it any ways!

4. Pretty sure that i want the 12-258 crank, but the crank spacer that you can hack of from and old harmonic balancer or cutting 10mm of the crank don't make sense to me???? one way will move the HB towards the end and the ether way would move it toward the radiator?????

5. what vehicles have the 12-358 eng?.....80 and older AMC...right?
did ford ever us this eng and if so in what?

Flash.

Click to expand...

#1. You can't use the 4.0L rods with the 4.2L crank. They are too long.

#2. IIRC the best quench height is around .050-.060
#2A The minimum clearance is .000 ha ha
#2B The stock fuel pump is fine. Injectors may be a tad small, but here at 5k feet, they would be fine.

#3. HO head has few advantages for a low rpm engine. IMHO not worth the effort. Just clean up the ports a bit yourself and call it good.

#4. The crankshaft spacer acts like a big washer. It goes on the outside. I turned one on the lathe, but you can buy one for around $20.

#5. I got my crank from an early Jeep. If you are running an automatic, don't bother with the heavy crank. It helps with a stick shift, but slows the throttle response.

Background: I've been building engines since 62. I built my stroker around 4 years ago and it runs great. The key is to spend your money where it counts. The first and most important thing is to have the valves sleeved, not knurled when you do your valve job. Second is to deck the block. I did mine about .025 and run the thin head gasket. Any more than that and you will need to get shorter pushrods. I run a heavy crank since at the time I built it I was running an AX-15. I now run an AW-4. The pistions I used are the H802CP's and they are easy to find and cheap, as well as get the job done.

I run a Crane cam #753901 with a grind #H-260-2. It yields a very streetable engine with great low end torque. It is a dream to drive since the torque is right at the rpm's where you drive. It is an absolute wonder I haven't lost my license with this thing.

Increasing the displacement without allowing it to breathe better is a waste. I run Clifford headers with 2.5" piping, high flow CAT and Magnaflo muffler. I have not changed the intake or throttle body, but I did go with the 24# Ford Performance injectors but here at 5k ft altitude, it ran a touch rich and I ended up designing and building an MAP adjuster. It passes emissions better than a new engine and looks totally stock other than the headers.

#1. You can't use the 4.0L rods with the 4.2L crank. They are too long.

so Even a $$$$$$piston wouldn't work........ran it on my eng sim last night, didn't make any diff ant 1500.

#2. IIRC the best quench height is around .050-.060


OK time for a dumb question......what does IIRC stand four?:dunno:

#3. HO head has few advantages for a low rpm engine. IMHO not worth the effort. Just clean up the ports a bit yourself and call it good.

thanks, plan on port matching and cleaning up the casting. actually porting the head would be a disadvantage for me i think!!!!

A. What is the minimal head to piston clearance?

:roflmao: OK how much clears would you need, do to rod stretch, at top rpm?

#2B The stock fuel pump is fine. Injectors may be a tad small, but here at 5k feet, they would be fine.

thats what i was hoping for!

#4. The crankshaft spacer acts like a big washer. It goes on the outside. I turned one on the lathe, but you can buy one for around $20.


does any one have a pic of this so that i can under stand better how it work?

#5. I got my crank from an early Jeep. If you are running an automatic, don't bother with the heavy crank. It helps with a stick shift, but slows the throttle response.


It a 5sd.

Background: I've been building engines since 62.

thats as far as my life has been lived :spin1:

Second is to deck the block. I did mine about .025 and run the thin head gasket. Any more than that and you will need to get shorter pushrods.

good point!!!


I run a Crane cam #753901 with a grind #H-260-2. It yields a very streetable engine with great low end torque. It is a dream to drive since the torque is right at the rpm's where you drive. It is an absolute wonder I haven't lost my license with this thing

unfortunately i don't now what rpm that is on mine (no tac ...yet)


Increasing the displacement without allowing it to breathe better is a waste. I run Clifford headers with 2.5" piping, high flow CAT and Magnaflo muffler

point taken

I did go with the 24# Ford Performance injectors but here at 5k ft altitude, it ran a touch rich and I ended up designing and building an MAP adjuster

I live at nearly 7,000 feet.:shiver:




Flash.

I've got a local yard that will sell me a crank and rods that are suitable to be turned and used for $100.

IIRC...if I remember correctly.

I think the pistons and rings ran me less than $150. You will have to bore the engine anyway. You can't use the block without boring if you have any miles on it at all. The ring land/grooves could cause a problem as the piston now has a longer stroke.

At 7k ft. I would not change the injectors, at least until you run it a while and see it is running lean.

Decking the block .025, using the thin head gasket, and the H802cp pistons will yield you plenty of clearance. Piston clearance and quench height are the same thing.

I don't have a pix of the spacer but you simply put the harmonic balancer on the shaft like normal. You will see that the crank is about .25" too long. In other words, if you use the standard washer and bolt, it will not seat against the balancer, so you put a roughly .25" donut around the shaft and then use the washer and bolt to snug it down.

At 7k ft, headers may not be quite as important and lots of guys do a stroker without them, but they really help.

Porting the head..... a little restriction can help the low end torque, but it's not that much. The key is, where do you want to spend your money. I assume your money is limited, like everybody elses. The point is that you can gold plate the engine or you can build a good solid daily driver engine that is a ball to drive. If you want a race engine and want every last HP, it is going to cost you.

You will need pistons anyway because you are going to bore the block. The H802CP's are not much more expensive than stock pistions for the most part.

Any good rebuild will include grinding the crank and reconditioning the rods. You just do the same thing on the 4.2L crank.

A rebuild should include a valve job. Due to wear, the valve guides should be addressed. Every crate engine I have ever seen has knurled valve guides. This is a BIG mistake. Knurling will give you good results for about 10K miles, then the guides will start sucking oil horribly. Spend a few extra bucks and have the guides sleeved. It is better than new and will last years. This is the single biggest problem with crate engines and is the reason I would never buy one. I might buy a long block but never a head.

So the difference in cost in building a stroker comes from the cost of the crank and rods, the difference in the cost of the cam, and the small difference in the cost of pistons.

It also cost me about $75 to have the block decked.

All in all, I figure a stroker adds about $400 to the cost of a standard rebuild.

Upgrades I would consider adding would be a header and exhaust. That can easily run you $700 for the cost of the header and exhaust.

Seriously consider getting 4.11 axles from a 4 cylinder. With the 31's you will want reduction to just get away from the light. I'm running 3.55's with 29's and saw a noticeable difference stepping up to the bigger tires - nothing major, just have to respect the hot Honda's now. It also made a difference in my back yard (which is pretty steep,) and the AT/KO's didn't take up the slack.

By accounts, you could then cut circles around all the IFS trucks on the trail.

Just a note. I was running a 4.56 D30 up front with 35's. I did the stroker build with an AX-15 and promptly started killing front axles. The heavy crank and the lack of any "give" in the system was terminal on D30 axles. I converted over to the dark side and started running an AW-4. The torque converter has some give to it and I stopped destroying axles.

I have since gone D44 front and rear.

The best way I can explain how much better low end torque the stroker has is to relate an experience. I was on the first simple ledge on Cliffhanger at Moab. It kind of bogged climbing it, so I just applied a little more gas and it went right up. It puzzled me until I looked down and realized I was in 4WH not 4WL.

For those of you who have ever done I-70 up to the Eisenhower Tunnel, I went over it recently fully loaded with 4 adults and never dropped below 75mph. Try that in a stocker.

Seriously consider getting 4.11 axles from a 4 cylinder. With the 31's you will want reduction to just get away from the light.

Don't now if it was a type or not but my eng is a 4.0......6 sylinder.

old-man.
So i don't have much chance of keeping the 30/35 combo alive with a stroker .....aspealey if i find a cam that will pull stumps out at 500 RPM?assgas: and us a standerd?

old_man said:

For those of you who have ever done I-70 up to the Eisenhower Tunnel, I went over it recently fully loaded with 4 adults and never dropped below 75mph. Try that in a stocker.

Click to expand...

That is crazy. My friends stock toyota tundra has a hard time doing that. :worship:

Nothing usefull to add other then that.

If i did end up going with the ford.....35 pound inj?........ the bigger inj. and ways. Would i need to go up to the higher pressure pump.....and pressure regulator, and if so will the pressure regulator of a HO bolt up to my excising fuel rail?
or is there a after market one that i would us?

one more thought do the early HO 4.0 us the same fuel sending unit and located at the front of the tank next to axle?

FYI:

You CAN use 4.0 rods...

but...

you need custom pistons due to the pin height and disc cc needed for proper quench and compression.

I got mine from Childs and Alberts in California...

mine are +.010 deck height for .045 quench with the oem head gasket...

IIRC I asked for a 35cc dish

$600 a set a few years back.

The nice thing about 4.0 rods is that you wind up with a longer dwell time...

that and custom forged slugs are usually forced induction safe

So what would the longer dwell time do or help with. would need a diff can profill right ......what els would be the diff?

edit what a bout the cold, piston slap......would that become louder with the short piston?

Flash said:

edit what a bout the cold, piston slap......would that become louder with the short piston?

Click to expand...

piston slap is usually only an issue during a cold start until it warms up and the piston expands...

I consider it a non issue when building a performance engine...

Flowmaster 40 and a louder stereo will fix it.

Gil BullyKatz said:

piston slap is usually only an issue during a cold start until it warms up and the piston expands...

I consider it a non issue when building a performance engine...

Flowmaster 40 and a louder stereo will fix it.

Click to expand...

:roflmao: :roflmao: :roflmao: That must be why i have never heard the piston slap it my 300,000 mile moter...........my muffler has a hole in it!

if the noise is that little, it won't bother me aether!

so is this your first 4.0 stroker with 4.0 rods? what is going to be the static compression when your done?

If you're looking for cam specs, I've got a .pdf of what I've been able to find so far, as well as "pre-built" Dyno2000 parts data files on my JeepPower group (groups.yahoo.com/group/JeepPower.)

I've noted that the Blue Racer cam seems to have good low-end response in sim, and you may also want to think about the OEMR AMC258 bumpstick (which does surprisingly well in simulated strokers.)

If you have Desktop Dyno2000, you can use the files I built straight up. If you don't, you'll need to get the .pdf sheet and build your own - cams I've been able to get enough data for you to do just that are all listed in the sheet, and I'm working on the rest.

NOTE - if you use another engine simulator programme, and are so inclined, can I talk you into building camshaft and cylinder head datafiles for it? I will then compress them into an archive (.zip and .rar,) and post them on the JeepPower group for other users. I only have Dyno2000 so far, so I can't build anything else - and I'd like to be able to distribute them all, if possible...

5-90

I don't see the blue racer cam in you pdf file spec's.

where would i find that one?

is blue race the name of the cam company or is it the name of the cam?

Flash said:

I don't see the blue racer cam in you pdf file spec's.

where would i find that one?

is blue race the name of the cam company or is it the name of the cam?

Click to expand...

IIRC, "Blue Racer WG5121" was the full name of the cam - it may not be in there (although I don't know why it wouldn't be. I'll have to check that...) Blue Racer was a marque of the old "Wolverine" group 'way back when, as I recall.

I'll re-check the file in a bit (gotta finish with this 1963FSM first...) and see if it's in there or not - if not, I'll have to dig out the specs and add it. I do seem to recall it behaving rather favourably with the stroker setup, tho - especially below 4000rpm or so.

5-90

Here's the cam specs on the Crane #753901 that I run

Lift Intake at cam is .2847 x 1.6 RR = .456
Lift Exhaust at cam is .3027 x 1.6 RR = .484

Cam timing @ .004 Intake Opens 19 BTDC Closes 61 ABDC Duration 260
Exhaust Opens 69 BBDC Closes 23 ATDC Duration 272

Cam Timing @ .050 Tappet Lift
Intake Open 5 ATDC Closes 29 ABDC Max Lift 107 ATDC 107 Duration 204
Exhaust Open 45 BBDC Closes 9 BTDC Max Lift 117 BTDC Duration 216

Recommended Springs #99833

Just ran you number on my dyno sim and at 1500 rpm(remeber, i'm looking for the max torque at the lowest RPM)
The best cam that i have found....to this dated, is the comp cam 68-115-4

Both cams gave max torque at 3000 RPM and had the same torque 260/259 fpt but, the comp cam made 35 more fpt at 1500 RPM.

I still haven't ran 5-90, blue racer cam......yet, on my dyno sim
But i will.

I have been having some fun with my "dyno sim program" and here is my favorite cams. Remember that low RPM torque is what I'm looking for in a cam. Max HP is put in for reference.

The first on is a 4.0 renix with the factory Renix cam. All the rest are 4.5 strockers with every thing els stock, except the cam!(258 crank and rods)

NOTE FPT OR fpt is Feet Pounds of Torque and HP is Horse Power.

stock renix with renix cam(stock stock) 163fpt@1500 RPM 210fpt@4000 RPM and 193HP@5500 RPM

4.0 w 258 crank and Iskenderian 1331-m 250fpt@1500 and 278fpt@3000 HP180@4000.

4.0 stock w/258 crank and rods comp cam 68-115-4 6 251fpt@1500 265fpt@2500 HP158@3500

4.0 w 258 crank Schneider 10056 cam 245fpt@1500 273fpt@3000 and 178HP@4000

Thanks to 5-90 and "groups.yahoo.com/group/JeepPower". There is a lot of cam spec for much, much higher HP cams but, these above are the max, low RPM cam that i used on my "dyno sim" out of many cams and brands.