Stroke it? Blow it?

[Dr. Dyno]

What about this: My 99 4.0L engine only has about 20,000 miles on it. Seems crazy for me to stroke it for more power at this point. Would anyone recommend a blower for someone in my situation? I would think that for me it would be better to get a blower now and then do a stroker set up for a blower when the engine finally goes down the road. What do you think?

marcus

Avenger superchargers make what looks like the best supercharger for the Jeep 4.0 so you might wanna look into that one:

http://www.avengersuperchargers.com/Product Info.htm

The Autorotor system with water to air intercooler is more efficient than a Roots or centrifugal type blower so if I wanted a supercharger, this would be the way to go.

 

[Gil BullyKatz]

Avenger superchargers make what looks like the best supercharger for the Jeep 4.0 so you might wanna look into that one:

http://www.avengersuperchargers.com/Product Info.htm

The Autorotor system with water to air intercooler is more efficient than a Roots or centrifugal type blower so if I wanted a supercharger, this would be the way to go.

According to most supercharger clubs/websites, this is THE best for supercharger applications:

http://www.kennebell.net/superchargers/dodge/wrangler40/wrangler40.htm

Cost is a bit prohibitive, but $300 will get you an Eaton with a little home fabbing... and I don't think you can use efficiency and supercharger in the same sentence


Gil "efficiency is relative to expectations" Bullycatz

 

[Dr. Dyno]

Yeah, Kenne Bell just recently introduced their supercharger kit for the 4.0 TJ and it's a very nice kit too, possibly even better than Avenger's. It also has 5.5psi and 8.5psi boost options. I don't have any pricing though but I expect it to be of the order of $4000-4500.

 

[Darky]

>>2.4L SRT-4 engine....replace the 4.0L inline 6 with a little Mopar 4 banger and gain 100hp while loosing weight? What's not to like?
>>built Honda K-motor with pink cam covers...."You got beat by a pink Honda engine!"
>>Renesis engine...tiny engine, way cool...room for extra batteries and maybe a hi-lift jack under the hood.

I'll agree with your choices, all except these three. As karter said, there's no torque. Especially in the Renesis and the Honda. The SRT-4 makes good torque, but not down low. Those might work in a street only application, well built. But not where Cherokees are supposed to be, i.e. on the trail. However, I like your thinking.

 

[Dr. Dyno]

If you want to save weight and have more torque right across the rpm range, the all aluminium Chevy LS1 is hard to beat with 320hp/345lbft right out of the box.

 

[aspera]

>>2.4L SRT-4 engine....replace the 4.0L inline 6 with a little Mopar 4 banger and gain 100hp while loosing weight? What's not to like?
>>built Honda K-motor with pink cam covers...."You got beat by a pink Honda engine!"
>>Renesis engine...tiny engine, way cool...room for extra batteries and maybe a hi-lift jack under the hood.

I'll agree with your choices, all except these three. As karter said, there's no torque. Especially in the Renesis and the Honda. The SRT-4 makes good torque, but not down low. Those might work in a street only application, well built. But not where Cherokees are supposed to be, i.e. on the trail. However, I like your thinking.

Not so fast. I chose those engines for a reason.
1. They are lightweight engines. That means that they get to make just a little bit less torque. If you have a 6000 lb Cherokee, you miss out on that advantage, though.
2. They rev high. That's a good thing. The Cherokee lump has low-end grunt...but a narrow powerband, say 2K-5K. The little motors might not make much power until 3K, but they can rev to 7 or 8K. Don't think from the low-end on up, but from redline on down. That means you don't have to shift gears right in the middle of something. Of course the best results would come from a Jeep that is geared low enough to keep the little engines spinning...but who ever heard of a Jeep with low gears?
3. Turbo engines make torque where you want it. Small turbo equals low-end torque and snappy throttle response. Big turbo equals high end torque and lag. Goldilocks turbo makes torque in the middle of the powerband, just right. Turbo engines can also have whatever amount of lag that you want. Turbo lag can be an advantage here. Just like Land Rovers are known for a soft "tip-in" of the throttle, turbo lag keeps the tires from getting shocked and breaking traction. Let the gearing multiply the torque into thrust...let the engine rev.
4. Turbos love a load. When stomp on the throttle in first gear (very little load) the engine will almost outrev the turbo. Boost will show up late. Do the same thing in fourth gear (bunch of load) and you can have full boost under 2K on some engines. That means a Jeep climbing a hill would be a good home for a turbo engine. A Jeep climbing a mountain (altitude) would be an even better home.
5. Turbos love automatics. Peg the boost and keep it there.

 

[Darky]

I guess the main thing would be to look at the usage...For mud-running where rpms are higher maybe, but I'd still want to build the I6 or another engine that already has a strong low-end, and turbo or super charge that for more mid and high end power. Rock-crawling, I don't know but I've never seen engine speeds above 5k, except with my little Tracker where I needed that extra oomph to get the tires moving. And even then, 5k was higher than I usaully saw. Is the Honda K an S2000? If not then that one would also fit your thinking. 240 horses at 8200 rpm, 2 liters, 8400 rpm redline...they've mod'd it now to displace between 2.2 and 2.4 I can't remember which, same power better low end. That engine really didn't come alive til around 6000 rpm. The way I look at it is imagine awesome low end power with a decent mid-range and high end, combined with low gears...that's the standard set up and its gotta have a reason. The low end power will be there to keep you goin if you start to bog down, and to get you going if you have to stop on a steep climb or crawl over a big ledge or other obstacle. You don't wanna be thrashing your engine that situation. That was the bane of my Tracker's rock-crawling skills (that and no articualtion). I always put on a good show with the engine wailing, tires kicking up dust and spinning, bouncing off of rocks, but it was a rough ride and mor eprone to breakage.

 

[Darky]

oh and for those who are interested in small block Chevy power, there's now a kit out there for swapping the new 6.0 in place of the 350 (5.7), it shouldn't take long before someone (maybe Advance Adapters) adapts this to fit Cherokees...up to 345 hp and close to 400 lb-ft of torque in an Escalade...even more in the crate engine they were showing.

 

[MudDawg]

Dang it...there yah go...thinkin' outside the box again... :scared: Now I have to go tell my bud with the turbo'ed 2.3 ranger that he has to give back all his mud boggin' trophies...that thing sure does sound sweet spooled up to about 8K at 20# of boost...

Edit: OOPS... I must have had a leak refilling my nitrous bottles...I don't know what i'm thinking.. :greensmok

 

[aspera]

I guess the main thing would be to look at the usage.QUOTE]

Yeah, I agree. Some combinations work better for different uses. Like you said, the modern Honda engines (K-motors and the 2.0L/2.2L S2K engines) would be horrible for a rock crawler...unless you geared it to take advantage of the rev range. If you have twice the usable rev range, then you can use gears that are twice as low. The little 4 banger might not make much torque at 2000rpm...but it can be multiplied more.

I always thought that a great use for the little 4 cylinders with big turbos was in boats. Boats are more concerned with top speed than anything else. Why use a heavy iron V8, and then worry about getting up on plane? Lake water makes the intercoolers work really well too.

 

[marcusguy]

Anybody have more info or links concerning using junkyard M-90s blowers on the 4.0L? Photos would be the best, especially home-made brackets and manifolds and such. thanks in advance for any help.

marcus

 

[Darky]

oh and for those who are interested in small block Chevy power, there's now a kit out there for swapping the new 6.0 in place of the 350 (5.7), it shouldn't take long before someone (maybe Advance Adapters) adapts this to fit Cherokees...up to 345 hp and close to 400 lb-ft of torque in an Escalade...even more in the crate engine they were showing.

a follow up to this one (my little edit button has run away from me ) Add on a supercharger to the otherwise stock 6.0 and you're over 400hp. This is in 4 Wheel and Off-Road (June I think)

 

[sjx40250]

Anybody have more info or links concerning using junkyard M-90s blowers on the 4.0L? Photos would be the best, especially home-made brackets and manifolds and such. thanks in advance for any help.
marcus

There is good reason why Kenne, Avenger and others charge what they do for their kits. It is not just a bolt on solution. They are engineered, somewhat hastily, solutions. There is more to it than most people would be willing to give away. It is a complex airflow and engine mangement challenge.

 

[aspera]

There is good reason why Kenne, Avenger and others charge what they do for their kits. It is not just a bolt on solution. They are engineered, somewhat hastily, solutions. There is more to it than most people would be willing to give away. It is a complex airflow and engine mangement challenge.

Avenger has to tip the girls accross the street.

 

[Blackash132]

I have been reading this thread and Dr Dyno's site on building a stroker. I would love to build a stroker for my 2000. My dad and I could work on it together cause he used to rebuild engines and I'm still learning. Couple of questions... If I were to build a stroker, I was looking on JRE site and they have a few kits to choose from. the 4.6, 4.7 and 4.8... The 4.8 is the cheapest kit why is that???

And would I have to beef up my tranny or anything if i were to just stroke it?
Also would I have to regear my Axles cause I'll be running 32's
Thanks for the help
and thanks for the help so far too, esp. Dr Dyno's write ups

 

[Dr. Dyno]

I suggest that you go for a 4.6L stroker. It's highly unlikely that the cylinders will need to be rebored beyond +0.030" (if at all) so if you stick to a 0.030" overbore, you'll still have enough meat in the cylinder walls for a second rebore if needed.
To achieve a 4.8L displacement, you need to rebore the cylinders +0.125" to a bore of 4.00". The cylinder walls become very thin by this time and you need to have the block sonically tested to see if it's safe to overbore this far. Unfortunately I can't get the stroker kit prices from the site but the 4.8 kit may be slightly cheaper than the 4.6/4.7 kits because Chevy/Ford/Dodge 4.00" bore pistons are very easy to find and cheaper than forged Jeep pistons.
The stock drivetrain will cope with the torque from a stroker but if you have oversize tires, you might wanna think about upgrading the rear D35 axle to a D44 or Ford 8.8.

 

[Blackash132]

thanks Dyno, I'll go with the 4.6 stroker. I have the C 8.25 in the rear and I'd love to get a D44 but is the C good enough for now... I know its better than the D35... Thanks again

 

[xuv-this]

consider building your stroker to take a light-med turbo later on. done right, with a good cam, that would compliment the strong low end, and give it a huge punch over 2500rpm. if you got enough cash, i would get the hesco head, too. a HELL of a lot easier to change a cam, too.

 

[xjfreak95]

this guy may help with the tranny questions http://www.importperformancetrans.com/toyotaauto.shtml

 

[big mike 27]

Wouldn't it just be totally cheaper than stroking it to throw like a 350 or a 351 in it? I don't understand why people pay $4,000 to stroke it and have everything done to it, and it's still making under 300 ft-lbs.