Jeep Strokers

What’s going on guys,
I’m new to the forum even though I have been wondering around on it for the past couple of weeks. I own a 1988 Jeep Comanche Renix 4.0 auto 4x4. I have had it for about 3 years. It is a Canadian model (block warmer and KMph speedo) and somehow it crossed paths with me down here in Texas and I bought it. It is a weekend/ Beach toy and so far I have managed to put 7000 miles on it in 3 years. It currently has the equivalent of 108,000 miles in KM. I am a regular member over at comancheclub.com and cherokeefourm.com. Here are a few pictures of my rig how it sits now.





Over the past year I have noticed a loss in power, and I have been blowing out seals as soon as I replace them. Also, I had excessive blow by since I bought it even with a clean CCV system. I did a compression test and these were the results:
Dry Test

Cylinder 1 - 125 psi
Cylinder 2 - 100-105 psi
Cylinder 3 - 145 psi
Cylinder 4 - 130-135 psi
Cylinder 5 - 140-145 psi
Cylinder 6 - 140 psi

Had a mechanic try to figure out the seals failing issue and he did what he called a “pressure test”, He said before he could get it to 30 mph it was reading 3 psi of crankcase pressure. This is a direct cause of the worn rings. So, I decided this is the time to call it and start looking into building a stroker. I have many questions though…. I plan to have a very reputable machinist do the machining and assembly of the motor in my home town. I spoke to him over the phone for about 30 minutes last week about cost of build, and what he suggests I use in the build. I will provide the motor and parts and he will do all the rest of the work for $1000 max he quoted. I’m ok with that to know that the assembly is done right. I have a lot of experience wrenching on motors but have never attempted to get lower than head gaskets in an engine. So I feel the most comfortable having him do the work. He has been open for 30 years and has build 100’s of engines; I have heard nothing but good things from everyone I talk to. He told me to stay away from Keith Black pistons and Eagle cranks. He has had a lot of bad luck with them over the past couple of years. He also said SCAT is what he is suggesting now a day. They have really stepped their quality up over the past couple of years.
I have started doing research on the renix 4.0 to the 96+ 4.0 HO motor swap and it doesn’t look that bad. The plan is to go with a 96+ because of the better flowing head, intake, exhaust, and bigger throttle body. I will probably get work done on the head or buy one that has already been ported and polished along with a better valve train from clegg. They run about $600-750. Or get the new all aluminum head that edelbrock just released for the 4.0, but it runs about $1500.00. In addition I will also have to buy a new header to match up with the 96+ exhaust ports. Also I plan on getting a bored 68mm Throttle body. I want this thing to have plenty of air.
As far as fuel goes, I’m going to need to get a better fuel pump and the hesco adjustable fuel pressure regulator along with ford #24lb+ fuel injectors depending on the size of the stroker. I will also like to get an air to fuel ratio gauge to dial it in, but I know they are pricy, if I have that though I should be able to get the mixture right by adjusting the resistance on the MAP sensor?
As for the build in all I would really like to stay under $3000.00 in just the motor. I know I can probably add another $1000 in injectors, fuel pressure regulator, fuel pump, header, and Throttle body. I think these are realistic numbers and might even come out under 4k total.

I would love to do a 4.9 stroker but I feel it will be more costly and problematic, so I will most likely just go the route of a 4.7. I haven’t picked out the recipe of the build yet because I want to get deep into some more research. Furthermore, from the research I have done I should at minimum be looking at 270HP and 300Tq with a stock 96+ 4.0HO head and stroked to 4.7L. I am hoping for more like 300Hp and 330Tq though. Which I think are possible numbers.

This is all my thought. Please tell me your honest opinions. I am here to learn and take advice. The majority of the people on this board have way more knowledge on all this than I do. That’s why I’m here.

Here are the kits I’m looking at. What do yall think?

http://www.cleggengine.com/stroker-kits ... -kits.html

Also what are realistic Hp and Tq numbers I can expect out of the kits? Is there that big of a power difference between the stages 1,2and3? And are the upgraded heads they offer really worth it? I know, I have a ton of questions, just help where you can please.. And thanks in advance.

You could build something like these:

4.6L low-buck stroker

Jeep 4.2L 3.895" stroke crank
Jeep 4.0L 6.125" rods
Keith Black UEM-IC944-030 pistons
9.6:1 CR
CompCams 68-231-4 206/214 degree camshaft
Ported HO 1.91"/1.50" cylinder head
Mill block deck 0.020"
Mopar/Victor 0.043" head gasket
0.050" quench height
Ford 24lb/hr injectors with adjustable FPR or MAP adjuster for '87-'95 engines
264hp @ 4900rpm, 324lbft @ 3500rpm

4.7L medium-buck stroker

Jeep 4.2L crank offset-ground to 3.915" stroke
Jeep 4.0L 6.125" rods
Keith-Black UEM-IC944-060 pistons
10.0:1 CR
CompCams 68-235-4 210/218 degree camshaft
CNC ported HO 1.91"/1.50" cylinder head
Mill block deck 0.018"
Mopar/Victor 0.043" head gasket
0.043" quench height
Flometrics F&B 68mm billet TB
Accel 26lb/hr injectors with adjustable FPR or MAP adjuster for '87-'95 engines
281hp @ 5000rpm, 337lbft @ 3700rpm

Thanks for the reply. when you say "low buck" or "medium buck" what kind of price range are we talking. Not including the head.

It looks like this would have the head part covered to your specs.
http://www.cleggengine.com/jeep-4-0l-st ... alves.html

I am more interested in the medium buck stroker.

zebvance wrote:Thanks for the reply. when you say "low buck" or "medium buck" what kind of price range are we talking. Not including the head.

The cost difference is mainly in the head and offset-grinding the rod journals of the crank to increase the stroke. You could consider the latter optional as this only increases displacement from 4657cc to 4681cc.
You could modify that 4.7L recipe by leaving the 258 crank standard and using Bulltear custom pistons instead of the IC944's. If you spec them with a 1.380" compression height and a 20cc dish, you can still have a 10.0:1 compression ratio but with zero deck clearance, thereby avoiding the need to mill the block deck.

Get the stage 2 stroker kit with +.060" pistons and spend the extra $30 for the moly rings in the options. The stage 2 head looks good, but you're going to want to send a core head to them so you won't pay $150 more. I'm not familiar with the new Icon 668s, but if they're the same dimensions as the 944s but with a deeper dish, then you'll want your machinist to deck the block .025"-.030" to achieve a zero deck height. Do your research on adapting the renix tps to the 91+ type(hesco has an adapter for $$$). As far as 68mm tbs go, you can spend $400 on a bolt in(you still have to grind intake manifold opening from 62mm-68mm/ask your machinist) or you can source a 4.7l v8 tb from 01-02 Grand Cherokee or Durango(got mine for $25), buy an adapter for newer(non-renix) intake manifold($77 on eBay), and adapt the newer tb's linkage to work with your cable(I chopped the nipple off an old 4.0 tb and welded it onto new tb). There'll be a bunch of other parts to source like headgasket (I recommend 26211pt), freeze plugs, hardened washers to space 96+ crank brace from hitting longer stroke crank, cam, pilot bearing/bushing, etc., but your realistic $3-4K range will cover it.
P.S. Your MJ looks worthy of a stroker.

great info. Thanks. I am open to all options right now, because I don't have clear direction on any of it right now.

I have a friend of a friend that has a Tj and stroked it a few years back. He found his build sheet and sent it to me. What are yalls thoughts on it. I though it was dirt cheap considering $1000 of it was the install. I also didnt see a crank on it? would his build be considered close to the "poor mans stroker" build?

At the top of the sheet Grind crankshaft. He probably had a 4.2 crank reground.
Al