Jeep Strokers

Good morning! my name is Keith and im down at Charleston AFB, SC. I drive a 2000 Cherokee and of course after my 0331 head cracked i replaced it. Drove it for 3 weeks and then lost compression after a sea foaming. As it turns out my motor is scorn/collapsed rings. I could just replace them. But after machine work and parts even with doing the labor myself. im looking at 800 bucks. Lucky me i stumbled onto someone selling a stroker they started but cannot finish. Which brings me to your site! I have Lurked these threads for quite some time now with aspirations to build a stroker down the road like many jeepers do. But im at a point where i need a new bottom end and the time is right So here is my question. (s)

I came onto an already machined/built block. With new everything. Bored .030 machined 4.2 crank and rods. New piston rings. New cam. already assembled. The gentleman has over 2000 invested and Is willing to sell it to me for 900. So question one. Do i buy it? His character seems very honest and knowledgeable. He didnt cheap out and went through 3 different blocks until he found one with no defects (55,000) when pulled from vehicle for build up.

2) Can my brand new CAST Reinforced 0331 Head from Clear water swap right over with out a port job?
3) Can i use my stock Valve train? (120,000 mi)
4) Ive done a head swap and multiple suspensions but never any major motor work. I Maintain aircraft for a living but i still feel UN-confident. But with most task i feel unsure until after ive done it. Is this one of those? im just nervous to spend 900 bucks on the short block. Then labor and gaskets and all this stuff just for it not to start. I think what im looking for here is some reassurance. My father and another jeeper who have done multiple engine swaps will be assisting me but none of them have done a stroker build.

I browsed quite a few build's/question forums. Their are just a lot of variables so i hope no one minds that i posted my own thread. Feel free to flame. Im just a guy asking questions.
Thank you in Advance.

At any price, I'd want a detailed itemized list of parts used. What year crank (and what it was machined too), Pistons, cam, bearings, timing set, pumps, ect. $900 does sound tempting

After that I'd find out if the block was decked any as that will hugely determine your target scr/dcr/quench.

Also see what year the donor block is just to rule out any possible fitment issues down the road

Your new head should fit fine along with the stock valve train... But you will need to confirm the cam in the block. You can run up to a .450" lift on the stock valve train.

Grab a Haynes manual for referrence for the install.

Here is all the information i have on the short block that someone else put together.

92' 4.0 Block that had 55,000 miles bored over .030
bathed checked and machined by a shop in South Florida
Calculated CR of 9.6:1
4.2 Short nose crank. I belive thats the 4 coutner weight one.
6.125" connecting rods from 92'
amc 242 timing chain cover 92' cast
OE timing chain and gear set- NEW
Sealed power speed-pro Hypereutectic pistons for amc 242 4.0L .030" (new)
Sealed power main, Connecting rod and Cam shaft bearing STD. (new)
Crane cams Truck torque Cam For Amc 258 4.2L p/n 753905 (NEW)

That's really all the info i have on it right now. He said the inside of the block was oiled before It was stored. He is selling it Because he's not finishing his wrangler project.

If you have any other things for me to look into please let me know in advance. Unfortunatly checking it out before hand isnt really an option because he's 600 miles away. I plan to have it freighted.

Thanks in advance for the support guys.

robswampthing wrote:Do i buy it?

Price isn't bad, however i would have another machine shop go through it and verify all the clearances and other items.

2) Can my brand new CAST Reinforced 0331 Head from Clear water swap right over with out a port job?

Yes, however you need to get teh details on that cam and see if it will work with stock valve springs.

3) Can i use my stock Valve train? (120,000 mi)

If the springs work w/ the cam I see no reason.

4) Ive done a head swap and multiple suspensions but never any major motor work. I Maintain aircraft for a living but i still feel UN-confident. But with most task i feel unsure until after ive done it. Is this one of those? im just nervous to spend 900 bucks on the short block.

You will be fine. The bolts on top of the transmission are a bitch. What I do is lift the engine up enough to tape pressure off the engine mounts. Remove the rubber mount part and then lower the engine down. That will give you enough clearance to reach the bolts with a swivel and an extension. The bolts are (IIRC) e-torx 12.

On the timing set included with it. If it is the single row roller chain style I wouldn't use it. If it is the silent link style it would be good.

Consider you will need 258 rods to use with those pistons, or get new ones. You cant use 4.0 rods with anything but forged pistons (on a stroker).

The seller assures me the pistons he had installed were appropriate for the 242 rods. He's sending me a detailed listing of every part and all measuents and tolerances provided b the machine shop that did the work. The cam Installed doesn't even go past the stock limits. I believe it's like .498 and the limit on stock valve train is .600 Also do I need a port job on my Clearwater new cast 0331 head?

robswampthing wrote:The seller assures me the pistons he had installed were appropriate for the 242 rods. He's sending me a detailed listing of every part and all measuents and tolerances provided b the machine shop that did the work. The cam Installed doesn't even go past the stock limits. I believe it's like .498 and the limit on stock valve train is .600 Also do I need a port job on my Clearwater new cast 0331 head?

Stock springs are more like .500" lift before bind. Its been a while since I checked on though. You will bind on the seal around .525 though. Not only is the bind height important, but so is seat pressure. Too little and you will have valve float. You don't need to port your head, but a simple clean up wouldn't hurt. Don't change the port dimensions, just remove the casting grain and blend all the sharp edges. Don't polish the intake but polish the combustion chambers and exhaust ports.

i looked into the crane cam, and the max lift height is 0.456 the builder assures me that is more for low end torque, since he was building it for a rock crawler. Also i discussed the 4.0 rods with the 4.2 crank with him and he said that with the hyperutectic (sp?) deep dish pistons the 4.0 rods are appropriate to achieve the 9.6:1 CR. While maintaining a stock deck height and head. As everything looks right now i will be buying it from him next thursday. If you look at my first few post i included all the information for the parts he used. If anything throws a flag for you let me know. I feel like im dealing with an honest person here. He really didnt want to let it go. He's been turning down offers for the past 12 months because he didnt want to sell it to someone that want's to just swap it in and redline it so they can say they have a stroker. I just want to make up for lost power with 32.5" tires and my lift, as well as gain some low end torque for off road. After this comes the regear to really gain back what was lost with the 32's.

thanks again guys
-Keith

Again, you cant use 4.0 Rods with those Hyper pistons. You must have 258 rods. With the rod and piston combo you have. The pistons will end up above deck.

that's very unfortunate news, Im not sure if the builder is aware of this. when i get the short block can I freehand turn the crank to see where the stop?

Muad'Dib wrote:Again, you cant use 4.0 Rods with those Hyper pistons. You must have 258 rods. With the rod and piston combo you have. The pistons will end up above deck.

x2

robswampthing wrote:that's very unfortunate news, Im not sure if the builder is aware of this. when i get the short block can I freehand turn the crank to see where the stop?

I hope is is aware. If he can't figure that on his own stay far away from it. The pistons will stick out above the deck so far that the head won't even bolt on. About .22"

Ahh, yes he was mistaken in His Add. He had a machine shop do all the work and here is the CORRECT specifications

The rods are the 5.875 4.2L rods
It's a Comp Cams 68-201-4 with the stamp # EP-88
So below I'm basically copying the math on the sheet here for you to go through.

Crankshaft stroke = 3.845
Rod lengths = 5.875
Piston diameter = 3.905
Piston height = 1.592
Head gasket height= .043
Quench height = 0.081
Deck Height = 9.453
Deck Clearance = .038

Now I plugged these #'s in along with your 0331 head that's measured to 56.5cc's and got these specific to your build

8.86:1 CR
276.3 cubic in
4.53 liters (bear in mind the 4.0L is really 3.965 and the 4.2 is 4.129)

Used all the numbers above in our calculator...

4.6L with 9.64 SCR 8.23 DCR and a whopping .082 Quench!

See attached Document

I'm going to be honest, I'm familiar with the terms but some of them I'm not sure what they mean. I'll do research on some of the terms

Just an update, the motor shipped today. I figured i would include a little bit of an update and info for those of you that helped.

I purchased these! ebay special http://www.ebay.com/itm/310136653389?ss ... 1497.l2649

If you guys are looking for injectors this seller has great review's and i messaged them asking if they could do a better price. With a 3 year warranty and replaced parts (not just tested) i was happy to give them my money
From all the research ive done those injectors do seem approtiate for my 2000 xj Fuel rail/wiring harness. Correct?

And here are some pictures of the short block i purchased.







And here's a picture of my Pride and joy.



Thanks guys!