More stroker build questions (getting closer)

[IslanderOffRoad]

The next chapter has begun in my engine build. I have some money now so I can get started on the stroker, and I was thinking of having a shop build the long block for me...

Until I started getting prices. A local place wanted $2500 to build a stroker, not quite as much as Golen or Hesco, and no shipping, but still more than I wanted to spend. At 2500 plus the other parts, I'm back into Chevy V8 swap territory.

As such, it looks like I'll be picking up a junkyard 4.0 and building it myself... I've never done an engine before, so I'm a bit hesitant, but it seems like it may be better for my wallet.

So the question is, what should I start with? Everything needs to come apart anyways to do the stroker, so is a "low mileage" engine really an issue? Only thing I can think then is that the head wouldn't need any work. A local yard has a 93 Complete Engine for $550 with 100k on it. Higher mileage than I think I'd want. I've also got access to a 93 short block with a melted piston for $100, the block is fine. An ebay company has rebuilt HO heads for $300. Would that be a better way to go since I'll probably end up replacing the bad parts anyway?

What should I use as a good aid for building the engine? 4.0 manual? 4.2 manual?

Any help is appreciated, this is probably the biggest project I've ever considered undertaking.

[JeepsAndGuns]

All a stroker is, is a 258's crank and rods in a 4.0's block with the 4.0's pistons. Its not hard to do. I am just starting on my stroker so I am in the same boat as you. But mine is gonna go into my 93 YJ. If you want to continue to drive your cherokee, just look for the cheapest 4.0 you can find to build on. That way you can still drive yor cherokee while your building your engine. Thats what I am doing. I found a 4.0 in a junkyard for 300 bucks, just picked it up today. My YJ is my daily driver, so I am building my stroker out of the junkyard engine so I can still drive my YJ. Next you will need to find the crank and rods from a 258. (I found mine on here a long time ago for like 60 bucks) Then you pretty mutch have all you need.

[IslanderOffRoad]

Mine's not a daily driver so I'm ok with it being down... was going to hopefully source the crank/rods from the current 258 to save some money, assuming they're in good shape.

[JeepsAndGuns]

Thats good. And since all your really keeping of the 4.0 is the block and head, go for the $100 one. It doesnt matter that the piston is melted, so long as the block is good. Have the head re-done (cleaned, magnafluxed, valve job) and have the block cleaned, checked bored and honed. No need to try and re-use the old pistions it might save a little money now, but you will pay later on down the road. If your gonna do it, do it right. Spend the extra money now so you dont have to later. And this stuff takes time, even more time when you have to save up the money, and buy parts when you can. It took me right at a year to rebuild the 401 I have in my cherokee right now.

Are you planning on putting in the 4.o's fuel injection, or are you gonna get a new intake and use a carb? I am pretty sure the intake and exhaust manafold from your 258 wont work on the 4.0's head.

[J10Joe]

from what i have read, your 258 intake will work on the 4.0 heda with minor mods. but you will need a exhust manifold from a 4.0.

[Stu]

EFI!!!! That's one of the biggest reasons I'm going for the stroker myself I'm putting it in an Eagle SX/4 though. We have 4 258s in the household, and only 2 of them are in cars, so I got those. Still need to find the 4.0 donor. But I'm really looking forward to fuel injection for many reasons. Plus, if you can get or already have a complete engine then you've got all the fuel injection stuff. If you go carb you have to buy an intake and carb. The clifford performance carb for the 4.0 is godawful expensive....though I'm sure there are other's out there. I'm gonna try to come up with a HO, or at least an HO head when I do mine. Better flow. Plus aftermarket cam, and maybe some fuel injection adjustments. Keep the posts up though! I want to hear how things go for you guys before I tackle it. I've found a couple writeups if you guys want them btw

[IslanderOffRoad]

The $100 one has no head... its just a short block. So I'd still need to get a head for it.

I'm not going to run EFI, I plan on going with a bigger, non-efi friendly cam.

I may end up just having a machine shop build the motor, piece of mind that its done right and I have a warranty incase anything breaks is really appealing.

The 258 manifold does work, but does anyone have close up pics of the modifcation needed to it?

I want to go with a 4bbl eventually, so I'll get a new manifold then, but for now the modded intake will suffice.

[Stu]

Well, one reason I've taken a liking to this project is that it is almost a direct bolt in. Have to do some wiring, and have to throw in an ax15 inplace of the t5, or put a crank position sensor on the t5. Truthfully the ax15 wouldn't be too bad because it has a higher 5th which will be nice once I get my new lower axle gears. I would definitely use the 4.0 manual as a guide, because for the most part that's what it is. I'm also planning on boring out the cylinders, and getting a bit more displacement. But the crucial factor in the decision, is realizing you don't need a custom crossmember, or motor mounts, or spend days trying to attach driveline, or oil filter problems, or radiator changes, or any of the other headache associated with cross make engine swaps. That makes it a lot more fesible

[Cecil14]

There are pics of the mods needed to use the 258 intake on a 4.0L head on my website: www.geocities.com/cecil_odo.

Milage is going to be a factor. 4.0L cylinders wear a lot at the top. The good thing here is that 4.0Ls can be bored quite a bit with no problems, just need to watch your compression the more you bore it. Just get the lowest milage engine you can get and you should be ok.

$550 for a 4.0L with more than about 40-50k on it is way too much. I just got a complete engine with like 18k for $300.

I would always have the head checked, unless it's new with a warranty.


aa

[IslanderOffRoad]

Cecil,

you gotta remember though, I'm in southern california. Parts cost more out here thanks to the nazi like smog laws.

To put a new engine in a smog controlled vehicle it has to be the same year or newer.... hence if you need a new 4.0 for you 93 Grand Cherokee it has to be 93+... a 92 isnt legal. this drives up the prices because engines are "less interchangable" than they should be. They know someone else will pay it.

[Cecil14]

Yes but ANY 4.0L will work for you. And unless they run the engine serial numbers (they may well) they won't have any idea what year the engine is. from '91 to like '97 or so the 4.0L didn't change. The only things that really ever changed was the heads and FI stuff. Most of that even still interchanges.


aa

[IslanderOffRoad]

Cecil-

Do you know if a 4.0 renix intake manifold will work with a H.O. head? A guy on ebay has Clifford Renix head intakes for relatively cheap.

[Cecil14]

If you are going to run FI then don't bother with the Renix setup. There's a reason they are cheap. I imagine they would probably fit, not sure. I don't think they changed the intake stuff when they went HO, I think it was mostly exhaust changes.


aa

[JeepsAndGuns]

From what I have read the older non-HO (guessing renix injected) heads are more closer to the 258's and flow poor. The 91 and up heads are the ones your looking for. Read this place, lot off good info, dont miss the links to the other parts at the top. http://www.jeep4.0performance.4mg.com/stroker.html


This is what I am gonna build.

4.6L

Jeep 4.2L 3.895" stroke crank
Jeep 4.2L 5.875" rods
Silvolite UEM-2229 +0.030" bore pistons
Increase piston dish volume to 30cc
8.8:1 CR
Crane #750501 192/204 degree camshaft
Ported HO 1.91"/1.50" cylinder head
Mill block deck 0.035"
Mopar/Victor 0.043" head gasket
0.058" quench height
2.25" exhaust
Ford 24lb/hr injectors with stock 39psi FPR for '87-'95 engines,
235hp @ 4500rpm, 327lbft @ 2000rpm

Being able to run 87 octiane gas is a BIG plus, yea I will loose a few HP from not going high compression, but this is my daily driver so being able to run the cheaper regular gas is what I like.

[J10Joe]

F***-Yeah!

From what I have read the older non-HO (guessing renix injected) heads are more closer to the 258's and flow poor. The 91 and up heads are the ones your looking for. Read this place, lot off good info, dont miss the links to the other parts at the top. http://www.jeep4.0performance.4mg.com/stroker.html


This is what I am gonna build.

4.6L

Jeep 4.2L 3.895" stroke crank
Jeep 4.2L 5.875" rods
Silvolite UEM-2229 +0.030" bore pistons
Increase piston dish volume to 30cc
8.8:1 CR
Crane #750501 192/204 degree camshaft
Ported HO 1.91"/1.50" cylinder head
Mill block deck 0.035"
Mopar/Victor 0.043" head gasket
0.058" quench height
2.25" exhaust
Ford 24lb/hr injectors with stock 39psi FPR for '87-'95 engines,
235hp @ 4500rpm, 327lbft @ 2000rpm

Being able to run 87 octiane gas is a BIG plus, yea I will loose a few HP from not going high compression, but this is my daily driver so being able to run the cheaper regular gas is what I like.