The things I have laying around stroker build . . .

[RedHeep]

So I have a 258 in the garage from an '86 CJ that I swapped for, then the guy backed out and never came and picked it up. It's been almost 4 years and I'm pretty sure he moved to Cali.

And I have the 4.0 short block from the '91, my first jeep, that I killed the bearings in with muddy water from a giant puddle. I tried putting main and rod bearings in it, but I replaced it because the oil pressure was zero and it had piston slap from the rings getting wiped.

How do I take those two items and make a stroker short block I can put my current 4.0 head and '99 intake/exhaust manifold on?

I'm leaning more towards reliable than I am all out performance. I don't want to break te bank, but if it makes good sense, I'll spend the money on it. My veterans bonus check is $1500, I want to see what we can come up with.

 

[Dr. Dyno]

You could use the crank & rods from your 258, add a set of cheap stock replacement 4.0L pistons/rings, and rebuild the '91 short block into a stroker.
Use your existing 4.0L head and '99 intake/exhaust manifolds to complete the build.
At a minimum the machine shop work you'll need is to have the cylinders overbored +/- the block/head to be milled flat.
Budget for a list of other stock rebuild parts such as oil pump, timing set, camshaft, lifters, pushrods, gaskets/seals, freeze plugs, harmonic balancer, and a set of oversize injectors.

 

[streetxj]

You could use the crank & rods from your 258, add a set of cheap stock replacement 4.0L pistons/rings, and rebuild the '91 short block into a stroker.
Use your existing 4.0L head and '99 intake/exhaust manifolds to complete the build.
At a minimum the machine shop work you'll need is to have the cylinders overbored +/- the block/head to be milled flat.
Budget for a list of other stock rebuild parts such as oil pump, timing set, camshaft, lifters, pushrods, gaskets/seals, freeze plugs, harmonic balancer, and a set of oversize injectors.

I think the 91-99 HO's used the same header design. It's the 2000 models that began using the dual exhaust manifolds/ y-pipe system.

 

[RedHeep]

You could use the crank & rods from your 258, add a set of cheap stock replacement 4.0L pistons/rings, and rebuild the '91 short block into a stroker.
Use your existing 4.0L head and '99 intake/exhaust manifolds to complete the build.
At a minimum the machine shop work you'll need is to have the cylinders overbored +/- the block/head to be milled flat.
Budget for a list of other stock rebuild parts such as oil pump, timing set, camshaft, lifters, pushrods, gaskets/seals, freeze plugs, harmonic balancer, and a set of oversize injectors.

I read your site and was curious what you thought about that build and if you had anything better to offer a few years later. I think for a set of pistons and a master rebuild kit I can put a nice reliable engine together.

I'll have to check the numbers on the 258 and see what crank I have and if I need to do anything to make the front end work.

 

[Dr. Dyno]

I read your site and was curious what you thought about that build and if you had anything better to offer a few years later. I think for a set of pistons and a master rebuild kit I can put a nice reliable engine together.

I'll have to check the numbers on the 258 and see what crank I have and if I need to do anything to make the front end work.

My own engine is an original poor man's stroker but when Keith Black introduced their stroker pistons, I modified the recipe on my site so you'll also see a modified poor man's stroker with 4.0L rods & IC944 pistons.
You can make any '72-'90 crank work. If it has the longer snout, you can either use a 1cm thick spacer or cut the snout 1cm shorter and bolt on a 4.0L harmonic balancer for a serpentine belt set-up.

I think the 91-99 HO's used the same header design. It's the 2000 models that began using the dual exhaust manifolds/ y-pipe system.

That is correct.

 

[RedHeep]

My own engine is an original poor man's stroker but when Keith Black introduced their stroker pistons, I modified the recipe on my site so you'll also see a modified poor man's stroker with 4.0L rods & IC944 pistons.
You can make any '72-'90 crank work. If it has the longer snout, you can either use a 1cm thick spacer or cut the snout 1cm shorter and bolt on a 4.0L harmonic balancer for a serpentine belt set-up.



That is correct.

Forged pistons are $$$. I think since I have the whole rotating assembly, I'll just go with the cast pistons, even though it may be heavier.

I think I'm going to upgrade the cam and most of the rebuild kits I was looking at were reasonably priced. I'm also thinking of finding a cylinder head and working on the ports so I can install everything and be ready for an engine swap.

 

[cal]

Its not about forged pistons (they arent even forged, actually). The KB pistons are designed to work with your long rods instead of the shorter 4.2 rods, and makes it easier to get quench managable.

Its worth spending $500 on.

 

[Vanimal]

what Cal said. Of course, you can go the ghetto route and deck the block to bring the quench down like i did. That costs money too, unless you have a machine shop and do it yourself like i did.

 

[RedHeep]

I'm not sure what your definition of forged is, but those are forged pistons, at least that's what the manufacturer is saying.

Each Icon piston is forged from high-strength, heat treated, 2618 aluminum alloy.

https://www.uempistons.com/index.php?main_page=index&cPath=8

I understand the difference between cast, hypereutectic and forged pistons. I've built engines before. My understanding was that the difference between using the 258 rods and the 242 rods was weight, not deck height or quench. That's why the Icon pistons move the pin lower in the piston so that you can use the shorter rods and maintain the correct piston height in the cylinder.

Not trying to sound know it all, because I don't. Isn't the longer rod/shorter piston the same as a shorter rod/longer piston? 'Splain it to me so I know.

 

[cal]

I'm going to admit that he typed ic944, and I saw kb944..

http://www.summitracing.com/parts/uem-kb944-030

 

[Dr. Dyno]

My understanding was that the difference between using the 258 rods and the 242 rods was weight, not deck height or quench. That's why the Icon pistons move the pin lower in the piston so that you can use the shorter rods and maintain the correct piston height in the cylinder.

The 258 rods are heavier than the 242 rods despite being 0.25" shorter. The Keith Black IC944 forged pistons were designed specifically for stroker engines and can ONLY be used with the longer 242 rods.
If you don't already have a set of 258 rods to use with cast or hypereutectic 4.0L stock replacement pistons for a stroker build, it makes sense to buy a set of IC944 pistons to use with your existing 242 rods. They won't cost much more than the combined cost of a set of 258 rods & cast/hypereutectic pistons.

 

[RedHeep]

Right, I've got a whole 258 sitting there, so spending $500 on a set of pistons doesn't make sense, unless I'm building a race engine, which I'm not.

I still love you Cal. The way I love brussel sprouts

 

[cal]

Dude I thought they only did that in Thailand.

 

[RedHeep]

Dude I thought they only did that in Thailand.

I'm worldly. It's catching on on the east coast.