Stroker time - JeepForum.com
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post #1 of 7 Old 02-20-2020, 07:44 PM Thread Starter
Remenissions
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Stroker time

So my 4.2 block bit the dust, but my head and crank are fresh out of the machine shop. Want to keep my carb setup without the hassle of finding a 4.0 carb intake manifold. I have a garage full of 4.2 parts and need to know what I can keep and what I need to replace with a 4.5 stroker build. I’m hoping to reuse my crank, rods, head, distributor, flywheel, starter, and belt drive fan. Probably trying to keep too much but this is my first swap and I’m not sure what all will interchange between these engines.

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post #2 of 7 Old 02-20-2020, 10:48 PM
BagusJeep
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jeepstroker.com

You will need a 4.0 block (larger bore) and that 258 crank (longer throw). The head is usually from a 4.0HO as it breathes better but as you knwo they are almost interchangeable, some mods to make. The rest of the internals can be a mix, see jeepstrokers.com for ideas on rod length, custom pistons etc.

Having a carb is unusual in that injection is so much better but is quite achievable.

Lots of info there on $1000 builds, upwards.

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post #3 of 7 Old 02-21-2020, 07:10 AM Thread Starter
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I want to keep my existing manifolds and I my carb is less than a year old. I just want to minimize the conversion as much as possible and use as many of the 4.2 parts as I can. I tried to register for jeepstrokers with two emails but haven’t got the confirmation email for either of them yet.
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post #4 of 7 Old 02-21-2020, 10:25 AM
dirtdudeaz
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Quote:
Originally Posted by Remenissions View Post
I want to keep my existing manifolds and I my carb is less than a year old. I just want to minimize the conversion as much as possible and use as many of the 4.2 parts as I can. I tried to register for jeepstrokers with two emails but havenít got the confirmation email for either of them yet.
As Bagus said, and I replied in your other thread, you need a full 4.0 to do a stroker. You need to use the head and you'll need an exhaust for a 4.0. The intake and accessories are up for opinions, but you'll find life easier swapping over to all 4.0 stuff and MPFI. I also think the $1K is too light of an estimate. I think you'll be closer to at least $2K even for a "poor mans" stroker.

If you can't stomach or afford it, find another 4.2 donor engine or block and build your current engine up.

By the way, if you went to another 4.2, the early 80's castings of the 4.2 block have a known casting issue that cracks at the water jacket midline; try and find a later casting number or earlier.
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post #5 of 7 Old 02-21-2020, 12:08 PM
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How much power is there to gain by what you propose to do? Is that the point of it all?


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post #6 of 7 Old 02-21-2020, 08:00 PM Thread Starter
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Jim, my goal isn’t making any real gains, just getting my Jeep back in the road with as little modification as necessary. My head and crank are sitting in the machine shop fresh and ready to go, and in spite of the carb’s downfalls, I prefer it to fuel injection because it’s simple and what I already have. And any motor I can afford at this time is going to get a rebuild, and since I’m gonna have it open anyway, swapping the crank and rods isn’t going to be an extra step.
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post #7 of 7 Old 02-22-2020, 06:51 PM
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There are some threads around here dealing with different carburetors on the inline-6 so that's an option too and not too costly. I think it's the Autolite (Ford) 2100 that has been used quite a bit. I had a stock one on my 68 Ford Mustang years ago and it worked flawlessly. The big problem I see with a carburetor is that as time goes on the guys that really knew how to maintain them are dead.
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