Has anyone actually built a stroker with a 232 crank yet?

[savagef82]

Sorry if there are examples posted on this very board, I just haven't found them yet.

Anyway, I bought a well worn engine from a 2000 XJ to start my build and then I found an AMC 232 crank to turn it into the 4.2L Milder mini-stroker.

I plan on using the 4.2L Milder mini-stroker recipe found right here. http://www.jeepstrokers.com/forum/viewt ... =15&t=3083

When I called my local engine builder/machine shop about doing the work that I can't do they told me that the recipe I wanted to use wouldn't work and they couldn't help me. This from a shop that has "Built many jeep stroker engines."

This was kind of a bummer so I came back here to do some research and found this post which still has me scratching my head.http://www.jeepstrokers.com/forum/viewt ... =15&t=4058

So has anyone out there already sucessfully built a 4.2 with a 232 crank and if you have can you please give me some tips or pointers or at least a proof of concept.

Thanks in advance.

[Knoxes]

I'm 3/4 of the way through - almost completely reassembled and ready to re-install. My build thread is in the Projects forum under the title "4.2ish mini stroker".

I'm not sure why the shop would say that it wouldn't work - can you be any more specific?

I will say that, if I had this to do over again, I wouldn't use the 232. For the return on investment, I don't think this is worth it. I will have a slightly better than stock motor, at a significant cost increase over a stock rebuild. For a slightly higher investment, I could have had a 4.6 or 4.7L with a significant increase in hp and torque.

[savagef82]

Thanks for the reply, I don't know how I missed your build.

The Machine shop I spoke with said that the stroke would be too long for the block when using the Silvolite UEM-2229 pistons.

Told me I would need to have custom pistons made.

After your return on investment comment I think I might just find a 258 crank and start a low buck 4.6 build.

More power and a lot more information out there too.

This of course depends on weather or not I can find a 258 crank for a price I'm willing to pay.

[Knoxes]

I can tell you definitively that those pistons, with a stock rod and the 232 crank will go over deck by at least 0.004 - that might be their concern. But the combination of the head gasket and the shape of the combustion chamber (in the head) will accommodate that. I expected it to be over the deck by 0.010. But that combination of crank, rod and piston came up shorter than expected (not sure why). In fact, the over deck is preferable because it will reduce the quench from the stock 0.07 to somewhere around 0.04 (depending on the head gasket, block decking, etc). I'm not sure if the over deck is generally common in engines, but it isn't unusual with these stroker builds. It would have been just about perfect if it had been flush, because the quench would have been equal to the thickness of the head gasket (0.043 in this case). But based on what I've, I was comfortable with a tighter quench. Mine should be around 0.035.

Yes, the 258 crank is expensive. And it's likely that you'll want a better cam, which means a better timing set, performance springs, etc. The costs definitely escalate. As it stands right now, I'm at about $2800. I projecting costs to be around $3200. If I had used the 258, I would expect to have spent about $800 more at this point.

[savagef82]

Thanks for all the details and numbers Knoxes, I'll take what you've done and show it to the local machine shop and hope this helps them figure it out. If not, time to find another engine shop.

As far as cost goes these things do add up quicker than expected.

I hope to save a couple bucks by going with the Comp Cams 68-115-4 192/200 and keep the valve springs that I have now.

If this doesn't sound like the best idea I'd love to get some feedback.

[Cheromaniac]

The Machine shop I spoke with said that the stroke would be too long for the block when using the Silvolite UEM-2229 pistons.

Told me I would need to have custom pistons made.

That's a load of old bollocks!
If you calculate a deck height of 9.453" (9.450"-9.456") for the 4.0L block, a rod length of 6.125" (6.123"-6.127"), 1/2 the stroke (1.75") of a 232 crank, and a pin height of 1.581" for the Silvolite 2229 pistons, you get a deck clearance of -0.003". At worst it could be -0.008" so even with a 0.043" head gasket, quench would come in at 0.035".

[savagef82]

Thanks for the reassurance. I knew they were completely wrong when they told me that.

Now I'll take them the information you've shared and find out if they are worth the prices they're asking. Not cheap either.

Probably worth my time to shop around the idea to a few more machinists/engine builders anyway.

[SilverXJ]

The machine shop may be thinking of the standard stroker using the 258 crankshaft