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Discussion Starter · #1 ·
304 question-guru\'s

The 304 in my CJ has a lip inside the top of each cylinder. It is about 1/4" down from the top. A co-worker mentioned that this is wear. I have seen worn engines that have a groove worn into the cylinders from the piston rings as it tops out on its stroke. I don't feel this is the case with the 304. Each lip in the cylinders is uniform all the way around. They protrude from the wall between .005 & .003 of an inch varying from each cylinder. My question
= Is this normal for my 304 or is this some serious cylinder wear? This is the first time I've opened up a motor from the AMC line.
 

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Re: 304 question-guru\'s

Sounds like normal cylinder wear to me. In order to remove the piston, you will need to use a ridge reamer to remove the unworn area. Any engine with a lot of hours on it will be this way.

79/CJ-7/AMC360/TH400/Q-TRAC/d30/d44/33's/RS9000s/Herculiner/Pro-jection 2D/MSD/4.10s/lockrights
 

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Re: 304 question-guru\'s

/wwwthreads_images/icons/smile.gif Will is right. It's cylinder wear./wwwthreads_images/icons/crazy.gif

CJDave
Quadra-Tracs modified While-U-Wait by the crack moonguy/wwwthreads_images/icons/wink.gif Quadra-Trac Team./wwwthreads_images/icons/tongue.gif/wwwthreads_images/icons/smile.gif
 

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Re: 304 question-guru\'s

Most small lips are rebuildable. Now, you will need oversized pistons etc. So the cost just went up at least $100 for the pistons and $? for the boring.

Pigpen
76 CJ5 360/T18A/Bronco gear D20/D30 big brake disc, locker/D44 big drum working on disc/ factory slip/4inch lift/33's/6000lb winch/All Fiberglass/electric fan/full cage/ appetite for MUD
 

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Re: 304 question-guru\'s

That's why they make oversize pistons. When I did my rebuild, I had to cut the lip off to remove the pistons. I had my block bored 0.030" over to make up for the 0.015" wear. As long as you don't have more wear than a 0.060" overbore can handle, your block should be fine. Have it checked by the shop that will bore it to make sure the block can be bored out. And have it checked for cracks.

79/CJ-7/AMC360/TH400/Q-TRAC/d30/d44/33's/RS9000s/Herculiner/Pro-jection 2D/MSD/4.10s/lockrights
 
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Discussion Starter · #7 ·
Re: 304 question-guru\'s

Too bad I don't have any buddies that work at a machine shop.Machining and boring seems like an option that I wouldn't want to take. Perhaps that amount of $$ it takes to over haul and machine the 304 is the same of buying an adapter and just going Chevy smallblock,,which brings me back to my first dilemna of what engine to dump in the CJ.

Everytime I take one step forward I end up two steps behind.
 

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Re: 304 question-guru\'s

/wwwthreads_images/icons/tongue.gif All things considered, if I wuz you I would investigate the possibility of swapping in a late TBI small block Chev-Lay......or even a Ferd. What you want to do is swap engine AND transmission and then adapt the transfer case to that. That simplifies things and saves money too./wwwthreads_images/icons/crazy.gif

CJDave
Quadra-Tracs modified While-U-Wait by the crack moonguy/wwwthreads_images/icons/wink.gif Quadra-Trac Team./wwwthreads_images/icons/tongue.gif/wwwthreads_images/icons/smile.gif
 
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