Am I screwed?
 

I have a gen 5 8.2 block with a bad cyl that is already 4.530 and a gen 6 with a "sloppy" 5.30 bore. Do they make a 4.540 piston that will work with a 6.135 rod? I've run out of money and want to see the water some one this year. Both are production blocks. Suggestions?

Call Diamond Pistons they modify self stock pistons for a fee.

how about sleeving that cylinder?

+1

Machinist was saying about the distortion in adjacent cylinders. After honing would likely give me too much piston to wall clearance. I would like to just go to a 4.560 piston but I'm told in on the production gen 5's and 6's that its ill advised for a marine application.

Yes sleeve it

Why not pick up a used block. All of that machine work is going to cost a lot of coin. I can't believe a used block bored to wherever you want it to be would not be cheaper?

i know you don't want to hear this but the smart play is to fix it right the first time regardless of cost. if that means not getting in the water then thats what it means. in 100 out of 100 cases trying to shortball a structural repair because you are short on cash ALWAYS , as in " every single time" ends up costing you more in cash and considerable aggravation later on when it fails prematurely and either ruins something else or just requires you to do it all a second time. i am not suggesting you can't make what you have work , one way or the other,.. of course you can. i am just suggessting that you don't make the same mistake that lots and lots of other people desperate to get on the water make...

Respectable answer, question is.. What's the correct fix? New blocks, new pistons, sleeving etc?

I was told a gen5 or 6 502 is a Siamese bore and sleeving one hole will cause distortion issues with cylinders on each side.

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That indeed is the case, just sleeve all four on that bank, back to reassemble. we have done this many times back in the early years when case flow was low, works out great (if done correctly)

Good luck with which ever way you decide to go!!

well... thats a good question and without seeing the parts and the sleeves available etc i don't have an answer. i think if it were me, i would do two things... first i would talk directly to someone that has sleeved these exact blocks ( not me ) using which sleeves and inquire as to success rate. the other thing i would do is look for a usable known good stock block or core. thats a pretty old system and there should be some hi hour ones around pretty cheap that could be rebuilt reasonably... or maybe give ATK a call and see if they have a shortblock to sell you .... not trying say one is better than the other but those are the options i would explore in that order. personally i would be nervous sleeving adjacent cylinders in a siamese block like that... but i never had occassion to try either.

You might call one of the piston companies and see what your options are, CP, Diamond, JE, Ross, Wiseco.

Sleeve it. I have a gen 6 502 block/motor with a sleeve in it for 6 years now and no issues.

i dont know of any good engine builders that will sleeve only 1 hole on a 502 .when the sleeve is pressed in it tends to distort the cylinders next to it .why not have a set of pistons made ??last set i had made were about 800 and were 502 .030 .getting them made .040 wouldent be an issue

I think that's the way I'm heading. Tossing the idea around of Diamonds. Hoping it cleans up @ the 4.540 mark. The second engine deff will (two small nicks where water sat). Maybe I'll run the 4.530 JE's with file fits in that engine and run it as is and bore the bad one to 4.540 and get some customs made up.

4.540 is .070 over. Std bore is 4.470, I forgot for a min and was thinking the same .040 is no big deal. Has anyone sonic tested a few blocks to see how far you can go?