Doing a top end/upgrade. couple questions, heads, rings and deckheight extremes. Options

[Aaron Cox]

motor ate a head gasket. pulled it apart before it could flame cut a cylinder or head.

so its apart. 71 x 94, with LARGE cam. has mahle euro '8:1 pistons" in it.
deck was setup at .031 but was running a head gasket.

heads have never been decked/surfaced. pulled em and cleaned em, 2 chambers have a sparkplug crack starting - so they need to be welded.

while its apart, i plan to re-ring it, hone the barrels, get the heads done, and???

questions - what rings do you recommend for mahle pistons?
certain rings justify certain hone finishes right?

heads need welding.
valves are sealing great to the seats. guides are good. (motor has 35 k on it since full rebuild.) when the head gets welded, will this require new seats/guides and a resurface?
what is the proper welding setup- my machinist may want to weld em cold, but i was told to pre heat em first - your thoughts?

when reassembling - how tight can i go on deckheight? the euro pistons have a .034" dish to em. should i trim the pistons .034 to make them flat, and trim the cylinders accordingly also?

trying to get as much CR with these 94mm pistons as i can, and running 91 gas.

last question- cam. how does the cam affect deck height? how tight can i go?

going to CC my heads tomorrow - before machining.... what is the range for a stock 2L head? 55-65cc's?

*on reassembly - head gasket will be omitted, and cylinders will be lapped into the head. valves will also be lapped into their seats again.

[Twystd1]

If you mill the top of the pistons, and cut the barrell down to match heights.
How much space between the top of the piston and top of the first ring?
That can be an issue in itself.
John will have the answers using some math and some measuring tools......
of what will work as far as deck height and interference problems.

I have much tighter decks on a 103 with flycut pistons on one engine... No problems.

I don't know stock piston heights at all....

AA... shoot over to STF and do a search on deck height + stock pistons. Jake and others have written profusely about this subject using stock pistons. I think you will find ALL the data you need there.

Make some time to go over to Brians shop where we can blast your cap....

And we can glass bead your heads at the same time..

NOTE. Buy new exhaust studs before ya put this bad boy back together again. Welding heads can do some weird shit to heads.

C

See ya tomorrow if you are coming my way.....

C