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Aaron Cox |
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Professional Lawn Dart ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() Group: Retired Admin Posts: 24,541 Joined: 1-February 03 From: Corona, CA Member No.: 219 Region Association: Southern California ![]() |
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. |
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Twystd1 |
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You don't want to know... really..... ![]() ![]() ![]() ![]() Group: Members Posts: 2,515 Joined: 12-September 04 From: Newport Beach, California Member No.: 2,743 ![]() |
Then he might not want to cut the pistons if he is looking for longevity.
If he is racing... No problem. And Aarons engine has seen way over 6200 RPM... Every time I drove it. (IMG:style_emoticons/default/chair.gif) (IMG:style_emoticons/default/WTF.gif) (IMG:style_emoticons/default/agree.gif) (IMG:style_emoticons/default/alfred.gif) Once the top AND bottoms of the cylinders are flat and coherant to each other. And the combustion chamber sealing area is decked FLAT. Then he will need to mock it up again and see what the clearances are. At that point. He can look at shaving the pistons... And the block side of the barrels. Until then.. it would be guessing on how much to remove from the cylinders or the pistons. Clayton |
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