gaz097 Bronze Donating Members 1,751 Member For: 13y 4m 2d Posted 05/11/14 10:06 AM Share Posted 05/11/14 10:06 AM From what I've found they run a bout a thou less in bore to wall clearance so yeah would be quieter. Link to comment Share on other sites More sharing options...
jimmixr Donating Members 686 Member For: 14y 3m 4d Posted 05/11/14 10:37 AM Share Posted 05/11/14 10:37 AM Yep..atomics are a cosworth forging. They run about 2.5 thou.. Link to comment Share on other sites More sharing options...
gaz097 Bronze Donating Members 1,751 Member For: 13y 4m 2d Posted 05/11/14 12:09 PM Share Posted 05/11/14 12:09 PM That's ridiculous. What does a naturally aspirated cosworth piston require? Link to comment Share on other sites More sharing options...
FORCEDG6E Member 145 Member For: 13y 3m 26d Gender: Male Location: adelaide Posted 05/11/14 01:02 PM Author Share Posted 05/11/14 01:02 PM I just hope my machinest knows what hes doing about all this becuase im lost Link to comment Share on other sites More sharing options...
jimmixr Donating Members 686 Member For: 14y 3m 4d Posted 05/11/14 08:12 PM Share Posted 05/11/14 08:12 PM No Idea what n/a tolerances are. But I do know a lot of LS1 applications actually run a interference fit of 1thou !!! That's why its imperative that a torque is used when machining. I had one made at great expense.. Link to comment Share on other sites More sharing options...
gaz097 Bronze Donating Members 1,751 Member For: 13y 4m 2d Posted 05/11/14 10:10 PM Share Posted 05/11/14 10:10 PM I just hope my machinest knows what hes doing about all this becuase im lostThey just machine to a nominal bore diameter so its pretty hard to mess up.The bore to wall clearance is built into the piston itself. Looking at my paper work Ross recommend a 5 thou clearance. That's why they rattle. Link to comment Share on other sites More sharing options...
jimmixr Donating Members 686 Member For: 14y 3m 4d Posted 05/11/14 10:51 PM Share Posted 05/11/14 10:51 PM They would rattle with those clearances.. Link to comment Share on other sites More sharing options...
Peppy_t92 Silver Donating Members 748 Member For: 11y 7m 20d Gender: Male Location: Liverpool Posted 05/11/14 10:56 PM Share Posted 05/11/14 10:56 PM Manley recommend 0.003" measured 1.1" down from the bottom of the oil ring Link to comment Share on other sites More sharing options...
jimmixr Donating Members 686 Member For: 14y 3m 4d Posted 06/11/14 12:37 AM Share Posted 06/11/14 12:37 AM Yeah because of the shape of the piston.Actually wider in the middle section Link to comment Share on other sites More sharing options...
straughsberry Donating Members 1,846 Member For: 17y 3m 5d Gender: Male Location: Broady, Melbourne Posted 06/11/14 01:24 AM Share Posted 06/11/14 01:24 AM Clearance depends on the type of alloy used. 4032 expands less so you can run tighter clearances. 2618 expands more so needs more clearance but generally are said to handle more. I see that the Ross units are made from 2618. 1 Link to comment Share on other sites More sharing options...
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