Loc Posted April 26, 2009 Report Share Posted April 26, 2009 How much compression can you run on a stock motor before it starts to let go and break. I was looking at running around 170 with 110 octane fuel for a dune/drag bike. But I dont want to go with that compression if I am going to make the bike unreliable. Quote Link to comment Share on other sites More sharing options...
Darthwall Posted April 26, 2009 Report Share Posted April 26, 2009 run around 100 octain feul Quote Link to comment Share on other sites More sharing options...
black sunshine Posted April 26, 2009 Report Share Posted April 26, 2009 Should probably weld/true crank. Also make sure the engine is sound before bumping up compression. If your compression is low, you can't change out domes to compensate. Quote Link to comment Share on other sites More sharing options...
278 Posted April 26, 2009 Report Share Posted April 26, 2009 Just get your crank true/welded, make sure your bearings are in good condition and maybe some wiseco pistons and you'll be fine 170 is pretty safe Quote Link to comment Share on other sites More sharing options...
Loc Posted April 26, 2009 Author Report Share Posted April 26, 2009 The motor is in 2004. It has 120 compression on both cylinders at 1400 feet. Would this setup last a season on 110 fuel. Who do you recommend to true/weld the crank. Quote Link to comment Share on other sites More sharing options...
00tbanshee Posted April 26, 2009 Report Share Posted April 26, 2009 i know kevin at herr jugs racing welds cranks Quote Link to comment Share on other sites More sharing options...
GrMeyer Posted April 26, 2009 Report Share Posted April 26, 2009 The motor is in 2004. It has 120 compression on both cylinders at 1400 feet. Would this setup last a season on 110 fuel. Who do you recommend to true/weld the crank. You dont need 110 gas for 120psi in the compression. you can run 91-93 and be fine unless your running some massive timing. when you get around 150psi is when everyone starts running 100 oct. so unless you get the fuel for free I would save the money from the gas and buy some mods. as for true and welding. Crankworks.com is $115.00 in Mesa Az. Duncan racing is $100.00 ATV Racing in Phoenix Az is $75.00 So all in all I just use google and search for it Quote Link to comment Share on other sites More sharing options...
Loc Posted April 27, 2009 Author Report Share Posted April 27, 2009 I am putting on a Trinity Stage IV head with 18cc domes and planning on running roughly 170 compression. That is why I am going to run 110 octane. Quote Link to comment Share on other sites More sharing options...
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