Compression ?

[Loc]

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.

[Darthwall]

run around 100 octain feul

[black sunshine]

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.

[278]

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

[Loc]

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.

[00tbanshee]

i know kevin at herr jugs racing welds cranks

[GrMeyer]

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

[Loc]

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.