70 gas question

henry g

New User
How could I get a 8.5:1 compression ratio? The F900R cam has been reground stock, and I'm using LP pistons. Will that get me there? Do I need to mill any off the head? I plan to relieve eyebrows and port match. Will the fixed jets in the Carb be sufficient for these gains? Thanks.
 
Stock piston is 6.15 to 1
LP piston is 7.3 to 1
If you can find one use a 720/730 Gas Carb. #95
Run the 70 LP Manifolds (Colder). The 720/730 intake is to big for a stocker 70. And yes-you could take some off the head. You could also bore the block bigger for 720/730 Gas pistons or A/60 Power Block Pistons both 6 inch. You can bore the block out to 6.125 with out trouble.
 

The stock cam timing will choke that engine's potential.
Josh Blackburn is the resident cam guru.
Port matching, blending off the rough edges from inside the ports and a 5 angle valve job.
Mill the intake eyebrows flush with the top of the valve seat. Open up the head area around the valve out to the full diameter of the cylinder bore.
What octane fuel will be used ?
The cam grinder should be choosing both the cam specs and the compression ratio.
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top