Blownsbc

How much timing can i run on a sbc blown alcohol, i started at 28 it seems conservative. can I get some details and help. Im running 17 lbs of boost on a 871 injected.

 

a buddy of mine runs a 406 with a 871 at 34 degrees with out problems.

 

Depends on the heads vs. the boost.

We ran 30 lbs of boost on a hydro years ago, with brodix -18 (with water jackets) which were a fairly thin deck head...designed for sprint cars. We Locked the timing at 32 degrees! If we flashed the prop early or had a little heavier air...at 33 lbs we would be changing heads as the chambers cracked and pushed into the water jackets. The rule we inherited form other programs was...NEVER go over 32 degees!

We now run brodix track-1 on our dragster. They have a very thick deck. With the SSI blower we snap to 30 pounds instantly and at 30 degrees, there is no issue. Stepped the same tune up to 32 and went from a 7.03 to 6.98 in 1800 lb car. Everything looked ok. Went to 34 degrees on fresh plugs, same tune up...went 6.97 but started seeing spots on the plugs. Went back to 32 and drank beer for the rest of the night, happy with a 6.98!!!

At 17 lbs...I cant say for sure, but watch the boost while you creep on it.

 

blwnsbc

thanks the heads that im using are AFR 235 they are a thick deck no water.

 

we run brodix -12 at 35 degrees

 

Pontus
We also run brodix 12 at 35 degrees whith psi screw 60psi whith no problems
and the one before me run it up to 38 degrees in a dragster.