Exhaust Port Turbulence

Godzilla · Post by **Godzilla** » Wed Feb 25, 2004 11:27 am

Hey everybody, I've got an exhaust port that has bad turbulence from .300 to .600. What should I do remove it or lower its intensity? Thanks for the help

SW · Post by SW » Wed Feb 25, 2004 1:54 pm

Is that flowing it with a pipe on it?
Shawn

Godzilla · Post by **Godzilla** » Wed Feb 25, 2004 2:40 pm

No pipe.

Post by **maxracesoftware** » Wed Feb 25, 2004 9:03 pm

Is that flowing it with a pipe on it?
Shawn
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Yes, that was the 1st question i was going to ask

what about valve job, all angles/widths
radius ?
and exh bowl diameter below bottom seat angle or seat insert?
and what exh valve head diameter ?
What percentage is throat area there -to- exh valve head diameter?

if you grind away too much on Short Turn curve can cause that

if you don't setup flow to go into exh port can cause that also

its a question that you would have to have the actual cylinder head in front of you to inspect porting and valve job specs

Post by **maxracesoftware** » Wed Feb 25, 2004 9:08 pm

Is that flowing it with a pipe on it?
Shawn
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Also try Flow Testing again with Pipe on exhaust port
at least 4 inches long

even with header plate adapter also if you run one

many times exhaust port is still in the process of turning when it dumps into atmosphere and can cause turbulence

flow testing with pipe can be different results as pipe helps continue on and straighten exhaust port before dumping

turn head around and flow test with headers on
see if same effect
if so
have to look at Short Turn / Valve Job
even valve margin thickness and backcut sometimes

SW · Post by SW » Wed Feb 25, 2004 10:41 pm

Looks like you covered everything i was going too, lol.With an exhaust port being as short as it is, and as high velocity as they are, that abrupt edge will do strange things sometimes.
Have you ever used exhaust port adapter plates to "trick" and exhaust port that you couldn't grind on? We did some of that with the circle track late model guys that have to run a non ported iron head.Kind of fun stuff to play with, if you can get away with it.
Shawn

Godzilla · Post by **Godzilla** » Wed Feb 25, 2004 11:34 pm

maxracesoftware wrote:Also try Flow Testing again with Pipe on exhaust port at least 4 inches long

You guys may be right - it's a Ford FE, which is really funky on the exhuast. I'll try it and let you know. Thanks