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Author Topic:   valves
H&HRACING
Dirt Roller

Total posts: 23
posted February 12, 2001 07:41 PM
SHOULD I HAVE MY VALVES CUT AT 30 OR 45 DEGREES? I'VE HEARD 30 IS BETTER. THANKS

sdhnc29
Dirt Full Roller

Total posts: 74
posted February 13, 2001 11:25 PM
Your valve angle will depend on what head you have. Don't use a 30deg. seat !! 30deg. seats will produce slightly better low lift flow numbers on certain heads , but for racing , use at least a 45deg. seat . Most of the newer heads (SB2.2 and some 18deg.)use a 50deg. Intake valve with a 35deg. back cut , and a 55deg. exhaust valve with a 38deg. back cut . These angles will improve flow quite a bit on heads with a deep pocket and a tall short side radius . A good basic place to start is with a 45deg. intake w/a 30deg. back cut . The ex valve usually likes no back cut , but a radius on the face of the valve . Hope this helps !!

H&HRACING
Dirt Roller

Total posts: 23
posted February 14, 2001 09:23 AM
im running the ovalport 2.3ford head. thanks for the info.

sdhnc29
Dirt Full Roller

Total posts: 74
posted February 14, 2001 06:47 PM
H&Hracing ,

I'm very familiar with the oval port 2.3 head . You will want to go with the 45deg. valve seat . Be sure to use a 30deg. back cut on the valve . Your intake valve seat in the head will like to see a 30deg. top cut, then a 45deg. seat , followed by a 60deg. cut and finally a 70deg. cut . Your exhaust will like a 30deg. top cut , then a 45deg. seat , followed by a radius into the pocket . I would suggest that you find an engine builder that uses a Serdi or a Newen seat and guide machine . They will have pre-formed cutters that will do all these angles in one shot . If you end up needing the Serdi or Newen cutter part numbers , let me know and I'll supply them to you .
I'm messing around right now with some different seat angles . I should have some flow numbers in the next week or two . If I find anything new , I'll send you a personal email .

Steve

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