GARY C wrote: ↑Tue Jul 02, 2019 6:58 pmI had heard the same about 60 degree seats, what you never hear is how as valve train got better guys started reducing seat angels and some back to 48* I think this is why you hear so much now about 50 and 52 but little about 55.ClassAct wrote: ↑Tue Jul 02, 2019 6:19 pmGARY C wrote: ↑Tue Jul 02, 2019 6:11 pm
One thing I found interesting around me is that the reputable shops that are known for good power don't even own 50 or steeper cutters, the main guy I deal with does have a 55 for exhaust that he does for some Mopar teams based off what they found doing testing with Allen Johnson, probably a Super stock kind of deal but they found a 45 intake and 55 exhaust to be best at least for that combo.
Some people are so afraid of going backwards, they never go forward. Their fear of failure paralyzes them. I know I was absolutely shocked at the amount of blowback I got from every quarter about steeper than 45 degree seats. I know some of them still won't budge. I get what Chad is saying. There are going to be times where a 45 may be better. Don't know how many times I've made more power and the car is slower. The power showed up chassis/tuning issues. Yet, the customer says the dyno lied. It's never their car or tuning or both is the issue.
I'd be leery of any shop today that isn't at least testing with other than 45 degree seats. I know that some teams were using 58 degree seats and some bullshitters were claiming 60 degree seats were being tested. I believe the 58, because I know who was doing that. The 60 I can't say. Could never verify that.
It's all about the SHAPE and always has been about SHAPE. The SHAPE of a correctly designed 50 or 55 degree seat has a far better shape than anything else.
I suspect some who are not finding results with steeper seats are not using the correct size and/or shape of valve to go with it.
Everything in my shop right now is 45 (personal stuff) and I have yet to see a big enough gain to justify changing anything I have for what I am doing but I think that is why this discussion keeps coming up. If I do any future projects and am willing to test I would like to do ex first and then int just to see.
If you are looking to find flow number improvements to wow you with steeper seats, you usually don't. You see it on the dyno, and then on the time slip. I've said it before and repeat it now...gross, or bulk or whatever you want to call it on the flow bench means very little.