Reduced low lift flow from porting...

[Warp Speed]

and it's not a 50?? Because you just don't put 50's on everything? About all I can think of??

Chad...are you saying its sealing on the 28, or the 55???? I also did some 55 degree stuff but that was usually big nitrous or some power adder for that. I did do one N/A 55 and that was for me. It was a ton of work and I didn't do it like I would had I had the chance to do it over.

Stock port and chamber?
What is the cam rule?

[SpeierRacingHeads]

Chad...are you saying its sealing on the 28, or the 55???? I also did some 55 degree stuff but that was usually big nitrous or some power adder for that. I did do one N/A 55 and that was for me. It was a ton of work and I didn't do it like I would had I had the chance to do it over.

Stock port and chamber?
What is the cam rule?

Stock Eliminator is just that, stock.

This engine has around a .450 lift

This combo is a 305. Made 360hp on the dyno. That makes it close to 1.000 under the index.

Heads flow around 210@.600 and 150@.600

[Warp Speed]

Stock port and chamber?
What is the cam rule?

Stock Eliminator is just that, stock.

This engine has around a .450 lift

This combo is a 305. Made 360hp on the dyno. That makes it close to 1.000 under the index.

Heads flow around 210@.600 and 150@.600

That's Awesome, congrats, and I sincerely mean that.
But again, pretty narrow set in an even more narrow circumstance wouldn't you say?
That would be like me using a cup engine to reference a turbo ls build, but worse! Lol
That's all I was saying.
Let's keep it technical.

[SpeierRacingHeads]

So I'll answer your question.. IMO!

In a velocity limited cylinder head. Either by a cc rule, stock casting rule, etc., the sooner you get that column of air moving, the better off you are. All these type heads will hit a wall because they are simply out of area. Your not flowing enough to worry about choke, etc at lower lifts like you are with bigger port volume cylinder heads which benefit from taking flow, etc. down low.

[Warp Speed]

So I'll answer your question.. IMO!

In a velocity limited cylinder head. Either by a cc rule, stock casting rule, etc., the sooner you get that column of air moving, the better off you are. All these type heads will hit a wall because they are simply out of area. Your not flowing enough to worry about choke, etc at lower lifts like you are with bigger port volume cylinder heads which benefit from taking flow, etc. down low.

Excellent response!
That's wasn't that hard was it?!? Lol
So are most combinations out there velocity limited, and if so why?

[SpeierRacingHeads]

So I'll answer your question.. IMO!

In a velocity limited cylinder head. Either by a cc rule, stock casting rule, etc., the sooner you get that column of air moving, the better off you are. All these type heads will hit a wall because they are simply out of area. Your not flowing enough to worry about choke, etc at lower lifts like you are with bigger port volume cylinder heads which benefit from taking flow, etc. down low.

Excellent response!
That's wasn't that hard was it?!? Lol
So are most combinations out there velocity limited, and if so why?

All stuff like this is. All Gen 1 Super Stock stuff, ASCS, bacically old school racing.

All this moved away with shallower angles, better cores, etc..

A Super Stock engine is the perfect study is friction loss. Like the video I posted. 172cc head. 1.98in MIN, flows 270 and 260 through manifold. Makes 655@7000. No vacuum pump. 10-1, old school 780 carb.

[GARY C]

Didn't someone who used to post here say he was using 50 degree seat on his .480 lift tow rig? And he did test the engine and IIRC it made great power for what it was.

I'm not so sure seat profile should be dictated by maximum lift.

I agree!
I have been hearing it work on anything from tow rigs to Cup, PS, Comp ect. And valve wear really isn't an issue as long as you keep control in check. I've never seen a proper, steep valve job not pick up torque and power in a high performance deal, and that is the same thing many have said about using it in lesser builds.
At the same time, the cons to the subject post the same articles and use the same reasoning. Which is fine I guess, but we keep beating a dead horse, and history here proves it doesn't end well! Lol
I think that the original topic was more related to the port itself but......?

Do you think there would be less chance of preventing things from going bad by simply answering the OP's question and presenting data as opposed to stiring stuff up in the middle of someone else's discussion?

What little bit of data out there gets reposted because it is all that is out there, from what I have seen it appears the difference is about 6 to 8 hp on average and to most people that is not worth changing everything they have.

Many of us do still run less than .550 lift on some builds, is it possible that your lack of knowledge or desire for these types of builds leads you to assume the wrong things?

I got the same nobody knows or if they do they ain't sating response to this head thread I did. I am sure in your line of work you guys keep asking question and retesting things to see how they react to new found improvements.
https://www.speed-talk.com/forum/viewtopic.p ... 2&start=15

[GARY C]

So I'll answer your question.. IMO!

In a velocity limited cylinder head. Either by a cc rule, stock casting rule, etc., the sooner you get that column of air moving, the better off you are. All these type heads will hit a wall because they are simply out of area. Your not flowing enough to worry about choke, etc at lower lifts like you are with bigger port volume cylinder heads which benefit from taking flow, etc. down low.

Excellent response!
That's wasn't that hard was it?!? Lol
So are most combinations out there velocity limited, and if so why?

All stuff like this is. All Gen 1 Super Stock stuff, ASCS, bacically old school racing.

All this moved away with shallower angles, better cores, etc..

A Super Stock engine is the perfect study is friction loss. Like the video I posted. 172cc head. 1.98in MIN, flows 270 and 260 through manifold. Makes 655@7000. No vacuum pump. 10-1, old school 780 carb.

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.

[midnightbluS10]

There you go, not gonna talk about it, just poke your chest out and get defensive!
1 case is what you brought up, which is a pretty narrow data set correct?!?
What are the rules on this stocker?
Maybe that has something to do with it?
What is the engine combination?
The problem is, you care too much!

I have no reason to talk about it??? It's been talked about to death, let it go.

I'm saying not everything needs a 50 degree.

Your the one that wants to argue about it.

I brought that up because I service his heads, he won, he's fast, and it proves not everything needs a 50.

I care too much? It's my living.

Poke my chest out? I gave an example. You are the problem Jay, period.

I'm the problem?!? Lol
I want to talk about the whys and how, you refuse.
Welcome back, the same old Chad!

The way you approach the situation is part of the problem. It's like you want to be argumentative. It's like you enjoy being combative. Especially towards people you disagree with.

[ClassAct]

Excellent response!
That's wasn't that hard was it?!? Lol
So are most combinations out there velocity limited, and if so why?

All stuff like this is. All Gen 1 Super Stock stuff, ASCS, bacically old school racing.

All this moved away with shallower angles, better cores, etc..

A Super Stock engine is the perfect study is friction loss. Like the video I posted. 172cc head. 1.98in MIN, flows 270 and 260 through manifold. Makes 655@7000. No vacuum pump. 10-1, old school 780 carb.

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.

[SpeierRacingHeads]

I have no reason to talk about it??? It's been talked about to death, let it go.

I'm saying not everything needs a 50 degree.

Your the one that wants to argue about it.

I brought that up because I service his heads, he won, he's fast, and it proves not everything needs a 50.

I care too much? It's my living.

Poke my chest out? I gave an example. You are the problem Jay, period.

I'm the problem?!? Lol
I want to talk about the whys and how, you refuse.
Welcome back, the same old Chad!

The way you approach the situation is part of the problem. It's like you want to be argumentative. It's like you enjoy being combative. Especially towards people you disagree with.

If this is for me, I'm 100% sure that results are proof. I feel whenever I post up a result or something I get accused of chest beating.

If I disagree, I'm going to show you why I disagree. Results don't lie.

[PRH]

I think Chad gets defensive when people are telling him how wrong everyone who’s not using a 50* or steeper seat, in some particular racing series.........where there are plenty of very knowledgeable people supplying heads and engines for those competitors........ many of which are the top performers in the country.
Like none of those builders or suppliers are testing things like valve seats angles, and/or aren’t smart enough to evaluate whether or not the changes were beneficial to the combo being tested or not.

Especially......... when it would appear they’re not even familiar with the rules and restrictions that are the at the core of what those classes are about.
Up until recently, the heads in NHRA Stock and SS had to use valves and seats that retained the factory seat angles.

It’s a bit naive IMO to think that the top builders for those classes didn’t start experimenting with valve and seat angles once that rule was lifted.......... and that if steep seat angles were the be-all-end-all of additional power........ they be using them.

There are a lot of rules for these heads, especially in Stock.
Many of the heads have pretty small bowls, and no porting or blending is allowed.
Some of these combos(quite a few actually) run less than .400 lift.
Many have valve to piston clearance issues that limit how much duration will physically fit in the motor.

My experience is........ I look at any type of blanket statement like “you should run 50* seats in everything” with skepticism....... since any one way of doing things is essentially never the best approach for all situations.

But again, pretty narrow set in an even more narrow circumstance wouldn't you say?

Depends on how you look at it I guess.
It’s a pretty popular class.
Last year at Indy there were 171 cars trying for one of the 128 spots.

[Carnut1]

If you really pay attention to the pic Chad posted you can see what he does and why. Low lift application, 23 degree with stock port. Great stuff! Thank you!

[GARY C]

All stuff like this is. All Gen 1 Super Stock stuff, ASCS, bacically old school racing.

All this moved away with shallower angles, better cores, etc..

A Super Stock engine is the perfect study is friction loss. Like the video I posted. 172cc head. 1.98in MIN, flows 270 and 260 through manifold. Makes 655@7000. No vacuum pump. 10-1, old school 780 carb.

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.

I 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.

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.

[GARY C]

I think Chad gets defensive when people are telling him how wrong everyone who’s not using a 50* or steeper seat, in some particular racing series.........where there are plenty of very knowledgeable people supplying heads and engines for those competitors........ many of which are the top performers in the country.
Like none of those builders or suppliers are testing things like valve seats angles, and/or aren’t smart enough to evaluate whether or not the changes were beneficial to the combo being tested or not.

Especially......... when it would appear they’re not even familiar with the rules and restrictions that are the at the core of what those classes are about.
Up until recently, the heads in NHRA Stock and SS had to use valves and seats that retained the factory seat angles.

It’s a bit naive IMO to think that the top builders for those classes didn’t start experimenting with valve and seat angles once that rule was lifted.......... and that if steep seat angles were the be-all-end-all of additional power........ they be using them.

There are a lot of rules for these heads, especially in Stock.
Many of the heads have pretty small bowls, and no porting or blending is allowed.
Some of these combos(quite a few actually) run less than .400 lift.
Many have valve to piston clearance issues that limit how much duration will physically fit in the motor.

My experience is........ I look at any type of blanket statement like “you should run 50* seats in everything” with skepticism....... since any one way of doing things is essentially never the best approach for all situations.

But again, pretty narrow set in an even more narrow circumstance wouldn't you say?

Depends on how you look at it I guess.
It’s a pretty popular class.
Last year at Indy there were 171 cars trying for one of the 128 spots.

One thing I would add to this is that if a 50 degree seat would increase power in any and every situation then ever aftermarket head you hear about would be running them... or at least a few would be and it would be the latest Hot Rod article of the new Extreme Magically Delicious head on the market.

But does that address the OP's issue or mine in regards to throat and flow on a 45 degree seat low runner head?