60* seats on LS Heads

[Joel Dubose]

Has anyone worked with 60* seats on Ls factory castings ? The chambers are really flat, so I was wondering if anyone has that worked out.

[flyingwedge]

Uhm, seats are usually quoted from horizontal. Perhaps your considering 30 deg. seats ? David Vizard has seen good results at "low" lifts, ie. a 2.05" /30deg flows like a 2.46"/45deg. Pontiac used 30deg., as oem. Some Nascars use 50-55deg,(extreme velocity and hight port angles). 30deg tends to loose intake flow at upper lifts,(aims charge more towards the cylinder wall )? Perhaps 35-37deg, would prove to be a good compromise ? Good Luck, flyingwedge.

[Ron E]

I'd consider 50° on intake, and 55° on exhaust if it's a high lift deal that is freshened on a regular basis. Otherwise, I'd stick with 45's. But, that's just me. Chamber strikes me as wrong for 55 or 60 deg intake seats.

[Joel Dubose]

What I'm looking for is someone that has flowed a head using 60* seats. The chamber angle is really flat. I'm wondering if 60* seat lost flow. How about 55* maybe I should go this route. What is the steapest seat angle that you have ran on them.

[Erland Cox]

How do steeper seats than 45 degrees work in an endurance engine?
How much more often must the seats and valves be freshened with 50 or 55 degrees?
Does 50 degrees wear out much faster than 45 degrees?

Erland

[crazyman]

Thanks, for divulging speed secrets, guys... Chamber shape plays into valve job angles..

[RL]

How do steeper seats than 45 degrees work in an endurance engine?
How much more often must the seats and valves be freshened with 50 or 55 degrees?
Does 50 degrees wear out much faster than 45 degrees?

Erland

From what I have read here you can use 50º on low mileage street/race stuff, but nothing more.
Endurance race stuff get freshened up at 100km, so it's not a problem.
Remember you can't use it on old soft factory stuff, it has to be with new high quality materials, eg harder seats and valves - you can pound out factory seats on a 3SGE with 45º 0.050" and 85lb springs, because the inserts are too soft -

[Joel Dubose]

Racers have been using 55* and 60* seats for many years. I have been using them for at least 15 years on longevity engines. Ie, NASCAR. Many company's have been using 50* seats on street engine . H D motorcycle, has been using them on there engine's. It's no secret to my knowledge. I'm going to be working on a pair of Ls style heads. I'm lifting them over an inch. It's a high rpm, high lift, drag race engine. I haven't worked on many of these heads. I thought that this would be a quick and simple question that would save me some time.
I've decided to get a junk casting and go after it before doing anything to the race heads.

[Ron E]

. I thought that this would be a quick and simple question that would save me some time.
I've decided to get a junk casting and go after it before doing anything to the race heads.

Eh....Sorry Joe. You of all people know there aren't many simple answers no matter how simple the question. My more detailed response would be, the chamber falls away from the seat too fast (too flat). Second, when using a 55, or steeper seat, I like for it to be a head with a good race style high port. The steeper seats demand more from the port at high lifts. However, I've always been able to use a 50° on low port heads.......


BUT, you already knew this years ago.

Good luck.

[Erland Cox]

Can't you weld the bottom of the chambers to get the transition you want?

Erland

[Joel Dubose]

Can't you weld the bottom of the chambers to get the transition you want?

Erland

I'm looking at the rules to see. I'm working on it now. Cutting a 60* seat into it. I'll fill the chamber with clay if it doesn't show the results that I'm looking for. I've seen on here 45* seats that flow really good. I'll see how it all turns out, its going to just take some time. Thanks all

[MadBill]

I'm not familiar with the chamber in question, but how about sinking the seats maybe 0.040" and adding two narrow top cuts splitting the difference between the chamber wall and the 60° seat? Say the high flow region of the chamber wall is at 30° from the valve face, so try a 50° plus a 40°cut ~ 0.025" and 0.030" wide respectively?

[airflowdevelop]

which casting? I have used 60 degree seats on a number of them w/ great results.

[rfl28]

Racers have been using 55* and 60* seats for many years. I have been using them for at least 15 years on longevity engines. Ie, NASCAR. Many company's have been using 50* seats on street engine . H D motorcycle, has been using them on there engine's. It's no secret to my knowledge. I'm going to be working on a pair of Ls style heads. I'm lifting them over an inch. It's a high rpm, high lift, drag race engine. I haven't worked on many of these heads. I thought that this would be a quick and simple question that would save me some time.
I've decided to get a junk casting and go after it before doing anything to the race heads.

You must be related to JoePorting!.....

[Joel Dubose]

which casting? I have used 60 degree seats on a number of them w/ great results.

This is what I was looking for, a guy with experience that was willing to help ,

Racers have been using 55* and 60* seats for many years. I have been using them for at least 15 years on longevity engines. Ie, NASCAR. Many company's have been using 50* seats on street engine . H D motorcycle, has been using them on there engine's. It's no secret to my knowledge. I'm going to be working on a pair of Ls style heads. I'm lifting them over an inch. It's a high rpm, high lift, drag race engine. I haven't worked on many of these heads. I thought that this would be a quick and simple question that would save me some time.
I've decided to get a junk casting and go after it before doing anything to the race heads.

You must be related to JoePorting!.....

This is what I get. I been on here and many of you have pm me asking for advice or needing help. I did my best to answer all of you. I worked through some very complicated issues and stuck with it till the end.
I have told you on here many time, I care about people, more than the projects that there working on. That means when I've helped it was because I was helping a person not gaining anything in return. Much of what I share took me a long time to figure out. Left alone it will take each of you a long time as well. I've noticed a trend on here for people to give there opinion rather than fact. It's not really a bad thing, its food for thought. But opinions about other people or there companies. I draw the line right there. I didn't have an agendas, I cared.
For the what its worth department, I've had the privilege to meet of talk to a lot of really great people on here. Some of them from other countries. Over and over those guys have done all that they can to give good feed back and contribute greatly. To them, my hats off. Proud to know you. I count you as friends.
Sorry to have used this as an example, it wasn't right. Hope we can drop agendas and move forwards on here.