Finding a way to check existing valve seat angles.

[65hardtop]

Is there a good way to figure out what the valve seat angles are on a set of heads? I have a set of racing heads that seem really good and would like to be able copy the same seat profile if I could. But in need a way to measure the angles.

[Frankshaft]

If I get a set of heads in that work good to freshen, and I want to find the angles, I usually can tell by looking, but, to verify, I will first use the valve grinder, set the angle I think the valve is, and give it a light touch. If I am wrong, say its set for 50, but its a 55, it will hit on the inside bottom edge of the seat. Then I stop, re set it to 55, and yep, its matches and cleans up. Then, once I know the angles of the seats, I pretty much know what the top cut and bottom cuts will likely be, and for the bottom angles I set up a single angle blade and put it up against the angle, until I find the right one. If its a 50 or 55, it will "usually" be steeper than 60, not always, but usually. Same for the top cuts. I will use a seat ginding stone, color up the seat area on the head, and light turn the stone by hand. If it hits close to the seat, its not that steep, if it hits towards the top, its steeper. Then I know.

I should add, on the bottom angle check, its just a visual, I am not cutting anything. You can look close and see if the angle on the seat, matches the angle on the single angle cutter. Again, if the angle is steeper, say I used a 65 single angle blade, and its touch on the bottom of the angle, its not that steep, likely a 60 or 62, so, put one of those in, until it touches flat.

[Stan Weiss]

As far as the valve goes. If you can get a good picture of the angle, there are computer programs which will let you measure the angle.

Stan

[hoffman900]

Yes. Free 2d CAD is way beyond most here.

FYI, for the rest, you can import a photo into CAD (use a free one), scale it, then trace, and finally dimension the angle.

[Rick360]

Sometimes I may be flowing a head for someone and not doing any work to it. I don't want to use a grinder in those cases so I do this ...

I have a couple thicker feeler gauge pieces screwed together thru the hole at one end tight enough to stay put unless you try to move them. Use those to form a V across valve head and across valve face. Hold it up to light to adjust to match the valve face angle, then align it onto a protractor to see the angle. It'll tell me real easy if its a 45, 50 or 55 but you'd have to be real careful to tell a 45 from a 46.

Rick

[Walter R. Malik]

Is there a good way to figure out what the valve seat angles are on a set of heads? I have a set of racing heads that seem really good and would like to be able copy the same seat profile if I could. But in need a way to measure the angles.

I put a pilot in the guide then use a small protractor.

[Charliesauto]

Is there a good way to figure out what the valve seat angles are on a set of heads? I have a set of racing heads that seem really good and would like to be able copy the same seat profile if I could. But in need a way to measure the angles.

I put a pilot in the guide then use a small protractor.

I like that idea, just don't have a small protractor. Can you post a photo of your protractor, or a part number.

Thanks

[JoePorting]

I have a couple of sets of junk valves that I have setup on all the usual angles. Then I just put Dykem on the seat I want to test and lap them in. This way you can actually measure the thickness of the angle too.

[pcnsd]

I hesitate to say this, but I use a 10" Micro-Vu optical comparator to pull the seat angle from the valve. All other angles seem to flow from the seat. The simple mechanical type optical comparators used to be common on the used market. I got mine for $150.

[user-30257]

Like small shops and hobbyists have access to that. Stupid, it takes literally 30 seconds to figure it out with a valve grinder. K.i.s.s.

Yes. Free 2d CAD is way beyond most here.

FYI, for the rest, you can import a photo into CAD (use a free one), scale it, then trace, and finally dimension the angle.

Lol, yes because a protractor won't work. We must use a simulation.

[user-30257]

And if the by is good, I bump with a stone, I have many single angle cutters for bottom, throat, seat, top cuts. most times if the angles i see are good i may bump just the seat and top cut. No sense in changing what works.

[user-30257]

And if the VJ is good, I bump with a stone, I have many single angle cutters for bottom, throat, seat, top cuts. most times if the angles i see are good i may bump just the seat and top cut. No sense in changing what works.

[hoffman900]

Like small shops and hobbyists have access to that. Stupid, it takes literally 30 seconds to figure it out with a valve grinder. K.i.s.s.

Yes. Free 2d CAD is way beyond most here.

FYI, for the rest, you can import a photo into CAD (use a free one), scale it, then trace, and finally dimension the angle.

Lol, yes because a protractor won't work. We must use a simulation.

A blueprint is nice to have on file instead of some hand scribbled notes.

[speedtalk]

Locked and off topic posts removed

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