Machining a heat riser valve

[Patrick H.]

Does anyone know if it's possible to machine the upper (flat) surface of a functioning heat riser valve to make it straight and reuseable? I have one on a 1972 that works, but the upper surface has a slight warp at one of the bolt holes. The area around the center ring seems flat, and I'd like to try and reuse the valve if possible. If it can be machined that would be nice but the weight is likely in the way. Just wondering if anyone has done this or tried it. Of course, I do have a new aftermarket valve on the way in case this doesn't work, but I've not had much success with the function of aftermarket valves previously.

[Dick W.]

Re: Machining a heat riser valve

Does anyone know if it's possible to machine the upper (flat) surface of a functioning heat riser valve to make it straight and reuseable? I have one on a 1972 that works, but the upper surface has a slight warp at one of the bolt holes. The area around the center ring seems flat, and I'd like to try and reuse the valve if possible. If it can be machined that would be nice but the weight is likely in the way. Just wondering if anyone has done this or tried it. Of course, I do have a new aftermarket valve on the way in case this doesn't work, but I've not had much success with the function of aftermarket valves previously.

Should be no problem with a vertical mill. Clamp the piece and make a couple of light passes.

[Patrick H.]

Re: Machining a heat riser valve

Machine shop is going to give it a try for me. We will see...

[Steven B.]

Re: Machining a heat riser valve

Buddy did one on his SB a few years back and as Dick mentioned on a vertical mill. I can't remember how much he took per pass but it was very few 1/1000's. It came out very well on the table. Steve

[Dick W.]

Re: Machining a heat riser valve

It also could be done on a magnetic table surface grinder.

[Patrick H.]

Re: Machining a heat riser valve

I told him I just want enough off to allow the flat gasket to seal well. He knew what I was after, and once I showed him how the spring could be removed he was willing to try it.

[Gary R.]

Re: Machining a heat riser valve

You could fixture it in a Bridgeport and fly cut it or grind it parallel on a surface grinder. The hardest part is fixturing it, cutting won't take long at all.