1959 Exhaust Butterfly Valve Removal

[Tony M.]

I hope everyone had an enjoyable weekend!

Has anyone found a replacement for the exhaust butterfly valve? I will never use my car in cold climate and feel that the valve could stick into it's closed position or at the very least cause a restriction to the exhaust flow on the right bank. I would love to remove it and replace it with a straight open spacer.

Questions: Does the spacer exist? Has anyone removed their valve?

Have a great week!

Tony Marra

[Mike M.]

Re: 1959 Exhaust Butterfly Valve Removal

get a fuel injected corvette exhaust SPACER. all the major suppliers have them. identical to yours except no butterfly internally. they come in 2" and 2 1/2" SIZE. mike

[Tony M.]

Re: 1959 Exhaust Butterfly Valve Removal

Mike,
Appreciate the support and have a great week!
Tony

[Frank D.]

Re: 1959 Exhaust Butterfly Valve Removal

I always just wired mine wide open with aircraft stainless steel safety wire, didn't have to disassemble anything nor remove an oritinal part.

[Patrick H.]

Re: 1959 Exhaust Butterfly Valve Removal

I've had marginal luck with the reproduction valves working properly. As a result I've purchased several NOS ones and have not had any problems with those.

Just an FYI for those who may be having problems.

[Tony M.]

Re: 1959 Exhaust Butterfly Valve Removal

Frank,
You are right!!!!!

Thanks again,
Tony

[Tony M.]

Re: 1959 Exhaust Butterfly Valve Removal

Patrick,
It actually works fine but in my mind, it is an area of potential concern with the unit stuck shut.

Thanks,
Tony

[Leif A.]

Re: 1959 Exhaust Butterfly Valve Removal

Tony,
If you're going for a "factory" look, you can remove the existing valve and, then, remove the butterfly with a dremel tool. Re-install and, from an appearance standpoint, all will be just fine.

[Duke W.]

Re: 1959 Exhaust Butterfly Valve Removal

Remember that part of ops check is feeling exhaust flow immediately after startup. There should be very little out of the right side for a minute or so. It's easy to use SS wire to rig up a "sling" between two manifold studs that will hold the valve open that you can slip on an off at your leisure.

Duke

[Tony M.]

Re: 1959 Exhaust Butterfly Valve Removal

Leif,
Certainly a good option and a touch less exhaust restrictive.

Have a great night and thanks!
Tony

[Tony M.]

Re: 1959 Exhaust Butterfly Valve Removal

Duke,
For educational purposes, what do you mean there will be very little out of right side for a minute or so?

Thanks again.
Tony

[Paul D.]

Re: 1959 Exhaust Butterfly Valve Removal

Good idea to squirt some rust penetrant on that valve when you service it. When I worked at a Chevy store in the early 80's, the rust penetrant all the techs used was GM heat valve lubricant. It worked great, but I doubt it is still available. Joe L. will know!

[Frank D.]

Re: 1959 Exhaust Butterfly Valve Removal

On cold atart the heat riser valve is closed restrictimg the PS exhauat out the tailpipe until the car warms up enough for the heat riser spring to open the valve.

[Tony M.]

Re: 1959 Exhaust Butterfly Valve Removal

Frank,
I need to review how this valve operates. I just figured that idle exhaust was not enough to open the valve and as engine speed increased, the valve stayed open.

I learn everyday!
Tony

[Leif A.]

Re: 1959 Exhaust Butterfly Valve Removal

Frank,
I need to review how this valve operates. I just figured that idle exhaust was not enough to open the valve and as engine speed increased, the valve stayed open.

I learn everyday!
Tony

Tony,
Re-read Frank's post. The opening of the butterfly valve has nothing to do with engine RPM...it is a function of engine/exhaust temperature. As the engine warms up, the butterfly valve begins to open. That's why at cold start up, the butterfly valve is closed and there will be very limited exhaust coming out of the passenger side exhaust pipe (per Duke). By not allowing the exhaust to exit, the intake can warm up quicker and open the carburetor choke as designed. Once the engine reaches operating temperature, the butterfly valve should be completely open. With all that said, if the butterfly valve is old and rusted, it most likely wont operate as designed...hence, the need to either replace or eliminate the butterfly valve altogether. Hope this helps.