1965 F.I. exhaust system--heat riser spacer??

[Darryl D.]

Does the above car use a spacer?

I ask because I have ordered a 2 1/2" exhaust system for my 57 including 2 1/2" manifolds and am wondering if I will need to use a heat riser spacer. Corvette Central does not show a 2 1/2" heat riser spacer in their online catalog.

[Joe L.]

Re: 1965 F.I. exhaust system--heat riser spacer??

Does the above car use a spacer?

I ask because I have ordered a 2 1/2" exhaust system for my 57 including 2 1/2" manifolds and am wondering if I will need to use a heat riser spacer. Corvette Central does not show a 2 1/2" heat riser spacer in their online catalog.

Darryl------

In your thread title you mention 1965 FI. However, in the text of your question you refer to a 1957. You cannot install a 1965 2-1/2" exhaust system on a 1957 Corvette. You could install the 2-1/2" manifolds but they would require forward exhaust pipes that were never used by GM. So, if you are installing 2-1/2" exhaust manifolds on a 1957 Corvette, you will need to totally non-standard forward pipes and I have no idea if a spacer would be needed with them.

If you're actually talking about installing 2-1/2" exhaust on a 1965 Corvette with FI (which was the original configuration), then you definitely need to use the spacer.

[Loren L.]

Re: 1965 F.I. exhaust system--heat riser spacer??

He said "including 2 1/2" manifolds"; he's going to end with a system of custom bends of 2 1/2" pipe.

[Darryl D.]

Re: 1965 F.I. exhaust system--heat riser spacer??

Guess I should have specified that I have ordered 2 1/2" system from C.C. that is for a 1962 with 57 tail pipes. I also have the repo 2 1/2" manifolds. It is my understanding that 57s did not use a heat riser and I assume that I will need SOMETHING in there to make the exhaust system fit properly on that side that is designed to have a spacer. The 57s would only be 2". Since I asked this question I found on C.C. that they offer a 2 1/2" spacer for the 62s so problem solved.

[Joe L.]

Re: 1965 F.I. exhaust system--heat riser spacer??

Guess I should have specified that I have ordered 2 1/2" system from C.C. that is for a 1962 with 57 tail pipes. I also have the repo 2 1/2" manifolds. It is my understanding that 57s did not use a heat riser and I assume that I will need SOMETHING in there to make the exhaust system fit properly on that side that is designed to have a spacer. The 57s would only be 2". Since I asked this question I found on C.C. that they offer a 2 1/2" spacer for the 62s so problem solved.

Darryl------


OK, I understand now. Actually, I had forgotten about the 2-1/2" system used for HP/SHP for 1962 only. So, you are using the 1962 forward system rather than some custom-manufactured forward pipes. As you found, that does require the spacer.

All original 1957-65 FI exhaust systems use a spacer, be it 2" or 2-1/2". That's because the exact same systems were used for certain other applications which did not have FI and, thus, used a heat riser. The spacer adapted these systems for use with FI applications. A heat riser valve cannot be used with FI applications since there is no heat cross-over passage in an FI adapter (manifold).

[Dan D.]

Re: 1965 F.I. exhaust system--heat riser spacer??

Darryl, this is the exact same configuration I have on my 57, and the CC spacer is fine. The pipes all fit, and I am using 57 tailpipes with it too.

-Dan-