C2 heat riser valve gutted?

[Jim R.]

Has anyone tried to gut a heat riser valve by removing the flapper and pin and can you do it and have the bell crank stay and still move, or when the flapper is removed does that allow the pin and bell crank to slide out. 65 327

[Joe R.]

Re: C2 heat riser valve gutted?

Hi Jim,

I don't remember the specifics, but I believe some welding is needed once the internals of the heat riser valve are gutted. Welding may not be the exact term. You can also buy a FI spacer to accomplish this, depending on what your goals are.

Joe

[Donald O.]

Re: C2 heat riser valve gutted?

I was able to gut mine with a small Dremmel abrasive cut-off. The rod and weight still look and work as designed, but no exhaust is routed to the intake manifold for cold start driveability. Plus, it did help with the dreaded e-10 fuel hot soak percolation issue. In time, perhaps another 20-40 years, the rod may get corroded away (or not, the OE didn't), but since by then I'll be a really really old coot, I won't care.

DonO

[Jim R.]

Re: C2 heat riser valve gutted?

Hi Don so you removed the entire flapper and left the rod only?

I was able to gut mine with a small Dremmel abrasive cut-off. The rod and weight still look and work as designed, but no exhaust is routed to the intake manifold for cold start driveability. Plus, it did help with the dreaded e-10 fuel hot soak percolation issue. In time, perhaps another 20-40 years, the rod may get corroded away (or not, the OE didn't), but since by then I'll be a really really old coot, I won't care.

DonO

[Donald O.]

Re: C2 heat riser valve gutted?

Yes, the small cut off disc merely cut the flapper disc at it's welds and small pliers broke it off where the disc couldn't reach. New gaskets on install and it has been installed for 12 years like that now.

DonO

[Brian M.]

Re: C2 heat riser valve gutted?

I did the same as Don years ago without issue. Removed the flapper only.

[Stuart F.]

Re: C2 heat riser valve gutted?

A lot of folks talk about replacing the valve or modifying it, but no one mentions anything about what they went through to drop the exhaust pipe down. I have a 63 with SHP 2-1/2" pipes, and wonder if I can drop the pipe down far enough to get the valve out. I can see dropping the pipe from the hanger at the cross member if I need to in order to gain some more drop at the manifold, but is that enough?

Stu Fox

[Russ S.]

Re: C2 heat riser valve gutted?

A lot of folks talk about replacing the valve or modifying it, but no one mentions anything about what they went through to drop the exhaust pipe down. I have a 63 with SHP 2-1/2" pipes, and wonder if I can drop the pipe down far enough to get the valve out. I can see dropping the pipe from the hanger at the cross member if I need to in order to gain some more drop at the manifold, but is that enough?

Stu Fox

Loosening the clamp at the transmission will give enough movement if your pipes aren't rusted together solid.

[Jim R.]

Re: C2 heat riser valve gutted?

Yes Stu just enough room to get it out.

[Stuart F.]

Re: C2 heat riser valve gutted?

Thanks Russ. My pipes are very clean aluminized with Stainless steel clamps, so I think I can get it to move.

Stu Fox

[Stuart F.]

Re: C2 heat riser valve gutted?

Thanks Jim. Every time I'm under the car for an oil change I ask myself "should I or shouldn't I ?". I have a spacer that I rounded out the inside of that I want to try.

Stu Fox

[Timothy B.]

Re: C2 heat riser valve gutted?

Can someone tell what the gain is by removing the blade vs just wiring the valve open in hot weather.

[Duke W.]

Re: C2 heat riser valve gutted?

If one is in the process of getting their car judged, you don't have to remove and replace the wire every time you enter a judging event. By removing the valve plate, but leaving the shaft, counterweight, and spring attached the heat riser valve has proper original appearance, so no deduction, which would be the case with the FI spacer on a carbureted engine.

Duke

[Gene M.]

Re: C2 heat riser valve gutted?

Can someone tell what the gain is by removing the blade vs just wiring the valve open in hot weather.

Less restriction, and even less if the casting is opened up to match the exhaust manifold. It is really not necessary if your Corvette is driven only in pleasant weather.

[Stuart F.]

Re: C2 heat riser valve gutted?

I have my FI spacer ground out round and I live in central Florida. Just trying to work up enough gumption to make the change. I hate crawling under my car, including for oil changes. My last one was a disaster, what with driving off the ramps, and a pinched o-ring that dumped lots of oil on my driveway. Fortunately, no damage, but I'm getting too old for this stuff.

Stu Fox