Exhaust Questions

[1966chevytrucks]

Does anyone have pictures of the exhaust butterfly that is on the passenger side exhaust? I would like to know which way it should be sitting. Mine is hitting the frame and i know thats not right. And is anyone still using them or is everyone taking them out/

[cru_zn_29]

The heavy weight is at the rear close to solonid. You must have weight on the frame side.

[x1buellist]

Mine hits the frame also.

[1966chevytrucks]

they must have put in in upside down as well bc mine is opposite of yours

[Dino Driver]

They use those to build heat in the engine until it's fully warmed up. There should have been some duct work around it at one time. The truck should run fine without them.

[rideblue00]

Originally Posted by Dino Driver

They use those to build heat in the engine until it's fully warmed up. There should have been some duct work around it at one time. The truck should run fine without them.

These did not have any ductwork.The butterfly closes and exhaust gases are routed back up into a crossover port through the intake manifold under the carb and out the drivers side exhaust manifold.

Its been awhile sice mine was together. Try flipping it over. I think the weight hangs down when it gets to running temp. I will have to go home and look at mine.

[XtechX]

Originally Posted by x1buellist

Mine hits the frame also.

So this image is the correct way?

[markeb01]

The valve in the photo appears to either be upside down or the clock position is off. The weight should never be near the frame. I can’t believe how hard it is to find a picture of an installed heat riser on the internet. I even went through the 1960 Chevy Truck Shop Manual and didn’t find an image there either.

The guy that built my first exhaust system used a large oversized flange for the exhaust donut which prevented the heat riser from opening more than 15 degrees. I discovered this on a 100+ degree day when I got stuck on the freeway behind a wreck. 45 minutes of crawling along, the temp gauge maxed out beyond the top of the scale and cooked the engine, blowing the right side head gasket. That was about 15 years ago and I’ve never used a heat riser since. I’ve also experienced problems with carburetor boiling after a hot soak in the summer (even without a heat riser) so I also run blocked crossover gaskets on the intake manifold as well.

The engine does take longer to warm up in cold weather, but I’d rather put up with that compared to boiling over in the summer.

[ozzyman]

I have a set of stock manifolds off my 327 with heat riser installed, they are off the engine but would it help to snap a pic of it? If so I can snap a photo after work in a few hours

[x1buellist]

Originally Posted by ozzyman

I have a set of stock manifolds off my 327 with heat riser installed, they are off the engine but would it help to snap a pic of it? If so I can snap a photo after work in a few hours

Yaeh, that would be awesome.

[cru_zn_29]

Pictures from a orginal 66 c20 with 327 2 pictures of heat riser right side & 1 picture of left side. Hope that works for you. Kenny

[ozzyman]

[1966chevytrucks]

Thanks guys i guess mine is turned wrong and possible up side down.