Wtb Ram Horn Heat Riser Spacer

[Dads 68 GMC]

My r.h. ram horn has a flat surface for a heat riser, I want the spacer that goes there that will accept the exhaust donut. I dont think this was a factory item but I saw one on the internet & was hoping somebody will have one,Thanks Philip

[nu2-72]

If I am thinking the same thing, does this have a butterfly in it?
I have one from a 76 Corvette in the barn. Don't know if that is what you are wanting. I can get a pic tomorrow.

[msgross]

I think I have one... Has a butterfly valve in it... let me check too..

[67cst]

i have one here you can have for the cost of shipping, i took some pics but cant post them until i get my laptop going, might be tonight, tomorrow forsure. let me know what you want to do

[67cst]

i should add that it is indeed the factory ramhorn style one with the butterfly style flap...thats the best i could describe it i guess

[Dads 68 GMC]

Thanks guys but I think you have a heat riser, heres a pic of what I need

[Dads 68 GMC]

maybe a heat riser would be fine, I have never used one before. Are there any advantages or disadvantages to using one?

[jerry moss]

just go to your local muffler shop. it's called a "heat riser block" and if they don't have one on the shelf they can order one. we usually keep one in stock where i work. we used a lot of them back in the 80's but not real popular anymore.

[PICKMUP]

You can just grind a bevel edge on the inside of the manifold for the donut to seal into...like on the other side.

[nu2-72]

Jerry couldprobably answer this better but I believe the item I have with butterfly is used for cold weather start ups. It should hold back on the exhaust and allow the heated air to warm the breather quicker. As the engine warms, the butterfly opens fully and allows the hot gasses to flow from the manifold. This would be through the heat riser pipe to the air breather snout and the shield that goes over the manifold itself.
I may be wrong and will go look right now.

[70inline6]

Two seperate entities -

The heat riser butterfly does indeed hold back exhaust gasses on engine warmup. The exhaust is routed through the intake manifold to the other exhaust manifold and out the exhaust. When the spring gets hot on the heat riser the butterfly will open and allow normal exhaust flow.

The air cleaner heat pipe just draws air across the outside of the manifold. The air cleaner flap door will close when the air cleaner sensor cuts off vacuum depending on temp.

To answer the overall question... you can use a standard heat riser and just grind the rivits off the butterfly (leaving the rod) and go with that.

[neonlarry]

I got one here:
http://www.lategreatchevy.com/produc...8&dept_id=1267

[nu2-72]

70inline6, you are right. I was thinking about aftermarket manifolds that have no crossover provision. In that case there would be extra heat in the drivers manifold only.
And I was also wrong on my part. Finally found it and it looks like this. Uses a sleeve and donut gasket. It is also flat on one side only.

[Dads 68 GMC]

Thanks all, & thanks neon larry,I'll order one from lategreatchevy. if I grind a bevel the donut might not seal & I hate exhaust leaks, Philip