[don black]

It's going to be great to tap into such a vast store house of knowledge! This is my first post.
Anyway,what I need to know is,how do heat riser ports(to the intake manifold) effect flow in that exhaust port?
Is the efort to seal the riser worth it? I'm aware of the need for manifold heat on street engines. Lastly what is a suitable method
for sealing the riser in cast iron heads. At the moment Cleveland
heads are the object of my attention.
Any and all info will be greatly appreciated.

 

[wildman926]

The heat riser does not affect flow of the heads.

Sealing them will result in longer warmups, but not that noticeable.

Felpro, and others make gaskets that block this off, or a street/strip manifold will not have provisions for this.

 

[don black]

Thanks for the reply WIldman
Basically we agree,but I was wondering if the brake in the wall of the exhausts port,for the heat riser, would disrupt the laminar flow of the exhaust gases, also thought that pocket of gases might create a high pressure area just at the wrong time,like when that valve opens on its next cycle?
Anybody have any thoughts about this?

 

[Charles F. Smith]

Blocking off the heat risers

Did this with a Ford 289 to make the exhaust crackle. We were going to use those roofing disks but the center intake bolts were too close together so we had to trim the disks (looked kinda like a "T"). Caused MAJOR problems when the intake gaskets slipped (we didn't know it and when we refilled the radiator we flooded the engine with anti-freeze/water.
I would not hesitate to do the job agan but the next time I would remove the distributer and the intake.
When we did finally end up lifting the intake we found a shop towel laying in the lifter gallery - where was that post about marijuana.
Charlie Smith

 

[don black]

gotcha Charles.

I'll add that to my not what to do list.Still would like to know if flow in those cylinders with the heat risers are are going to equal the flow in cylinders with out it.

I'm trying to build a set of Cleveland heads for my Windsor motor and I don't have access to a flow bench.

Any help anywhere?