Hello Guys Just some quick advice needed. I have some buick 455 heads 1971, I also have an Edelbrock b4b. Should I close off the holes for the heat riser on the head or should i just leave them be?
For faster warm-up they are helpful, I think I'm going to leave mine open on my GSX, just want to turn the key and go with it
Exhaust heat will heat it up more, and quicker. The aluminum transfers heat faster, so even with exhaust heat blocked off, it will still warm up faster than an iron intake with exhaust heat blocked. That's what I am thinking anyway.
I'd plug them, I would be worried about getting the carb too hot as compared to how fast it warms up. Too hot can boil the fuel in the bowl, these newer fuels don't act the same as the oil stuff did. Plus cooler air charge makes more power
I've got a performer with a manifold mounted choke coil and I block mine, but during this weather I have a hard time getting the manifold warm enough to bring the carb off of high idle. Not going to change it, but it happens.
There's a good idea greatly restrict them down........I haven't ran a choke in years. I don't street drive my car, sometimes I over look that fact.
Cold intake air makes more power...until it's so cold that the fuel won't vaporize. Then the power plummets, the cylinders wear, the HC emissions increase...all sorts of bad things happen. That's the wonderful thing about a heat riser valve. When closed, the manifold heats quickly. When open, there's much reduced manifold heating (although perhaps more than needed for warm-weather performance use.)
