Why did Buick design the heads with that exhaust part in the heads? More flow, better cooling? Thanks. Robbie
Don’t know. Fitment in chassis? Control of flow? Higher torque? More importantly, they were first to design the high swirl combustion chamber.
Is this question keeping some up at night, and also what can you do about it? The answer is that in most cases it helps to create a slower more gentle better flowing transition from the valve bowl into the runner.. This allows a smaller port area to be used which keeps low rpm velocity up which in turn makes for more torque. It also helps to minimize reversion which helps the motor to burn cleaner and contributes to better power. here’s a photo of a typical pro stock modification that was done to Ford Boss 351 heads. these heads have a large port area where it’s not needed but a terrible very short transition from the valve bowl to the exh flange. note how the exh port area of the whole length of the head was cut out / notched over 1.5 inches deep back towards the valve and for near the full height of the head,. a steel or Aluminum plate was then machined up and bolted on and then ported to get a better transition and better flow numbers.
You are talking about the exhaust crossover passage. It warms the bottom of the carburetor to promote better fuel vaporization and to prevent carburetor icing in Winter weather. That is where the paint burns off.
Actually not Larry. I meant the exhaust ports inside the head which connects to the exhaust manifold.
Part of it is valve train design....inline....sitting on a 4.31 bores.....the size difference mafe it that way by default vs port shape or flow imo....less material..less money
Yup... and that pretty blue (Pontiac) and red (Buick) paint just will not stay pretty on those areas!
Valve train area is another thing I was thinking about. But how do we explain the Stage2 design. And why not do the same transition trough the exhaust manifold/headers?
Fantastic, this is just the topic I want more info on. Why are the Buick Stage 1 combustion chambers so small, 66cc's? The Gen 1 SB 350 Chevy heads are are 78cc's. Did Buick do this, to promote higher higher flow rate and better swirl? Is this part of the reason Buick engines make so much torque? Maybe someone can shed some light on this subject. I've always wondered because I know the pistons in Buick 455 engines sit down in the hole about .045 plus, when you add the head gasket in, it's even deeper. Makes me wonder how Buick engine make HP & high torque with this design? Can't wait to hear the answers. Thanks Vet.
I am not the designer. I am just asking about it. The way the passage is in the head that connects to the exhaust manifold. You don't see that on old V8's all the time. And i know that It burns off. That was not my point.
Look at it like this......Lets just you have 2 heads from the manufacturer lets just use the chevy.... the 78cc heads are for the low compression and chevy 66cc heads are a high comp head.
Your open post is just what it is... Just how would you design it???? Are you head designer? how would you make the HOT exhaust gases get cold in a nano-second..... Because in reality it sound like to your complaining about the paint burn of the heads and manifolds even the intake.
Ok, I get it on the Chevy 350. What about the Chevy 327/365 HP that has 64 cc combustion chambers. This engine came out with 11-1/4 CR. Why do Buick heads have small combustion chambers? I want to understand Buick's engine design because it seems to be different than anybody else's in the 1970's.
