New block, a further discussion

[Ol' Ron]

Having built a few flatheads, I can tell you that there' very little you can do to the ports to improve Horese power very much. AS a normally aspirated engine the shape is just wrong and making it bigger doesn't improve it as much as the work involves costs. A Today's Bonneville engine's have big bore cam tunnels to allow for higher lift roller cams, and on Racing gas have trouble making 200 hp. One of the biggest problems is the size of the engine. Many of the racing engines are over 300ci and still have the same ports to feed the engine. Adding a mear 5 lbs of boost to a stock port and streetable cam will push the power well over 200 hp. Richards 276 had stock ports and valve size and i drove it, There was very little more you could ask for this engine. My new truck engine is a 290 ci STOCK flathead and the torque is un-believable. Unfortunately, it's pretty buch done by 3500. A new block would only interest those that wanted to keep the flatheads on the road. Like me.

[Henry Floored]

Originally Posted by Ol' Ron

Having built a few flatheads, I can tell you that there' very little you can do to the ports to improve Horese power very much. AS a normally aspirated engine the shape is just wrong and making it bigger doesn't improve it as much as the work involves costs. A Today's Bonneville engine's have big bore cam tunnels to allow for higher lift roller cams, and on Racing gas have trouble making 200 hp. One of the biggest problems is the size of the engine. Many of the racing engines are over 300ci and still have the same ports to feed the engine. Adding a mear 5 lbs of boost to a stock port and streetable cam will push the power well over 200 hp. Richards 276 had stock ports and valve size and i drove it, There was very little more you could ask for this engine. My new truck engine is a 290 ci STOCK flathead and the torque is un-believable. Unfortunately, it's pretty buch done by 3500. A new block would only interest those that wanted to keep the flatheads on the road. Like me.

Ron if I had anything to say about porting I would suggest these things:

First the end exhaust ports would be wide open at the top just after the valve pocket. Then they would curve around the cylinders and exit the block with no dog leg. This is exactly how the Lincoln 337 is done.

Secondly the center exhaust port convergence area would be solid and shaped in such a way as to form a back port wall and port separator baffle.

Thirdly Ron I'd put a shape to the intake ports. In stock form they are pretty straight, have almost no short side radius, and slam the charge into the back of the valve pocket. I think there is room to "ramp" that area and lessen the approach angle of the intake port.

Now I agree that racers like bigger camshaft diameters and I don't think there'd be much of a problem providing them with enough material to overbore the camshaft tunnel.