Re: Hot Rod Options

Posted by Rusty O\'Toole On 2010/2/26 20:01:57

There has been considerable discussion of this very point on this board and on others.

For certain technical reasons related to breathing and compression, a flathead engine should respond well to supercharging.

This was proven in the 30s when Cord, Auburn, and Graham built successful supercharged flatheads as production cars. They proved to be efficient, powerful and trouble free.

Turbos are not recommended. Flatheads suffer from exhaust valve overheating and valve failure when turbocharged.

The big limiting factor is cooling not crankshaft strength. You should be able to get near double the stock horsepower out of a Packard without too many problems, but will not be able to sustain such outputs for more than a few minutes before a critical degree of heat is exceeded.

The most powerful Packard straight eight was the 1954 359 cu in 212 HP model. It had 9 mains and an aluminum head.

You should be able to get close to 400HP out of one of those. For how long, and how many times before it blows, is another question.

Forged pistons, careful blueprinting of the bottom end and keeping the revs down to 5000RPM or less should keep the bottom end together.

Then, there is the heat issue.That can be controlled up to a point by using a new aftermarket aluminum head, keeping the cooling system clean and pressurizing to 16 pounds or more.

What you are talking about is quite doable and would make an impressive project.

The fact that you could build a Chev 350 to make the same power, for 1/5 the money and effort, is beside the point.

Besides where's the fun in building yet another (yawn) small block Chev?