Scream'n 318 ?

The guy that put the engine together was on old school die hard racer. He said to me do not touch the heads and don't listen to what anyone says but hey I'd read all the mags and listened to all the internet forum experts that said the heads where choking it to death and I made the ports bigger and stuck in larger valves and then went to different cams and then to 360 heads and NONE of those performed like that engine did.

I spoke to my machinist yesterday about it and he said a fellow racer he competes against came in one day with his engine and said he wanted just a freshen up and DO NOT TOUCH THE HEADS or change anything. Anyway he looked at the heads and saw it only had a 1.74 intake valve and 1.5 exhaust in an early small port design. It had some bowl work done and some chamber relief work but other than that looked stock. He said he couldn't understand how it was making the power it was with such a small valve and no port CSA. When the guy turns up to pick it up he asked him about the heads and the guy said when they showed up from the guy who did them he wanted to punch his lights out because he paid 3k for them and very little was done or looked to have been done to them but when on the engine it ran quicker than he had before.

There's a lot more to making power than just airflow. When a car makes power with very little perceived airflow people will ignore it because it challenges their understanding of how an engine works and that means they will have to rethink their approach to how they build engines. When you've been doing it one way for decades its hard to see it any other way.


I’m confused. You used a better head and slowed down so the better head was bad.

The size of the valve is just as dependent on how much area you have to feed it as is bore size, maybe more.

You can stick a 2.08 valve in a 302 head and it will be a pig because the port can’t support it.