MTFCA Forum

I got a call from Larry at Valley Head Service this morning with some questions pertaining to the work they are doing on my Rajo B head. The first question he had is about the lift on my cam. I have a Stype cam in the motor. I bought it so long ago (close to 20 years) I am having memory problems. I got the one better than stock but not the full race one. I thought it was a 270, but I looked and the middle option is listed as a 280. Are they marked somewhere? Also dose the number refer to the lift in thousandths of an inch? Dose anyone know where I can get lobe dimensions for the Stype cam to send the shop? I tried calling them but got no answer and left a message.

Thanks as always for any information.

280 refers to the lift. .280”

Pretty much any engine rebuilder should know how to measure cam lift.

The engine (with cam installed) is in Alaska, the head is at a shop in California. I am sure he could measure the cam lift if it were not several thousand miles away from his shop.

Les Schubert wrote: ↑

Thu Mar 03, 2022 4:06 pm

280 refers to the lift. .280”

Thanks, that’s what I thought.

Measure the cam side to side, measure heel/toe, subtract the side to side from the heel/toe that is lift.

my cam is marked on the small end with 280. you have to have the hog head removed to see the small end
Harold III

It is my understanding that increased lift equals increase opening of the valve. That means the valve projects further into the space between the piston and the head. Some rocker arms amplify that lift with different ratios. If I am anywhere near correct with my assumptions then a standard lift (.250) might be desirable with 1.5:1 or 2:1 rocker arms? I am not any sort of expert on this topic but I listen to a lot of guys who have been down this road.

B Rajo heads flow well past the .420" lift that you would get with a 280 cam and 1.5 rockers. The intake flow curve for the head is not even close to flattening out or falling over at .420 lift.

I agree with Dan. Your Model B likely has 1.5:1 rocker arms. .280 Stipe will get you to .420 lift. That should work well for your engine with a proper carburetor. I personally like the Carter BB 1 with an adjustable jet. The Winfield Model M201 B would be my second choice.

I got a call back from Josh at Stipe and he sent me the cam card for the .280 cam, which shows that it is a .280 lift. He also says that they are still producing cams for the T but doing it in batches.