408 stroker build

As Rumble said, get on the phone. Call 10 different grinders. The one you get on best with will almost always get you the best cam for YOUR application. You MUST be honest. Take notes. Email is worthless because it’s near impossible to have a conversation with email, although I did it a few weeks back and it worked out well. But the guy I was emailing was super pronto in his replies, and even replied after hours. He is a rare bird.

You can use the Vizard 128 method for getting an LSA. If you know how to use it. As your compression ratio goes up from about 10.5:1 you have to add one degree of LSA per point of compression IIRC. As you go lower than 10.5:1 you have to take away one degree of LSA.

The formula is volume of one cylinder divided by intake valve diameter times .91 and you take that number and subtract it from 128. Sooooooooo...

Just taking a 340 for an example...the volume of one cylinder is 42.5 cubic inches (for a standard bore). 42.5/2.02 is 22.376237*.91=20.362375. Then it’s 128-20.362375 and you get 107.63763 and you round that up to 108. I would run it at 107, but that’s me. And that’s IF you have about 10.5:1 compression.

If we use a 408 with a 2.02 valve you’d end up with 105. Which makes sense if you think about it. You’ve added displacement and the intake valve is the same diameter, so you need to get more overlap to get the cylinder filling.

What you don’t get into the cylinder at overlap you can’t make up later in the intake stroke.

Again...this is a pretty close approximation. You still have to figure duration.