schmidtmotorworks

Thanks to input from this group I will be making patterns for a short runner ls1 manifold.

Since I am not expert Gen 3 engines I need some guidance on a few issues. Please direct me if you can.

1. Nearly everyone suggested that the design be made for a 90mm throttle. Are the 90mm throttles all the same regarding the bolt pattern and gasket face? Can you reccomend a gasket to design to fit?

2. Are there any differences between the heads that need to be considered? I read on one site that an LS1 and LS6 port required different manifolds. Is that correct? If so what is the difference?

3. Can someone tell me what the angle of the port floor and port roof are relative to the deck? I need this to design the runner so that it will have a smooth transition to the head. An answer within a few degreees would be close enough. If you have a head sitting around and some measuring tools please help me out on this one.

4. What port opening dimension do most people end-up with after a head is ported? Are they significantly raised or lowered or moved left or right?

5. I bought a 1998 LS1 intake to use as a model for the bolt hole positions and mounting features. Is there anything about this manifold that I should be aware of that would make it a bad choice for duplication?

6. What about nitrous bosses? Any suggestions?

Thanks for your input.

Jon Schmidt