what is the intake port timing on a 3rd gen engine? how far do y'all increase the timing in all types of porting

thanks scott

 

let me refresh! what are your intake opening and closing degrees on a large street port turbo plates?

 

http://www.yawpower.com/dectech.html

 

I was looking for what you racers will port to? not what a template will do for us?!

 

road racers are limited to either stock, this http://www.scca.org/documents/Club%20Rules...tDefinition.pdf or a bridge port, non turbo



turbo guys can just turn up the boost. in fact with a turbo you might have better results from a milder port and getting the rest of the setup right (right turbo, exhaust etc etc)

 

WHAT ABOUT FOR DRAG CARS?

 

what about drag cars? they run everything you can think of.... hell they run low 10's on a stock engine, then bridgeport it and run 12's....

 

The nice pictures of the SCCA E production rules for ports were done by Dave Lemon at MazdaTrix.



It affects the opening side of the port. And depicts a rule that should not be violated, not only for road racing, but because having the leading end of the side seal cross a port unsupported shortens the life of the side seal. This early opening line is to eliminate the (How close can I get to a bridgeport) thinking.



Thus the comments on notches (comb ports), grooves (finger ports). All were used to walk around the port rules when the IMSA racing stocks were running years ago. Lemon was in that series.



SCCA allows bridgeports in the GT classes, so early opening is part of the bridgeport and not a problem.



So, my bridge port opens at 110 degrees BTDC and closes at 80 degrees ABDC. This is a lot of timing, and it shows up as poor low end. No power below 7,000 RPM. Best power at 9,400 RPM and top RPM is 9,600 RPM. This on a 12A. 250 HP at 9,400 RPM



I suspect (but do not know) that Daves end irons have the web removed and act as a single giant port with timing later than the original 6 port (70 degrees). So the intake might look like a 4 port if you get to see it.



His best power is probably above 10,000 RPM. So it is not a street engine by any stretch of the imagination.



Maybe 260 HP depending on choke size.



Put a junk iron in the drill press and drill through the port areas to see how far you can go until you strike water.



Lynn E. Hanover



This is the DKM 54.



The rotor housing spins.

The spark plugs are inside the rotor.