Okay Lynn,

 

you need to slow down!! If you want to take the wings with you on your "to be BD-4" you need let go on the racing with your engines :))

 

If I P-Port my engine (no racing-factory-P-Port housings...) can't I "adjust" timing so that it does make sense with a turbo?

P-Port just seems so much simpler on everything, especially the intake manifold, besides flow should be way better than with anything side-housing.

I know the horror stories about bad idle/etc. with P-Ports, but most forget that these stories are about all-out-racing equipment.

If I am not wrong the original NSU-car engines where P-Ports and idled just fine. So I (wild)guess it is the same like with piston engines, all depends on application and adjusting valvetiming (ports) accordingly.....

 

Correct me please, as I am still all the way down on the learning curve!

 

TJ

At best the Pport would look like a short version of the exhaust port. And then it would have to be turboed to work at all. Just assemble a housing rotor, iron, stationary gear with a degree wheel on the crank, and look at open times, side port vice any Pport you can draw on the housing. You will have to do this anyway, why not now.

 

Suppose you make it small top to bottom, with open and close way late to minimize the amount of intake charge leaving the engine unburned. With late closing it will have to be on some boost just to taxi.  

 

Notice how many degrees that both the intake and exhaust are wide open. See why a Pport big enough to make good power will not have a detectable bottom end. About 6,500 RPM is where it comes up on the tune.  

 

This works fine for NA use. The idle is not even a problem. If you turbo just enough to maintain sea level, or just a tad above, then it would still work, but still no bottom end.

 

You can do it. You can turbo it a bit. You can go fast. It is a bunch of work and it takes a long time and lots of money. Just design a port that has the least amount of overlap.

 

Lynn E. Hanover