I am swaping out my engine for a TII this winter. Once I get the N/A engine out, I plan to tear it down and rebuild it with low compression rotors and strengthend gears. I may port it, haven't decided yet.

Anyway, anyone know if there was any particular reason why mazda did not use the 6 port design that the N/A engine's have on the turbo models? That was pointed out to me a little while ago and I am starting to wonder about that....

Should I just sell this engine and rebuild an acutal 4 port TII engine? I've already got the TII I'm installing, just thinking about what I should do with the N/A here.

 

Be prepared to invest a LOT of time and money if you're planning on getting this engine to run right. Otherwise, get a TII engine and rebuild that. Since you're in for a rebuild either way, the TII engine is a much more trouble free and cheaper route.

Steve

 

The reason the 6-port engines were used in the N/A, is basically so that you could have smaller runners with less airflow during low RPM operation, for increased torque. With a turbo, you do not have this problem. Im not sure if the actuating system would work properly under compression anyway. My recommendation would be to sell the 6-port engine, and just use a turbo2 engine.

 

I was reading a thread and I guess the turbo has a harder time keeping up boost when the ports open. Something like boost leaks down.

 

So you want to use 6 port housings to basically "make" a TII engine? Don't do it. 6 port irons do not flow as well as 4 port, and are much more limited in terms of porting. If you are going to go through all the trouble to tear down the engine, might as well make it 4 port...

 

Hey, I appreciate all the advise. I kinda expected more of a negative lean towards this idea, but I was not sure, hence why I asked!

Looks like I'll just keep this engine around for either an N/A car (maybe and FB ) or a buddy of mine's been looking for one for his MGA project.

I'd still like to hear from anyone who may have actually done this, however.

 

You just heard firsthand advice from the Turbo NA guru. Don't do it.

Steve

 

Aaron (who answered above) has already done it. It is something that I wouldn't even want to attempt.