couldn't you make control unit to control a smaller pipe that's inside the big p-port one that opens up below a certain rpm and closes the big intake?

 

huh? I got confused reading your reply. Sorry

 

I will.

 

Yes Mike, the smaller the p-port the less intake and exhaust overlap the engine has and a smoother idle can be achieved. On a large Peripheral intake port and a large p-port exhaust there is some serious intake charge being sucked right into the exhaust stroke.. Is called SCAVENGING..

 

So what is the best port size and timing?



(and still nobody knows what to fill the side ports with?)



J

 

Thats the thing, best port size for what? With a pport you can make power high in the RPMs (i've heard around 13,000RPM and so), yet the 787b had its redline at 9,000RPM because it made all of the power, torque, and fuel efficiency it needed at that redline and below.

And the old NSU's were street legal pport only cars, that idled and drove like regular cars.



So it's just like an intake cam, how wild do you plan on being?

 

if you read the rest of the bible, errr racing beat manual, they recommend using devcon (plastic steel) for filling the intake ports. its a 2 part epoxy that mixes up like JB weld and you pack it in the port (please, no perverted comments) and smooth it out about 1/8th of an inch stepdown from the side housing surface. VERY crude attempt of showing you what i mean:



surface of side housing \/ opening of intake port

--------------------------------_______-------------------------

where to stop devcon at/

 

I see, I suspected something like that. I should actually get that Racing Beat catalogue already but I'm allergic to spending almost $30 for a catalogue (by the time it gets to me).



I will have to study this timing issue in detail it seems.



J

 

yeah thats one of the hangups to a diy pp housing. that and the labour time to actually do the machine work+a new rotor housing is not much cheaper than a new pp housing



mike

 

I would think that JB weld, or some sort of high strength epoxy would work. Or weld in and machiene the weld flat?



BTW i like this thread.....i'm learning about streetability on baby bridgeport motors..which is what i want to do with my vert