Im trying to find out how much it costs per housing for peripheral porting, and basically who is the best at it. thanks,



Dan

 

Take good used housings to a machine shop, and bring aluminum tube with you. Pick the tube you want (as far as port sizing goes).



Get quotes to have them bore the housing out (to your specs, generally people who make their own peripheral port housings use the outer coolant passage casting as the centre of the hole), and they mill the tube (which becomes a sleeve) for insertion



You can go with an interference fit, or non-interference and use an epoxy to prevent leaks.



You would have to engineer it yourself though, as far as manifold design goes (flange or clamps or what have you), and after the sleeve is installed, you would have to cutaway the excess hanging in the middle of the housing, and do the final port window yourself.



But you get to design it, and you save alot of money too.



I was quoted 200 bucks Canadian per housing at a local machine shop, and they said they could calculate what kind of interference fit to run in the sleeve so no epoxy would be required. They mill the housing to be a smaller hole than the sleeve (thousandths of an inch difference), and they shrink the sleeve with nitrogen, slip it in the peripheral hole, and let it expand. Sort of like a ring gear on a flywheel.



However I was planning on epoxying anyways, and I found a better deal elsewhere locally (if you can believe it).

 

I have access to a mill, lathe and CNC bed mill, but I dont know anything about ideal shape, size, angle or placement. If there is some sort of "cheat sheet" then I'm all for it. I am not a mechanical moron but I dont have much machining experience, and zero porting experience, which makes me a bit skiddish about doing it myself. That and the fact that I will have a considerable ammount of time and money wrapped up in the engine alone.

 

Rob at Pineapple can do a decent P-Port

 

I spoke to Mandeville about this yesterday. He built my 20B and I was thinking about going with a p-ported 4 rotor instead. He said adding p-ports to the stock housings is not the way to go because of the port angle.



The Mazda p-ported housings are around $2400 a pop. He has his own housings cast for around the same price. I believe they are designed to be a stiffer than the Mazda units.

 

He said adding p-ports to the stock housings is not the way to go because of the port angle.



That does'nt really make sense to me. Is it not possible to get the proper entrance angle when boring through the housing?

 

I thought the same thing.

 

Paul Yaw has made them, WWW.Waypower.com, and Racing Beat has them in their catalogue.



Lynn E. Hanover

 

from Yawpower.com website:

Porting



Porting can vary a great deal from one motor to the next, but the prices below should give you a rough idea.



"Street Porting" for street engine - $650

"Street Porting" for race engine - $950

Bridge Porting - $1,500.00 to $2,000.00 Depending on application.

Peripheral Port Intake, and Port Exhaust - $2,000.00 (Requires Custom Intake Manifold)



1000 per housing seems a bit steep to me, but then again that is the only price I have seen so far. I did email racingbeat for a quote (not including the housing), just have not heard back yet. I know there are a few shops in New Zeland that will do it so I'm gonna look into that as well.

 

We got ours done for around $200 per housing for the machine work and materials. The machine work involved is relatively simple.