Danomite

Who did them, and what is the quality/finish like? Pics if you got them please

C. Ludwig

On the 2nd page of this thread there are some pics. https://www.nopistons.com/forums/ind...howtopic=59567 The housings are used and dirty so the finish on the housing itself looks very crappy but you can still see the port work.



Stamler Machine in Louisville, KY bored the hole for me. The tubing came from McMaster-Carr. On page 27 of this thread I gave a list of the standard tube sizes available. http://www.rx7club.com/forum/showthread.ph...00&page=1&pp=15 Gives you a good array of options to begin port sizing.



Boring the whole is uber simple. I took some pics of what Scalliwag had done on his machine to Stamler and they chuckled a little bit at using a hole saw and then went to work. They referenced the tubing on a lather to ensure it was round then bored the hole in the housing .002" undersized. I froze the tube for a while then stuck them in the holes with a little help from a hammer and block of wood. Then I TIGed the outside joint and filled the waterjacket around the tube with Devcon. Took 20-30 minutes per housing to finish off the inside with some die grinder work.



Check the yellow pages for machine shops and take them some pics and a junk housing to practice on. If you can finish the port yourself there's not much involved in boring the hole.

Danomite

thanks for the link, looks nice btw



not considering runner angle, where is the ideal port location relative to the inside of the rotor housing? Judging by the cutaway pic of the R26B there is a considerable ammount of overlap.

Maxt

With machining, d-porting of housing, and filling material, 400.00 per housing on supplied housings



I am not sure what Mandeville is on about, I know alot of racers and shops that are using converted stock housings, with no problems and very high power output..

ColinRX7

There is plenty of room to play with on a stock housing as far as port angle goes, that statement doesn't make much sense to me either.



Perhaps he's assuming people generally take the easiest route and use the guide that's already cast on the housing?



Getting angle is easy, you're already taking it to a machine shop, it doesn't make much of a difference to them what angle they go at.

Danomite

From www.yawpower.com:



Mszda factory P Port

Intake Open 86 deg BTDC

intake Close 75 deg ATDC

Exh Open 73 deg BBDC

Exh Close 65 deg ATDC