PDA

View Full Version : Porting and Nitridied Side Housings


Carl
8th November 2002, 08:56 PM
Hi there to all you rotary fans out there,I am new to the forum but not to rotaries and thought you might like to hear that you can do things to side housings such as having them lapped(removal of material ) as long as it is fairly minimal,ie about the wear that you have in an FD engine when it needs rebuilding lets say 50,000 miles or so. Also nitrided housings have been used by Mazda way before the FD in other rx7s.If you talk to Racing Beat they always lap their housings.;)
As regards porting side housings there are many routes you can take and much depends on what model of car you have and what you want to acheive but if you have any porting done then the whole package must also be looked at too so the they all work together for best result.
Exhaust porting can be done on almost any engine, and benefits will be seen as long as the exhaust is also upgraded, of couse the down side is that noise usually goes up and especially on non turbo cars,so once again you need to make sure that the wholepackage works together.
If you are contemplating racing then the parameters change a whole lot more as you may or not be permitted to alter your ports.

Hope that this is of interest to someone

Carl

Glenn Butcher
9th November 2002, 09:41 PM
Hi Carl!

Thanks for the information, I wasn't sure if the FD end plates could be lapped.

Does the nitride go quite deep into the metal?

Thanks mate!

Carl
10th November 2002, 10:13 AM
Hi Glenn,
you can lap fc and fd rx7s housings generally only once cos the grooves for the coolent seals are in these housings, in the 1st gen which are also nitrided you may get away with more than this as the seals are in the rotar housings. as to the depth it is deep enough for the lapping.
Nitriding on production engines started in 1978, this does not mean that an earlier engine is going to wear out to quick though, it just means that they dont wear quite as well as the later ones. anyway it seems that FDs dont last long enough to find out LOL.
:D

Glenn Butcher
10th November 2002, 11:04 AM
Hi mate,

That is great information, in Oz we use to use the RX-4 13B type housings (I think they were R5 type at a guess) - the long port type. We were able to lap them ok, as I know they were nitrided so there should be any difference on the FC and FD etc.

I am going to post another question for you on Apex seals now - I'll start a new thread.

Grizzly
16th January 2003, 10:54 PM
I'm sorry i'm a little confused? Do you lap your Housings or Plates?

Chris

Glenn Butcher
16th January 2003, 11:09 PM
Hi Chris,

Do you mean does Carl lap the End and Intermediate plates? or the rotor housing?

Or are you just asking if he laps the End Plates and Intermediate plate - therefore I'm pretty sure he does just the once.

Grizzly
16th January 2003, 11:19 PM
I was getting confused as i though Carl was Laping the Rotor housings as well as the Side plates.

Doh! its late heads gone to sleep, Sorry.

I'm just used to calling Side housings "Plates" and rotor housings "Housings"

Crossed wires i think.

Chris