Some shops say new side housings are a must and that they cannot vbe refinished, other guys say 9 out of 10 times old side housings are reusable, and they can be micro lapped? what the hell is that? Also a few shops told me that new ones will last longer and give more power. SO what is the consensus on these things, new, lapped or mazda reman housings?

Also, I am going to get the thing street ported at the same time. Shou,d I do teh ecenstric shaft an doil mods, etc. I was also told that bigger apex springs are a must for high boost ( I am running 15lbs on stock tin, don;t know whethere that is high boost or not) but anyway, others have said stock springs are apex seals are good enough.

I haev been told so many differnt things, an dof course all these things affect the price from about 2400$ to 4500$

My feeling right now is just to get mine rebuilt with new rotor housings, stock eveything and a street port. Oh yeah, and of course all new seals and gaskets.

What do you guys think?

 

Actually they can be lapped and reused multiple times depending on how much is taken off in the process.

To make it simple for you: if they do not take off more than .002" the wear factor will be about same as stock.

If more is taken off, they will wear out faster. The more that is removed, the thinner the remaining nitride layer becomes and the softer the metal. For a stock or NA engine is does not matter that much.

The question is how long due you expect your modded engine to last. If you want 100K miles then new housings are needed. If 50K is good enough, reuse the old ones until about of .010".

Some builder say theyare reusable untill the engine stack will not align with the manifolds.

 

Thanks Chuck, but won't I make more power with brand new housings? 50k is fine for me, I will only see 15 psi max anyway.

What abou the springs?

 

I am in the same boat right now... Charlie @ Mazcare is trying to have me get my rebuild done there but they don't streetport like I wanted... do you have some viable options closer to Ga. besides Pettit??? I just want to make sure this whole process can be done in one swoop. Its tough to decide what else to have done other than my clutch since this would be the time to do it. If you have any info on making my decision easier it would be greatly appreciated.

Thanks,

Brett

 

KZ1,

When side housings are lapped, they grind off the metal until the surface is flat just like a new housing. It will produce just as much power as a new housing. The nitride layer in the metal goes down a few thousands of and inch. This layer does not affect power. It only affects how fast the metal wares down.

Of course you use all new seals for the rotors.

I think you might be getting side housings confused with rotor housings. You can reuse the rotor housings but they can not be machined to like new condition like can be done with the side housings. If you reuse rotor housings with high mileage, even if they are in good condition, you will loose power here. This is were many rotary owners are cheapscapes! A boinger owner would never rebuild an engine without rehoning the cyclinder
bores. Both housings together equate to the cylinder bore. Just as the rotor equates to the piston.

 

going to 3mm seals requires careful machining of the rotors, if the rotors are still good (or you're getting new rotors), there's no reason to go to 3mm seals. Get the 2mm Hurley seals -- many tuners are running singles with a lot higher boost than 15 psi and they are still using 2mm seals.

 

thanks, you are right I meant to say rotor housings. I am definately goign to get new ones.

on the 3mm apex seal issue, I think it is good for guys like me that like to adjust the tunnign, etc. This is more of a project car, and 3mm will offer me more durability against poor tunning. I was told that if they are machined right and installed right they don't rob power, etc.

Thanks guys, good info.

 

Hi Phil,

If I was in your position and needed an engine rebuilt the first thing I would do is call the two people I respect the most when it comes to engine rebuilds.

My first phone call would be to:

Rob at Pineapple racing 503-233-3878.

http://www.pineappleracing.com

My second call would be to:

Dave at KD Rotary 610-614-1214

http://www.kdrotary.com/

I would explain to them my situation and ask for their expert advice. My decisions would rely heavily on what Rob and Dave recommend.

Part of your issue is who will be doing your rebuild. Ultimately whatever you decide to do, you must have faith and confidence in your rebuilder. So, I would suggest that you need to select a rebuilder first if you haven't already. Since I am in California I would be having my engine rebuilt by Pineapple in Portland, Oregon. I realize you are in Georgia, but you could actually ship your engine anywhere to be rebuilt, so keep an open mind about selecting your rebuilder.

 

Just food for thought: It is EXTREMELY hard to mill for 3mm seals. It has to be perfect or you will be in huge trouble right off the bat.
(I own a Bridgeport mill and do stuff on the side for fun - I wouldn't even attempt it since I KNOW that 2mm grooves from the factory ARE perfect) I would only do it if I NEEDED new rotors, could not afford new ones and knew a VERY skilled operator who had done it successfully many times. 3mm seals might be slightly stronger than 2mm but are going to produce a lot more drag which will probably negate any increase in hp you will get by running higher boost. Any detonation is going to blow seals - I don't care if they are 10mm!
Tuning is everything on super high output engines, whether boingers, boxers, rotaries, whatever........
ALSO (whew.... ) very few rotors are "worn" out - they last a hell of a long time unless they have been obviously damaged. If they are cleaned carefully, measured and clearanced properly with new seals they can last "forever". You might want to consider new gears (doubtful if you need them) and new bearings (not a bad idea since they are really not that all that expensive and easy to replace.)