badass7

I had my engine rebuilt a little over a year ago and went with used rotor housings. A friend of mine just came back from RP and Ari told him that the only way to go is with New Housings. Now, when I was getting feedback from all the major builders at the time of my rebuild I was told by most that used housings were the way to go. When I told Cam at Pettit that Mazdatrix told me new housings were a must he actually told me that used are better because they have already been heat cycled. So, what is it?? Seems like most of the builders go with used with only a handful recomending New ones. If I had to do it again...I'd prolly go with the New housings. What do you guys think??

badass7

Doh!!!....didn't know you can only vote once. So, just vote for the New or Used housings and disregard the 2mm and 3mm seals option..

jumprdude

You can't lap rotor housings (see your poll)

New rotor housings are the way to go, lots of the time rotor housings get pretty worn and are not re-useable.

Side housings are reusable, provided that the surface is free of grooves and the run-out is well within Mazda specs. They can be lapped if necessary.

3mm apex seals are only used if re-using rotors. On a high mileage engine, I'd prefer new rotors and 2mm apex seals as well.

Sidestick

iTrader: (1)

I got rebuilts. My engine only lasted about 25k miles before it started eating coolant without ever being overheated. Examination after teardown, showed the water passages were severely corroded. I'll never use a rebuilt engine again.

badass7

Wow, who rebuilt that engine?? Was there any sign leading up to the failure...other than eating of coolant. Also, at approx. what mileage did you notice that?

Sidestick

iTrader: (1)

I got rebuilts. My engine only lasted about 25k miles before it started eating coolant without ever being overheated. Examination after teardown, showed the water passages were severely corroded. I'll never use a rebuilt engine again.

DK

iTrader: (5)

Well since my apex seals exploded and grooved up the housings and rotors, I had to replace both. The guy who built my motor was in disbelief, "Daniel ... what were you doing when this happened?" I told him what happened -- the motor was at idle and had just been started up 3 minutes earlier.

newRX7fan

iTrader: (1)

Always get new rotor housings unless they are very low mileage. Also new apex seals of course. The side housings depend on their condition and whether they've been lapped before. I'm told rotors are pretty tough (cast iron?) and usually don't need replacement unless they're damaged by broken parts inside the chamber.

I got this info from Tripoint and Rotary Reliability; also Mazdatrix's web page. Although Tripoint didn't like to lap side housings since they are tuf-rided (sp?); treated so that the surface is stronger than the metal and lapping them would remove this.

Sidestick

iTrader: (1)

That engine was a ******' Mazda Reman. Me not getting another rebuilt actually meant another Mazda Reman from the dealer.

No, there was no other indication. Actually, it started out as being hard to start shortly after being driven (hot starts). I had no idea it could have been the engine going, being the mileage was so low, it still drove well (strong) & idled perfectly. When I knew it was really fucked was driving home one night & the low coolant warning started coming on with the temp going up. I had to stop about 4 times & beg for water to keep going just to make it home (a 60 mile commute). The next day was when I really noticed the white smoke/steam from the exhaust.

Oh, just remembered, there was one incident that something was wrong. Approx. 2 weeks before the aforementioned story, my stock AST exploded. I thought it was just the shitty stocker giving way. I had a spare which I installed & which also exploded on the way home that night of my story. That confirmed what I thought.

From what I recall, the hard starting started about 2-300 miles before the incident.

vosko

iTrader: (4)

my engine has ALL NEW housings only 3 parts are used on my engine rotors and eshaft you get what you pay for

Bacon

iTrader: (12)

hey that sounds like mine...wait isnt the same guy building ours

j9fd3s

iTrader: (3)

you always use new housings unless the old ones are really low mileage (under 20ish). with the mazda remans you can tell when they reuse the rotor housings because it will have a hard time starting hot.

mike

SPOautos

Normally I'd go with new housing unless I found a used one in really good condition. I'd imagine the difference is when Mazda rebuilds one they throw in any housing they can find that meets "specs". When Cam uses a used rotor housing its probably in excellent "like new" condition. I know when I was visiting Pettit I went thought thier clean room where they build the engines and all the housing looked really really good. I dont know if they were new or used but they were nice and very clean.

As for the cooling issue from corrosion, if they would clean it out real good before using it I'd imagine that would solve the prob. I know the housing I bought used was in excellent shape and the very small amount of corrosion that was there I cleaned out so it looked new. I probably spent 1.5-2 hours cleaning the housing to be spotless.

I guess it comes down to the condition of a particular used housing. If its in excellent condition there shouldnt be any problems. If is a piece of **** that was turned back in to Mazda and has been reused in 5 motors over a period of 10 years I'd imagine its crap.

BTW - New rotor housings cost over $600 each so it adds a lot of $$$ to the rebuild

Later,