What do you think about the rotor housing photo?
Is it repairable?
Is it a Paper Weight?

 

Previous Photo..did i compromise the Housing?

 

You beadblasted the inner housing surface? Uh oh. If not for that, I would guess you could fill that pit with some of the metal / epoxy putty that Mazdatrix sells (NOT JB weld!). There is a very special factory process that makes the inner contact surface. If you could get that gray residue off the inside of the surface you could inspect it and make a decision about if it would be possible to reuse it. Looks like there is a big scratch on it (second pic), which is a no-no for reusing a housing.

 

My amateur opinion is that its clean enough to be a paper weight. Remember the word amateur(probably misspelled). Only five or six engines. One failure a year after the rebuild on one. It was the outer 0'ring on the rear housing. Corrosion. Its was too close to the oring and it finally leaked big time. The wall of the groove on the rear housing collapsed. I learned my lesson.

See https://www.rx7club.com/forum/attach...postid=1350789

 

http://www.geocities.com/thefastn2fu...neteardown.htm

my other photos...

The Trachoid Surface has tape on the housings to protect it in the cleaning process...looks like a scratch but its not..

 

The " metal / epoxy putty " is that a viable solution?
or a solution for about 10,000 miles? I want atleast 50k out of this engine.. thanks

 

Like I said earlier, I'll look at the housiings sunday. That corrosion looks bad. And that engine has a history of water in the front housing. I might have tried Devcon if the engine did not have a previous history of Coolant issues.

We may have a good housing in the donor engine we tear down Sunday!!! Relax and enjoy Saturday!!!

 

using a combination of the epoxy and some form of agressive sealant for the o-ring doping (not hylomar) you should be able to get away with using that housing. I didn't use hylomar on my engine because I would rather not have a water soluble sealant on a water passage. I used another form of non-hardening flexible gasket maker and the name escapes me right now. (devcon product thats black and sticky as ****) considering that its an outter o-ring surface in question and the outter edge of the o-ring mating surface is still intact there will be very little load on the epoxy filling that corrosion and you'll have no likelihood of having water in the chambers from that situation.

 

I'll backtrack here. It was the inner o'ring groove that collapsed from corrosion on the engine that I mentioned.

Looking at that picture of yours, the o'ring sits inboard of that roll pin in the picture. It sits inboard of that roll pin by the dia of the roll pin in the picture, so the corrosion is already in the o'ring area.

Yeah, try the Devcon and write back in a few years telling us how it worked out. I thought it over and agree with Jimmy325 to a degree. Wouldn't do it myself though. I'm too wormy.

 

Id get a new housing my man. thats gonna put too much faith in that oring holding and not breaking... i'd get a new one.

 

I would also suggest getting a new housing just to make sure. (or a used in exc. condition to save money)
You don't want to be puttting too much faith in "decent" or "fixed up" housings on a high performance engine.

If you decide to fix it, then as others have said, the sealant to use is DEVCON it's what ALL the top builders use when they make their monster ports, peripheral ports, and repairing stuff.

 

It looks like a may get a new housing.. I need this car to be my 'Daily Driver' (for an extended amount of time)before the wife shoots me..lol!

Engine will go in:>
http://www.geocities.com/thefastn2furious/


I just want this RX7 to be fixed and completed.. I have a Turbo II(attached photo) waiting in the wings for me to Overhual and port...

 

I agree that for the most trouble free easiest remedy that you would use a better housing. But when you think of the characteristics of an epoxy designed for aluminum, you're dealing with a substance that is far easier to shape than welding more aluminum to the housing and then machine down flush. The outter o-ring has to handle a whopping 15psi of fluid pressure. (not much!) and the pressure is going from the bad side of that groove outward which actually pushes the o-ring into the housing. All of this is irrelevant once the material has been replaced with the epoxy anyways and the epoxy will not corrode, possibly even preventing the housing from additional deterioration.

I'd personally go with a new housing, but if you were really hard up I was trying to make it easier on ya by offering a cheap solution.

 

Definitely... thanks for the input.. I definitely like the options.. I will keep everyone updated .. on the final decision.. thanks!