rx7anator

ok well i got my spare motor apart to begin the street ported turbo 12a project.

and it looks like i have some flaking on the rear housing...how big of a deal is this?


also on the front, center, and rear plates. if i just bearly touch them and lap if off. will it hurt em to much. (i read that laping them will decrease life...is this true?)

what can i use to clean out all the nasty yellow/white **** in the coolant passages?? the ozzyjuice wouldnt clean it all out.

Thanks

Brad

Rx7carl

Will it work? Yes. Will it make for good compression numbers and power? no. Ive reused housing like that b4 for the engine in my daily driver (80psi comp). But I wouldnt re-use those in any engine I wanted to make any real power with.

As for the lapping, you can put some lapping compound on one plate and use the other plate on top. Make figure 8's and you should get a good flat finish on both housings. Yes it will remove the nitrided metal, but nothin you can do about it unless you have it re nitrided. I dont know of anyone who bothers to do that.

Search in the tech and performance sections. There was a long *** thread on cleaning internal engine parts.

coldy13

Can you get a better picture of it? I'd say it'll be fine to use. I did a comp test on my last engine before I pulled it apart. 105+/-3psi on all faces. Once I opened the engine, it looked like ****. TONS of chrome flaked off(probably 5x worse than your housing), 4 side seals split in 1/2, 3 broken corner seals, all corner seal springs flat, apex springs kinda weak, but still alright. How did it still make almost perfect compression? I have no idea.

Rx7carl

105 is not perfect. And that what he'd probably get from reusing those housings. A new or properly rebuilt stock port, iron seal engine should make 150psi.

coldy13

105psi on a piston compression tester holding the release valve. It always reads lower than it should, main thing I was looking for was how even all the faces were. The engine I built with perfect housings and seals made 115psi on the same comp tester.

peejay

Wow... 105psi?

Using that method I would get 70psi on my street port (with perfect housings) if I left the valve shut, and 25psi if I held the valve open. Rather long hose on my pressure tester, I can practically hold it while sitting in the driver's seat as I crank the engine.

rx7anator

so i shouldnt worry about gettin the housings setup on a cnc and laping them...then get some compound and rub em together huh..thanks (im gona check out that thread to)

yeah im having compression problems now. thats y im starting this project earlier then i wanted to. so im not gona take the easy way out.

oh welloff to ebay to find some housings.

thanks

Brad

peejay

I wouldn't even bother lapping them. If they are grooved barely deep enough to catch a fingernail, don't worry about it.

rx7anator

ok front houing is excatly the same...is there any way to fix this.? do they make sleeves so i can machine out the old one and press a new sleeve in?

i REALLY dont wanna pay 400 apiece for new ones...if not repairable i guess im head to atlantarx7

Brad

Rx7carl

Nope sorry. Only solution is replacement.

rx7anator

i bet if someone made a replacement sleeve that would press in they would make a killing.

think..it would be basically new housings for atleast half the price.

oh well im gona have to go to atlantarx7 so i can find some housings that arnt in to bad of shape.


is there any difference in the front and rear housings??? (is the back bigger?)

Rx7carl

Actually the real solution would be stripping and the replating the chrome surface. Somone over in the tech and performance section has done it. Long term results not in yet.

peejay

The machining costs alone would be more than the cost of new housings.

Plus, the heat transfer wouldn't be as good. The stock sheetmetal insert has the aluminum cast around it, which is the next best thing to having it be all one solid piece.

rx7anator

i didnt think about the machine time/money as i can do it myself.

also i can get connections to get just about anything metal related done.

so can i just bearly kiss the housing surface and take off the crome surface..then (not COMPLETELY sure how to do this part) re crome them.

ill search the tech formes to...

thanks

Brad