If the side seal spring is indeed looser then before. Could this be the reason why soo many aftermarket companies are haveing troubles with FI. I would also like to know if Synthetic oil would be better

 

I have zero proof that there is a side seal spring issue. It "could" theoretically explain what has happened though. Don't just extrapolate that there is a spring issue based off of this just as we shouldn't necessarily assume all engines have a side seal problem. The only issue is the clearances and this I do find to be an error on the part of Mazda.

 

All very interesting. But I'm interested in how the 13b can have that timing.
RG, how do the 13b primary ports open at 32 ATDC and close 40 ATDC?
That is some real short timing. But then the REAL TRICK is
the 13b secondarys open at 32 ABDC and close at 30 ABDC?
That is the longest timing I have ever heard of.
But I'm a rotary freshman and need the education.

Did I miss something? Or are you just testing to see who is paying attention?

 

would the seals on the renesis rotors eating up the housing in the 13b have something to do with this increased gap, maybe for the housings protection or something?

 

Richard I started getting confused with the whole ATDC/ABDC thing and apparently got some terms mixed up. They all open at wherever ATDC and close wherever ABDC. Thanks for catching that! I'll go back to fix it.

Remember also that the rotaries timing is based on a 1080 degree eccentric shaft rotation rather than a 720 degree piston engine crankshaft rotation.

 

I knew what happened I just wanted to give you a bad time.

Plus I just looked at an overlay of the cycling of a piston vs rotary and it is all very clear to me.

 

RG, one more thing. It seems to me that the seal clearence is like piston ring end gap. However the gap on a ring closes as they heat up. Is there any sort of thermal effect in the rotary that would close it's gap?

Say if the rotor expanded within the case. And there was less expansion of the cases.

 

You think the rotors could expand that much? That's an interesting concept. If they could, that'd definitely account for the rotors tearing up a 13b housing.

 

If the rotors are aluminum it expands at a rate of .0012 inch per 100F per inch. Meaning if they are 3 inches wide that is 0.0036 per 100 degrees of rise I don't know how hot they get but if they go to say 400 then that would be a rise of 300+. So it is .011+ expansion.
Now what is the case made from and how hot does it get?

You guys know these things, I do not.
BTW if the part is steel it will expand about half as much.

 

The rotors are made from cast iron.

The housing is steel.

 

Then my theory is useless.

 

It was a great idea though RP. Keep em coming!

 

FYI - I was thumbing through the engine workshop manual and found some specs that you may find interesting.

Clearance between side and corner seals
Standard - 0.0020-0.0059in
Maximum - 0.0160in

Rotor and side housing clearance
Standard - 0.0020-0.0074in
Maximum - 0.0020in

 

Did you mean .020 max?

Are these the numbers for the Rx 8? Because they do not seem to match what has been said here.

 

It's in the engine manual. If you have that, and have been holding out on me, i'll be slapping you.

and richard, thatd make a lot more sense.

 

No. There is a separate engine manual for the RX-8, at least that's what robertdot told me.

 

It's true :P The shop manual has no information on taking the engine apart. Canzoomer has the engine manual, I am told, though I haven't looked because I find his site a little difficult to navigate.

 

No, 0.0020" is the correct number or at least that is what is listed on the specs page. I'll scan the page tomorrow so that everyone can see it for themselves. :D

 

Yes, there is a separate "Engine Workshop Manual". I bought mine through CanZoomer but you should be able to get it through any Mazda dealer. Just ask for P/N 9999-95-E13B-MSP.

 

Off-topic:

My Mazda dealer told me the engine manual is included with the rest of the workshop manual, which is wrong, unless they meant the externals. Sucks how I have to get two manuals; the old RX-7 manuals included the entire engine workshop manual.

edit:

I was wondering if one could design seals with different materials.

Are the side seals constructed of iron? What about the corner seals? I think it's pretty weird too regarding the clearance issue. I can't really visualize what is going on without a working model.

 

Off-topic: I wonder if someone can scan those.

 

I only point out that if the normal clearance is .002 to .0074 how the hell is max .002?

 

Odd. I just realized that. Are you sure those are the right specs?

 

You know what you are 100% correct. This problem does not exist. But it happened to me. Maybe somebody screwed up really bad when my engine was assembled. Mistakes do happen.

 

Is it possible for you to pinpoint what went wrong, Mr. Port & Polish? I dread a similar case if I ever had my engine assembled.