Zero Clearance Side Seals

[Barry Bordes]

I like to set up my side seals as tight a practical. There are different thoughts on this minimum spec.
I have seen recommendations from .002” -.004” for turbo applications.

On my last engine build-up I mistakenly switched two side seals causing a
.002” clearance. This resulted in scrapping the RE front plate because of a
.004” wear groove on it in the area of combustion (where heat/expansion is greatest).

I decided to try .000”! Found this in an early Mazda paper.

What do you think?
Barry

[Chadwick]

The problem I see is the chance for the side seal to get jammed and loose compression on one face.

Dan

[cewrx7r1]

Mazda's race prep manual lists .0039" to .0059" for 13Bs. But this is from 1996.
I do not know if this has changed.

[tom93r1]

Thats kind of a cool idea

[Barry Bordes]

Mazda's race prep manual lists .0039" to .0059" for 13Bs. But this is from 1996.
I do not know if this has changed.

Yes Chuck you are right, but the regular workshop manual states .002"-.0059" and Racing Beat recommends .0015”-.004”( this may be a NA spec).

I guess I should have said it runs gap-less. It still has clearance to expand into the added corner seal slot.

Barry

[Signal 2]

Just thinking out-loud here....and I'm in the middle of only my first rebuild so go easy....
What about potential carbon build-up in that corner seal slot. I see some clearance for length, but is there risk with loss of what little "side" clearance there is within that slot due to expansion and/or carbon? What would be the result of the side seal and corner seal being effectively fused together if that happened?

[Barry Bordes]

Just thinking out-loud here....and I'm in the middle of only my first rebuild so go easy....
What about potential carbon build-up in that corner seal slot. I see some clearance for length, but is there risk with loss of what little "side" clearance there is within that slot due to expansion and/or carbon? What would be the result of the side seal and corner seal being effectively fused together if that happened?

My swag (scientific wild ass guess) would be that it wouldn't much more of a problem. I'll have to tell you in a couple of years.


Barry

[GoodfellaFD3S]

I'd have to go check the feeler gauges, but I'm pretty sure I clearance side seals at .0015 to .002. Nice and tight, and havent had a problem yet. Of course, we recommend a pretty long breakin period of 1500 miles before serious boosting.

[Barry Bordes]

This is the way to get a precision cut.

Barry

http://i287.photobucket.com/albums/ll129/bbordes/rx7sidesealgrinding.gif (http://s287.photobucket.com/user/bbordes/media/rx7sidesealgrinding.gif.html)

[Herblenny]

http://www.rotarycarclub.com/attachment.php?attachmentid=787&d=1206964763
Pretty neat barry!

So, are you going to be ready for DGRR??

[a7xh7]

seems cool..

[cewrx7r1]

Those special coner seals should seal better, but where can you buy them?
If you had a good machine shop, maybe you could make them yourself.
The question is, where they not cost effective for Mazda, or only used in rcae engines?

[Barry Bordes]

Those special coner seals should seal better, but where can you buy them?
If you had a good machine shop, maybe you could make them yourself.
The question is, where they not cost effective for Mazda, or only used in rcae engines?

Yes Chuck, I am not sure why Mazda hasn't used them for production. Possibly the extra machining and fitting.

I also wonder if the reason could be that the normal blow-by of the side seals might help to float the rotor between the housings.

As for who makes them, I make them myself with a special diamond cutting tool. I can cut a set for you.
Barry

[Barry Bordes]

Phil, thanks for installing the picture correctly for me. How do you do that?

Barry

And I am still building my engine but expect to be there. I may have to go with Jack.

[afgmoto1978]

Barry,

Neat idea, but what about Apex seal clearance, assuming you had more clearance at the apex seal (two faces) you would see unwanted binding at the side seal from the apex seal rotating at the point of peak combustion pressure. Only one way to find out, and that's to test it out.

If money was no object, zero clearance on everything after Nikasil coating, or something of similar low friction properties. Ceramic coating......

[a7xh7]

you would see unwanted binding at the side seal from the apex seal rotating at the point of peak combustion pressure.

i was thinking the same. cant really avoid it(by cutting out more space to move) and keep the seal tight, so if theres any rotation of the corner seal it may cause binding and eventually wear the broad surface of the side seals.

[Barry Bordes]

I cut each side seal to the specific rotor location. Unfortunately each rotor corner is slightly different. I then rock the apex seal to check for binding of the side seal. If any is found I increase the cut on that side.

One advantage I noticed was that on final assembly the apex seal always slides in fully. It is perfectly aligned. No fishing with a pick to straighten the lower corner seal position!

Barry

[zonblitz]

I was at Barry's last week, he is the wizard!

I am seriously hoping he is ready, if not I think he should ride with Jack!

/hijack..... Hey Barry I fixed that a/c!

[Phoenix7]

I'm not too familiar with engine work but what's the benefit of this?

[Barry Bordes]

More compression.

Here is a poor picture of leak from my last .003” clearanced side seals (cleaned by 50/50 water/meth).

Notice the clean trailing side vs. the leaking leading end.

Barry

http://i287.photobucket.com/albums/ll129/bbordes/125-2540_IMG.jpg

[Phoenix7]

I see the difference between the trailing (right side) and the leading (opposite) sides of the rotor and that was due to the large clearance you had before between the side seal and the corner seal.

So, the larger corner seal (with the groove in it for the longer side seal) lowers compression by....?

I'm looking at this pic (no access to the FSM for specs right now) and I can see how your corner seal(s) are different but since I'm not familiar with internals I don't fully grasp how the compression is lowered by reducing/eliminating the clearance.

http://rotarycarclub.com/attachment.php?attachmentid=762&d=1206700401

http://www.turborx7.com/images/rebuild/Specs11b.jpg

I'd love to hear more about his when you have time.

[Barry Bordes]

The gapless corner seal doesn't leak any compression!

http://i287.photobucket.com/albums/ll129/bbordes/zeroclearancesideed-2.jpg

The leaking seal was set-up with a tight clearance of .003", the Factory minimum.

http://i287.photobucket.com/albums/ll129/bbordes/125-2540_IMG.jpg

Barry

[AHarada]

This is an awesome intriguing idea. I saw on your same thread on the other place that you're not running this. How is it doing? What side seals are you using?

[Barry Bordes]

The trimmed version of the Mazda side seal is part number is N3Y1-11-C11. There is a longer untrimmed version, but Ray Crowe could not find it. He ordered an older number but it turned out to be thicker (.8mm instead of .7mm).

Does anyone know this untrimmed part number?
Barry

[My5ABaby]

Wouldn't that raise compression due to no escaping (or what not) air?

[Barry Bordes]

Wouldn't that raise compression due to no escaping (or what not) air?

Yes, it gives higher cranking pressure and running pressures!
Barry

[My5ABaby]

Yes, it gives higher cranking pressure and running pressures!
Barry
Oh, earlier you said less compression. I got confused. :D

[Phoenix7]

That's what has me :confused:. My brain says compression is maintained constant if there is no clearance for the seals to flex so I don't see how compression is lowered.

I'm also waiting on an email to see if I can get a hold of that SAE article.

[My5ABaby]

That's what has me :confused:. My brain says compression is maintained constant if there is no clearance for the seals to flex so I don't see how compression is lowered.

I'm also waiting on an email to see if I can get a hold of that SAE article.
He misspoke earlier, it appears. It does raise compression.

[My5ABaby]

That's what has me :confused:. My brain says compression is maintained constant if there is no clearance for the seals to flex so I don't see how compression is lowered.

I'm also waiting on an email to see if I can get a hold of that SAE article.

I have access to all the SAE documents here............. they're just on Microfiche..... :banghead::banghead::banghead::banghead:

[Phoenix7]

well I was able to access SOME SAE Papers but the one you need (regarding cooling) is not there. I'll keep looking.

[My5ABaby]

I found the paper in my stacks of stuff...

[Barry Bordes]

Oh, earlier you said less compression. I got confused. :D

I looked back through the post looking for where I said that you get less compression. Help me find it and I will correct it.

We want to seal the rotor chamber as well as possible. This makes the engine start better, run crisper, and of course, gives more ultimate horsepower!

Barry

[My5ABaby]

Post 20.

[Barry Bordes]

Post 20.

Thanks Rob, I changed it to more compression.

I meant that the gap type cornerseal would leak and lead to less compression but I see it was misleading.

Barry

[My5ABaby]

Thanks Rob, I changed it to more compression.

I meant that the gap type cornerseal would leak and lead to less compression but I see it was misleading.

Barry
:icon_tup:

[RETed]

Really?
You gonna resurrect a thread from 7 years ago???

Geez Barry, you're breaking one of the most oldest netiquette rules out there.

Please stop doing this.

Thread closed.
You're welcome to reopen another thread - hell, even identical title if you want.

You're asking what would've been the proper way to handle this?
1) Start new thread...
2) Reference new thread back to the old thread...
NOTE: Try and leave threads that are inactive over a year - most definitely over TWO YEARS - alone.


-Ted

[chibikougan]

1. Publicly attacking the administration's actions when it comes to administrative forum issues. Internal issues are just that, INTERNAL. PM the appropriate channels and discuss the problem and solution without making a heated an e-fight about it.

:icon_no2:

[RETed]

Barry, leave it alone.
You're acting like a baby.

LEAVE THE THREAD CLOSED.


-Ted

[Barry Bordes]

You two are trolling an informational thread.

[RETed]

The fact that you're backing both Howard Coleman and BDC shows that you do not have a logical grasp of the facts.

Howard Coleman has been REPEATEDLY defeated in his incredulous claims, so he has a very negative reputation.
Sure, he talks a very good game, but it is not based on facts.

BDC is a con man - simple as that.
I have had a long history with this idiot - way beyond you started posting on the Internet.
To refute my countless posting and replies on the matter, you still side with this asshole.
Where is BDC Motorsports now?
What about his Facebook page?
He has flown the coop.
The guy has finally given up trying to con the RX-7 community with this bullshit and lies.

For you to back BOTH of these idiots shows that you don't know which side is up.

You resurrected a thread over FIVE YEARS OLD.
You can troll up whatever technicalities you want to, but this is breaking netiquette rules before you even thought there was an Internet.

I posted the proper way of referencing on old thread, but you INSIST on doing it your way.
Which means...you're doing this just to spite my decision on the matter.
FUCKING GROW UP YOU FUCKING BABY.
LEAVE THE THREAD CLOSED.

This matter has already been brought up to the admins and higher up's.
It's a matter if a decision is being made.
Until someone says something, I will keep telling you that YOU ARE WRONG.


-Ted