I read in a magazine (Modified.. possibly the best import magazine out there) that at a recent championship event, Ari Yallon was staging his car, and then he threw an apex seal. He got pissed off so he reved the **** out of the engine, and suddenly it came back to life (figured the seal got lodged in the housing and then fell back into place) and was running fine, so he took the race (and I think even won it).

They weren't sure if this is exactly what happend, but that is what the magazine said Ari and the guys figured.

 

If the seal got lodged into the housing, your housing is toast.

Most likely, one of the seals binded and he got enough vacuum on a couple of cycles to unbind it. It could be incorrect seal measurement (like side) to poor tolerances on milling (apex seal).

He got lucky since even pulling a stuck seal can still risk damage to the housings/seals.

J

 

Either way, really strange. I've never heard of anything like this happening before. I doubt it has to do with incorrect seal measurement or poor tolerances on milling since it's Ari Yallon (www.rx7.com)

 

Of course, Ari is perfect.

J

 

I think it falls under the "weird **** just happens" category. Knowing Ari's reputation he probably had a shitload of boost cranked into it and he just got really lucky.
He got even luckier that he did not really tear the hell out of it when he rapped the hell out of it.
I would like to know what his slot clearances are though. That is an area that if you talk to several racers you will get several different answers and even more different views on why they go a little loose, a little tight, or whatever vague area that may be considered in between. And some of them would not tell you **** about it.
Does anybody know what seals he uses? To support that theory it would have to be a one piece seal.

 

He probably collapsed a seal spring. Definitely didn't get lodged in the housing, thats for sure.

 

That's what I was thinking... but the article mentioned lodged in housing, which is a guranteed finished engine pretty much.

How rare is that to have a seal spring colapse?

 

NO NO NO you guys are all wrong it was magic pixi dust sprinkled into the intake and took the broke seal and welded the pieces back togather... I knew ari had some kind of a advantage over the comp

 

Sticking a seal happens all the time. Sometimes it pops back in, sometimes it doesn't. **** happens

 

Actually, the apex seal expanded causing it to stuck. It happens all the time so its not an uncommon problem. it all depends on what seals you're running.

 

how do you then get it to unexpand? and why do they expand?

 

I asked Ari over the phone once what clearance they run with the 3mm seals. He said that they don't bother adjusting the clearances on them.

Of course this could just be him protecting his competitive advantage. Then again, I adjusted mine, and let me tell you it's a pain.

 

yes, I wouldnt doubt that he is protecting something. Just like that 700-750 rwhp @27 psi with n2o,I dont think it posible, could be though. I saw under the hood once but cant really remember what i saw just bits and pieces.

 

That's possible power for a 13B, especially a drag car. I've seen dynos of guys with street driven RX-7's making that much power at similar boost levels (26-32 psi) with NO n20. (usually bridgeported engines, sometimes p-ported which allows even more)

 

Still how the hell does the seal expand?

 

I am assuming that Steve was talking about heat causing it to expand. If Ari is not checking clearance as someone said he stated during a phone call (which I find it hard to believe he does not check every detail) he may be a little too tight. Too loose could cause a binding as well I would think. But too tight would seem most probable.

 

Yeah, but i thought that the expantion would be accounted for when assembling a motor. Guess not, if it grew and then binded.