I think we're comparing apples to oranges. It was said earlier in this thread that the Hurley 3mm's seem to be ok.

My take on all this is that there are 2 issues. I think the 3mm's are a little stronger. That's why they can get away w/ running non-hardened seals, more material for strength. The second issue is rotor seal groove clearance. When using a 3mm seal, the groove is machined out and provides perfectly even support across the entire length of the seal.

I just rebuilt mine w/ the new Mazda 2mm, 2pc seals. The rotor that lost it's seals had some "flare" in the groove. Clearance measured .003 deep in the groove but toward the edge, on either end, it was up to .006 near the outer 2mm. My old seals had a wear pattern that you could see where they rode against the groove edges. This pattern showed where they weren't supported.
My Hurley's broke where the end was not supported evenly. The combustion force pushing on the seal broke the top edge about 3/4" in and about 1/8" deep. Exactly where it wasn't supported by the rotor. I used another rotor I had. Now what appears to be happening is that the Mazda seals(and maybe Bruce's new seals) are strong enough that they don't need to be supported perfectly even across the entire length.

Does this make sense?

 

These are for my friends (Asvos) engine.
Lets see what will happen.

 

Ha! I can spot a fellow Bruce Turrentine customer a mile away

I was wondering when someone was gonna come forward and break the secret as to why Hurley's are good....

The bottom line is this: the less "pieces" a seal has, the better (1 piece being ideal). This is simply because any single "piece" component will always have better thermal expansion characteristcs (vis-a-vis the rotary) then a multi-piece component.

If a seal is soft, harden it! There are a myriad of ways to do this (flux-hardening, shot-peening, glass-peening etc...). And all those methods are the EASY ones

Why did I go with Hurley's? Because my engine builder recommends them. Anyone who knows him will tell you listen to his every word. If the best builders (Rick Engman, B. Turrentine, Carlos Igleasis et al) are using a part... its a good sign.

Cheers,

Hakan Uras

 

I just seem to find it interesting that everyone blames the seals for thier blown motors, etc. Not that poor tuning would have anything to do with it, god forbid it is your own(or your tuners) mistakes.

 

I can say with certainty that my tuning is VERY mild. AFR's graph in the high 10's across the board under boost w/ both my new WB and the local Dyno's high end WB. Timing is a max of 13deg's at 15psi too. I also know that a big Rotary shop in Texas had 6 engines blow on their dyno that were built w/ the Hurley's. I heard this from them in person. I think it's an issue of just too much combustion pressure for the seal material/design. Mine and believe all the others, including Resource, are at 400rwhp or above.

 

It's not so much a tuning issue as a customer service issue... the gentleman who did my tuning is among the best known, and most knowledgable rotary tuners in America. Yet he hates Hurley's. Why?

A customer of his blew 5 (yes, five) motors due to Hurley seals. Evidently, the company had (or has?) serious issues with quality control. However, from a strictly engineering standpoint, 2-piece seals are better then 3-piece, and one piece seals are better then 2-piece. I *think* Hurley was the first company to come out with 2 piece apex seals and that's why a lot of people like(d" them. Also, I think Hurley seals don't do as much damage to the rotor and housings as Mazda OEM, or ceramic seals do.

 

Good tuning can solve just about anything.

A friend's employee used to daily drive a 2000HP big block Chevy.... the car had super high compression. It was just VERY well tuned....AND it was carb'd AND non-turbo!

 

its been a while.
has anybody got anything good to say about hurley..
I didnt think so.

 

The use of Hurley (and Atkins) seals have increased the $ value of the cars that remain on the road because those cars use other manufacturer's seals.

 

Well a good thing I have heard about Hurley is from the guys in Puerto Rico love them. Motor is still rebuildable after taken it apart compared to ceramic or Mazda seals

Gregory

 

And your point is?
I've gone through several rebuilds with STOCK MAZDA 2-piece 2mm seals, and I have had ZERO problems with them. What does that mean? I have no need for that Hurley stuff.


-Ted

 

>Well a good thing I have heard about Hurley is from the guys in Puerto Rico love them. Motor is still rebuildable after taken it apart compared to ceramic or Mazda seals<

Well...the idea is avoiding the rebuild !!!

Many Rotary shops were using/selling them as a optional heavy duty seal but are now staying away from them.
I personally believe there has been some changes in their seals since they were released years ago.
I've seem them break at the corner tip so many times for no apparent reason...A/Fs and timing were very safe.

Been using the Mazda stuff since then and sticking with them.

Any word the the Aviation seals ?????

JD