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-   -   Help!!! Blew My Seals Again!!! (https://www.rx7club.com/race-car-tech-103/help-blew-my-seals-again-196508/)

seven 06-15-03 05:16 AM

Help!!! Blew My Seals Again!!!
 
Hi Guys,

I seriously need some help. Blew my apex seals again. They are the 2mm ceramic equivalent types. I had the engine runned-in for 2K+miles already, B4 boosting. Have extra 4 injectors and large fuel pump to substantiate the boost, and a microtech MT-8 to control every other thing, and using a TO4E turbo. The car was properly tunned. And I had it down for the drags with 16psi of boost, everything was fine, till I hit the highway and hit 17psi, and the seals gave way!!! Why? Isn't this level of boost rather low for my setup? This is the second time that I have blown my seals. Do you guys recommend going to 3mm ones? Or do you have any brands to recommend?

Thanks!

tims 06-16-03 10:17 AM

its not tuned correctly. detonation is what broke the first and second set of apex seal. if they were ceramic seals then the tuning is way off. I broke the rear end plate on my first engine with poor tuning and bad detonation and the apex seals were still fine. sounds like more time tuning, before racing it. assuming the engine builder is putting the engine together correctly and making sure all clearances are correct.

seven 06-16-03 07:16 PM

Hi Tim,

Thanks for the info. Have just gone down to the workshop, and seen the seals. These seals are the 2piece with a better compound material, which they have bought from a supplier in UK. I guess they are not the ceramic type afther all. Could the detonation be caused by the spak plugs? Cause I found out they were using normal plugs instead, unlike the ones that the rotary engine uses. Pls advise

Best Regards,
Shawn

tims 06-16-03 10:02 PM

the wrong heat range plug could be a problem, but the real problem is continued detonation. the Hurley apex seals are as good as stock and should tolerate 17psi in a properly tuned engine. as long as the workshop is assembling the engine correctly and have made all clearances for severe duty the problem must be in the tuning. work on making the engine run correctly before racing again. good luck and start slow.

seven 06-16-03 11:03 PM

Hi Tim,

I am facing a rather weird experince, Before this setup, I was running a stock 13bt with a hybrid knightsports turbo and Microtech, with 12A gearbox, and the mid range and high speed cruising was better. Now with this new setup, the take off is faster, but mid range and top end isn't that fantastic. And furthermore, the seals always breakdown during high speed cruising instead of drag sprint. Is this due to the tunning setup not done properly for high speed?

Thanks,
Shawn

tims 06-17-03 08:32 AM

yes, it keeps breaking because the engine is not tuned correctly. it may last for 15 sec blasts down the strip but eventually it blows. work on the tuning.

maxpesce 06-17-03 10:53 AM

Check the TIMING - and especially the Lead/Trail split - The more BOOST you run the more you need to RETARD the Lead timing & (iirc) reduce the Split.

seven 06-17-03 07:20 PM

Hi Guys,

Appreciate your help. By the way, what can I install to monitor, whether my engine is about to detonate? A exhaust temp gauge? air fuel ratio gauge? Cause I dun want to go through the hassel of having the seals break due to improper tunning, as I do not know how to tune, and can only rely on my tunner. Besides increasing fuel and retarding the timming, what else do you recommend me to do to prevent detonation. I have long praised the rotary engine, but my buddies( piston maddies ) are starting to laugh at me on trusting the rotary's reliability. Pls help.

Thanks,
Shawn

tims 06-18-03 08:24 AM

all those are good and maybe a knock sensor if you can't get the tuning right. also check the intake air temps while tuning and make sure the intercooler is sized right. good luck and work on the tuning before rushing to the track.

seven 06-19-03 03:49 AM

Hi Tim,

Just got off the phone with my mechanic. He said that two of the apex seals had it's corners worn off. My mechanic also said that he will provide me with 2 settings in my microtech ecu, one for race which will be running on racing fuel, and the other setting for road use which runs on 98octane. Could the seals have worn because the timming was not retarded the last time and I was only running on 98octane? And what kind of boost should I be using for road use? Do I have to get the seals break-in again? Cause the drag race will be nearing pretty soon, and there will be in-sufficient time for breaking-in. Pls advise.

tims 06-19-03 08:39 AM

the break in time for engines is important, but it shouldn't take weeks or months to perform. engine needs to be run at low load for a couple hours. I would assume that most of the parts in the engine except the apex seals will be used, so break in will not be as critical. or do the break in while tuning on a chassis dyno. boost settings can be whatever you like up to the point where the turbo doesn't flow anymore. check with turbo manufacturer. melted apex seals sounds like intake air charge is to hot or mixture is way to lean or both. work on the tuning before racing it or you may be rebuilding it again. I ran my car for almost three years and when it was torn down the only problem it had was the apex seals were worn down(not melted just normal wear). this included (3) 3 hour enduros and more than 20 race weekends. with proper tuning the engine should last.

seven 06-19-03 07:14 PM

Hi Tim,

Thanks for all the info's you have provided me all these while. I will perform all the necessary steps as per your repllies. Hope to prove to my buddies that the rotary is still reliable.

Cheers!
Shawn

luiml73 06-20-03 01:38 AM

Hi,
Have you considered upgrading your Microtech to a LT8. I think you can send it to AU. and it only cost $100. From what I read The LT8 can tune your car more precise.

Contact these forum members

No7yet and 10 secrx7

And you should post on the microtech forum to get more help.

Good luck

Luis


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