Hello All!

Well for a while now my engine has been running fairly poorly. At idle I get 10 inches of vacuum sometimes 9 and it has hot starting issues, but it does still pull strong. I have tried to check just about everything but left the most important to the last, oh well.

It is street ported with 3mm apex seals, I compression tested it tonight and on the front rotor I get 75-75-75 and on the back rotor I get 55-55-55, I think that is very low for the rear rotor. I guess I am just wanting to know if you agree that it is dying. Any comments?

Thanks
rx7boy22

P.S. If I have made any mistakes in this post please bare with me I am new to posting on the forum

 

That sounds on the weak side. How long have you run the motor?

Dale

 

Well you see I had a AEM wideband to go with my datalogit to now find out it is so wacky, I bought it when it first came out and found that I was having a hell of time tuning with it and have had detonation. The engine still survived many time though and then I thought it was tuned pretty good and all of a sudden one day it pinged and was never the same again, the motor has only about 10,000 km on it, not much. I now have an innovative lm-1 which is running perfectly.

 

Your apex seals may be shot. You aren't experiencing coolant problems or saturated oil are you?

Jeremy

 

Sounds to low to be lucky. Try putting some oil in the housings and see if it will bring the compression up a bit, maybe your OMP went and you'll get really lucky that nothing warped and there was just low compression...

 

Ok I will add some oil to the chambers tonight and see if I can get the compression to show higher #'s. If I do get higher #'s should I check the Metering Oil Pump? If so what is the best way to check it?

Thanks
rx7boy

 

Also I am not experiencing a coolant problem but the oil does seem like it does have quite a gas smell

 

b

 

......

 

Well tonight I added some oil thru the spark plug holes and the front rotor got 95-95-95 and the back rotor got 60-60-60, it maybe hit 65-65-65.

I think I need some new seals. What do you guys mostly agree is the best seal out there today? Are the seals from rotary aviation really the best on the market (at least they say they are) or do you think that I should check into some ceramic seals?

Thanks
rx7boy
John

 

If you want genuine seals you can buy mine!!!

https://www.rx7club.com/showthread.php?t=393701

 

Didn' he post that he had 3 mm seals? You can't go back to 2 mm, can you?

Not trying to be an ***, just curious.....

 

You're right. Oops.

 

So anybody still have any suggestions on which seals are better?

 

Becuase there is no definitive answer. Some people say RA seals are better, some people say OEM seals are better. Simple truth is that it really doesn't matter; any seal will break/crack if something bad happens.

 

I'm not sure that it is just a matter of worn seals, it could be a warn housing. If it is a cracked or broken apex seal then you would normally get 2 high and two low readings. You won't know definately until you break it down, but I'm just letting you know it could be more than just the apex seals

 

Yep, when rebuilding, it's more than just replacing the seals. EVERYTHING has to be checked and measured. Anything not within spec, needs to be replaced (rotors, housing, etc).

Sometimes, rebuilds can be very costly if a lot of parts are out of spec. In these cases, remans are the best alternative.

 

If the rear rotor has a uniform 60-60-60 compression, wouldn't that mean at least 2 of the apex seals were uniformly worn or damaged, if it was the apex seals causing the problem? It seems strange that 2 or possibly 3 apex seals were all slightly damaged in the same way. Maybe there is a problem with the housing, or perhaps its due to a completely different seal than the apex seals.