I have a freind that has a freind that has a factory mazda comp tester. So the next time im taking it on the dyno. I think he's gonna bring it along, so we can do a correct messurment of the compression.

The engine has about 3-400 miles on it now. So it's bearly run in. Im hoping to put atleast 200 more miles on it this weekend. But im abit afraid of driving the car on the street, since it's not fully street legal. And the DMW would yank my license plates right out of my hands, and give me a big fine for not paying taxes on the increased HP i have now Wich would be in the area of 50000 USD.

So im abit reserved about driving it on the streets. But hey need some fun tho.

JT

 

$50,000 fine! I'd be a little more than reserved.

 

For feed back on the bridgeport vac during idle - my large 1/2 bridge engine would pull 12-11in/hg idling at 1500RPM, so for a full bridge, I'd expect 10-8in/hg.....so its sounds *about* right.

One day I'll be reporting my experience with these seals..........

 

Sven,
All is well with the seals. We are running a much richer a/f ratio than before and still made as much (6hp less) 777rwhp. Not too shabby for an 11.0 a/f

 

^^
Gotta like that. Keep the updates coming. Would like to see a pic of the car here
Thanks Ernie
Sven

 

So i finaly opend my engine after having some problems with the car, with it breaking up alot under acceleration. After i did a compression check and the numbers where almost dead even. This is on a normal compression gauge so wont be 100% accurate. But the needle jumped up to 60psi on all 6 sides wich is not bad for a bridge port.

But i decided to take the engine out anyway. So i did, and the front rotor look quite good. There was quite abit of water residue from the E85 inside but not too much. And it looked quite good. There was a black ring going around the plates from the bridge, but it looks like soot of some kind. Might be oil residue i think.

And the apex seals had some sticky blak gue on them. When i got to the rear rotor i got a supprise. I had 3 broken side seals that where 2 of the seals where missing about 1 cm of the seal, and the 3rd one was missing about 2.5 cm of the seal. And they where all broken off it looke like, no damages to the rotor or the housing. Except for a small dent in the closing of the bridge port. Then when i got to the other side of the rotor, i had a stuck side seal and corner seal, and the rotor had hit the front plate and made som scratches in the front plate. Not sure if it's salvagable yet but will find out.

The apex seals also looks dirty and some sticly oily residue is left on them.

Now to the realy strange thing is, the car starts up fine, and idles realy good even tho with these problems on the front rotor.

I will post some pics on monday, cause i left my cable to my cell phone at work, so i can't get them out atm.

JT

 

Anyone have any suggestions to why my engines eat's side seals?

JT

 

Did you use new housings? Did you clearance the rotors? Did you ask who built the motor what they thought? High heat or very high boost can cause it too. If your rotors were hitting too hard, meaning your engine could be flexing too much. Could be alot of reasons.

 

Really high oil temps from a plugged oil cooler, etc, can cause side seals and springs damage too. As far as the rotor hitting- did you over rev the engine at all?

 

Yes the housings where brand new. And i checked the width of the housings against the rotors and they where good. I built the engine myself, only had the porting jobb done by someone else.

Im also using the Guru Racing/Extreme Rotaries stock stud kitt. So i don't think it has been flexing. I did over rev it though when i miss shifted from 3rd to 4th. It was up to about 10k or so. But i do have a rev limiter but i don't think it got it.

I have not had over 20 psi of boost. And the temps on the front rotor where this happend has always been bellow 800 degreece celcius. Im running E85 so temps are quite low. Oil temps are also quite low, im max seeing 93 degreece celcius after 8 laps at the track.

I also noticed that my rear main bearing is quite worn, even tho the bearing was brand new when i installed it 5 months ago. So im guessing there might be a balance problem here as well. Gonna have it balanced up when i get the new rotor.

Do u think i can use up the front plate again? There is a scratch in the front plate, but i can bearly feel it. Il post some pics tomorrow when i get ahold of my usb cable at work.

JT

 

Side seal problem sounds like over porting or not having enough chamfer on the closing edge/open edge transition of the port. "Except for a small dent in the closing of the bridge port." The small dent is in the actual bridge port or the main port? The rotor making contact with the side housing most likely was from the over rev.

~Mike..............

 

^^

Thanks Mike, that was pretty much my take on it too.

 

In May of 2007 NRS Ceramic Power Seals made their way into another UAV application, a single rotor air cooled 30cc engine. The client manufactures these engines and has tested several different apex seal materials as well as several rotor housing surfaces. After testing NRS Ceramic Power Seals the client is more than pleased with their performance.

They even ran the ceramic seals on cast steel housings with no chrome or treatment of any kind. Performance like this really opens up options when testing and choosing housing materials. Take what you know about materials, surface treatment, coatings and heat treating and re-define what is possible when you choose NRS ceramics for your design application.

I was told; your apex seals are absolutely amazing! They’re brilliant! What you supplied was fantastic!

 

Here is the link to the website, check out the resources tab for pdf files of the specs and video of the engine running.

http://www.cubewano.com

 

Congrats Sven.
Another + for NRS!

 

hmmm, if i had the cash i'd be placing an order today.
been folowing this thread from the begining and am loving the results.... maybe one day i'll join the NRS users club

 

So i finaly had time to get the pictures out of my camera to show how everything looked like internaly after i tore the engine apart.

Let's start with a few pictures of the NRS 3mm seals. As u can see they are quite dirty, and i belive it might have something to do with the castor based 2 stroke oil im using. I was recomended to use it with E85 but i might need to change to something else cause the seals and everything is quite sticky.




And now a pic of the intermediate plate where the side seals broke. U can see the small dent in the upper right corner of the small bridge port.

This is how the sideseals looked like. The closest one is a refrence side seal that is the correct leangth so u can see how much was torn off.


The next 2 pictures is of the rear rotor housing.



Next 2 is of the front rotor housing.



Now this is a picture of the front plate where the rotor has touched the plate. Is the plate salvagable?


This is the lover part of the intermediate housing where the side seals had broken.


This engine has gotten alot of abuse, but the rotor housings and NRS seals are in realy good condition and have taken alot of abuse. It did push 530rwhp with broken sideals.

Jan-Tore

 

Had to post the last picture here since we are limited to 10 pictures in each post


And the last picture is of the rear main bearing. This was brand new when engine was put together, so im guessing there is an unbalance in the engine as well.

 

Who did that port job? im not an expert but isnt' that bridge to thin to support the corner and the tip of the side seal?

 

Those ports look to be the problem of your broken side seals. Those look rough, brother. You'll want to clean those up (Make them more symmetrical and bring those edges down some).

I don't see any copper on that bearing, right?

Curious about the oil, need to figure out what to run with my E85.

 

Those ports are HORRIBLE both in its shape and lack of a finish. Your side seals broke due to impropper bridge porting. Hack job, the person porting has no clue on what he is doing. The bridge cuts go too far in towards the main port and theres not enough support for your side seals and corner seals. Find someone else to port for you, those housings are junk now in my opinion. What oil/fuel ratio were you running?

~Mike................

 

i use Motul Micro and a 2% blend, will open my block later this year and check if it works will also put in my new NRS apex seals!

 

The engine is supposed to be ported by a verry good engine tuner in england. He's been building bridge ported engines for over 20 years.

Yeah i do think also that the bridge is too small, after what has happend. On the rear rotor the bridge is about 0.6mm thicker and there is no problem with the side seals on that side.

The AFR's i was running was between 11.3-12.0 at 20 psi with E85

The secondary ports looks much cleaner then the pri ports. I have a verry good intermediate plate i might be using wich is just street ported. But i will see what im going to do. Will need to port up the exhaust ports as well.

I was running a 1% premix of castor oil.
http://en.wikipedia.org/wiki/Castor_oil

Just more problems it looks like, oh well i hope i can get the car back together again soon. Looks like il be going to Joergen Blennow in the south of sweden to get the engine balanced with new rotors. And a new intermediate housing.

What do u guys think about the scratches in the front plate after where the rotor hit it?

JT

 

I'd measure them, but a good rule of thumb is if you can catch a nail on it, don't use it. Personally, I'd be looking at another set of iron's anyways given the porting issues. I've only ever had a half bridge engine so my experience is limited, but I can bet you if you mock a rotor up and run it over that front plate, you'll be amazed at how close the corner seal is to falling into the port's opening...

Best of luck with the rebuild, but the most impressive part of that tear down is the housing/apex seals. Some odd chattering going on at the plugs on the rear rotor, but the front looks absolutely gorgeous!

 

yeah im not sure what's up with the black marks around the rear leading plug. It might have something to do with the rear leading coil is starting to fail. And it was running abit high egt temps on the rear rotor.

JT