Could you post pictures of the seals and housings/ports if you have them? I'd especially like to see detailed pictures of the exhaust ports if you could. Thanks.

thewird

 

"uneven wear on the leading edge"

does the uneven wear extend across the entire length of the apex seal or is it only where the exhaust port is? is the wear a flatted surface? 3 thou is fine for clearance. were the corner seal springs flattened? how about the apex seal springs? is there alot of carbon on the rotors and rotor housings? what heat range plugs were you running?

hc

 

The uneven wear extends past the exhaust port is. Yes, a flatted surface. The corner seals springs were fine as for the apex seals springs, they look good but have not taken any measurements. They dont' look flattish as if the engine ran lean for a long time. Not a lot of carbon at all, only places there is signs of carbon is after the exhaust part and around the spark plug area. She was running all 9's. I didn't tune the car, so I don't know what timing was used or AFR tune to.

 

havent had the chance to get on, but thanks javier for answering those questions

Howard: btw- I wasnt saying an apex seal would solve my problem, i was curious what others were using and what they thought of them.
t-von: & I did send off my injectors to get cleaned& tested at witchhunters

Thanks for giving feedback guys, anything helps solve what could be the problem.

 

I don't quite understand this whole scenario.

Engine got a 500R, got tuned, and then was pulled for low compression. Was this uneven wear present then? Or was it rebuilt due to wear, put back together, and now you have this problem?

If it is the former, how long was the engine together with the 3mm seals?

Also, were any compression checks done before the tune? It sounds to me like it could be a simple "whoopsie" during tuning but you'll certainly want to rule out all possibilities so it doesn't happen again.

 

i think your motor had two problems:

since the apex & corner seal springs aren't collapsed the motor didn't run very long at a lean AFR.

given your apex seals are flatted across the entire length and have proper groove clearance you have a lube problem.

if it wasn't heat (lean AFR) it was lack of lubrication that flattened the apex seal shoulders. you say you were premixing 1 oz per gallon. that should have been fine from a lube aspect. are you SURE you had the premix in the motor all the times you were under boost?

did you buy the car w the motor in it? if so, are you sure the seller premixed? it seems to me that somewhere during the motor's life it suffered from a lack of lube which did in the seals.

the second problem is the chipped apex seal... that'd be knock. it could have easily be caused by running 9 spark plugs. your GT500 puts out 60 pounds of air (450 rwhp) at one bar and 70 pounds at 1.5 bar (525 rwhp).

that's alot of air which caused very high CCP (combustion chamber pressure). you need to run 10s or more w a GT500. if you look at ANY rotary you will see deformation around the spark plug boss... this is caused from too much heat. you need to run as cold a plug as you can fire w your ignition to decrease this deformation.

if a plug gets too hot it can also set off the mixture (gasoline autoignites at a mere 450 F degrees). instant broken apex seal.

w a GT500 you absolutely must run AI (300 CC/min water will do the trick).

no more chipped apex seals.

howard

 

Howard, we're definitely on the same page wrt lack of lubrication, I asked the question back on the first page

I've been running a 500R setup since early 2007 with Aquamist water injection and 10 series NGK race plugs all around. Coincidence ?

 

As stated, apex seals wont solve your problem. However, once you do figure out the issue and resolve it, go back with the ALS 2mm 2 piece seals or the RA 2mm 2piece seals. Nothing but great results, they wont damage your engine internals or turbo like the other seals mentioned. Everyone has their own opinion which is obvious by this thread, but if you dont do the rebuilds yourself and have to pay for the labor then go with the seals I mentioned, it will save you money in the long run.

 

I've had great results using both steal and ceramic seals. Corner seals...thats a different story. Your best bet on corner seals is stock. (no matter what). Once peice corner seals will stick at higher hp levels. Apex seals....Right now Im using NRS ceramic 3mm seals. I have re-used them in 3 motors when doing a refresh. (never done this prior with any other seal). The big draw back with ceramic is if your motor goes( ie...clogged fuel filter)...or any other crazy reason, your ceramic apex seal breaks; it WILL take out EVERYTHING in your motor including your turbo. So not only can it cost you alot to buy the apex seals, but it can cost double if you have to replace everything else.
I have make upwards of 800rwhp on atkins 2mm cryo'ed apex seals. The motor lasted over a year too before loosing compression.
When I build my next semi-pp motor I will use 2mm PTS seals. Nothing seals better then a 2mm seal, thus making more power. And if your motor does fail, the PTS seal will not likely break into pieces, thus saving vital engine parts.
My .02..just make sure you use OE corner seals.

 

Why are you going with PTS vs ALS? I know money is not an issue, I was just wondering why one over the other?

 

Ernie, are you using one piece or two piece? I'm running NRS 1 piece 3mm seals and have detonated my motor with audible detonation on more then one occasion due to a fueling issue and its still going strong. When it detonated, it was with 14 AFR @ 16 pounds of boost.

thewird

 

Not sure how you survived, but you better find some wood to knock on, lol. This is nothing more brittle then ceramic. That said, it is slippery and very light.
I have the one piece 3mm ceramic's. Personally I am not a fan of ALS seals because they warp too easy. But that also is an advantage because they won't break. Nothing wrong with them though. The "super seals" used to be the "in" seal to use. Now it looks like the ALS seal is.

 

I've found the super seals also warp easily.

 

I found the same. Probably the easiest to warp out of any seal.

 

I guess all things considered it's better to have warped seals than bad internals however if the motor wouldn't have blown in the first place with other seals than the point is rather moot. Of course if the seals bent in the first place perhaps something was wrong with the tune in the first place. Maybe these seals just need to have a 100% tune?

 

To the seals defense, I did use them prior to using water/meth inj which has helped 10 fold.

 

hehe, same here! It's the magic juice

 

Ionno, I've had so much luck I guess you could say with my one piece 3mm seal. It happened twice while I was at the DGRR. The first time it happened, I had my foot in it for at least 2 seconds before I looked at the wideband after hearing a strange noise coming from the engine. When I looked down and saw 14 AFR, I instantly assumed I blew the engine and would have to have it trained home. But after letting off it sounded fine. Later in the day after going up and down the gap, it happened again but this time I was watching it so it was a second at most. Once I was back home it happened once at a track as well and then I eventually fixed it.

This was all in the spring of 2009 and my car saw over 10 track days after that and added a lot of mileage including going to Florida. Now the engine has over 30k km on it and absolutely nothing wrong with it but I'm going to open the motor up because I'm curious what it looks like inside after all that abuse in a little over a year.

I agree with hondahater, if the seal warps you need to open up the motor anyway and replace the seals which is basically a rebuild. And there are other things you been to replace as well when you open up the motor. I personally would rather just have the seals take the punishment and not need a rebuild. Maybe its because I'm a road coarse guy and expect a longer life out of my engine ^_^

thewird

 

i ran NRS one piece 2 MM seals/NRS springs last year at the 507 SAE level (20 psi) with no problems.

i recently disassembled my motor expecting to see good things and was actually surprised how nice the housings looked. the housings looked like they had not been run. zero chatter marks. actually zero carbon with the exception of a touch around the lead plug boss.

seal groove clearance exactly the same to the thou.

i run Atkins solid corners and am interested in ernie's comments.

i have switched turbosystems and will be shortly firing up a GT4094r. i expect to make 600 max SAE rwhp. my primary objective is to run over 200 at the Texas Mile in October. i will need 600 to do it and should go thru the lights close to 8000 rpm in 5th. i will be running a Tremec T56.

howard

 

I think focusing on the seal as the root cause is an incomplete analysis of the problem. We must go to the next level... why are they failing?

Our main clues are:
1)- Wear on the center leading face of the apex seal.
2)- Carbon spots next to the spark plug area of the housing.

We can mitigate the problem with stronger seals or softer, more flexible seals. We can buy a little more time with better lubrication. But the root-cause of broken apex seals is the hump at the spark plug.

The solution is a combination of a better water pump, more flow at the plug bosses (porting the passages per factory peripheral racing housing specs), and colder spark plugs (suggested by others).

If we can get this hump at the spark plugs level our engines will last a very long time.

My thoughts,
Barry

 

Howard,
Sounds awesome goin for the 200mph mark. I considered it, but after talking to Ari for awhile, we were thinkin the FD would gear out with the current final drive ratio's available. Your thoughts?
Good luck!
E.

 

Barry,
Your points are dead on, but a FD (or any other car) with double the power from factory isn't going to last forever. Its just wasn't designed for 500hp levels. Yes you can prepare it...ie..water injection, billet e-shaft, billet rotors, but still crazy things happen when your making high hp.
E.

 

"FD would gear out with the current final drive ratio's available"

i will run a 3.90 gear, proper tire diameter and a particular T56 5th ratio. 200 should be 7600 but i am hoping for more. there is even the possibliity of 6th which will be .64 (Ford 6th).

"just wasn't designed for 500hp levels."

there just is a limit due to the huge CCP being generated and housings are going to give a touch. that's why i have no interest in anything on the sunny side of 600 as the game changes hugely at that point. i can understand wanting more, it's just not for me.

"root-cause of broken apex seals is the hump at the spark plug"

root cause is the immense breathing ability of the rotary and the turbo being able to deliver so much air into the motor. huge CCP, huge temps and with it the focal point is the lead plug boss as Barry points out. many broken apex seals are chipped at the angled end however, which indicates knock to me. this knock could be autoignition due to the inability of the plug to lose the heat. certainly cooling system mods can help.

hc

 

Ernie, very true.

We are a very small group compared to the piston engine development groups, but they keep improving their product even though it is at a very evolved state.

We must do the same to an even greater degree. WE must identify, prioritize, and address our biggest problems and come up with solutions.

We have a group of very talented individuals but we can't seem to stop our infighting (Babel Effect) and work together.

Is it possible that we could start a section of the Forum for those who would like to work together to solve problems by experimentation?

Anyway off the soapbox,
Barry

 

Always ran atkins 2mm going to try ALS next