Double_J

iTrader: (28)

Those nozzles look great.

Just thinking out loud but if the water spray was more gradual do you think it would have had less impact on the lower end response?

peejay

I stopped noting this kind of wear when I started paying close attention to apex seal groove clearance. Made me a little sad, since I realized that all of my rotors were junk. 4 thou is still too much, even if the slot isn't actually V'd out.

Assuming a good air filter, I'd make sure that there is no way for unfiltered air to get in. This is where a smoke machine is awesome to have.

RotaryEvolution

iTrader: (30)

talk about a pissing match about stupid ****...

the higher the horsepower= more wear, higher RPM=more wear.

too much spring tension= more wear, hard seal material=more wear

you see where i'm going? even OEM seals eat housings with chatter or claw marks if you run them too high, too hot and too long.

ceramic seals are about the only material that isn't susceptible to this type of fatigue. BUT they are only a hair above OEM seals as far as how fragile they are versus detonation, won't even get into cost comparison as most already know the difference in pricing of the seals. not a great seal for drag racing but have pulled apart and rebuilt endurance engines with ceramics and i could hardly tell how old the engines were, regardless of the many many hours they had been driven and hard. ceramics are also hell on not just the rotor and housing but EVERYTHING in the associated failed chamber, if you lose a seal then you basically throw away that half of the engine.

as mentioned, 2500 miles when mainly doing drag racing is hell on an engine. if you want to reduce "clawing of the engine" then you need to tear it apart more often and deglaze the surfaces to prevent galling from getting exponentially worse.

peejay

To be fair, I've never seen an iron seal not destroy everything on the failed half of the engine, either. Including some side housings when chunks would get caught in the intake port. Nasty.

RotaryEvolution

iTrader: (30)

odd, i rarely see iron and steel seals destroy anything other than a rotor/housing.

some rare occasions a piece of metal gets dragged across the oil seal track, even gouges outside the track mean nothing unless they are quite deep.

point is i see themes with all these threads where seal "x" destroyed my motor! quite strange considering we have seen a topic about this on every seal on the market! strange no? not really because there is factors as to why they fail, generally it is too much or too little internal combustion lubrication. we've seen it on atkins seals, then it moved to RA seals, then it moved to hurley seals, then it moved to ALS seals, then to... you see where i'm going. the only engine i saw clawed to death was on OEM seals strangely enough and others have seen it also.

so lets put the bullshit about seals being the main culprit to bed, it's actually the setup, break in and usage. how many people premix fuel for that first 500-750 miles on their fresh engine? because you know that the seals are getting no OMP lubrication during that period and then the engine has to undertake abuse of 6k RPM launches, 9k RPM peaks and sustained full power runs.

but anyways, to the topic. my preference for a bulletproof n/a PP engine would utilize ceramics, a drag racing engine would use softer more malleable seals and the best long distance seal is of course OEMs which have proven to last well over 200k miles even on the old style 3 piece seals, newer 2 piece seals should go well beyond 300k. mid range high power daily driven engines need something in the middle, probably why RA seals have been so successful when everything is ideal.

stock= Atkins/OEM
drag racing= Goopy racing
endurance n/a= Ianetti ceramics
DD high power= RA super seals


seals do have preferred purposes and that is my preferred purpose for seals. if i were to list ALS i would put them with drag racing seals, softer malleable alloys do not last as long as more brittle alloys/iron. brittle alloys fracture prior to bending, softer alloys wear rapidly but bend before breaking so the tradeoff is mileage for damage when the seals fail. ALS seals are too expensive for what you get, period and is why i didn't list them, like anything if they want to be competetive then they have to use competetive pricing.

the rotor housing surface is much like a rotor bearing, if debris gets in there and it begins to gall it will progressively get worse and worse. if it starves of lubrication it will begin to grab the surface metal and attempt to mate them together. if the revs are too high and seal mass too large then the seal bounces as it passes over the trochoid face. put 2 and 2 together.

if a shop is using 1 seal for every purpose then they are doing it wrong. some seals fare better with varying conditions but that is still far from ideal, most of the manufacturers designed their seals for a specific purpose but of course they leave it to guesswork because they sell more product if they leave it up to you to figure it out.

Howard Coleman

iTrader: (6)

" i rarely see iron and steel seals destroy anything other than a rotor/housing."

"even gouges outside the track mean nothing unless they are quite deep."

"generally it is too much or too little internal combustion lubrication"

" it's actually the setup, break in and usage."

worthy of a repeat

internal lubrication of the apex seals is not to be taken lightly IMO. i have long been a fan of premix. long being 1983 when i took delivery of Roger Mandeville's IMSA RX3 sp converted to SCCA GT3 specs. 1 oz per gallon was the Mandeville program. one motor failure (10,300 rpm Road Atlanta in top gear) in 72 races and four Runoffs.

having taken apart lots of brews, i am continually amazed how much carbon is onboard. a combo of zero crankcase oil and AI totally solves the carbon all over problem but may not solve the lubrication requirements.

6 months ago i spent a bunch of time looking at 2 cycle oils and i concluded that it might be quite important to use the correct 2 cycle oil for the application.

2 cycle oils do vary significantly as to properties.... even as they may share the same gov'mint classification.

i wanted an oil w alot of backbone. of course backbone costs money, surprise surprise.

i now use nothing but Redline 2 cycle oil and expect to see good things from my internals going forward.

caveat: i am not a chemist or oil engineer. i do believe there are significant differences in 2 cycle oils and i do believe the differences are important. i also prefer to err on too much rather than too little lube. even w 1.5 oz/gallon my plugs look light chocolate..

howard

silverfdturbo6port

iTrader: (26)

I always use the powersport frame of thinking when it comes to 2 stroke oils. Many people dont know but there are 2 stroke oils that dont lubricate as well as some engines need. For small engines ie chainsaws weedeaters ect... they can use a low grade 2 stroke oil.
But talk to any powersport racer and they will tell you that low grade 2 stroke oils will cause premature engine failure. THe same goes into affect with rotarys. Dont use a walmart/autozone shelf oil. Look into oils at a powersport shop or like idemitsu.
I premix in all my engines ans always will. No sense in injecting a motor oil not designed to burn clean like mazda had them setup. Clean burning oil= better lubrication=less wear=less carbon=less heat=long engine life.
Hope this is helpful to anyone.

tom94RX-7

iTrader: (5)

My air filter was dirty on the front side cause its in the opening at the bottom of the bumper, and it was not oiled.

I have always used the pennzoil outboard semi synthetic 2 stroke oil sold at advance auto parts, 1oz per gallon, so perhaps it just wasn't good enough for my use and all the extra water that was going through my engine.

Thanks guys

RotaryEvolution

iTrader: (30)

cheaper 2 stroke oils work ok for lower power/lower RPM engines. i use off the shelf cheap brands for long trips but when i crank up the RPMs i prefer full synthetic lubricants like AMSoil and Redline synthetics.

in my experience pennzoil is about as low as you can get with engine/2stroke oils. about the only thing with a pennzoil label i will use is "syncromesh" because it is lighter than most other transmission lubricants and allows for quicker shifting.

Dudemaaanownsanrx7

iTrader: (23)

Great thread on the comparison of pre and post turbo WI. At what psi are you spraying the water? Maybe injecting the water later would help offset the slower spool. I found I used much less water when I increased the injecting point from 3 psi to 8 psi. Really the water doesn't need to be injected until 10 - 12 psi or even as high as 15 psi, at this point the turbo is already well on it's way and the water shouldn't slow it down much if at all. I didn't pay attention to my spool when going from 3 to 8 psi, my turbo is already pretty slow anyway.

Going to respectfully disagree, myself and others have run water only and high boost. I've personally run as high as 26 psi, I would run that daily except I need a better clutch. I also have a few guys running my same kit and 25+ psi. There's the other guy from Australia running over 35 psi. Then you have loud mouth rice racing who despite his in your face marketing has numerous logs of different cars running 25+ psi on water only. Water per volume removes much more heat than methanol. If maximum power per psi is your goal then 50/50 would probably make more power due to the lower IAT's, if you crank the boost up and let the turbo make the power then I would say water will be much better at suppressing the knock.

Agreed, there's a writup on here on sticking a vacuum hose in a container of water and holding the rpms up so the car doesnt die during the process. Something caused those grooves but I really see no reason to suspect anything to do with the water being sucked in. My first thoughts when I saw the pictures was either metal shavings or dirt that somehow got in the engine. I don't suppose there was any damaged bearings or something? I kind of skimmed through the latter half of the discussion, too many long winded posts to read through. Hope you can figure out what caused it with definitive proof so it can be remedied in the next build, but probably all you can do is build the next engine the best you can, tune smart and hope for the best. You were pretty lucky with that engine for a long time. I recall 20+ PSI on stock twins with the water sometimes not activated? I'm not surprised there were some signs of detonation inside the engine. Building high horsepower engines becomes a bit of trial and error after a certain point, and sometimes they blow because of a stupid mistake regardless of how careful you are.

tom94RX-7

iTrader: (5)

My progressive controller starts spraying at about 5 psi, and It's not full pressure until about 15-18, I forget what it is set at exactly. I set mine to spray early around 5 psi because the kit's instructions recommend it and because when drag racing shifting gears the boost hits full boost quickly so you want to make sure its spraying quickly and up to pressure at full boost.

I know my engine lost a little power directly after the water injector check valve problem.

I was running about 20 psi on the stock turbos without any water injection for a few years. Was it smart, I guess not haha, but I got good results and wasn't blowing the engine.

Dudemaaanownsanrx7

iTrader: (23)

Well I generally am not one for coincidences but it's still a possibility. On the other hand most people that steam clean the engine don't do so under full boost on a dyno. I still can't see how the water could cause massive grooving, I would understand if the apex seals or springs were flattened causing a loss in compression due to extreme pressures. The grooves just don't seem like they could be attributed to any sort of liquid. *shrug*

Your engine did survive the 20 psi on stock turbos. Whether it is smart or not is objective. It made for interesting threads and showed whats possible. Your engine still made great power afterwards and didn't pop any seals so I see no issue in that, I'm sure you were prepared for a popped engine so that was the risk you were willing to take. I imagine there was at least some detonation going on at one time or another during those waterless trips down the 1/4 mile. Not enough to break a seal but enough to show some pitting in the rotor. (who needs a perfectly flat rotor surface anyway) lol

Anyway, do what you think you need to do and continue testing the limits in whatever way you feel comfortable with. If everyone quit after something went wrong then we would still be crawling on hands and knees.

silverfdturbo6port

iTrader: (26)

Here is a theory for others to think about possibly.
You state your check valve had a problem. You have the check valve in line to stop from back purging the lines. So say your lines were back purged adn you hit a the knock thresh-hold that the water is helping you with but if it hits that thresh-hold before the water can reach the engine then you might get a result like this.

This might be a idea way out of this planet but its a idea i had.

RotaryEvolution

iTrader: (30)

a more imaginable result is pushing those teeny tiny turbos well beyond their happy zone, cramming more air through a tiny straw creates heat, heat that the engine had to absorb. without the water i imagine the seals just couldn't take the ICTs that it was trying to swallow.

the IAT sensor also gives a false sense of security, it accumulates liquid water/methanol and falsifies the IAT readings with auxiliary injection. it may tell you your AI is working but i wouldn't bet your piggy bank on the reading to be the actual temp of the air entering the engine.

tom94RX-7

iTrader: (5)

The check valve problem was only for a few days. The car was making 528-532 hp, then I had the check valve problem, the oring wasn't seated and water was getting sucked past the oring seal into the engine under vacuum, also filling up a puddle in the ic (post ic WI was hooked up) and then that water was getting forced into the engine, this also happened during the first dyno pull after the problem started.

The only other thing I did at the same time as this was i removed the primary injector diffusers. I didn't bother to mention this because I highly doubt removing those diffusers would cause my engine to lose about 30 HP. The water injector check valve just so happened to have this problem at the same time. So I really don't think the diffusers being removed caused any problem, they did not break when I pulled them out.

tom94RX-7

iTrader: (5)

Not sure what you are referring to in your first paragraph. I switched to the single turbo and started using the water injection all the time about one year ago.

I also found that spraying pre turbo made my ait's read higher compared to spraying post ic and that is spraying after the ait sensor so no water before the ait sensor.

silverfdturbo6port

iTrader: (26)

The diffusers are designed to help with atomization so thats probably is your 30hp robbing culprit.

Dudemaaanownsanrx7

iTrader: (23)

Oh somehow I was imaging that the engine was consuming a massive amount while under boost. But yeah if it was a nipple on the UIM or really anywhere after the throttle body then under boost it would have boost rather then vacuum. There is absolutely no way the water had anything to do with the engine breaking. Even if you filled the intercooler up entirely with water the air would never move enough water out of the intercooler to cause any chance of damage to the engine, and certainly not put grooves in the chamber face. As for any water consumed during vacuum, at most it would steam clean the engine, blow out white smoke and maybe cause the engine to die out. Again you would not have the damage shown in the pictures. I am certain the water was not the cause of your failure.

Maybe you broke a leg off of the diffusers when removing them, or maybe removing them changed the airflow enough to offset the tune, or maybe an injector was not plugged back in properly. Any one of those or a hundred other reasons are way more plausible then water from the intercooler doing any damage. For sure look elsewhere for your problem.

Barry Bordes

Brent, the reason you, Rice, and others can use higher boost than these tests indicate is that you use
a retarded spark to lower your peak pressures and IMEP. If you optimized the timing of your ignition
event the tests would appear more accurate.

Notice that these conservative limits closely correspond to the commonly held opinions (and experience)
for the limits of: rich fuel (15psi), water (20psi), and water/meth (30psi).

Notice too on your colored chart how much of an increase the green highlighted Meth/water has over water.

Barry

Barry Bordes

This is an example of how the peak pressure changes as you optimize your ignition event.

This is an early test with retarded ignition. Right now I am over 1300 psi peak pressure and 350 IMEP.

So if I lose the meth/water on a run....... well you know the rest of the story.

Barry

tom94RX-7

iTrader: (5)

My maps, datalogs and dyno files are in a zip folder here https://www.rx7club.com/attachment.p...5&d=1328856064

It is the attachment in the first post.

Zero R

iTrader: (1)

Quote of the day.

You wont get me to run ALS or RA or anything other than a OEM 2pc seal on just about anything short of a drag car. All the softer seals wear housings over time. Some severely. I had housings here that over one summer and 5k miles were destroyed. We've ran the OEM seals to 700whp without issue. I've ran ALS seal and SCR seals to 900whp without issue on drag engines 13B BP alcohol 40psi car runs 7's. They are great for that. Putting "bendable" or "unbreakable" seals in your customers car that makes 400+whp on pump gas is not a smart move. He some life out of the engine. OEM 2pc seals are more than capable, it's proper fuel and proper tune that's needed that's it. A friend of mine overseas wont tune any car that uses water/meth for fuel. "His argument is you have all the money to build this car but not enough money to run the proper fuel?" I tend to agree for the most part. I wont use alcohol for anything other than anti-freeze. Water only, keep it simple with one fuel source.

I'm not so sure they leave the guess work up to you to figure out for more sales as much as they don't have the time money and resources to figure it out themselves.


Tom, I like the post on Pre and post WI. I think you're right about one works well for the street and one work better for the track. I can assure you it isn't water causing your issue. Barry is pretty dead on about 25% and not running much over 20psi on water only.

~S~

tom94RX-7

iTrader: (5)

What does everyone else think about this? agree or disagree? I don't see how that is possible. thanks.

NeoTuri

iTrader: (2)

If the diffusers are responsible for atomization to the degree that is implied, then yes, I could see how "globs" of fuel would burn slower or not enough, thus giving up some power.

tom94RX-7

iTrader: (5)

There was puddles of water in the ic when I was boosting and during one dyno session, this excessive amounts of water was getting forced into the engine, after this I found the WI check valve oring problem and fixed it. At the same time as this is when I removed the primary injector diffusers. The grooves in the rotor housings we were debating what caused them, I thought it could have been from all the extra water going through my engine for a couple days, washing away the cheaper 2 stroke oil, after this I did a compression check and it was a little low, and power was done alittle on the dyno.

Months later, the corner seals broke during drag racing due to detonation, little too lean and not enough WI at the time.

When I removed the injector diffusers, I did not break them, they came out all good in one piece. The tune did not change. I made sure the injectors were plugged in good, if one was not working it would have been running lean and would have blown up pretty quick I would guess. The car was still running strong, ran a 10.46 when the corner seals broke right after shifting into 4th gear, but it was showing a little drop off in power on the dyno a few months before this after the wi check valve problem and diffusers being removed.

I will run better 2 stroke oil next time, and more of it.