Biggy VIII

personal experience. too many examples of rapid wear, piston slap etc on mahle pistons installed...

94AWDcoupe

iTrader: (125)

stock evo 8 pistons are mahle. nothing wrong with mahle pistons. I had rapid cylinder wear using JE 2618 pistons as well. just didnt document lke this. its definitely alky that washes bore of oil.

two 650cc injectors is not alot. they arent run past 75% for one thing. they follow the duty cycle of primary injectors. so they are not just turning on full blast like some methanol kits do.

2 gallons of ethanol lasts from 20-40 gallons of 93 depending on how heavy my foot is.

mt057

iTrader: (6)

Would the washing out eventually allow for fuel to contaminate the oil in the pan? I am going to rebuild and had recently noticed a slight fuel smell when checking my oil. I had heard that that it could happen so I always check. The engine has about 130k on the clock.

94AWDcoupe

iTrader: (125)

oil dilutes very quickly. best oil that stays thick is Brad Penn hands down best oil to use.

94AWDcoupe

iTrader: (125)

So I did a new test on the last engine. I added a little oil to the fuels. few oz. of lucas oil additive per ten gallons to the 93 octane. and 2 oz per gallon Klotz added to the ethanol. not a long term test. there was around 3500 on the block when I got to see the cylinders. they look very good. I would say the oil additives are making a nice difference and I going to continue to use it. I am starting with a new block again as i wanted to change compression. so I am starting over again. I also set piston to wall very tight on the mahles this time at .002.

Technical10

iTrader: (2)

Interesting. I would say that your alcohol start point is way too low. I do not start with it until 15psi on a stock Evo 9 turbo as max boost I run is 25psi. On larger turbos that I have run... I have started alcohol at late as18-20 psi as my boost setpoint was at 35-38psi. That was a Borg Warner S366.

Also to have that much injector for alcohol... as long as it is not just on/off and is progressive you should have been fine, but I suspect that by using such a low start point that you are just not using it efficiently.

I have just popped the head off of my Evo 8 for the first time in 9-years when I built the motor. Guides were a bit tight on the exhaust side and the double spring kit was replaced with a beehive kit. Other than that, bearings looked good, rings were excellent, and the walls were also perfect. All that time the car has made anywhere between 450hp and 900hp and run pump gas with alcohol injection or at the higher end some C16 with alcohol injection.

Technical10

94AWDcoupe

iTrader: (125)

I have run alky kits triggered at 16psi. I like it way better at 4psi. transition is butter smooth and the turbo most definitely spools faster.

Technical10

iTrader: (2)

I just reread this thread and what came to mind was when you stated that the alcohol injectors mirrored the primaries at 5psi--- that is a problem no matter how you attempt to tune it as honestly that is not possible to properly transition, and here is why...

I will go back in time with a Haltech E6K or E6S series of standalone ECU's. Without getting into much with the premise of how it controls fuel, I am more concerned about staged injection. With that it was the primaries up to a point, then you add in the secondaries at the same pulsewidth... in that case, you clearly define a breakpoint of when you transition to both sets of injectors... no matter how much you tried--- there was a hump or dip in the A/F ratio. Now move forward to current times with staged injection-- primaries and secondaries have completely separate maps. Because of that, you can blend in the secondaries while not affecting the primaries. Yes you still get a waver in the A/F ratio, but it is completely manageable and acceptable. The same can be said for that and adding alcohol injection-- it is all separate maps that work together.

That leads to your setup. With that size turbo and boost levels, your 880cc primaries should be plenty and alcohol is not necessary--- but I agree with spool as well as the other benefits that it provides--- do not misinterpret what I am saying and I still stand behind running alcohol injection 100%. I also had more written then began to think about what you are using for fuel pressures for both systems. At 5psi what is your gas fuel pressure and your alcohol pressure? At 10,15,20,25.... that all is relevant and leads to a host of other questions.

So with your alcohol system--- more setup information would be nice to know, but I believe you are flooding it and washing the cylinder walls, plain and simple. Again, for that level of power, a single nozzle system that modulates the pump or one that keeps a static high w/bypass pressure (or 1:1 rising rate pressure with boost) and modulates either a solenoid with nozzle or injector that is completely independent of the primaries is the way to go. Whether you do so through a complete standalone ECU (ProEFI, Haltech, ViPEC, etc), aux table of sorts dependent on stock ECU mods, or a controller like the Alky Control or Snow Performance--- that will give the proper control.

Again, 9-years and as many miles with no wear. I also recently ran a compression and leakdown--- compression was 170psi across the board and leakdown was verified with two setups to confirm the readings of less than 1%.

Remember, I am wanting to see you get things resolved and figured out. Sometimes it is simply hard to accept that although it runs right... it is on a path of self destruction. Also take what is being presented and run with it.... it may be partially right or trigger the right set of questions to solve the problem.

Technical10

94AWDcoupe

iTrader: (125)

you can read about the alky setup here. there is a dyno graph the shows the a/f curve. it transitions beautifully. drove on one tune for over 2.5 years. maybe I drive my cars a lot harder than other people. there are way too many possible factors that affect results. I am just offering my data. if you are getting better results, great. I dont have any data on your setup or how you drive. so I have no comment.
https://www.evolutionm.net/forums/wa...st-way-go.html

2winscroll

Detonation caused this, look at the pics.
2 years ago wow

ridenrunwv

Why bring back a thread from 2 years ago if it's not related to a problem you're currently having and can't find info on?

... Even worse to do so and post something that likely isn't even true.

2winscroll

If you knew anything about reading carbon traces, you would know. Smooth carbon ok, sandy pitted carbon bad. This motor probably had to much timing in the low to mid load ranges causing mild detonation. The upper ring land has scored at the very top of the cylinder, you can see the scoring only at the top, classic of mild detonation.

Bringing it back so people can learn something, and be properly informed. Hopefully your open minded, Consider yourself schooled.

2winscroll

Im not an idiot like technical10, I have actually seen this before.

ridenrunwv

Hmm. I didn't even notice that scoring at first. I guess I need to look into detonation damage more because I wouldn't have expected it to cause that type of damage.

2winscroll

http://www.enginelogics.com/engine-detonation/

Read this