SlowCar2

rapid wear cause by borewashing? check it out

http://forums.evolutionm.net/showthread.php?t=252352

SlowCar2

lol...you guys got no pistons

mazdaspeed7

But it still applies to the guys running alcohol injection.

The problem here is the basic nature of alcohol. It dissolves oil. At peak boost, when the engine is working its hardest, and needs the lubrication the most, the alcohol injection is dissolving the oil off the cylinder walls(or housings/seals for rotaries), leading to accelerated wear.

SlowCar2

what is the clearance on the housing/seal?

mazdaspeed7

Theoretically, the clearance between the seals and the housings would be zero. It has to be to seal properly, and for that to happen, the surfaces have to contact each other.

I dont think rotaries would see housing wear problems so much, as both have a wear coating applied. Piston engines normally do not have treated or coated bored. But you would see a problem in the seals, apex especially. Apex seals are susceptible to localized overheating from friction when there isnt adequate lubrication, either from the OMP or premix. This can result in seals warping(mostly non-oem seals), or a loss of the heat treatment on stock seals, which will cause them to wear rapidly.

SlowCar2

thanx for the quick lesson on rotaries!

Node

iTrader: (1)

That makes me understand about what someone told me for reasons not to go alky.

He said that alky because it evaporates at such a low temp and so fast that its changing its chemical makeup very quickly
It gets into your oil, gas, and eats at seals, rubber lines. etc
The motor should be flushed w/ gas only (no alky) after using it each time

I can see how it can get into your oil, dunno about the gas.
And isn't meth supposed to corrode alum too? I know it corrodes a lotta ****.
I'm still looking at 50/50.

Howard Coleman

iTrader: (6)

"someone told me reasons not to go alky"

run water, run mix, run alcohol..... they ALL work.

take your pick, but do not make a choice based on "someone told me"

100% methanol is my preference.

i run a rotary w the Alkycontrol system. i run two M10 nozzles for around 1250 cc/minute. i have replaced around 25% of my pump gas w alcohol from 5.5 psi on up to max boost for me at 23 psi.

i run a turbosystem of my own design. two TO4s w two 3 inch downpipes that makes over 80 pounds per minute of air good for 640 rw rotary hp when tuned out. i am around 500+ currently at 18 psi.

i digitally log just about everything. i log digitally egts preturbo from each rotor separately. i log backpressure preturbo digitally. i log fuel pressure digitally, along w all the usual stuff...

so i KNOW what's happening... if you log enough stuff you don't have to be smart.

since i have the data re the issue relating to alcohol and "wall washing" i thought i would share.....

the chart above is part of the log from my last run of the season... oct 30. it was a roll-on 3rd gear pull w boost as high as 18.7 psi. the clutch started to slip and i got out of it.

afrs were in the 11s.

given the delivery from my two TO4s (around 80 pounds per minute at 17-18 psi, my injector duty approx 70% (850 1600) and the amount of methanol, over 1200 cc/min, as well as shredding a 400 ft pound capacity clutch my guess is i was making over 500 rwhp on this run.

note that my AFRs do not get overly rich as i get out of the throttle. my egts also do not dive. this indicates to me that there isn't a major run-on issue. i have discussed the concept w Julio (Alkycontrol) and his conclusion is that there isn't enough alcohol going thru the motor to effect wear. he runs in the 10s on pump and alcohol w his 231 cu in 2 valve 3850 pound buick. so do 100s of his customers. he should know.

as an additional note, i ran my alcohol all season last year and i consistantly gained compression throughout the year. my highest compression reading was the day i put it away for the season.

the key though w re to this thread is found in the above chart. notice as i get totally out of the throttle and the boost drops w the TPS that the egts and afrs stay steady.

no indication of a big flood of alcohol or the afrs would have gone miles rich.

i suggest the linked person post his pictures and info on turbobuick and let Julio comment on your situation. he may have a problem, but it does not lie within the fundamental design of a progressive system.

howard coleman

hondahater

iTrader: (2)

Well this makes me think of a few differant questions like.

1. Does the piston cars have any sort of premix that is involved in this? I know that the ka out of a 240sx injects oil onto the pistons but I'm not sure if that is indicative of too many piston motors out there.

2. This may be a dumb question but wouldn't this me more prevalent on people that are actually removing a portion of thier gas and adding in the same percentage in alk/water just because of the huge amount being used?

3. is there an oil that is not susceptible to being broken down by alky (higher end synthetics) or is that just a trait they all posses?

dis1

This is an interesting thread because our rotary engines inject oil for the apex seals to basically hydroplane on. No oil means they will rub on the housings and wear out pretty fast. Nobody is doubting the potential performance gains or AI here. The topic is the long term effects of injecting meth. If meth could potentially compromise the oil injected it could mean a shorter engine life. I doubt it though. Many places in the country now sell E10 gas, which is 10% ethanol. This is in its own right a separate debate as to what effects this might cause to a rotary. However according to the manual the Rx-7 is approved for E10.

I'm planning on running washer fluid personally.

Turblown

iTrader: (12)

Looks like too much ring pressure and too much piston clearance.

Auxiliary injection is not enough to wipe cylinders of oil.

If it was wear problem air craft wouldn't run it.

Node, I've watched compression numbers on a few alchy rx-7s, never seen a problem over time, 10/20k miles. I've also played with different premix ratios, on and on. You're not injecting enough to worry about it.

Marcel Burkett

If you read the guys posts , he keeps saying that his AFR's go pig rich when he lifts off the throttle ...., kinda emphasizes the need for a PROPER positive shutoff valve , doesn't it ?

crispeed

Normally on piston motors and rotaries to some effect, over fuelling resulting from abnormal rich mixtures and unburnt fuel would cause damage to the bearings at first. Some piston motors are not tolerant of this to the effect that in a very short time of under 2000 miles serious damage do occur.
It's true that alcohol/methanol fuel is very hard on the lubricating oil of a motor but as long as some type of premix is involved along with regular oil changes most of the claimed abnormal wear is really at a level that is is not even worth mentioning. I'm basing that on my experience with rotary motors that run on 100% methanol. This is not the same for piston motors though. Most the people running 100% methanol on piston motors are required to do oil changes very frequently especially if force induction is involve to the point where the oil can be completly contaminated just after one run down the 1/4mile.
Now since everyone here are mainly concerned about the effects of water or methanol injection to their rotary motor I can say that the small percentage being injected into the motor should not cause any short/medium term damage. If your additional injection system is doing it's job most of the fuel is absorbed during the combustion process anyway. If you still have any concerns then use some type of pre-mix in your additional injection system. I know some claim that the manufacturers don't think it's neccessary to do so but most of those people are not familar with rotary motors. Personally from what I've experienced with running on 100% methanol fuel there should be some type of additional premix added. There are some lubricants out there that were designed to work with methanol/alcohol fuels to point where corrison and abnormal were is eliminated. They do so without causing any bad side effects such as excessive carbon build up from unburnt oil etc.

radkins

I pulled my last motor apart that had been run on AI for a full year at 20psi and found no signs of abnormal wear. I run Klotz lube in the Meth.

crispeed

Which one?
The UP-lube or Benoil?

radkins

UpLon

crispeed

Very good.
Klotz is probably the most respected out there presently.
They have set the standard anyway.

finnicky7

How much libe per gal? Where is it available?

finnicky7

lube