AImec Racing

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AImec Racing

The problem is my oil is not lasting more than 1K miles. I noticed it ‘cause about every 1K miles the car begins to smoke, and is because the oil wears to quick and the viscosity decrease drastically and its able to pass through the turbo seals. I also notice it because the oil pressure begins to drop. I change it and the smoke disappears and the pressure stabilizes, but just for 1K more miles. When I drain it, it looks like water and it has a strong fuel smell.

If think its been mixing somewhere. It might be the side seals but the engine is freshly rebuilt (less than 5K miles) and the compression is good. I have tried Mobil-1, Purple and Amsoil,,, all at 20W-50 …so the oil grade/quality should not be the problem.

I have been told that might be the fuel cruse map to rich and I already worked into that to see if it will extend the oil life, but I just don't see how the oil could be mixed with the fuel independently if the car is flooded at the fuel map... Is this possible?

If someone passed through this or any thoughts/ideas please let me know...

thx!

BlaCkPlaGUE

What are your oil temps?

AImec Racing

have not meassure ,,, but engine runs pretty cool... always between 75-80 ºC

dubulup

if you have a single and one stock cooler...its pretty hard on oil. fresh rebuild and not properly clearanced side seals will do this. Are you running a catch can...might help a little.

Mr rx-7 tt

iTrader: (5)

Sounds like a clearance or heavy wear problem with the motor.

GoodfellaFD3S

iTrader: (213)

You may want to try the amsoil series 2000 20w50.....based on my experiences with it, it may hold up longer for you.

Mr rx-7 tt

iTrader: (5)

105 wt gear oil. (Just Kidding, please don't try it)

GoodfellaFD3S

iTrader: (213)

Lol, careful, you never know what people will try

I should have been more specific---I believe the series 2000 amsoil to be thicker than the 'normal' synthetic amsoil. Thus, 20w50 series 2000 will be thicker than normal synth amsol 20w50.

gnx7

iTrader: (10)

You need to send out a sample of your oil to be analyzed. That will tell you what is going on. Looking at oil with simply the discoloration tells you nothing.

I highly recommend doing an oil analysis though, this can help you fine tune your combo for maximum durability. I recommend you get in touch with this guy here specifically, as he's got a ton of experience with racers:

http://www.bobistheoilguy.com/terry.html

AImec Racing

I thought about the side seals but is just hard to believe... i chk all clearances while tear up. but you never knows....

Mine is R2 ,,, so 2 oil coolers ... i'm running a catch can...

I wont try gear oil...

sample is good idea,,, might try it...


I tuned the fuel map,,, the car mileage increased 50 miles per tank so its going better now... it has been like 500 miles since last change, the pressure began to drop but not as before... though, it looks like will last more but not as it should be yet...

what about Amsoil Racing 60... has anyone try that one?

thx for the opinions... keep posting any ideas....thx!

maxcooper

Running rich on part throttle cruise will definitely lead to more oil dilution. I am not surprised things seem better now that you leaned it out.

-Max

rx7tt95

My engine builder (CLR) prefers Castrol 20W50 as it apparently holds it viscosity better than the synthetics. I've been a die hard synthetic user in the past (Royal Purple and Mobil 1) but decided to heed his advice. I did notice in the past that oil pressure would drop over time with the synthetic stuff, especially Mobil 1. The Castrol stuff does appear to maintain pressure levels for longer intervals. I just tried the new extended performance Mobll 1, guaranteed for 15K miles (20W50) and I'm happy to report the pressure is up there and consistent, just as good as the Castrol so far. Yes, I'll change the oil long before the 15K interval recommended on the bottle :-)

APEXL8T

Shannan McMaster from import motorsport told me years ago to go with high vis regular oil and one quart synth. Many stock FD would have low Vis synth and would come in to the shop with a little smoking and small loss.

AImec Racing

Thats good to know!...any experience/idea of why that will lead to more oil dilution??? ... to much fuel will be able to pass through the seals?

AImec Racing

man... thats was just my next move after tuning the fuel map...i was thinking the same way so glad to here it works for you...

what about 60? yet anyone tried it...?

AImec Racing

just to let you know that the problem was indeed the fuel map tunning, specificallly cruse, iddle and vaccum load....my oil is lasting now as should be an the pressure is consistant...


thx all for your help!!

Carl Byck

Interesting, I have never noticed a loss in viscosity with Syntec (my first choice), or Mobil 1. On Balance, after break-in, I would still choose synthetic, for several reasons; First, the operating temperatures have been documented to be substantially lower by countless sources, many of them specific to Rotaries. Second, the resistance to coking in the turbo CHRA is key IMHO to longer turbo life. When I ran 20-50GTX, my oil feed line on the turbo was often partially blocked by coked oil, since switching to synthetics, I have never seen any clogging at all. Third, in the event of an oil starvation problem, the car, and/or the turbo will last many times longer before failure due to the far superior film strength of synthetics.
Also, remember, that you see the product in its lowest viscosity state. When subjected to the mechanical forces within a motor, the oils viscosity actually increases. In essense, the the more crushing force applied to the oil, the thicker it becomes.
How long did it take for you to start loosing oil pressure, and why do you attribute it to a loss in viscosity? I will go out on a limb, and say that I strongly disagree with your analysis of why your oil pressure was dropping. It may have to do with the fact that the oil was synthetic, but I am sure it was not a loss in viscosity, perhaps synthetics are more sensitive to contamination...
The followin link will explain the apparent stability of Castrol GTX, it is, in fact getting thicker, while the sythetic will tend to maintain its original values for a longer period. http://www.amsoil.com/performancetests/g1971/index.aspx

After reading the above link, I will be doing some further research, but I maybe making a change to AMSOIL in the near future. Carl

Carl Byck

As an aside, my race motor will employ a seperate mechanical injection of synthetic two stroke oil from a seperate resevior. Carl

maxcooper

If there is always way more fuel than you have the oxygen to burn, some of it will make it's way into the oil (by going past the side seals). If you run less rich, less fuel will make it's way into the oil.

-Max

cewrx7r1

iTrader: (2)

This is not true.