Interesting oil mix v EGT test

[rossi46]

Hi All,

Have just completed a test on my RB using various oil mixes v EGT, bit dangerous but I needed to know this is what I did :

Test Equipment

AIM MyChron4 http://www.aim-sportline.com/pages/kart ... chron4.htm and a back up from a world touring car both calibrate to +/- 1 degree C, fitted 150mm from the exhaust port as instructed by AIM.

Engine dynoed by Al at Diablo

1 mile stretch of road, full throttle, plug chop at the end each run.

Test 1

4% mix Putoline MHX - Nice plug colour, chocolate brown EGT - 565 degrees C , engine pulls and perform well

Test 2
3% mix Putoline MHX - plug colour getting darker EGT - 525 degrees C , engine a little wooly and feeling rich

Test 3
2% mix Putoline MHX - plug colour very dark brown EGT - 498 degrees C , engine didn't rev out so well now feeling very rich.

I know the less oil you ran would richen the mixture and also run cooler but I wanted to try it as I was bored and very intrigued by this. I am not saying you should try it as it could possibly not lubricate the big end bearing very well, I am using an Alpha crank in mine and as above Putoline MHX which is fully synthetic competition oil, which maybe lubricates better than other oils . If you have used it before you will see it like treeacle when you pour it .

If you have any comments on this please let me know, I am intrigued to know what you think.

D

[corrado]

What % was used when it was dyno'd? I'd assume 4% as the carb seemed to be spot on, but what would those figures be if you had it set up on the dyno if you were using 2%? As carb now running rich at 2% surely Al would have rejetted it?

[drunkmunkey6969]

Wow...i'm loving this! Its exactly the type of geeky unimportant nonsense that intrigues me too!

I'm not joking either.... I know some people think its all b@[email protected] they are right....but its ths type of b@11@x i love. Soory.

So rossi...

Test 1 ...engine at its hottest...not good.

Test 2 ...engine gets cooler...which is good, but its running rich ...not good.

Test 3 ...engine gets even cooler...which is good, but its running rich, and it haseven more reduction in lubricity ...not good.

So test 2 seems like a good middle ground, if you can solve the rich mix....but will this just push the temp back up?

Can test 2 be repeated, but with main jett leaned off? This way you get a decent 3% mix, and less 'wooly' performance....but i want to know how temp increases. If temp goes up, but to less that test 1....its a winner!

Also....shame you couldnt get BHP figures on each run too!!

[corrado]

Guess we had the same thoughts Dan?

[Avantone]

The data confirms that reducing the fuel/oil ratio makes the the motor run richer and so the temperature falls.

What would have been useful would have been to have corrected the jetting to see what happened to the temperature and power output (assume both would increase but is the extra power worth the extra heat?).

Just on the side, I've always maintained that a 2% mixture is fine (used to race at the ratio) - when was the last time anyone had a small/big end failure due to poor lubrication?

A worthy test that shows that using a quality modern lubricant could save you money and increase performance if used at an optimum (lower) ratio.

[drunkmunkey6969]

when was the last time anyone had a small/big end failure due to poor lubrication?

Not that often.....but a few have had piston/cylinder seizures though.

Reduction in oil % may not be a problem for bigend bearings....but will it reduce cylinder lubrication too much?

I'm not saying you are wrong....i'm just asking the question, as i don't know the answer.

Although i do know a well known sprinter ran at 2% mix also with no problems........

[elgarra]

I'd be very interested to see how this pans out.

I run my 172 at 2%, (previously 3%) with the thinking that the extra cooling gained from the richer mix would offset the drop in lube. (I use TTS)

I did notice that the motor felt a little woolier, but i put it down to it being the start of the summer when i made the change and jetted accordingly.

A whole new world is opening up in front of my eyes......Cheers Rossi.

[rossi46]

What % was used when it was dyno'd? I'd assume 4% as the carb seemed to be spot on, but what would those figures be if you had it set up on the dyno if you were using 2%? As carb now running rich at 2% surely Al would have rejetted it?

dont know mate not been back to Al's yet but soon as I get chance I want to do a session with him doing the same thing on the dyno to see the jetting differences and power and torque commparisons, I am a bit geeky like this it comes with the nature of my job

Take for instance, autolube systems on something like RD350 LC or the similar I used to have one back in the day, and it never used as much oil as a Lammy due to the fine tuning of the oil / mixture control, maybe I am wrong but does the vespa use autolube ? has anyone checked to see how much oil they use compared to an RB or TS or any tuned lammy.

Opening a can of worms here me thinks

[Avantone]

when was the last time anyone had a small/big end failure due to poor lubrication?

Not that often.....but a few have had piston/cylinder seizures though.

Reduction in oil % may not be a problem for bigend bearings....but will it reduce cylinder lubrication too much?

I'm not saying you are wrong....i'm just asking the question, as i don't know the answer.

Although i do know a well known sprinter ran at 2% mix also with no problems........

But even then how many seizures are down to lubrication rather than weak (fuel/air) mixture?

There are so many strategies for improving cooling and improving the effectiveness of the lubrication, I'm sure the ratio could come right down without any issue.

(RB kits and people that can't measure oil excepted )

[elgarra]

What % was used when it was dyno'd? I'd assume 4% as the carb seemed to be spot on, but what would those figures be if you had it set up on the dyno if you were using 2%? As carb now running rich at 2% surely Al would have rejetted it?

dont know mate not been back to Al's yet but soon as I get chance I want to do a session with him doing the same thing on the dyno to see the jetting differences and power and torque commparisons, I am a bit geeky like this it comes with the nature of my job

Take for instance, autolube systems on something like RD350 LC or the similar I used to have one back in the day, and it never used as much oil as a Lammy due to the fine tuning of the oil / mixture control, maybe I am wrong but does the vespa use autolube ? has anyone checked to see how much oil they use compared to an RB or TS or any tuned lammy.

Opening a can of worms here me thinks

The autolube is disabled on my 172, but it gave a mix of 2%. I know the Project Dreadnaught (172 T5) of Scootering fame ran autolube modified for a higher ratio. (Diablo moto?) The only problem i believe it had was when the nitros was fitted.