39 replies to this topic

[firefox]

Right smat ass i will ask u a question if the oil is to thick will the engine use more fuel

Of course it won't, by the way smat, is spelt SMART...........

Ha ha ha ok typing error, well if on start up and the oil is thick it must make the mixture richer, well that is the way i understand it

[firefox]

Right smat ass i will ask u a question if the oil is to thick will the engine use more fuel

Of course it won't, by the way smat, is spelt SMART...........

Ha ha ha ok typing error, well if on start up and the oil is thick it must make the mixture richer, well that is the way i understand it

Seeing as you've refrained from making it personal, would you like to tell me why you think that is bad ? Because this is exactly how the SU works, think about what would happen if it didn't make the mixture richer.......... You want the piston to rise as slowly as possible, this is how the acceleration enrichment happens..............

Nothing personal bud we are all on a learning curve yeah but yeah but 20/50 starts off the same as the 3 in 1 which is as we have said sae20
but in hot weather i will sharply go to sae50 now isnt that to thin, would it be better if you tuned it to except the constant Sae 20 i dont know, if i am wrong
if i am i will try mine with engine oil

[retired]

Folks,

Please try to understand the difference between the 3 in one that you buy in your local hardware shop

http://www.3inone.co.../multi-purpose/

which is **** or sewing machine oil, or penetrating fluid at the best

and the 3 in one that Burlen refer to

http://www.3inone.co...ucts/motor-oil/

which is SAE20 equivilant - so close to 20W50 when at normal carb temperatures.

There is no comparison to what an SU carb requires compared to the normal 3 in one you see in shops.

[firefox]

Thanks for the input bud yes it is 3 in 1 motor oil as i have already put on,but thanks for preventing
any confusion

[Gr4h4m]

As this is in forced induction, you need an oil that doesn't thin out with heat. I used to use millers 20/50 and this is how my car was setup on the rollers, remember if you change the oil spec you may then get leaner or richer spots as the piston lift speed may change.

Everything you do to a carb will have an effect on afr. Changing the dash pot oil to a thinner MIPS will likely cause you a lean spot if you change this after your car has been setup.

[stretch tech]

i use air line lubricant/oil seems to work fine but i'll find out on the rr soon enough

[firefox]

MMMMMMMMMMMM i have a Lt of that might give it a go, will last a while

[stretch tech]

MMMMMMMMMMMM i have a Lt of that might give it a go, will last a while

when i came to fit the carb and fire the engine up for the first time, i realised that i had forgot to put oil in the dash pot this was the most oil looking thing within reach so i picked it up and poured it in, admittedly by mistake but it seems to run and accelerate just fine...who knows, i could be on to a winner

Edited by stretch tech, 05 August 2012 - 08:15 PM.

[firefox]

MMMMMMMMMMMM i have a Lt of that might give it a go, will last a while

when i came to fit the carb and fire the engine up for the first time, i realised that i had forgot to put oil in the dash pot this was the most oil looking thing within reach so i picked it up and poured it in, admittedly by mistake but it seems to run and accelerate just fine...who knows, i could be on to a winner

yeah similar thing for me bud a garage that did my audi clutch he was a mini racing nut, gave me a bottle of zenith su oil
he said that he always uses it, or 3 in 1 motor oil if he runs out,

[danie garry]

from my memory, a 20/50 oil will be at its lowest viscosity of 50 when cold, very cold, below 0c if i remember rightly which is rarely seen inside a carb if at all! the oil thickens to a 20 rating at temperatures up on 100c or so which again i dont think a carb would ever see. so my reckoning on that is that the oil would be sitting a approx 30 rate most of the time? thats my theory anyway!!
personally i topped up the dashpot on my carb today with 20/50 as i'v never given it a second thought until i saw this thread!!

Edited by danie garry, 24 August 2012 - 10:40 PM.

[firefox]

I found this interesting see the part on Oil type

http://www.zparts.co...arb_111601b.htm

[jakejakejake1]

Surely the oil is thicker (higher viscosity) when cold, thus making 20w50 more like a 50 wt oil, slightly thicker than what was recommend, which is good for the most part as it would help enrich under acceleration?

Jake

[danie garry]

Surely the oil is thicker (higher viscosity) when cold, thus making 20w50 more like a 50 wt oil, slightly thicker than what was recommend, which is good for the most part as it would help enrich under acceleration?

Jake

yea you're right, got mine arseways! il fix it now!

[ACDodd]

Hehehe I love this thread, the point is there is NO one best oil. It is the oil that gives you the correct enrichment on acceleration that matters. This can vary from 3 in 1 to just about any thick grade purely because of wear and production tolerances.

The savvy tuners use the best oil for the job, and that certainly is not 1 grade!

AC

[Turbo Phil]

Couldn't agree more. I found anything thinner than 20/50 would cause a big leanout as mine came on boost if the throttle was fully depressed rapidly when cruising. But a friend actually ran baby oil in his & had good results.
As with a lot of things it's an experiment & what works for one may not work for another.

Phil.