14 replies to this topic

[Mini Man Sam]

Need to fill up dashpot, don't know what oil has been used in past, have noticed a post that recommends using auto transmission oil.

Question is this

Will it matter if I mix oil types or should I stick to oil as detailed in owners manual

[Bluemini]

What is it with auto oil? It makes no difference. I just use normal 10w40 engine oil in mine and it works fine.

[B1ondini]

I was once recommended to use brake fluid. I have used this ever since - in fact, I topped mine up with it yesterday.

I have found by experimenting (on a Chevette) that if you use brake fluid, you get a quicker throttle response than with engine oil.

Just for a bit of fun, I once took out all the fluid from the dashpot and tried that, (You must make sure that the engine is warm as it won't start otherwise), the throttle response that I got was almost immediate.

Who knows what damage is occuring, but it's fun anyway!

Have fun,

B1ondini.

[Madmax]

ive used 3in1 oil before, engine oil...as long as its got a reasonable thickness its fine, not treacle mind...

[Guess-Works.com]

Brake fluid is a no-no, as it's a water based solution which is also very corrosive.. If that went through your carb just think what it's doing to the valves & piston.

I generally use 3in1 as it comes in a handy tin :cheese:, you can get genuine SU carb oil, in a couple of grades, and engine oil is ok, ( however I find it a little too thick for winter driving )

Auto fluid is just another grade of oil, but if you don't have an automatic (not mini), is rather expensive to buy a 1 litre tub for only one purpose.

[dklawson]

This is a topic for any car with SUs or Strombergs, not just Minis. The argument goes something like: The thinner the oil, the faster the needle opens the jet in the carb letting more fuel in. I know people running 50W oil all the way down to automatic transmission fluid (10W equivalent). Really, any oil can be used and you just have to try different weights until you find an oil that makes the car drive and "feel" the way you want for your manner of driving. There is no "right" oil.

Regarding brake fluid, it's not a good choice. I don't know about the corrosive comment, but it is hygroscopic and will cause the steel bits of the dashpot to rust if you don't replace the fluid often... just like bleeding/replacing your brake & clutch fluid every couple of years.

[TimS]

i thoght generally if you have an engine that revves p quicker then a thinner oil should be used to alow the increment of fuel and air to be the same

[miniman5]

auto matic transmision oilk is better not sure what grade you need though

[rozzer!]

i thoght generally if you have an engine that revves p quicker then a thinner oil should be used to alow the increment of fuel and air to be the same

the guy who i use to do my mini tuning and stuff recommends brake fluid. it has to be topped up every couple of weeks anyway so corroding the carb isnt a problem as its not in there long enough! even 3 in 1 oin is too thick. albeit i am running twin strombergs not su's!

[Retro_10s]

3-1 is too thick?! I dont think so.

10w40 - 20w50 (20w50 might be a too thick but ultimatlely it's up to you to decide how you like your car to drive) is a good starting point, The carbs were designed to run on the same oil as the engine does.. if it's a bit sluggish, thin the oil down with some 3-1.

Personally I like a nice smooth throttle response with no piston bouncing, 10w40 all the way. Brake fluid... get lost!

Edited by Retro_10s, 28 January 2007 - 01:52 PM.

[miniboo]

holy thread revival batman.

[Retro_10s]

holy thread revival batman.

Lol my thoughts exactly robin, f251dgc must've been trawling thorugh the forum

[Bass Man]

Personally I like a nice smooth throttle response with no piston bouncing, 10w40 all the way.

What are the discernible symptoms of 'piston bouncing'..?

[taffy1967]

Don't know but I hear this stuff is good:-

Burlen Fuel Sytems Carburettor Damper Link

[TOMMO0302]

A little OT, but apparently if any of that Brake fluid was to find its way into the inlet manifold, it would result in a Batman stylee Smoke Screen!? Anyone confirm or rubbish that statement?