47 replies to this topic

[danny19boy86]

what oil do put in the dashpot and how much

[danny19boy86]

after fitting the carb

[jb93]

I use the same as I put in the engine (20w/50). Fill it until its just below the top, and have a cloth on hand for when you put the dipstick back in, as any excess will force its way out.

[adam davies]

I use 20w/50but i add some WD40 to thin it out a bit

[danny19boy86]

thanks

[danny19boy86]

I use 20w/50but i add some WD40 to thin it out a bit

why

[yousmeg]

I use 20w/50but i add some WD40 to thin it out a bit

why

thinner oil makes the piston rise quicker

[danny19boy86]

ok

[firefox]

Austin Morris hanbook says 13mm from the top and do not use heavy grade oil get some SU/ Zenith damper oil

[jb93]

When I put thinner oil (3in1) in mine, it had a right fit , is it different for every car?

[firefox]

A series or A+ and Su carbs what is the different to many different types of motor oil
stick to damper oil it is not going in the engine

[firefox]

The tech guy at burlen fuel systems told me to use 3in1 or damper oil he was shocked when i told him a leading mini shop had told me to use engine ,not knocking the guy's who use engine oil or recomend it but carb's should run better with correct grade

[bmcecosse]

Use whatever you want - I use 3 in 1. But you will get 100 different opinions on this. BMC Works Rally Minis used EP90 in the carbs - to stop the pistons banging up and down on rough stages......... The thinner the oil - the faster the piston can rise, letting more air into the engine. So as long as the mixture is set rich enough so the engine doesn't 'gasp' - this the way to go. Of course the spring above the piston also controls the rate of rise - and the ultimate rise height. If the spring is too strong the piston may never open the throat fully......

[AndyMiniMad.]

+1 for 3 in 1..

[jaydee]

20w50 oil is fine, a 10W40, 3 in 1 is fine, all depends on how your carb is tuned!
Seriously, dashpot oil have to be choosen carefully because it dictates the mixture enrichment under acceleration.
It is part of tuning the SU carb. The needle profile, the spring weigth and the oil viscosity should all match together.
As above, studing how SU carbs work will really help you to understand how you can carefully select the correct dashpot oil for your carb.

Edited by jaydee, 03 October 2011 - 08:55 AM.