• Hey Guest!
    British Car Forum has been supporting enthusiasts for over 25 years by providing a great place to share our love for British cars. You can support our efforts by upgrading your membership for less than the dues of most car clubs. There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Upgraded members don't see this banner, nor will you see the Google ads that appear on the site.)

ZS damper oil?

Share this page

Gliderman8

Gliderman8

Great Pumpkin
Gold
Offline
I need to add oil to the ZS dashpots....
What type/weight oil do I use?
As always, THANKS!
 
That is an ongoing controversy. I just use 20w50 motor oil, some use 10w, 30w, ATF, SU damper oil, etc. Different oils will give more or less resistance to the damper. I've never had any problems with 20w50 though.
 
I'd avoid anything too thin, like ATF, Marvel Mystery Oil, even 3 in 1
I use a mixture, the main ingredient is Bars Rear Main Seal Repair oil.
But I wouldn't say go out and buy a quart of it to fillup (2) dampers that only hold 3.5 cc's. But if you can find a use for one of the oils that are advertised as being for high mileage engines, I'd get that.
The reason is that both those oils keep that little PIA to replace O-ring around the needle adjuster plump and leak free.
I put some Bars in a leaking carb 4 years ago and still holding.
 
I have heard a rule of thumb 'use the same oil as you have in the crankcase'. Perhaps the notion was that then you would be using lighter oil in cold areas/months and heavier oil in warm areas/months.

I think the answer is to experiment with different weights and observe the characteristics of acceleration.

I see no reason to by the SU labelled bottle of oil as the variable (so far as I know) is weight and most of us have a plethora of choices already on the shelf in the garage.
 
Geo Hahn said:
I have heard a rule of thumb 'use the same oil as you have in the crankcase'. Perhaps the notion was that then you would be using lighter oil in cold areas/months and heavier oil in warm areas/months.
Click to expand...
I believe that is in the factory owner's manual for the TR3, which also specifies different straight weight oil for different temperature ranges.

I use straight 20 weight, because it seems like my engine needs a bit more enrichment when the outside air is cold. But the actual performance difference between that and 20W50 isn't enough to argue about.
 
Thanks everyone for the helpful advice.
 
Back
Top