Morris Minor Owners Club

Can you please advise which oil to put in carbs.Would it be engine oil or 3 in 1 thin .

I use engine oil.

Something I pondered for a long time myself, until I discovered the proper stuff and found it wasn't that expensive.
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Best wishes,
Mike.

I used 20W/50 engine oil in my HS2 Carburettor for many years until I was at a show once and, like Mike, bought a bottle of the proper SU SAE 20 dashpot oil for not very much. I also now have a bottle of the Penrite oil. I can't say for certain the change in oil has made any difference but it certainly hasn't been detrimental.

20W/50 engine oil is perfectly suitable for the dashpot damper of a SU carb.

Thank you all.Like to do the right thing cheers.

Given 20 weight oil will be the same weight as 20w50 at room temp I can't see any problem at all using either.

Guess the proper stuff is a bit more costly...

Guess the proper stuff is a bit more costly...

I am still using the bottle I bought a couple of years ago. So it would depend on how often you dismantle yor carb and need to replenish the oil.
Very handy for me, as both Sally and Elsie May have rebuilt engines, hence a need for fresh oil and I have recently converted Hetty the Herald to an SU HS4 (from a Solex).
So a worthwhile purchase IMO.
Best wishes,
Mike.

Yes, the bottles of SU oil last for ages. I can't say it works any better than 3-in-1 or engine oil, hence people offer varying opinions, as above. The main thing is to ensure the little dashpot doesn't run dry, so check it periodically.

I have tried all sorts over the years but I settled on engine oil a long time ago.

I've always used 3-in-1.....

Heavier oil in the SU dash pot is a variation on the heavier dash pot spring.
I have even tried EP90 and it works just as good as the heavier spring.
Earlier SU dash pots did not have the damper spring just a piston with a weight around its centre plus some early SU dash pots did not have the damper.

Indeed Phil - I have 3 SUs in my possession which rely solely on the weight of the piston (no spring or oil) - only 1 is fitted to a car though.

Keith Calver has some good opinions on the oil to be used in a dashpot - https://www.calverst.com/technical-info ... shpot-oil/

Matt
Many thanks for the link - useful information there.
Which leads me nicely onto:-
I have just been given a copy of the S.U. Reference Catalogue ALT9524 issue 12/4, December 1998.
Whilst not new by any means it has all the details needed for the maintenance of classic cars fitted with S.U. Carbs.
Contains:-
History of S.U.
Exploded diagrams of all variants of the S.U. carb with part numbers.
Needle details for all vehicles with S.U. carbs.
Details of main jets, piston dampers, float lids, floats, needle valves, throttle spindles, throttle levers and throttle and choke linkages, fuel supply pipes, gaskets, carb bodies, float chambers and dashpot oil.
It also covers S.U. fuel pumps and their mounting.
It is a really good reference/parts list book and a copy should be on every classic cars enthusiasts book shelf.
Still available from Burlen Fuels and I believe it is free when S.U. parts are ordered.
http://burlen.co.uk/su-reference-catalogue.html

Phil
you might be interested in the
https://britishcarbreakfastclub.com/tec ... 7ggn1cSs7c
if you're not already aware of it.
One of the books they have is Tuning SU Carburettors. Also a 1968 publication.

geoberni
Thank you for the link but I already have the 1968 1st impression Tuning S.U. Carbs book in question on my engine tuning library shelf along with the following -
viewtopic.php?f=4&t=61780
Regards
Phil

I should have known a man of your calibre would already have it