What's your Co?

[KOY 23]

Hi Dave.
I'm referring to Stromberg and Burlen, I should have copied and pasted the unanswered question from yesterday, which would have made it clear.

[GDPR]

Which supplier do you mean? Triumph supplied the engines, developed by Ricardo, and BL supplied the manual - which states to use the seasonal grade of engine oil. Which in the UK is 20W50.

Until proven wrong, I'm happy to follow the manufacturer of the engine, as I've done for over 25 years.

Mike's post #36 explains how things work, and if correct, the thicker oil when cold should richen the mixture slightly, meaning I can dispense with the choke sooner. Now that I have tubular manifolds the hot air intake pipe is no longer fitted, so this should help compensate for the fact that there is no hot air entering the carbs.

Or am I talking total b******s as usual?

I am in agreement with you there Dave - and would add the rider that I would never ever use either 3 in 1 as it has penetrative/destructive to rubber properties or Trans Fluid which some idiots think is appropriate, although rubber tolerant is too thin.

We used the same oil as in the engine throughout my life in the Main Dealer, and had no issues at all - frankly, the way garages are for chasing the filthy lucre, if there was a way they could have charged for a "special damper oil" they certainly would!

[milothedog]

I am in agreement with you there Dave - and would add the rider that I would never ever use either 3 in 1 as it has penetrative/destructive to rubber properties or

Trans Fluid which some idiots think is appropriate, although rubber tolerant is too thin.

We used the same oil as in the engine throughout my life in the Main Dealer, and had no issues at all - frankly, the way garages are for chasing the filthy lucre, if there was a way they could have charged for a "special damper oil" they certainly would!

It's specified in some applications Russ, Some older Mercedes's spring to mind IIRC

Ian

[Staggard]

I have always used 3 in 1 even back in the day in SU's and Stroms never had a problem. I personally don't see the difference between 20/50 and 3 in 1 as far as rotting rubber goes, although I have see the effects of petrol on rubber so I presume the diaphragms to be petrol resistant there for oil resistant. I have just immersed a diaphragm in 3 in one to see how long it takes to go rotten. Trust me the girl friend is not well pleased

[jagorstag]

I remember in my Volvo 360 (B19A engine) they recommended automatic transmission oil for the Stromberg carb. I assume that might work ok for the Stag strommies as well, perhaps?

Cheers,
Joakim

[HersnotHis]

Some bedtime reading for you. http://www.partinfo.co.uk/files/VOSA...05%20&%207.pdf Section 7.3 page 6 will answer your question. and the manual will answer all the others re an MOT. But be warned, quote the manual to the tester, testing your car at your peril .

Ian. (ex MOT tester 1977-1983)

So this discussion is only relevant to Stags first used after 1st August 1975

[milothedog]

Your car still has to satisfy the tester via a visual check and for economy and the health of your engine you want it set properly

[Andrew S]

Made the adjustments to my mixture to around 1.8% and used it for work today and the jerking has gone completely at 1500 revs and was a delight to drive. MOT Saturday so hoping for the pass on Co and will be interesting to see. The only thing I noticed this morning was that the cold weather afftected the warm up time but there again, I went straight from a side road to 50mph so the air flow and temperature delayed the normal warm up and it struggled to reach 1/4 on the temp gauge. So, very pleased and was worth the time in the garage in the cold Sunday.

[KOY 23]

Result!

[Lingen]

Andrew. Good news, and perhaps you should get a garage heater! However, 1.8% is pretty lean. I think 4.5% was the recommendation, although that is right on the MOT limit now if it needs testing. I would try to get it nearer 4% if you can. It should run even better, and, surprisingly, should also give you a better MPG.
Mike.

[V Mad]

I find that I can adjust mixture for best idle, and get a very low CO reading, well below the 4.5%, perhaps as low as 1%. But the car runs and accelerates smoothly, and generally shows a good plug colour. So the running mixture is right, but the idle mixture may well be weak. Of course it would sail through the MOT if my car was a later model.

I have been running like this for about 3 years, and see no reason to change it.

I wonder, what mixture do the EFI guys run at idle and why?

[KOY 23]

I find that I can adjust mixture for best idle, and get a very low CO reading, well below the 4.5%, perhaps as low as 1%. But the car runs and accelerates smoothly, and generally shows a good plug colour. So the running mixture is right, but the idle mixture may well be weak. Of course it would sail through the MOT if my car was a later model.

I have been running like this for about 3 years, and see no reason to change it.

I wonder, what mixture do the EFI guys run at idle and why?

See post 43.

In reply to your question, whatever I want because I can.

[Andrew S]

I agree its low but just want a hassle free MOT in this weather and afterwards can tweak it () For now, being that I use the car for a daily commute subject to weather, i just wanted to get rid of that jerking which must have been due to over rich mixture. I would have thought that if it was over rich, it would just leave a cloud from the exhaust and not cause any running issues, but it clearly has