Smoking engine ?

[Lynn Eades]

Cummins Blue diesel oil because the diesel oil has more zinc that most petrol engine oils. The diesel oil is high detergent and might help to un gum your oil rings (which sounds like the problem to me?)
If not then a mono 30 grade oil high in zinc (important) The zinc has been largely removed from petrol engine oil for "enviromental" reasons.
Do some research to bolster your choice.

[Richard Farrant]

Originally Posted by Lynn Eades

Cummins Blue diesel oil because the diesel oil has more zinc that most petrol engine oils. The diesel oil is high detergent and might help to un gum your oil rings (which sounds like the problem to me?)
If not then a mono 30 grade oil high in zinc (important) The zinc has been largely removed from petrol engine oil for "enviromental" reasons.
Do some research to bolster your choice.

I would not recommend using a high detergent diesel oil in an engine of this age which is probably been running on the old style monograde with little or no detergent. You may think it will un-gum the rings, but worse than that it will release all the sediments in lower part of the engine and put them in circulating and hence cause damage to the bearings. I have been 55 years in the trade working on engines and would never use a high detergent oil in and old engine of unknown history. Just changing the oil will not get rid of the sediment.
If it had just been overhauled and clean inside, then a different matter.

[carrierbarry]

Both good answers, thanks for the help. What would you recommend Richard. New plugs, clean air filter, oil change ,,clean oil filter. And some fresh fuel.
I’m sure it’s just we’re she’s been sitting idle though the winter.
What grade of oil would you use?

[Richard Farrant]

Originally Posted by carrierbarry

Both good answers, thanks for the help. What would you recommend Richard. New plugs, clean air filter, oil change ,,clean oil filter. And some fresh fuel.
I’m sure it’s just we’re she’s been sitting idle though the winter.
What grade of oil would you use?

Hi Barry
I wouLd run the engine up and get it hot, then drain the oil. Smell the oil to see if there is any hint of petrol. If so there may be petrol leaking through the fuel pump diaphragm and into the oil and thinning it out which could be a cause of the smoke. The specified oil for Carriers by British army was SAE 30 and I would use one of the Classic 30 oils which you often find stocked in local motor factors.
I did suggest in an earlier post to take the plugs out one at a time to see if any particular ones were oily as that could indicate a problem withiN that cylinder.

[Ron Pier]

I concur with Richard regarding the detergent oil. Ron

[carrierbarry]

I checked plugs, no oil. But running a bit rich.
Took leads off one at a time ,each time engine missed.

Think I’ll change oil.

[Lynn Eades]

Richard has a good point about using a diesel oil in an older engine. I dont know the details of your engine and that's why I suggested you do some research. I run a "Total" brand diesel oil "Rubia "mono grade 30 which is designed for older engines. As it happens, I don't run a mechanical pump because I have seen some problems with old diaphragms and modern fuel, that have lead to oil dilution and run bearings. I also run a full flow oil filter in my cooler line.
The benefit of the high detergent oil is that once the engine is clean it will stay clean. I have run this oil from a major rebuild.
The Cummins Blue recommendation came from a study on the Ford Barn Forum and was the result of a study of various oils and their contents of various additive packages. The problem with modern (mainstream) petrol oils is they lack enough zinc to protect the cam and followers from premature failure.
Richard's "Classic 30" is good advice (not that I am judging him in any way) The "classic" bit covers the zinc issue. The straight 30 grade recommendation is about the greater ability of the mono grade to transfer heat. I too am an "A" grade mechanic of 50 years in the game, but I have probably done less engine work than him.