Heavy wet sumping

[magnusk750]

No problem with your english, I think it's far better than mine. Annars kan vi snakke skandinavisk, jag är svensk, men bosatt i Estland Thanks for pointing out about about the non return valve, will check that.

[magnusk750]

More oiling troubles. For the first time I had the engine running for a while. 5-10 minutes. It's the second time I have it running, first time just very briefly. Proper oil return, but under valve covers it's totally dry. Bottom end is 55, cylinder heads probably 52-53-ish. Two screws valve covers, but no oiling grooves in the rockers.

I can see several reasons for dry valves-rockers: 1. wrong or incorrectly fitted head gaskets. 2. Not been running long enough to pump up oil to the heads. 3. Cylinder heads and rest of engine don't fit together. 4. something else?

[dave16mct]

More likely to be the metering jets blocked in the heads. They have a very small hole, less than 1mm. I use a very fine guitar string to clear them but I think you'll have to remover the heads to clear them. Early 55 had a different oil metering jet (next to the oil filter in the crankcase) then quickly changed back to the rotating oil distributor 022385. Perhaps check that if you've got the distributor that it's OK. My 55 twin had the distributor and I had no problems.
Dave

[magnusk750]

Let the engine run for ten more minutes (while oiling with an oil can). Still no oil to the top ends. Removed one cylinder head. There's no metering jets in these cylinder heads, channels in the heads are circa 3 mm. Totally dry in the channels. There's plenty of oil in the cylinder bores, perhaps even more than needed, but I'm not an expert. From the emgine number mine's on of them with a metering jet instead of rotating oil distributor, so next thing is to check that area. I think I have the parts to convert if needed.

After what I've read there are three different rotating distributors, with holes 3/64' (1,2 mm); 1/16' (1,6 mm) and 1/32' (0,8 mm) The one I found in a box is 1,2 mm. Is there a reason to enlarge the hole to 1,6 mm ?

20240521_222329-II.jpg

[dave16mct]

I would leave it at 1.2 mm for now. When you fit it you must use the correct copper sealing ring under the cap. If you use a fibre washer you can end load the distributor.
Dave.

[magnusk750]

That's useful info Dave, thanks. Will soon order from AMC classic spares anyway.

[magnusk750]

Think I've found the culprit, don't know if it's good or bad. The 55 only metering jet that is screwed into the crankcase is there, but someone has thrashed it while trying to remove. It's totally blocked, I couldn't even push a 0,35 mm guitar string through it. What to do? The channel in the casing is straight, ends in the oilfilter channel. If I remove the oil filter, pack the channel with a clean cloth (or something better?) then I should be able to drill through the jet with a 3-4 mm drill bit? Of course thoroughly remove all swarf afterwards, but should be possible without causing trouble, or what you think? Alternative is to take the engine apart right away?

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[dave16mct]

Tricky but I think you could drill into it and perhaps bang a screwdriver ground to a square-shaped taper, you could unscrew it. Drilling right through it looks easy enough if you can collect all the swarf afterwards.
Dave

[magnusk750]

My thought for the moment, if nothing better comes up, is that I drill it through with a 4 mm drill bit with plenty of grease on it and then clean with pipe cleaners several times. If drilling for then trying unscrew it would have to be with a tiny drill, perhaps 2 mm, more likely to break. A quality 4 mm drill is already pretty sturdy.