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JP3 smoke from cylinder heads, after putting in new pistons and rings


DannyD

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11 minutes ago, frangar said:

It’s really not a hard job though to grease the rocker shaft & top the oil up…for me it’s part of the joy of owning a vintage engine rather than a digger power plant 

Yes that's a good point! 😉

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1 hour ago, john.k said:

The grease and oil rocker shafts have different part nos......indicating the threads are likely different........also note ,the JP3 lists elbows for the greasers,so you can get at them 

The threads are the same, the difference is in the oil way machining on the later shafts. In practice it makes little difference.

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No not yet, I'm currently blaming the oil I used, normally I have the Golden Film Classic SAE30 but it was a bit hard to order this time so I used Castrol classic XL SAE 30.

Before I pull the engine apart for the thirty time I wanna change the oil first to the Golden Film. I could order it now but it will take till the first week of december to get here.

 

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1 hour ago, DannyD said:

No not yet, I'm currently blaming the oil I used, normally I have the Golden Film Classic SAE30 but it was a bit hard to order this time so I used Castrol classic XL SAE 30.

Before I pull the engine apart for the thirty time I wanna change the oil first to the Golden Film. I could order it now but it will take till the first week of december to get here.

 

I found one of the VW campervan specialists was the cheapest place for Morris Classic SAE30 bought online.

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1 hour ago, Tracy D'arth said:

I can't see what difference using another oil will make to oil fuming. Its not the oil that causes fumes.

 

My thoughts too, unless its oil leaking out onto something very hot.

 

The smoke drifting around in the videos is more likely to be crank-case gas or combustion (exhaust) gas leaking out of somewhere. 

 

 

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Spec says it meets Mil-L-2104B,which was the requirement back in the 60s,so it should be ok.......New rings in worn chrome bores take a very long time to wear in,so that may be the cause of fumes.....honing chrome with a normal hone has no effect. 

Edited by john.k
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On 23/11/2021 at 13:43, DannyD said:

Do you have a picture of the conversion?

 

Oil feeds to the rocker shafts on a JP3 which  originally drove a searchlight generator. I was told it was originally supplied to the RAF, hence the RAF blue paint colour, to a military spec. As far as I know the oil feed is original.

20211126_113723.jpg.698e643b3f4d75b890bf63da7b0affaa.jpg20211126_113734.jpg.6fed7b2deb514c52e675095d886872ad.jpg

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On 26/11/2021 at 10:08, john.k said:

Not wise to use anything but a HD diesel oil in any diesel........or youll end up with stuck rings.....rather a lot of oil in a JP3 too,sort of motor Id be changing once a year ,if it needed it.

I believe that manual stipulates an oil change every 250 hours. That's what I do on mine anyway. If you have a dry sump engine that's 6 gallons per change, which is not cheap.

 

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1 hour ago, monkeyhanger said:

I believe that manual stipulates an oil change every 250 hours. That's what I do on mine anyway. If you have a dry sump engine that's 6 gallons per change, which is not cheap.

 

My manual says 450hrs…dry sump so 6+ gallons. That works out at one a year for us. 

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1 hour ago, Tracy D'arth said:

With no oil filter (no pump I am told)  I would have a socking big neodymium magnet in the sump and change the oil less often to save the dwindling world resource. 6 gallons is tooooo much. 

It has gauze filters for the bigger bits of metal and a oil pump....runs at about 15-20psi......and I dont think a magnet would pick up white metal from the bearings....mines actually more like 7 gallons but such is the joy of vintage engines.....I love it!

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Engine in the pic has no compression release levers......and IMHO ,the copper lines are to remote greasers.......at one time I had a couple of the searchlight generators as spares for my three Broom.Wade SV125 compressors with JP3s.......poor mans 350 cfm for sandblasting boats........with a worn 3/8 nozzle ,the three Listers would be flat out ,and they went for years .

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23 minutes ago, john.k said:

Engine in the pic has no compression release levers......and IMHO ,the copper lines are to remote greasers.......at one time I had a couple of the searchlight generators as spares for my three Broom.Wade SV125 compressors with JP3s.......poor mans 350 cfm for sandblasting boats........with a worn 3/8 nozzle ,the three Listers would be flat out ,and they went for years .

The decompressors are knobs on the large side cover plate on the engine. I assume they hold the pushrods up, rather than acting directly on the exhaust valves as the version mounted on the rocker covers do (but I have never taken the side cover off to look). And although the photos don't show it, those copper pipes are connected to the main pressurised oil supply.

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