JP3 - two questions for the price of one

[starman]

I need to change oil in my dry sump JP3M. Any top tips on an easy-ish way to do it and what the oil capacity is.

Q2. When I increase the revs from idle the engine goes through a brief period of shudder before smoothing again as the revs go up more. Is this an inherent point of imbalance as it's always been there? Does so whether in gear or not.

[frangar]

For the oil change I use a brass sump pump with a length of hose fixed to the inlet which in turn has a short length of rigid pipe fixed to it…after running the engine for an hour or so to get the oil warm I then drop it in the oil tank and pump it out to a container…Just undo the big spring clips holding the gauzes into the plate in the tank.....then take the big side door off and do the same with whats in the sump.

 

Its much much easier when the oils warm! I then swab the last bits out with rags and newspaper finishing with some rags dipped in paraffin.

 

Its also worth taking the strainer out of the sump to clean right underneath it especially if you don't know how long its been in there! You will need a big whit spanner for this…I can check the size later.

 

You will need about 6 1/2 to 7 gallons of oil to replace…I use Morris Golden FIlm SAE 20. Remember to bung about a gallon or so in the sump before putting the side door back on…don't overfill the tank…I leave it about 3 inches below the max mark until I have run the engine then top it up once the level has sorted itself….check the level just after the engine has stopped as they can let oil back into the sump when stopped.

 

Not sure about the vibrations….mines a twin so vibration is all relevant!

 

Cheers

 

Gareth

Edited March 24, 2014 by frangar

[steamraiser2]

JP3s do not "shudder" as the revs increase when in good order. Perhaps one of your cylinders is not doing much work. Checking out valve clearances and getting your injectors pop tested would be a good idea. Poorly seated valves is also common.If the engine is heavily worn a rebuild may be needed to sort it out. Is it smokey?

[starman]

A bit of blue smoke but not overly so. Starts perfectly, runs well, just this brief shudder as I wind on some throttle. I'll check clearances and do injectors.

[J R ALSOP]

Check the flywheel, I once saw someone who looked shocked when one came off, it stood stationary whilst still turning, and then went down the workshop floor accelerating till it went through the wall about 40 feet away.

[Grace and Favour]

Check the flywheel, I once saw someone who looked shocked when one came off, it stood stationary whilst still turning, and then went down the workshop floor accelerating till it went through the wall about 40 feet away.

Ooh - - - that would bounce around an engine room nicely wouldn't it (?)

[Roadsteam]

I heard of a fluid flywheel going walkies once from off of a diesel railcar engine(11.1ltr Leyland) at full chat, it cleared IIRC 6 railway lines and partially demolished a house before stopping, it would have been a similar weight to a JP3 flywheel.