JP2 injector pump

[monkeyhanger]

I have a JP2 in my boat, which I built from an incomplete pile of pieces (the engine, not the boat). The missing pieces were sourced, bit by bit, elsewhere.I bought the injector pump from a young guy in the northeast, included it in the engine build, and the engine runs. (and has done for 20 years) However, I've always had at the back of my mind the thought that the pump I have may not the exact one for my engine. I know that these pumps were fitted to several types of engine, each of which will have had their own fuel delivery requirements.Does anyone have any data as to which pump should be fitted to which engine?

My engine is a 1949 marine unit( I checked the number with a list printed in Waterways World many years ago), and the pump I have is numbered BPE 2B 707100. Also stamped on the pump body is S533 and No14556R. My own suspicion is that the pump was originally fitted on a stationary engine as the outlet ports on the top have had the numbers 1 and 2 reversed. Would this make any difference to the running of my engine if it came from a stationary engine?

Any information and/or thoughts would be much appreciated. Jack

[steamraiser2]

BPE 2B 707100 is the pump type on my JP2 engines as well. It is the standard inline CAV pump for twin cylinder engines.I suspect that your pump may have originally been driven from the other end which could explain the apparent reversal of the cylinder numbers. I once had a JP3 that had a "backwards" driven injector pump (the pump was bolted on back to front). I fitted a different cam to it and all was well. So it is not the wrong pump but may have the wrong elements etc. If the engine starts well and is not chucking out huge amounts of black smoke I would leave well alone.

Edited June 27, 2011 by steamraiser2

[monkeyhanger]

BPE 2B 707100 is the pump type on my JP2 engines as well. It is the standard inline CAV pump for twin cylinder engines.I suspect that your pump may have originally been driven from the other end which could explain the apparent reversal of the cylinder numbers. I once had a JP3 that had a "backwards" driven injector pump (the pump was bolted on back to front). I fitted a different cam to it and all was well. So it is not the wrong pump but may have the wrong elements etc. If the engine starts well and is not chucking out huge amounts of black smoke I would leave well alone.

Thanks for the prompt reply. I have recently had new elements put in the pump, and had it recalibrated. The engine always starts first time and doesn't smoke more than would normally be expected, but it does seem to have a mind of its own as regards tickover. On occasions it will run well for (say) a week, then it will decide to tick over slowly, and the hand start mechanism rattles, so I adjust the speed up a little, then the following day it runs faster and I end up fiddling again to slow it down a touch. The joys of old engines, I suppose!

On a slightly different tack, I find that I have an amount of leakdown of diesel from the upper chamber of the CAV pump into the oilbath at the bottom, so diluting the oil. I'm concerned about wear and potential damage to the cam due to the lack of lubrication of the diesel compared to pure oil. I find that I regularly have to put a good squirt of oil in there to compensate, with the subsequent problems of overfilling the pump sump. Do you think I'm being overcautious? Jack

[frangar]

On a slightly different tack, I find that I have an amount of leakdown of diesel from the upper chamber of the CAV pump into the oilbath at the bottom, so diluting the oil. I'm concerned about wear and potential damage to the cam due to the lack of lubrication of the diesel compared to pure oil. I find that I regularly have to put a good squirt of oil in there to compensate, with the subsequent problems of overfilling the pump sump. Do you think I'm being overcautious? Jack

 

When cruising I have a suction pump that I use about once a week or so to suck the diesel/oil mixture out then refill with fresh oil....Mine too was rebuilt but this seems to be a bit of a trait of these pumps.

 

Its quite an easy job just to stick the suction probe down the dipstick hole and remove the mixture then top up with an oil can with some engine oil in it....I use the same one as I use for the rockers...to the right level on the dipstick,

 

HTH

 

Gareth

[monkeyhanger]

When cruising I have a suction pump that I use about once a week or so to suck the diesel/oil mixture out then refill with fresh oil....Mine too was rebuilt but this seems to be a bit of a trait of these pumps.

 

Its quite an easy job just to stick the suction probe down the dipstick hole and remove the mixture then top up with an oil can with some engine oil in it....I use the same one as I use for the rockers...to the right level on the dipstick,

 

HTH

 

Gareth

Sounds like a very sensible solution. My pump, unfortunately, does not have a dipstick fitment, so I have made up a small swan neck pipe and fitted it to what I assume is the oil level plug in the back of the pump body. I have a small catch can located underneath the swan neck to collect the drips. Interestingly, if I drive the boat gently, or have a few locks to go through, the catch can will remain empty. If I have a lockless section and get the chance to wind the engine up for a length of time so that it gets good and hot, I can then expect to find a can of oil/diesel mixture there the following morning. I've often wondered if there may be a crack in the pump body which only opens up enough when it gets really hot. Jack

[frangar]

Thats interesting about the lack of dipstick...I thought all these pumps had them!...will have a look to see if mine has a level plug as well....mine doesnt take much oil at all to get it to the right level on the dipstick...about 13 squirts of the oil can!....out of interest which port is marked 1?..the one nearest or furthest from the centre of the engine?....When I first got my boat the timing was well out cos a previous person had used the marks on the flywheel...all very well but the flywheel was from a JP3 and mines a twin....It still ran tho albeit a bit smoky and with a tendency to kick back on the hand start.....it also possibly was the cause of the big end bearings failing due to the firing stresses being at the wrong time!..The JP manual does tell you how to check the timing by removing the delivery pipes and the springs & ball stops...then you can take off a side door to see the piston position.

 

HTH

 

Gareth

[monkeyhanger]

Thats interesting about the lack of dipstick...I thought all these pumps had them!...will have a look to see if mine has a level plug as well....mine doesnt take much oil at all to get it to the right level on the dipstick...about 13 squirts of the oil can!....out of interest which port is marked 1?..the one nearest or furthest from the centre of the engine?....When I first got my boat the timing was well out cos a previous person had used the marks on the flywheel...all very well but the flywheel was from a JP3 and mines a twin....It still ran tho albeit a bit smoky and with a tendency to kick back on the hand start.....it also possibly was the cause of the big end bearings failing due to the firing stresses being at the wrong time!..The JP manual does tell you how to check the timing by removing the delivery pipes and the springs & ball stops...then you can take off a side door to see the piston position.

 

HTH

 

Gareth

 

I'm not on the boat at present, so I've had to dig out some old photos from when I built the engine in my front garden! From the photos it appears the the front (flywheel) cylinder is fed from the port furthest from the engine centre line.

I assume you're referring to spill timing the injection- I've done that and it's correct. Jack

[steamraiser2]

The CAV pump needs less oil than you think. Fill it to the mark and they usually chuck some out. The rattling hand start is common and the cause is usually the tension on the governor spring allowing the revs to drop too far. Lister never set the engines to idle as slowly as us vintage engine guys like! Get a new spring and adjust accordingly and you will find that the tickover will stabilise. If you have fuel leaking in to the pump you have an element leaking. The problem is that the diesel in the oil can cause accelerated wear on the pump cam over time and wash out the pump bearings. Changing the bearings is easy, sourcing a replacement pump cam is a different story. Rocking horses and all that. You do not want to know what getting a new cam ground will cost!

[David Mack]

I'm not on the boat at present, so I've had to dig out some old photos from when I built the engine in my front garden! From the photos it appears the the front (flywheel) cylinder is fed from the port furthest from the engine centre line.

 

That's not entirely helpful! On the engines with industrial origins, the flywheel is on the opposite end to the marine version.

 

David

[monkeyhanger]

That's not entirely helpful! On the engines with industrial origins, the flywheel is on the opposite end to the marine version.

 

David

It's the marine version. Pump and flywheel are next to each other. Jack

[by'eck]

I'm not on the boat at present, so I've had to dig out some old photos from when I built the engine in my front garden! From the photos it appears the the front (flywheel) cylinder is fed from the port furthest from the engine centre line.

I assume you're referring to spill timing the injection- I've done that and it's correct. Jack

 

It's the marine version. Pump and flywheel are next to each other. Jack

 

Your port routing seems normal for JP2M as shown here - same on my older engine as well

 

Edited June 28, 2011 by richardhula

[monkeyhanger]

Your port routing seems normal for JP2M as shown here - same on my older engine as well

 

I'm certain I looked through the engine 'ole doors at this engine at the weekend at Braunston. Don't recall seeing the 'ecky thump name, though. Jack

[by'eck]

I'm certain I looked through the engine 'ole doors at this engine at the weekend at Braunston. Don't recall seeing the 'ecky thump name, though. Jack

 

Yes you did although it wasn't my engine/boat. The picture best showed injection pipe routing though.

 

My engines still waiting to be fitted in new shell although that should be soon

Edited June 28, 2011 by richardhula

[monkeyhanger]

Thanks to all the people who ventured forth with information. It looks like I've got the correct injector pump, which was my main concern. I've still got to sort the diesel leakdown problem, however. I've got another pump as a spare, which, incidentally DOES have a dipstick, so I guess I'll have to give that a try and see what happens. Thanks again. Jack

[RLWP]

There is a famous, and useful expression which may well apply here

 

"If it ain't broke, don't fix it"

 

Just a thought

 

Richard

[sebrof]

I have recently had my injector pump overhauled. It came back looking like new. The advice I was given was to drain the oil once a year, and replace.

[GRLMK38]

A boater friend has a JP3 Marine and mentioned that a small amount of "fluid" (which I assume is either oil/diesel or both) is leaking from what sounds from his description like the dipstick on the fuel pump.  After some searching around I have found this post.  Is the diesel dropping in to the oil common?

 

What is involved in a proper repair or is it acceptable to extract and add fresh oil periodically?

[BEngo]

The leak is usually from between the pumping element barrels and the casing.  New elements may cure it, for a while.  That is a pump overhaul job.

 

Really it is not a major problem.  I have not heard of accelerated camshaft wear caused by diesel in the oil. Keep an eye on the level.  Suck or drain out the oil/diesel mix when full and add some fresh oil through the dipstick hole.  About 25 squirts of an oilcan is needed on mine YMMV.

 

Shutting the fuel tap when not running may help slow the leakage rate.

N

[GRLMK38]

Thanks @BEngo - the engine does low hours so even if accelerated wear was an issue it's not what it would be if it was on the move all the time.

 

Interesting point about the fuel tap.  He has a gravity feed so I will mention it.

 

I haven't seen the dipstick yet, are the desired levels obvious?

[BEngo]

2 hours ago, GRLMK38 said:

Thanks @BEngo - the engine does low hours so even if accelerated wear was an issue it's not what it would be if it was on the move all the time.

 

Interesting point about the fuel tap.  He has a gravity feed so I will mention it.

 

I haven't seen the dipstick yet, are the desired levels obvious?

Yes.

N

[frangar]

4 hours ago, BEngo said:

The leak is usually from between the pumping element barrels and the casing.  New elements may cure it, for a while.  That is a pump overhaul job.

 

Really it is not a major problem.  I have not heard of accelerated camshaft wear caused by diesel in the oil. Keep an eye on the level.  Suck or drain out the oil/diesel mix when full and add some fresh oil through the dipstick hole.  About 25 squirts of an oilcan is needed on mine YMMV.

 

Shutting the fuel tap when not running may help slow the leakage rate.

N

I’ll second that advice. When I’m out boating I usually suck out the diesel & refill with oil every couple of weeks...when the level is rising above the max on the dipstick. Possibly  overkill but that’s me! 

[RLWP]

2 hours ago, frangar said:

I’ll second that advice. When I’m out boating I usually suck out the diesel & refill with oil every couple of weeks...when the level is rising above the max on the dipstick. Possibly  overkill but that’s me! 

Not overkill at all! If the camshaft goes in your pump, you'll be looking for a new pump

[frangar]

1 minute ago, RLWP said:

Not overkill at all! If the camshaft goes in your pump, you'll be looking for a new pump

Indeed...mines a twin.....pump camshafts aren’t easy to come by. 

[john.k]

And here we have the strange fact that a CAV Bosch pumping unit made in 1934 has only a fraction of the back leakage of a unit made in Mumbai yesterday.........yes ,all "legacy" Bosch spares are now made in India,which means all mechanical injection,including the VE/VF rotary pumps.

[GRLMK38]

Thanks for all the advice.

 

We have just removed 450ml of diesel/oil mix and replaced it with clean engine oil up to the mark on the dipstick.  Fuel tap is now turned off.

 

It will be checked regularly from now on and removed/replaced as needed.  It was a case of "you don't know what you don't know".

 

It does show the merits of checking drips and leaks, that's how this got noticed.  Diesel was dripping past the dipstick when the engine was running.