Lift pump/cam lobe 1.8 BMC

[Ocean30]

Ok here we go! 
 

So a friends 1.8 BMC had a run away incident due to pump seal failure and subsequent diesel in the oil. A common story, however….we replaced with a re furb pump and got it up and running before it would just die again. So, checked for air and no air. Changed filters etc and came back to the lift pump which was also replaced. Now this is the interesting bit. It seems like the lift pump is not pushing through fuel. As if the lever is not being activated by the cam lobe on the cam shaft. It has been healed in correctly so I know this is not the issue: when I placed my finger on the lobe on the camshaft and felt about I could feel a piece of metal spinning freely on the cam lobe. We turned over the engine and found that there was little movement on the lobe. I then held the pump in place with my hand and got the engine turned over. No resistance or pressure pushing the pump towards my hand. 
 

my hypothesis is that during runaway the Cam lobe on the camshaft has somehow failed and has become in effective? Thoughts? 

 My friend is now considering blanking off fuel pump and fitting a in line electric pump. anyone fine this and any recommendations? 
 

Thanks for your help as always. 
 

Simon 
 

 

[Tony Brooks]

It should not be a cam but an eccentric, however I thought they were forged as part of the camshaft and then hardened. Nitriding comes to mind as the process. I can't see how anything could detach itself unless by some weird occurrence the hardened surface fell off. I agree, lank the hole and fit an electric pump. I think any electric pump will do, Facit is the name a lot of motor factors stock.

[Ocean30]

Cheers Tony. I wondered if someone had the crank shaft out once and welded a shim to the original lobe that would have been cast. It’s really weird for sure. I’ll get hi to order an electric pump and blank off. Might stick a camera in the hole to see more. Will keep you posted. 

[Tracy D'arth]

Its an eccentric that drives the pump and it is part of the camshaft casting. I have never seen one or part of one detach.  I would love to see a picture of the inside if you can borrow an endoscope or buy a cheap one off ebay that is usb.

I can't see how a runaway would do this. Perhaps as you say at some time it has been modified.

Instead of an electric pump have you considered using a gravity day tank?

[Tony Brooks]

Some thoughts. That pump body on the petrol engines often had a thick thermal insulator between two mounting gaskets rather than a single gasket. Has an insulator been fitted on your engine.

 

It is all too easy to bow the pump body mounting flange, has anyone fitted a thicker gasket, thereby moving the pump lever further from the pump.

 

That type of pump body was fitted to many different makes of engine with the operating lever being different, are you sure you have the correct one.

 

I wonder if, at some time, the lever was fitted behind the eccentric, so it bent and was incorrectly straightened.

 

If you post a photo of the pump - side view showing the operating lever - we might be able to see if anything is wrong.

 

As both Tracy and myself are having difficulty in understanding what you say about the eccentric, a photo through the mounting hole just might give a clue.

 

[beerbeerbeerbeerbeer]

[Tony Brooks]

3 minutes ago, Goliath said:

 

Yes, we know what it should look like, but does it. The OP has described a fault that is all but unbelievable so I have been trying to work out what may actually be wrong with it.

[beerbeerbeerbeerbeer]

I expected you knew what it looks like. 
But I like the diagram. 
So posted it. 
 

 

[john.k]

Whats not uncommon is for the pivot of the lever to flog out the crap alloy and so all the cam lift is lost motion in the pump...........there is a very simple cure ,and that is an electric lift pump...............might also be interested to know for the last 25 years Jap diesels in cars and utes dont have lift pumps at all.........the injector pump pulls fuel up from the tank ,through a filter and into the pump,all without the aid of a lift pump.

[RLWP]

10 hours ago, Tony Brooks said:

 

Yes, we know what it should look like, but does it. The OP has described a fault that is all but unbelievable so I have been trying to work out what may actually be wrong with it.

 

I wonder if he's got the lever tucked underneath the cam, not pushing against the side

 

Richard

[Tracy D'arth]

If the lever had gone on the wrong side it would be mangled now.

 

The only thing that I can think of that could be spinning free on the camshaft eccentric is the bearing shell that has come out of the bore in the block. If this is the case the engine will need to be completely stripped to replace it. I do hope that I am wrong. Never seen it happen.

[Tony Brooks]

18 minutes ago, RLWP said:

 

I wonder if he's got the lever tucked underneath the cam, not pushing against the side

 

Richard

 

That is why I asked for a side view. Did you see where he says there is a loose silver metallic ring around what he calls a cam, but is probably the eccentric?

1 minute ago, Tracy D'arth said:

If the lever had gone on the wrong side it would be mangled now.

 

The only thing that I can think of that could be spinning free on the camshaft eccentric is the bearing shell that has come out of the bore in the block. If this is the case the engine will need to be completely stripped to replace it. I do hope that I am wrong. Never seen it happen.

 

That makes sense, but I think that the cam followers would stop it getting to the eccentric (not that I can remember exactly where the bearings are in relation to the eccentric). In fact, it is the only thing that does make sense. I, too, have never seen one come out.

[Tracy D'arth]

I have fitted hundreds of lift pumps and never managed to get the lever on the wrong side of the cam. Is there a special knack in achieving this faux pas?

[Tony Brooks]

Just now, Tracy D'arth said:

I have fitted hundreds of lift pumps and never managed to get the lever on the wrong side of the cam. Is there a special knack in achieving this faux pas?

 

Having had new apprentices who managed it without a problem, it seems the knack is to tilt the pump down by the flange as you insert it and then force it onto the studs.

[Tracy D'arth]

25 minutes ago, Tony Brooks said:

 

Having had new apprentices who managed it without a problem, it seems the knack is to tilt the pump down by the flange as you insert it and then force it onto the studs.

That would be the way but why would anyone try to fit it at such a crazy angle when it has to sit square on the block?  I have noticed over the years that the length and shape of the pump lever arm has changed somewhat.

 

I am trying to remember where on the camshaft the eccentric is. Its not between 2 cam followers so I am thinking it is next to a bearing shell but for life of me I can't picture it. Has anyone a view of a camshaft out of the engine? or a sideways cut away drawing of the port side of the block, a petrol e B series will do.

 

********As you were, the manual shows the eccentric between the inlet valve followers of #1 and #2 cylinders so nowhere near the bearings which are of course front, back and centre of the camshaft.**********

So it cannot be a bearing shell rattling around on the shaft.  But what is it? Please a picture through the hole.

Edited March 28, 2023 by Tracy D'arth
add

[beerbeerbeerbeerbeer]

any good? Best I got

Edited March 28, 2023 by Goliath

[Ocean30]

So it’s not my engine. We have tried two separate pumps and there doesn’t appear to be any contact with the lobe and the arm on the lift pump. Fitting it up isn’t an issue. I’ve done these before. 
We turned the engine over whilst holding the lift pump flush with the block by hand and there was absolutely no resistance, as if the lobe is making no contact at all. 
Stuck a camera in the hole last night and everything is good in terms of lobe. No extra shell. I believe the lobe has excessive wear thus no lift of fuel. I’ve checked the lift pump and it appears like the correct one. Although I’m assuming there was only 1 design? I think we are going to bypass and fit in an electric pump that is self priming. This poor chap hasn’t been able to use his boat for a year as he has not been able to get to the bottom of it all! And to top it off he’s wife has been diagnosed with cancer☹️. 

[Tony Brooks]

Thanks Goliath, that certainly looks as if what may be the eccentric is next to the middle bearing, so it makes Tracy's suggestion more likely.

 

I note the OP did not mention the loose metallic ring in his reply above.

Edited March 28, 2023 by Tony Brooks

[bizzard]

Something has happened there. Possibly one of the old pump levers has somehow machined the cam lobe down to circular so it won't work the pump. A similar thing used to happen on the old Ford ohv petrol engines in the 105e Anglias. A cast follower tapped would snap a bit off it's foot and would then perfectly machine the cam down to circular, always an inlet valve for some reason.

[Ocean30]

I stuck a screwdriver (lightly) against the lobe and turned over. Very small amount of movement. No extra shell fitted. 

[john.k]

There would be a groove worn in the cam the same width as the lever pad ......I cant see the whole eccentric being worn away............now ,maybe some ijit has ground the eccentric off the cam for whatever reason..................then ,of course its a BMC ......maybe Red Robbo made it.

[Tony Brooks]

27 minutes ago, john.k said:

There would be a groove worn in the cam the same width as the lever pad ......I cant see the whole eccentric being worn away............now ,maybe some ijit has ground the eccentric off the cam for whatever reason..................then ,of course its a BMC ......maybe Red Robbo made it.

 

I rather think not, it is a 1.8 and may well have been made in Turkey.

 

I discounted your earlier suggestion because if the pivot was worn, I would expect an oil leak. I have never known an eccentric to wear as the symptoms imply, so would love to find out exactly what has gone on. I wonder if the petrol engine cam shafts that used an electric pump had the eccentric.

[Ken X]

30 minutes ago, Tony Brooks said:

 

I wonder if the petrol engine cam shafts that used an electric pump had the eccentric.

I had a quick look at my Morris Minor and Mini books and Mr Visard seems to say that BL used the same basic camshaft style across all the petrol engines.  The eccentric lobe is visible on my Morris Minor Workshop Manual and the Morris is electrically pumped so it seem reasonable to suspect it was a common basic design camshaft.

[Tracy D'arth]

2 minutes ago, Ken X said:

I had a quick look at my Morris Minor and Mini books and Mr Visard seems to say that BL used the same basic camshaft style across all the petrol engines.  The eccentric lobe is visible on my Morris Minor Workshop Manual and the Morris is electrically pumped so it seem reasonable to suspect it was a common basic design camshaft.

Correct, they used the same camshaft forging for most small engines.

 

We used to have a problem with Ford V4 and V6 engines where the mechanical pump wold not deliver sufficient fuel. The road side fix was a piece of plastic hose shoved onto the arm to run on the timing gear inside the front cover.

 

Sounds like a similar problem. These pumps have a lot of free movement usually and they only need the last  few tens of thou extra push to work. So if you lose a few mill from the arm and/or the eccentric they stop pumping.

 

I would try a bit of nylon pipe on the arm, bet it will work then.

 

  As I said there is more than one pattern of arm too.

[Ocean30]

Two photos. The old pump had a different face as you can see, the one with the two gaskets. The new one with the red gasket was fitted.