BMC 1.5 - snapped oil jet

[jhodgski]

As disussed in this thread - http://www.canalworld.net/forums/index.php?showtopic=71880&page=3#entry1457033 - the oil jet snapped when I was removing / replacing it from a bmc 1.5 i am installing.

 

I have taken the replacement out of my old engine - which, incidentally, screws into and out of my old engine very easily.

 

When trying to screw the old oil jet into my *new* engine, with about 5mm of tightening to go, it suddenly meets a lot of resistance. This is probably the same resistance that I screwed through before with the original oil jet, thereby breaking it.

 

I cannot get my eye level with the entry hole to see what is causing the resistance (and it's probably too dark to see in there anyway) but I have inserted a metal wire (part of a straightened coat hanger) and there doesn't feel to be anything in the way at all. (In fact, if anything, there seems to be more freedom here compared to the old engine.)

 

Here is a photo of the new oil jet and what's left of the oil one (the snapped off part is somewhere in the engine - hopefully RIP in the sump...)

 

https://db.tt/xK2aIwln

 

Q1. Does anyone have any tips for how I can get the new oil jet in place without forcing/shearing it again.

 

Q2. Would it be OK for me to run the engine without an oil jet - ie, so I just screw what's left of the old oil jet back in (which screws all the way in very easily)?

 

Q3. Do I need to worry about the sheared-off part of the old oil jet which is in the engine somewhere?

 

Thanks in advance,

James

 

PS - I've created a new thread for this as it's an issue in its own right and I think would be taking the aforementioned thread too far off-topic.

[bigste]

This is what you need. Should be one in every toolbox. Probably just needs a tap running through it.

http://www.ebay.co.uk/itm/5M-7mm-6LED-Waterproof-Borescope-Endoscope-Video-Inspection-Scope-Camera-/141471110197?pt=UK_BOI_Medical_Lab_Equipment_Medical_Equipment_Instruments_ET&hash=item20f055d435

I've used one to inspect bores via a spark plug hole on several occasions.

Edited December 16, 2014 by bigste

[jhodgski]

OK, thanks. I'll get one ordered tonight.

[MtB]

This is what you need. Should be one in every toolbox. Probably just needs a tap running through it.

http://www.ebay.co.uk/itm/5M-7mm-6LED-Waterproof-Borescope-Endoscope-Video-Inspection-Scope-Camera-/141471110197?pt=UK_BOI_Medical_Lab_Equipment_Medical_Equipment_Instruments_ET&hash=item20f055d435

I've used one to inspect bores via a spark plug hole on several occasions.

 

 

A mirror and a torch are excellent for seeing around corners and into holes too.

 

Invaluable in my line of work.

 

 

MtB

[Tony Brooks]

If you run the engine for any significant time without that jet you will wear the camshaft and injector pump drive skew gears.

 

Until you find out why the jet snapped off no one should tell you that it is OK to leave the old one in there. Especially as you say you can hear noises in the engine. I think it will just be lying in the bottom of the sump and out of harms way but I only think that, I do not know.

 

You have to find out why you can not screw the other jet back in.

 

I am almost wondering if someone has done a rag round the big end repair before they sold the engine to you.

[jhodgski]

Ok, thanks, Tony. Excuse my ignorance - what is a rag round the big end repair job?

[ditchcrawler]

One down from replacing the Big end shells with a leather belt

edit to add

My dad had the engine of an Austin 1500 rebuilt, when it broke again we found the big end shells shimmed out with strips of time sheets.

Edited December 16, 2014 by ditchcrawler

[Tony Brooks]

Ok, thanks, Tony. Excuse my ignorance - what is a rag round the big end repair job?

 

Pretty much as it says. I just can not see how anything could jamb up that oil jet (but am always happy to learn from others experiences) so I began to wonder what on earth could produce a physical obstruction INSIDE the engine and can not really come up with anything. However I note that the "new" oil jet is bent. Was this bent when it came form the last engine or did it bend when you were trying to fit it to this one.

 

When you checked the oil pressure release valve did you make sure no washers had been used to pack the spring. Either below the spring in the valve itself or in the hexagon "bolt".

 

Clutching at straws here. Just in case a crank web is obstructing the oil jet it would be best to check the end float on the crankshaft but I doubt it is possible to get enough to allow a web to foul the jet. At the front pulley lever the front pulley away from the engine. The lever it (somehow) back into the engine. There should be an almost imperceptible amount of fore and aft movement. If we are talking a measurable amount then the engine needs stripping (thanks to Bizzard for reminding me on another thread).

[p6rob]

Give Calcutts a call and ask them what could possibly cause such an obstruction and where the broken bit might have got to. They've been really helpful over the phone and in person.

01926 813757.

[jhodgski]

I looked inside the old engine and, indeed, there was nothing there to obstruct the oil jet.

 

I'm pretty sure it was slightly bent, though, when we took it out of the old engine, but can't say for sure.

 

I straightened it but it wouldn't go in. So I had to trim 15mm off the end for it to go in.

 

Before that, we put tippex on the end of it before screwing it in then had a look with the endoscope and it was hitting something metal - presumably a wider part of the camshaft, but can't say for sure.

 

Is it worth me taking the sump off and going in to with the endoscope to have a proper look?

 

Could someone expand for me on Tony's last paragraph - not sure what any of it meant.

Cheers, p6rob, I'll give them a call on Monday.

[pete.i]

Do you have a workshop manual for that engine? If you haven't I can email you one. It isn't particulary good as workshop manuals go but it's better than nothing. Also I have a BMC 1.5 engine out on a bench in my garage that I am about to strip down , again. You are only 40 miles away so if looking at my engine would be of any help then give me a PM and I'll let you have my details.

Edited January 24, 2015 by pete.i

[RLWP]

The manual is here: http://the-norfolk-broads.co.uk/downloads/bmc1500L-diesel-workshop-manual.pdf

 

Richard

[pete.i]

Thanks for that Richard. I thought that I had read that they had taken that down so I didn't look. That's the one I have.

[jhodgski]

Thanks for the link to the manual. I'm still none-the-wiser tho re Tony's last paragraph - is there a particular page I should be looking at?

 

Thanks for the offer, Pete, but I already have my old engine in bits so that is coming in quite handy in terms of clues.

[Tony Brooks]

Clutching at straws = something that is very unlikely but now everything needs considering, however unlikely.

 

The crankshaft has two pairs of thrust washers fitted either side of one of the main crankshaft journals (bearings). In a vehicle one pair stops clutch operation pushing the crankshaft out of the front of the engine and the other pair stops the shaft "sliding" backwards when the engine is tilted. There is a set maximum front to back free movement allowed on the crankshaft (I am not going into the manual to look it up but say 0.3mm or less). This fee movement is end float. If it is excessive those thrust washers are worn at the least.

 

Crank webs are the parts that stick out of the side of the crankshaft that joint the big end journals to the main journals.

 

Now, I do not know if those webs can ever get close to the oil jet but if they did and if there was excessive end float maybe the crank web is hitting the jet and damaging it.

 

You seem to be having so much trouble with this "new" engine that I would think it would now be very worthwhile taking it out of the boat and taking the sump off to see exactly what is going on. If you invert the engine you should not need to be messing with an endoscope.

 

I also wonder if someone has fitted a high lift camshaft off an MG or some such and a cam is hitting the jet.

Edited January 25, 2015 by Tony Brooks

[Arthur Brown]

From this thread and it's partner (excessive oil pressure) I am of the opinion that something is wrong inside this engine.

 

I'd look to evaluate the cost of a full engine out investigation. There is a broken bit in there somewhere and there is a reason for the high oil pressure.

 

I see the options being; take the engine to pieces and blow out every part of every oilway, or run it to it's end and buy a new engine. Neither option is cheap, in fact probably they are probably the same order of cost, but if you chose the time to take the engine out it's far safer than having to moor up somewhere when the engine finally stops.

 

I keep thinking of what an old motor mechanic said to me when we had an engine in pieces -"use cotton rag to wipe, use cotton waste to block oilways" - that was in the 60s though I doubt it's changed.

[RLWP]

I also wonder if someone has fitted a high lift camshaft off an MG or some such and a cam is hitting the jet.

 

That isn't how high lift cams are made. If they were, you wouldn't be able to thread them through the bearings in the block. High lift cams have a smaller diameter base circle

 

Richard

[Tony Brooks]

 

That isn't how high lift cams are made. If they were, you wouldn't be able to thread them through the bearings in the block. High lift cams have a smaller diameter base circle

 

Richard

 

I started to add that it was unlikely for the reason you say but in view of the OP not knowing what crankshaft end float is I decided to drop it off.

 

I still think there is something very odd about this engine and it probably needs careful stripping and inspecting to find the cause of both problems. This is as long as the oil pressure has been verified by a known good mechanical gauge.

[RLWP]

 

I started to add that it was unlikely for the reason you say but in view of the OP not knowing what crankshaft end float is I decided to drop it off.

 

I still think there is something very odd about this engine and it probably needs careful stripping and inspecting to find the cause of both problems. This is as long as the oil pressure has been verified by a known good mechanical gauge.

 

I agree. Chances are there is something wrong inside the engine, and the chances or diagnosing it from outside are slim, the chances of fixing it from the outside even more so

 

Richard

[jhodgski]

I have taken the sump off this morning (engine still in boat). I didn't have the endoscope with me, so I took a couple of vids with my phone.

 

I will upload the vids to YouTube later, but it looks like the oil jet must have been hitting the camshaft (on one of its wider points. I can easily check this now the sump is off with a new oil jet. (Any ideas where I could get one from??)

 

I found the snapped piece of oil jet safe and well in the sump.

 

I didn't see any signs of rag or anything like that. The inside of this 'new' engine (it's not 'new'new - just new to me) looked just like the inside of my old engine.

 

What I really don't understand, if the PRV is working, how could I possibly have high oil pressure anyway???

 

Is there more chance that all the electric senders / gauget have been wrong??? (When I bought the current pair, I asked the guy if mechanical gauges are more accurate and he didn't seem to think so. OK, he only sells them for a living (rather than working with them), but I think trying a mechanical gauge will need to be my next stop.

 

And if that also reports high oil pressure, why isn't the PRV releasing it?

 

(I've just taken the PRV out again. It was nice and loose and, as Tony mentioned, no washers in there to pack out the spring.)

[Tony Brooks]

For BMC spares and knowledgeable advice phone Calcutt Boats and ask for Roger Preen.

 

Have you checked the free length of the PRV spring as advised weeks ago?

 

Mechanical oil pressure gauges are far more reliable than electric ones but as long as both are working correctly there will only be marginal differences in accuracy. If you question implies your new gauge is an electric one are you 100% sure and have you re-checked that the gauge and sender are matched. Both for maximum gauge reading and US or European standard resistances. Mismatching them will give odd results and not be reliable.

[Tony Brooks]

What I really don't understand, if the PRV is working, how could I possibly have high oil pressure anyway???

 

Is there more chance that all the electric senders / gauget have been wrong??? (When I bought the current pair, I asked the guy if mechanical gauges are more accurate and he didn't seem to think so. OK, he only sells them for a living (rather than working with them), but I think trying a mechanical gauge will need to be my next stop.

 

And if that also reports high oil pressure, why isn't the PRV releasing it?

 

 

1. Because the spring pressure is too high for some reason or if the oilway to or from the PRV is blocked.

 

2. People who sell things are often complete bull shite merchants if it makes a sale. I may believe them once but if their advice seems suspect I go and check in some way. In short do not trust a vendor, check yourself. Some may nopt even know there are two standards electric gauges and senders are built to so may not supply a matched pair.

 

3. See 1 above.

 

As far as the oil pressure is concerned I suppose it might be possible that the bearing shells have been fitted so the oil way is blocked so little oil can weep from the bearings. Not sure if this is possible on a 1.5, too long since I had one apart.

[jhodgski]

Anyone have any ideas where I could get a replacement oil jet from?

Edited January 25, 2015 by jhodgski

[Tony Brooks]

I am giving up on both threads. How many times does the OP need telling Calcutt Boats - that is unless he has contacted them and has failed to tell us about the outcome.

 

The manual I consulted gives a HOT normal running oil pressure of 50 psi so 60 psi COLD is probably not worth worrying about. 80 psi may be rather different but the engine and oil needs to be hot. If the pressure goes too high the oil filter may fail in some way.

 

If the oil pressure "pulsing" is caused by the relief valve then in my opinion the valve must be sticking, otherwise it would take up some mid position that allowed just enough oil to leak back to the sump to maintain a steady pressure. I doubt an electric gauge would react fast enough to show the minor "shimmys" a free valve might make.

 

This just seems to be going in circles with much advice being ignored so I for one have had enough.

[jhodgski]

Thank you, but I haven't ignored any advice from anyone...

 

Before I wrote my previous post, I refreshed the page but for some reason your 2 earlier messages didn't appear (i.e., I have only seen them now).

 

 

So I have just spoken to Calcutt and will send me a new oil jet. If anyone is still here / interested, I will post an internal photo of how it looks when it is in place - hopefully that will show what it should look like (rather than showing it fouling on something again).

 

Calcutt advised to use a 15/40 mineral oil rather than a straight 30 to reduce the oil pressure, so I can post the results back - despite the risk, of course, of Tony Brooks having yet another grump at me...