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BMC 1.5 oddities, advice appreciated.


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8 hours ago, Tony Brooks said:

Have you had the skew gear oil jet and strainer out for inspection and cleaning? If not it may be a good next step because if its blocked/collapsed it would suggest the skew gears may very well need further investigation.

I have not but after all the information I'm getting here I'm pre pairing my tools in order to try all of these approaches.

 

check the timing chain/tensioner, pressurize and listen for leaks, pull the skew gear + strainer. It will be a bit before I can make it to the boat but I’ll post my results.

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5 hours ago, bizzard said:

The old Motor factors ''Brown Brothers'' with whom I had an account with used to sell the compressed air test kits, but for petrol engines, with adapter to screw into 14mm and 18mm spark plug holes and an air hose. :)

That takes me back , Brown Brothers  . Actually I've still got  one of their huge catalogues  and what you described was called a cylinder leakage tester and cost £34 in the late 60's. A nostalgic read a Brown Brothers catalogue for anyone that was in the motor trade in that era.

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1 minute ago, Troyboy said:

That takes me back , Brown Brothers  . Actually I've still got  one of their huge catalogues  and what you described was called a cylinder leakage tester and cost £34 in the late 60's. A nostalgic read a Brown Brothers catalogue for anyone that was in the motor trade in that era.

 

2 minutes ago, Troyboy said:

That takes me back , Brown Brothers  . Actually I've still got  one of their huge catalogues  and what you described was called a cylinder leakage tester and cost £34 in the late 60's. A nostalgic read a Brown Brothers catalogue for anyone that was in the motor trade in that era.

Indeed I had and used an earlier version of that catalogue.,

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I've been doing a bit of digging trying to figure out the injection pump timing tool but I still haven't figured out what all the geometry would need to be. Has anyone already puzzled this out? 

image.png.c972e99d6235852adddf4aebdc279b49.png

 

Looks to me like perhaps this is another tool for establishing the master spline at 5 O'clock. If that's the case, and all that needs doing for a notch to be made opposite the master spline I should be able to make one. Anyone able to weigh in on the alignment of that notch?

 

Also came across this Tempest version of the BMC 1.5 manual, seems like it has a lot of great info, additional drawings as well.

https://drive.google.com/file/d/1_nglPfi5gnKQ_w9qtlc_gwAGM-NilaIn/view?usp=sharing

 

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7 minutes ago, Julian Xavier said:

I've been doing a bit of digging trying to figure out the injection pump timing tool but I still haven't figured out what all the geometry would need to be. Has anyone already puzzled this out? 

 

 

Looks to me like perhaps this is another tool for establishing the master spline at 5 O'clock. If that's the case, and all that needs doing for a notch to be made opposite the master spline I should be able to make one. Anyone able to weigh in on the alignment of that notch?

 

Also came across this Tempest version of the BMC 1.5 manual, seems like it has a lot of great info, additional drawings as well.

https://drive.google.com/file/d/1_nglPfi5gnKQ_w9qtlc_gwAGM-NilaIn/view?usp=sharing

 

 

No, it's for taking the backlash out of the drive to the pump.  If you set the engine at 22 BTDC no.1 compression and the skew gear is fitted so the gauge can be fitted with the master spline in the correct position then the base timing will be correct but what can and will vary is the backlash in the drive so you twist the gauge to take the backlash out and set the pointer to the datum on the gauge.

 

As your engine runs the master spline must be in the right place so take note when/if you take the pump off.

 

 

Yet more info here http://the-norfolk-broads.co.uk/downloads/bmc1500L-diesel-workshop-manual.pdf

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Ok, I think I'll still try making one of those, unless this was the timing tool that you mentioned members might be interested in?

 

image.png.df3e302eb4ed8359b1baa4a54bea0597.png

Or is there yet another...

Edited by Julian Xavier
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The timing gauges are unobtainable in the UK so I think there may be a market. I won't need to be adjustable, the simple one with the slotted plate and scribed line would do the trick. Maybe if the work goes well make another post and ask.

 

Like this one:

 

Screenshot from 2021-02-09 21-12-38.png

Edited by Tony Brooks
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This is what I have come up with based on the information in the manual, though I'm not certain about the placement of the notch. I'd be interested in making these for anyone that could benefit from the use of them, not looking to make a profit.

 

image.png.be7507ac5bbaf392c0c1ac66b54af042.png

 

Best case scenario these may be candidates for 3D printing, in which case I could simply make the file available, no shipping necessary.

Edited by Julian Xavier
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I've been going through a similar process since my engine overheated when moored in a corner of a basin on a winter mooring, the shallow water and silt meant the skin tank wasn't effective, I changed the head gasket before Christmas but for many personal reasons it's taken until yesterday to actually get the engine to fire up albeit it was smoky, so I suspect more work is needed to get the timing right.

 

On your engine double check the compression figures. The BMC 1.5 is a 23:1 compression ratio engine, so, according to Google, you multiply atmospheric pressure (14.7 psi at seal level) by 23. Giving a cylinder pressure of 338 psi.

 

Edit to add: Following correction of my statement by Tony Brooks. Then account for Boyles Law, multiply the above by (according to Google 1.4 is a good number) to allow for heat from compression. So, 338*1.4. = 473.  Without knowing exactly how to calculate Boyles Law. If you can measure over 420psi  you're in the right ball park and if the readings are within 10% for all cylinders, the engine and head gasket are healthy.

 

I've got the original glow plugs, so finding a suitable compression tester adapter wasn't possible so I had to modify one.

My readings were 350, 350, 350, 300 I replaced the atomiser washer and injector copper seal on #4 as there was evidence of blow by. I'd also had a bit of an issue removing #4 glow plug and the thread no longer sealed properly. I then installed a Timesert insert and the readings are now all 350psi.  Once bled, the engine fired up, it was smoky, probably due to the wd40 I'd used to clean some of the carbon from the top hat of #4. It was a bit too cold for my liking and threatening to snow, so I called it a day and will carry on adjusting the timing when I next get a chance.

 

If your injectors are good and the pump's good, it only really leaves timing.

 

I've also been working on a 3d printed timing tool. The splined part has literally just finished printing and  there's still a bit of work to do on the outer ring but it's looking quite promising.

 

Rob

timingtool.jpg

spline.jpg

Edited by p6rob
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4 minutes ago, p6rob said:

I've been going through a similar process since my engine overheated when moored in a corner of a basin on a winter mooring, the shallow water and silt meant the skin tank wasn't effective, I changed the head gasket before Christmas but for many personal reasons it's taken until yesterday to actually get the engine to fire up albeit it was smoky, so I suspect more work is needed to get the timing right.

 

On your engine double check the compression figures. The BMC 1.5 is a 23:1 compression ratio engine, so, according to Google, you multiply atmospheric pressure (14.7 psi at seal level) by 23. Giving a cylinder pressure of 338 psi. I've got the original glow plugs, so finding a suitable compression tester adapter wasn't possible so I had to modify one.

My readings were 350, 350, 350, 300 I replaced the atomiser washer and injector copper seal on #4 as there was evidence of blow by. I'd also had a bit of an issue removing #4 glow plug and the thread no longer sealed properly. I then installed a Timesert insert and the readings are now all 350psi.  Once bled, the engine fired up, it was smoky, probably due to the wd40 I'd used to clean some of the carbon from the top hat of #4. It was a bit too cold for my liking and threatening to snow, so I called it a day and will carry on adjusting the timing when I next get a chance.

 

Your compression figures are too low initially and too high for the 2nd and 3rd tests, however, they are pretty consistent across cylinders, so may just be down to calibration of the gauges. If your injectors are good and the pump's good, it only really leaves timing.

 

I've also been working on a 3d printed timing tool. The splined part has literally just finished printing and  there's still a bit of work to do on the outer ring but it's looking quite promising.

 

Rob

timingtool.jpg

spline.jpg

 

Wrong calculation for the compression pressure. You take no account of the increase in volume of the air caused by the heating effect of compression. To calculate the pressure you need to get into the Boil's and Charles's Gas laws. (Don't ask me how to do it, I was all too happy to forget those calculations when I left college and by the time I was teaching mechanics that sort of thing was no longer required.

 

You calculated pressure is also absolute pressure, not gauge pressure so to convert to gauge ass 14.7 PSI.

 

I have a feeling the manual used to give about 435psi as test pressure but can't be sure and the on-line one most people use does not give a value that I have found.

 

Comments on your commendable effort for the gauge.

 

1. I can't see the master spline so without it will be possible to insert it into the drive in the wrong position.

 

2. If you intend to scribe the datum line on the rim of the disc then either a pump fixing stud or studs will prevent it being inserted into the drive or, if the disc is small enough to clear your risk parallax errors when  setting the pointer.

 

2.

 

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21 minutes ago, Tony Brooks said:

 

Wrong calculation for the compression pressure. You take no account of the increase in volume of the air caused by the heating effect of compression. To calculate the pressure you need to get into the Boil's and Charles's Gas laws. (Don't ask me how to do it, I was all too happy to forget those calculations when I left college and by the time I was teaching mechanics that sort of thing was no longer required.

Thank you, I did wonder but when I compared these figures to NA petrol engines that I have compression ratio and pressure data for they correlated, so there's some extra info needed for diesel engines?

 

 

 

21 minutes ago, Tony Brooks said:

 

You calculated pressure is also absolute pressure, not gauge pressure so to convert to gauge ass 14.7 PSI.

 

I have a feeling the manual used to give about 435psi as test pressure but can't be sure and the on-line one most people use does not give a value that I have found.

 

Comments on your commendable effort for the gauge.

 

1. I can't see the master spline so without it will be possible to insert it into the drive in the wrong position.

There is a master spline and reference marks so it shouldn't be possible to get the timing in the wrong position.

21 minutes ago, Tony Brooks said:

 

2. If you intend to scribe the datum line on the rim of the disc then either a pump fixing stud or studs will prevent it being inserted into the drive or, if the disc is small enough to clear your risk parallax errors when  setting the pointer.

The outer is still a work in progress but thank you for pointing that out. I'll make the changes for the next iteration which I'm working on now. Your comment has made me notice the outer wall is also too thick, so needs a few more tweaks.

 

I'm almost fifty but every day is a school day. Your patience is appreciated.

 

Rob

 

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5 hours ago, p6rob said:

I've also been working on a 3d printed timing tool. The splined part has literally just finished printing and  there's still a bit of work to do on the outer ring but it's looking quite promising.

 

Rob

timingtool.jpg

 

That's excellent Rob! What did you use to establish the proper angle between the master spline and the timing notch that you have on the outer disc? I see in the manual some mention of 208 deg but really not sure what that means. 208 degrees from the master spline?

 

Also according to the figures discussed for the compression it seems that my engine is doing just fine on that front. I really have no idea how the mechanic I called previously could have come up with values as low as 220psi when this is what I read:

 

image.jpeg.26be88ecc40d32d6cff794921d9043c8.jpeg

 

 

Anyhow, I checked the oil strainer to the skew, seemed clean and clear. I ran the compression test above. The motor still had a hard start but once she runs that's it, I will have to have a friend along next time I cannot see the exhaust smoke from inside the engine compartment. Whilst running I rotated the injection pump (CW seemed to slow the revs, CCW sped them up). Ultimately I rotated the pump very slightly CCW and it seems to run faster for the given throttle input and perhaps smoother, very hard to tell though, the whole boat experiences significant vibration while the motors running and I'm not sure how much is normal for this motor. 

 

Next time I get out to the boat will be the real test. I will try to start cold (with the glow plugs), and see how it goes. If this still doesn't improve the starting I'm going to try changing the battery cables out to series and go for 24v on the starter, see if the extra oomf starts it up or burns my starter out, hoping for the former. It could be that the extra juice would get her going quicker, might be better for the motor than the endless cranking have had to do in the past.

 

 

Edited by Julian Xavier
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It seems like this motor will be in great condition once I figure out the timing or whatever else is causing me issues on cold starts. I'm looking forward to getting it squared away so I can clean up and paint the motor.

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Rather than risk wrecking an expensive starter motor or use ether/acetone accelerant, try a small gas blow lamp played in the inlet manifold whist you crank it.

You will not get a smooth tick over under 850 revs and these engines have a vibration period with the standard flywheel around 1100 revs.

I would advance the pump whilst the revs are still increasing then back it of 2 degrees to give you a starting point.

 

Is the fuel in the tank really OK or is it years old? Try 10% kerosene mix.

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The fuel is likely two years old, however I do add Stabil diesel treatment to it every 6 months. That said I can swap out for fresh diesel to see if it makes a difference. I have used starting fluid (with ether) and that works like a charm, but I would like to find a different solution as so many people caution against it, plus It seems to me it shouldn't need it with the compression I'm getting.

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45 minutes ago, Julian Xavier said:

That's excellent Rob! What did you use to establish the proper angle between the master spline and the timing notch that you have on the outer disc? I see in the manual some mention of 208 deg but really not sure what that means. 208 degrees from the master spline?

 

I was lucky enough to borrow a genuine universal timing tool once. The zero degree mark is in the centre of the master spline. So, yes its 208 degrees from the centre of the master spline.

  • Greenie 1
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1 hour ago, p6rob said:
 

I was lucky enough to borrow a genuine universal timing tool once. The zero degree mark is in the centre of the master spline. So, yes its 208 degrees from the centre of the master spline.

 

That is good info, thanks

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2 hours ago, Julian Xavier said:

Anyhow, I checked the oil strainer to the skew, seemed clean and clear. I ran the compression test above.

 

 

Did you also check the oil jet, it's a separate vertical hexagon just to one side and below the horizontal strainer hexagon. If the strainer was clean I am all but sure the jet will be OK as well but worth a check.

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Tony, yes I checked both. The strainer had a couple of Small splinters I could not identify. They could have been metal or portions of gasket or even carbon. The second component seemed clean but I noticed a of bit resistance while reinstalling it.

 

image.png

image.png

image.png

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Hopefully unrelated but my oil pressure gage stopped reading somewhere along the line, I suspect it was just the sender (when I measured it it came out to 153kohms with the engine off). I've ordered a replacement and shut the engine off, I don't like running it without being able to keep an eye on the oil pressure.

 

The new sender is on it's way with a 1/8NPT thread, anyone happen to know what the threads are in the motor? It looks to be 1/4NPT or 1/4BSP.

 

While I was at it I ordered a new temp gage and sender, it bothers me that even after running in gear for up to an hour the temp generally hangs out around 120-140F. The 82C thermostat is on its way as well, it is currently fitted with the 72C, though I wouldn't expect this to make a difference after a sufficient amount of run time.

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24 minutes ago, Julian Xavier said:

Hopefully unrelated but my oil pressure gage stopped reading somewhere along the line, I suspect it was just the sender (when I measured it it came out to 153kohms with the engine off). I've ordered a replacement and shut the engine off, I don't like running it without being able to keep an eye on the oil pressure.

 

The new sender is on it's way with a 1/8NPT thread, anyone happen to know what the threads are in the motor? It looks to be 1/4NPT or 1/4BSP.

 

While I was at it I ordered a new temp gage and sender, it bothers me that even after running in gear for up to an hour the temp generally hangs out around 120-140F. The 82C thermostat is on its way as well, it is currently fitted with the 72C, though I wouldn't expect this to make a difference after a sufficient amount of run time.

 

Are the senders you have ordered compatible with the gauges? There are two standard US & Euro. If you mix senders and gauges you get readings that are very roughly half or twice what they should be. The two types often use different thread sizes/diameters.

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Mind you Julian the climate in California Santa Cruz is I think pretty warm all the year round and that engine should probably start quite easily even without using the heater glow plugs when you've completed fettling it up. Incidentally my cousin Mel lives near Santa Cruz but up in the hills-woods a little, he was very worried about all the forest fires up there last summer.  You might even know him, a lot of folk do especially in the folk and old Rock music world. He frequents the Felton music hall-club which is somewhere there.  His name is Melvyn Cleaver, he's a sort of young 74.:)

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Ah! I'll have to look him up. I live in Boulder Creek not too far away we were evacuated during the fires, I hope your cousins home was left intact. COVID restrictions put a bit of a damper on meeting new folks at the moment. And to your point, yes the climate is very moderate here, another reason why the starting issues trouble me. I am hoping that the timing truly takes care of it. though to get more adjustment out of the injection pump it looks as though it would require bending the injector pipes. 

 

Another option would be to increase the speed of the starter. Very subjective but it sounds like it's turning over just fine as is. Earlier the state of the battery cables was asked after, they are all brand new. I bought brand new 4/0 wires, short as possible and made all of the connections myself with solder in the terminal ends. I could have gone heavier on the wire gage but I seriously doubt that's my limiting factor. It's an option to bump up the starter voltage but I am weary of destroying the starter output gear.

 

All that said I made my adjustment earlier in the week and had to wait for a cool motor to see if the starting has improved. Might get back out to the boat this afternoon.

Edited by Julian Xavier
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11 minutes ago, Julian Xavier said:

Ah! I'll have to look him up. I live in Boulder Creek not too far away we were evacuated during the fires, I hope your cousins home was left intact. COVID restrictions put a bit of a damper on meeting new folks at the moment. And to your point, yes the climate is very moderate here, another reason why the starting issues trouble me. I am hoping that the timing truly takes care of it. though to get more adjustment out of the injection pump it looks as though it would require bending the injector pipes. 

 

Another option would be to increase the speed of the starter. Very subjective but it sounds like it's turning over just fine as is. Earlier the state of the battery cables was asked after, they are all brand new. I bought brand new 4/0 wires, short as possible and made all of the connections myself with solder in the terminal ends. I could have gone heavier on the wire gage but I seriously doubt that's my limiting factor. It's an option to bump up the starter voltage but I am weary of destroying the starter output gear.

 

All that said I made my adjustment earlier in the week and had to wait for a cool motor to see if the starting has improved. Might get back out to the boat this afternoon.

I don't even know his address we just email each other now and again. He moved out there when he was about 30 years old. Unfortunately he tends to live on Facebook in his old age. He was a landscape gardener and then a crane driver. It shoulld really spin over well with the normal 12v, have you renewed pistons or piston rings, if so it will be a little stiffer for a while. If you have another battery with rhe old top exposed cell connecting bars you could easily tap off 1 cell to give you another 2 volts, making 8, but I wouldn't go higher.

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