Damaged BMC1.5 Crank Pulley

[Jen-in-Wellies]

On a neighbours boat. While refitting the crank pulley, the woodruff key slipped while it was being tightened and has cracked the pulley ?. This includes the surface that the oil seal runs on. The pulley has three grooves. The inner for the engine water pump and alternator, the outer for the raw water pump. Does anyone have an old one, or know where one can be obtained? IT looks like the two small pulley grooves were added to the original one, but they don't easily come apart.

 

Jen

 

 

 

 

[Slim]

That pulley looks very similar the pulley on my 1.8. My engine came out of a  Telecomm Sherppa circa 1981.

[Tracy D'arth]

ASAP will have the standard pulley [which will have a rubber bonded harmonic balancer ] but the extra two small pulleys are not BMC. They seem to be bolted on through a hole drilled in the center of the pulley which has been filled in somehow.

Callcut may be able to help if you cannot use the old pulleys. Doubtful though.

 

The 1.8D pulley is larger on the O/D but the same center.

 

I have in the past arc welded up such damage and very carefully filed it back to fit, its tricky but possible. As you say, its the oil seal that is the problem.

TD'

Edited June 20, 2020 by Tracy D'arth

[Jen-in-Wellies]

11 minutes ago, Tracy D'arth said:

ASAP will have the standard pulley [which will have a rubber bonded harmonic balancer ] but the extra two small pulleys are not BMC. They seem to be bolted on through a hole drilled in the center of the pulley which has been filled in somehow.

Thanks. I looked closer and there are the threaded ends of two studs protruding from the engine side of the big pulley. I gentle pry with a screwdriver pulled the small pulley off. It looks like the standard pulley from ASAP, or Calcutt will do, with the small ones refitted. It will need some careful marking out to get the studs in the correct place on the replacement. The outside diameter of the main pulley is 185mm. Is this the usual size for the 1.5 version? One would think so, but never make assumptions!

 

Jen

 

 

[Man 'o Kent]

Assuming that the damage can be welded/brazed/sifbronzed, (depends on the metal), then there are on the market very thin sleeves for very effectively repairing shaft seal surfaces.

Lip seals require a very good surface to work on, far better than you could expect to get on a repair without spending a shed load of money. However given a reasonable standard of workmanship such a sleeve can be glued in place with the correct grade of Loctite. The sleeves are so  thin that the usual lip seal can be used.

[Tony Brooks]

@RLWP knows about very thin sleeves that he has used in this sort of situation. In this case I think you would have to get it welded but if you then sleeve it you won't have to be so accurate at filing.

 

As that is a damper pulley the flywheel shoudl have been locked while tightening or loosening it in case the rubber insert is damaged- I bet he held the pulley.

[Jen-in-Wellies]

3 minutes ago, Man 'o Kent said:

Assuming that the damage can be welded/brazed/sifbronzed, (depends on the metal), then there are on the market very thin sleeves for very effectively repairing shaft seal surfaces.

Lip seals require a very good surface to work on, far better than you could expect to get on a repair without spending a shed load of money. However given a reasonable standard of workmanship such a sleeve can be glued in place with the correct grade of Loctite. The sleeves are so  thin that the usual lip seal can be used.

Also known as Speedi Sleeves. That is another possibility.

Jen

[Tracy D'arth]

32 minutes ago, Jen-in-Wellies said:

Thanks. I looked closer and there are the threaded ends of two studs protruding from the engine side of the big pulley. I gentle pry with a screwdriver pulled the small pulley off. It looks like the standard pulley from ASAP, or Calcutt will do, with the small ones refitted. It will need some careful marking out to get the studs in the correct place on the replacement. The outside diameter of the main pulley is 185mm. Is this the usual size for the 1.5 version? One would think so, but never make assumptions!

 

Jen

 

 

I haven't got a 1.5D pulley to measure.  I would phone ASAP or Calcutt and ask them to measure a new one, it could well be a 1.8D pulley, they were a common swap to get more revs on the alternator.

 

Sleeving the seal surface is a good idea but you will need to repair the keyway area even so as the woodruff key has very little length in the pulley groove. Its the same key that locks the crank sprocket I think, you have to be super careful when refitting it that the crank doesn't turn in the sprocket and muck the timing up.

[ditchcrawler]

I dont know where you are but this is at Skipton

https://www.ebay.co.uk/itm/Bmc-1-8-Diesel-Engine-Spares-Repairs-Boat/333626629209?hash=item4dadb25c59:g:Eh0AAOSwX09e5-Vh

 

1.5

 

https://www.ebay.co.uk/itm/Bmc-1-5-diesel-engine/164244453968?hash=item263dbb7a50:g:-~8AAOSwNX1e5gA5

Edited June 20, 2020 by ditchcrawler

[Tracy D'arth]

1 hour ago, ditchcrawler said:

 

 

1.5

 

https://www.ebay.co.uk/itm/Bmc-1-5-diesel-engine/164244453968?hash=item263dbb7a50:g:-~8AAOSwNX1e5gA5

That's the strangest 1.5D BMC i have ever seen, its a 3 bearing crank.

Ex tractor?

[ditchcrawler]

4 minutes ago, Tracy D'arth said:

That's the strangest 1.5D BMC i have ever seen, its a 3 bearing crank.

Ex tractor?

No idea, I have never pulled one to bits

[Rose Narrowboats]

1 hour ago, Tracy D'arth said:

That's the strangest 1.5D BMC i have ever seen, its a 3 bearing crank.

Ex tractor?

I've never seen a 1.5 with more than three main bearings?

 

I think the tractor crankshaft only differs in that the bore hole for spigot bush is bigger.

 

The 1.8 is five main bearing.

[Tracy D'arth]

Of course it is, extreme age and exhaustion setting in. Hell, the hundreds I have stripped and I get confused, time I gave up!

 

1 hour ago, Rose Narrowboats said:

I've never seen a 1.5 with more than three main bearings?

 

I think the tractor crankshaft only differs in that the bore hole for spigot bush is bigger.

 

The 1.8 is five main bearing.

 

[Slim]

37 minutes ago, Tracy D'arth said:

Of course it is, extreme age and exhaustion setting in. Hell, the hundreds I have stripped and I get confused, time I gave up!

 

 

You had me scratching my head all afternoon. I last rebuilt a 1.5 about 30 years ago and I thought I remembered it having 3 main bearings but was not too sure. Pleased to see my memory was right. Now, what did I have for lunch?

[Tony Brooks]

15 minutes ago, Slim said:

You had me scratching my head all afternoon. I last rebuilt a 1.5 about 30 years ago and I thought I remembered it having 3 main bearings but was not too sure. Pleased to see my memory was right. Now, what did I have for lunch?

Well yours is  a lot better than mine. having rebuilt loads of the 70s I could not remember how many bearings the crank had.

[Slim]

1 hour ago, Tony Brooks said:

Well yours is  a lot better than mine. having rebuilt loads of the 70s I could not remember how many bearings the crank had.

I could distinctly remember having the crankshaft sitting on my desk using it for a paperweight for the day.  

[TNLI]

On 20/06/2020 at 11:56, Tracy D'arth said:

ASAP will have the standard pulley [which will have a rubber bonded harmonic balancer ] but the extra two small pulleys are not BMC. They seem to be bolted on through a hole drilled in the center of the pulley which has been filled in somehow.

Callcut may be able to help if you cannot use the old pulleys. Doubtful though.

 

The 1.8D pulley is larger on the O/D but the same center.

 

I have in the past arc welded up such damage and very carefully filed it back to fit, its tricky but possible. As you say, its the oil seal that is the problem.

TD'

I've asked both and they are not in production. It seems the only solution I can find is to buy a scrap one that is in good condition. If anyone knows of a company that is currently reconditioning that unobtanium bearing, please let us all know. I plan to inspect that rather important pulley bearing after my engine is moved for its crankshaft inspection et al.

[Tony Brooks]

Pulley bearing? Would that be the front main?

[TNLI]

I presume he means this general type.

Crankshaft Pulley Torsion Vibration Damper TVD R257 - 5 YEAR WARRANTY | eBay

 

Lots of different sizes still in production by Gates in particular, BUT none of them list the BMC. No luck contacting Gates yet.

DriveAlign torsional vibration dampers | Gates Europe (gatestechzone.com)

Edited March 1, 2022 by TNLI