BMC Alternator type?

[The Dogs Pollacks Brother]

Would anyone know the part number or details of the alternator for a BMC 1.5 engine?
The reason I ask is that it looks like the one on the engine is a replacement by a previous owner and the pully wheel does not line up with the engines water pump and crank pully wheels, i.e, the belt does not run "true" on the alternator and as such is damaging the belt and may cause damage to the water pump bearings.
The current one is a Lucas make but thats all I know.
The problem is with the top two locating points/brackets on the alternator as they will not line up correctly with the engine mounting locations.
Many thanks guys.
Jeff.

 

[Tranona]

Think you will find the problem is with the mounting brackets rather than the alternator. Early engines used dynamos which had different mounting points on the block, so retrofitting an altrantor rquires fabrication of brackets. My MGB had the same problem - the early blocks are different.

 

[The Dogs Pollacks Brother]

Ah ha..........sounds feasable.
May have to use a little bit of "adapting" somewhere then!
Many thanks.

 

[The Dogs Pollacks Brother]

I have since found out that the alternators fitted were Lucas 16ACR, 18ACR or 17ACR-M.
Does anyone know if these would each have different sized/spaced mountings?

 

[pvb]

I have since found out that the alternators fitted were Lucas 16ACR, 18ACR or 17ACR-M.
Does anyone know if these would each have different sized/spaced mountings?

I think they have different stator lengths, so the distance between front and rear brackets will vary. However, the front bracket on each should be in the same position relative to the pulley.

 

[The Dogs Pollacks Brother]

Yes that would make sence pvb......... the alternator currently has a bolt acting as a spacer between the engine mounting bracket and the front alternator bracket, thus pushing the whole assembly forward and not aligning the pullys. If we mount the front brackets correctly, the rear one is then "in line" with the engine mounting. It must surely be a "botch" job and the wrong one is fitted. Time to take it off and get to a scrappy me thinks with some measurements written down.

 

[grumpygit]

I have since found out that the alternators fitted were Lucas 16ACR, 18ACR or 17ACR-M.
Does anyone know if these would each have different sized/spaced mountings?

I think you will probably find the datum at the drive end will be ok for the 17 ACR with a standard fan and pulley. The mod will have to be to the rear bracket mount. The later A127 alternator should also fit the same as the 17 ACR, the A127 does have a different shaft size though, so the pulleys are not interchangable.

 

[pvb]

Yes that would make sence pvb......... the alternator currently has a bolt acting as a spacer between the engine mounting bracket and the front alternator bracket, thus pushing the whole assembly forward and not aligning the pullys. If we mount the front brackets correctly, the rear one is then "in line" with the engine mounting. It must surely be a "botch" job and the wrong one is fitted. Time to take it off and get to a scrappy me thinks with some measurements written down.

As long as the front one is properly positioned so the pulley is aligned correctly, the rear bracket isn't such a problem. You can use a length of threaded stud, with steel pipe spacers, to get the alternator mounted securely (although a proper bracket would obviously be better).

 

[The Dogs Pollacks Brother]

Thats exactly what the problem is pvb........the front one will line sweet as, thus putting the fan belt and pully wheels in perfect alignment.
The problem is, with the front lined up, the rear bracket of the alternator will not fit on either side of the engine mount as it is in direct contact with the end of the bracket, ie, tips of both alternator bracket AND engine mounting are touching......

 

[pvb]

Could you swap it for a different version of the ACR? Different version should have rear bracket in different position.

 

[The Dogs Pollacks Brother]

I think that is the best option tbh.........I will take the existing one with some engine bracket measurements, or even a template?, to a scrappy.
Thanks pvb.

 

[gordmac]

As far as I am aware the alternators are all intended to fit the same bracket, looks like you have the wrong bracket. The rear mounting lug should have a tube that slides in the hole in the alternator to allow for any small variations.

 

[grumpygit]

As far as I am aware the alternators are all intended to fit the same bracket, looks like you have the wrong bracket. The rear mounting lug should have a tube that slides in the hole in the alternator to allow for any small variations.

Not if it originally had a Lucas C40/42 dynamo fitted, they where longer in the body. If you extend with threaded bar and spacer make sure it's all a good fit and tight, the ACR's where notorious for snaping mounting lugs if they came loose or misaligned.

___________________________________________________________________

 

[gordmac]

If it used to have a dynamo it must be very very old! If possible to get the correct bracket for an alternator that is the real solution.
Only time I have had a lug break on the ACR was when they were fitted with the sliding bit in the back lug seized.

 

[Tranona]

If it used to have a dynamo it must be very very old! If possible to get the correct bracket for an alternator that is the real solution.
Only time I have had a lug break on the ACR was when they were fitted with the sliding bit in the back lug seized.

From memory the problem is not with the mounting bracket, but the mounting holes on the block are in a different place for the dynamo, so it is not just a case of using alternator brackets - it has to be custom made, or like my MGB (same block) bodged.

 

[raven]

I have a BMC1.8 in my boat and have found these people to be brilliant both in terms of supplying parts and dispensing good advice...

http://www.thornycroftparts.co.uk/storepage207758.aspx

 

[The Dogs Pollacks Brother]

Thanks guys..........
The mounting "lugs" if you like, are actualy part of the engine block so are cast into position.
Can't say either way if it origionaly had a dynamo on it or not.
So are you saying ALL alternator mounting "holes" are in a same, standard position?

 

[vyv_cox]

So are you saying ALL alternator mounting "holes" are in a same, standard position?

I have not posted on this topic, as my engine is the BMC 2.2 litre, although I suspect the dynamo and alternators fitted are probably similar throughout the range. Mine may have had a dynamo originally but when I bought the boat it had the 35 (?) amp alternator with an external regulator that looks to be similar to the one for a dynamo. I replaced that with a 50 amp alternator supplied by Chertsey Meads Marine, who have been very helpful. They also supplied new brackets, which are all quite different for the later alternator.

The old alternator is about 2 inches longer than the new one, for which a deeper rear bracket was needed. The new slotted adjusting arm is considerably shorter. The new forward mounting is in a very different position, which required some cutting of the original mounting to install.

 

[The Dogs Pollacks Brother]

New brackets you say?......my in-experience is confusing me now sorry.

The mounting "lugs" or "brackets" or "holes" on the engine are part of the block,i.e, cast into place so whatever happens, they are staying as they are!

My problem is the locating holes on the current alty will not match up with them unless the alty is mounted to far forward (with the aid of spacers/packing) on the front "lug", but correctly fitted on the rear "lug" of the engine. This then puts the pulley wheel out of a true line for the belt.
When you say new brackets, do you mean an alteration to your alternator,i.e,mounting holes custom moved if you like?
Or have they supplied you with some sort of adjustable bracket so that it can be adjusted to suit various needs?

Have looked on tinternet for adjustable alternator mounting brackets by the way.....plenty in the states for converting make "A" to fit engine "B",i.e, specific type to type, but nothing universal here in the uk.........

Just a plain old trip to the scrappy me thinks (again).

 

[pvb]

A quick Google seems to suggest that your engine's mounting lugs were designed for a Lucas A127 alternator. The diagram below is the clearest I could find of the dimensions of an A127-type alternator. Might be worth checking the dimensions against your mounting lugs and seeing whether an A127 would be the right fit. If so, you can get 70A and 90A equivalents fairly easily. Note that the Lucas A127 was apparently made as a left-hand or right-hand version, depending on where the adjusting lug is.