Refitting engine

[AdrianS]

Got all my engine parts back from the engineering works after having the crank journals ground, new timing side bush fitted and reamed, reborn to 40 thou over and new pistons.
So....the rebuild starts.
It would be better for me to rebuild on the bench but then fitting the engine is the problem mainly due to weight. I stripped it in the frame so only had the crank cases and crankshaft to lift out which was manageable on my own.
I fitted my B40 engine complete after rebuilding it and it was a bit of a struggle but the A50 engine is a lot heavier and probably a bigger squeeze into the frame.
What do you do?

[DAVE BRADY]

Hi Adrian,

This were a bike lift comes in handy.  I assemble the crankcases with crank rods and cam.  Then after putting this in the frame assemble the rest on to the cases.  The working height is about right and the height can adjusted to make it easier eg. max. height for gearbox and primary but a bit lower for working on the head/rockers.  If you do not want to buy a lift a ex-hospital bed can be adapted or make a simple platform with a ramp that will bring the bike up about 45cm.  Higher is better but some of the assembly could be done sitting on a stool.
A lift is not just for rebuilds but makes everything from chain adjustment to wheel removal/refitting so much easier.
The last thing you would want to do is find that you haver completed the rebuild but have put you back out in the process.

Dave.

[AdrianS]

I've just acquired a second hand hydraulic bike lift from a member of the UKGSER site ( which I am a member of) so I will christen it on the A50.
I would have liked to rebuild the engine on the bench but the weight and refitting into the frame puts me off doing it that way.

[Mike Farmer]

 

I always put the frame over the engine. But not a go'er if you have a rolling chassis.

Failing that  build engine in frame. Or get some @young blood' to do the lifting

Mike

[MGI]

It is quite surprising as to the weight of some of these engines. Even the B series are seriously heavy lumps as a whole.

[AdrianS]

I think my B40 engine is about 35 kilos or just under 80 pounds. The A50 is around 130 pounds and while I can lift the engine off the ground , it is manoeuvring it into the frame which is difficult.
I did put my back out messing with a Bantam engine (25 kilos) a few years ago just because I was handling it in a awkward position.
I would have liked to have seen the arrangement BSA had on the production line for fitting the engines.

[Bess]

Hi,
    Worth a read:

https://www.bsaownersclub.co.uk/bsaoc_forum/index.php?topic=8335.15

Best wishes...

[AdrianS]

I'll take note regarding the chain!

[ChrisG]

I asked a former apprentice at Armoury Rd how they used to do it at the works. He wasn't sure but remembers there being a very thick rope hanging down.
My guess is the engine would be complete so full weight and they put the rope around the bottom of the barrels. They must have used a hoist and got it to the right height and pitch (leaning forward) and swung it into place. Bearing in mind they were doing this day in, day out, they would soon get expert at it.

[wardy]

I'm pretty much ready to stick my A65L engine back in the rolling chassis. If anyone has a photo of the correct positioning of the engine plates at the rear I'd be grateful - the drawings are a bit nondescript

[Mike Farmer]

 

Assuming the engine plates are already bolted to the engine they will only go in one way. I would suggest that you leave them loose on the engine so you have plenty of wiggle room when you are lining them up.

Mike

[wardy]

They were completely unattached Mike. I think I've got them loosely attached the right way round (by measuring the lugs/brackets they have to fit to). The holes that mount to the back of the engine are clear enough because of alignment, I've got the "long" bit of the plates facing downwards, which looks correct

[AdrianS]

The holes at the back of my engine are a different size as are the bolts to the plates so impossible to install the wrong way. My A50 is 1962, not sure if later cases are much different.

[DJC]

Hi - I am restoring a '66 Lightning. Having taken the engine out of the frame AFTER removing head and barrel but otherwise complete, I decided there was no way it would go back in the same way without damaging the new paint on the frame (or damaging me !). I have yet to put engine back in but what I have done is do a trial fit with bare / empty crankcases. Lay the bare frame down on its right hand side (protecting the paint with carpet or similar of course) and drop the engine (no head or barrel) in from the top, locating the front bolt in the frame first then swinging the back of the engine down. If you do this with bare cases you will soon find out what angles work - then when the engine is built up you just need to follow the technique you have learned. Well - thats the theory anyway. Like I said I havn't actually done it yet !

[Mike Farmer]

 

If you have the frame without forks etd. (If its already got the fork fitted it makes it more difficult)

Lay the engine down on the clutch side and carefully place the frame over it. I suggest whichever way you choose that you wrap the frame in old cloth or paper to obviate the risk of paint damage.

From experience this is the easiest method I have found, and you can do this over a complete engine without any stresses and strains.

Mike