1958 BSA A10 Golden Flash Engine Installation - Tips and Advice

[Petergj]

Hello everyone,
I have the engine for my 1958 A10 GF Swinging Arm fully rebuilt with the head and barrel attached to the crankcases but the dynamo, magneto and carburetor not yet attached. Looking through this site, I can find engine installation advice for an A10 plunger bike but not the swinging arm bike.
Any advice from the wise on this site on how to install the engine would be much appreciated - I realise having two people on hand is a good starting point but should the engine be lifted in from the right hand side, can the dynamo be fitted when the engine is in the frame and should the gearbox be loose fitted in the mounting brackets (or can the gearbox be fitted once the engine is installled)? Any tips and advice would be much welcomed.
Thanks in advance for any help.
Regards,
Peter

[Billybream]

Just the engine should be fitted and the gear box afterwards, never tried it with cylinder head and barrel assembled, that's a heavy lump. You will need to protect your paintwork, pipe lagging or similar is ideal around the front down tubes, the dynamo and mag can be fitted with engine in frame together with the carb.

[Klaus]

Hello Peter,

you can fit the nearly complete engine with the exception from carb, dynamo, headsteady.
My advice, screw out the highest bolt from the inlet rockerbox cover, it will come very close to the frame
by fiting. Best way is from the right side with a jack between the frame, so you can move the engine up and down
to fit the bolds easy.


regards Klaus

[jhg1958]

I fitted my by laying the engine on its right side then lowering the frame onto it.

Bolts slid in no trouble. Easy to move the frame and I did it on my own.

John

[Swarfcut]

  I do it bit by bit, engine unit alone, supported by front and rear lower mounts then add the gearbox and finish with the top rear mounting plates. That rear top rocker cover stud is different from all the rest....the difference being a flat in the middle to aid removal and installation of the stud in situations where it comes close to the frame top tube. With no rocker box there is plenty of room, fully assembled motor is a tight squeeze.

 BSA frames are far from perfect, leave all the mountings loose to get components to settle without strain. A custom spacer is usually required  to bridge the gap between the frame lug and the lower rear mount on the primary chaincase. Then when all is happily in place a final nip up, Loctite on the threads, and it starts to look the part once more.

 Preparing the fixings in advance, nice smooth running threads etc makes life easier for grovelling down in the dirt.....

 Consider the breather exit while you have access. Some folks modify  "The Hole" to accept a tube to direct oil and vapour to the chain, rather than just letting it vent.

 Swarfy

[Rex]

I fitted my by laying the engine on its right side then lowering the frame onto it.

Bolts slid in no trouble. Easy to move the frame and I did it on my own.

John

I do the same, but maybe the OP was a rolling chassis rather than a bare frame?

[Worty]

Wooden box one side with complete engine on, narrow blocks between the frame, tilt on side and shuffle in - adjust as necessary.

[Petergj]

Thanks to everyone for your comments, The engine was installed today with help from a friend with the lifting (with the barrel and cylinder head on the crankcase, its a heavy lump!). The process was :-

Use pipe insulation to protect frame paintwork.
With the front engine plates, upper rear and lower right hand side rear engine plates removed, lift the engine into the frame and support with a jack on the underside of the engine.
Secure the head steady to prevent the engine falling out!
Install the lower right hand side rear engine plate and two bolts on the rear of the engine.
Install the front engine mounting plates to frame and engine.
Install gearbox and upper rear engine plates (removing one of the rear engine bolts temporarily).
Tighten everything up.

Apart from the weight, the process is fairly straightforward. Some rocking of the engine is necessary to align bolt holes - keep the fasteners finger tight until the very end.

Onwards to the rest of the re-assembly and thanks again.

Cheers,

[groily]

I think you were wise to assemble the motor on the bench and take the pain.
Less risk of busting rings or fouling up with the rocker box and is what I always do with any (pre-unit) engine that will go in. Usually with the g'box already in place but mag and carb (and dynamo if there is one) off.
Determining whether they'll go in is easy - if the b****er's come out it'll go back  . . .
It helps to be a BFB (Big Fat B*****d) of course (guilty) but even when I've turned into a Weak FB, I'll still try I think.

(Whatever IS that hard projecting lump in my lower abdomen I wonder?? No, not that one  . . .)

[Petergj]

Hello! I now have the correct spring for my cush drive and I'm looking for some advice on assembling the cush drive. What is the safe way to partially compress the spring so the retaining nut can engage with the thread on the crankshaft without getting cross threaded?
Any comments appreciated.
Thanks,

[Worty]

Do you have the SRM type conversion nut or the original?  Don't know if it makes a difference, but the original went straight on with mine without having to compress the spring (either at all or too much).

[Catz]

I've got the SRM conversion on my bike and it didn't need the cush drive spring to be compressed.

[Swarfcut]

 Just a word of caution. The nut SHOULD go easily onto the shaft thread, some aftermarket examples need the nut thread to be cleaned up with a tap.

 BSA amended the cush assembly from  its earliest incarnation, and several types of nut can be encountered.

   67 1098   1954 only

   67 1137   1955 only

  42  71       1956 onwards.   This is the one with the two slots for the ineffective tab washer.

 Earlier Plunger cush is completely different, with an extended nose on the nut.

 All fit the crank, so plenty of scope for the wrong part.  As stated, no initial compression of the spring should be necessary.

 Plenty on the Forum about the different cush types, the heavy handed torque setting required, locking compounds and the split pin to stop a loose nut machining a neat hole in the primary chaincase. Well worth a looky, if only to confirm ALL the correct parts are to hand.

Swarfy.

[bikerboy]

Strange I have always put the gearbox in first even if I have rebult the complete engine on the bench. I must admit I only normally build the bottom end on the bench and put the barrels on once the engine is all bolted up usually.