A65 teardown

acadian · May 4, 2022

File this under s--t POs do, dismantling primary and timings sides. Lucas rotor was stuck on the shaft, and I mean welded-stuck, tried any number of pullers, heat, tapping threaded holes, etc. Finally ended up drilling through and using long bolts, was able to find nuts thin enough to slip in behind rotor and engage the bolt threads, this with some additional heat finally got it moving and then off.

PO had fitted a new centre to the rotor and doweled it in place, but that wasn't the issue, discovered gobs of green locktite

Other interesting finds, when I went to remove timing side inner cover I discovered a broken tacho drive tab, and what appears to be a bent drive shaft, this leads me to believe someone tried prying off the cover without removing the drive shaft

kommando · May 4, 2022

That is gruesome, DPO's have a lot to answer for.

acadian · May 19, 2022

Slowly coming along, machined out the guides, bores are still standard

mean gene · May 19, 2022

Hope you have better luck with the timing side crank bushing, god only knows what you'll find Keep sending pics

Onder · May 20, 2022

Your tool room skills look up to the task.

acadian · May 20, 2022

TS bush and journal mic'd up at .0015, that journal appears in good shape, as do the crank journals, they look like they were recently ground to 30 under, explains the new connecting rods.

The drive side output shaft looks in bad shape though, threads are pooched, but I'm more worried about the state of the splines. I'm not sure if it is serviceable, my plan was to send the crank and TS cases to EdV in Michigan for the bearing conversion.

Onder said:
Your tool room skills look up to the task.

Depends on the day of the week, this was Friday, monday's not so much....

Onder · May 21, 2022

Not happy. You may well be better off finding another crank. It may be cheaper too.

Fast Eddie · May 23, 2022

I’m interested in folks thoughts on this… if good quality modern oil is used (see Comnoz’ guide) and if a modern remote oil filter is used… does the timing side bush need replacing for a bearing?

Matchless · May 23, 2022

Fast Eddie said:
I’m interested in folks thoughts on this… if good quality modern oil is used (see Comnoz’ guide) and if a modern remote oil filter is used… does the timing side bush need replacing for a bearing?

For the amount of use these bikes will get probably not, but I've just done mine on the '71 Lightning I'm currently building. It just seems like a better option to me & is stright forward to do if you are a capable engineer, as Acadian appears to be.

Martyn.

baz · May 23, 2022

Fast Eddie said:
I’m interested in folks thoughts on this… if good quality modern oil is used (see Comnoz’ guide) and if a modern remote oil filter is used… does the timing side bush need replacing for a bearing?

I used to go to an old time bike shop in Ware
The proprietor was Dick Rainbow if you mentioned the devimead /SRM end fed crank conversion he used to hit the roof
He used to race an A65 and never had a problem with the timing side bush ever !
I suspect his motor was very carefully assembled and I suspect he changed the oil pretty regularly
He reckoned a road going A65 crank should last 100,00 miles

acadian · May 23, 2022

baz said:
I used to go to an old time bike shop in Ware
The proprietor was Dick Rainbow if you mentioned the devimead /SRM end fed crank conversion he used to hit the roof
He used to race an A65 and never had a problem with the timing side bush ever !
I suspect his motor was very carefully assembled and I suspect he changed the oil pretty regularly
He reckoned a road going A65 crank should last 100,00 miles

Being new to BSAs, I've noticed the bearing conversion is as much a contentious a topic with Beezer folks as anti-sump valves are with us

acadian · Aug 24, 2022

Hoping someone can help, I need to know the total length of the swingarm bushing tube, tube only. Please and thank you to anyone who can assist!

Edit: the specs in the manual are a bit odd, giving a total width of 9.25" for this section. The span between the gussets is only 8.3125. I've checked the frame alignment, all seems OK, the gussets are not deformed in anyway, and certainly not anywhere near .9375.

I'm attempting to engineer a different bush arrangement by making tophat bushings that will clamp the S/A tube and draw it up against the primary side gusset. My goal is to provide a larger bearing surface between the endcaps/spacer pieces, eliminate the inner spacer tube, and constrain lateral movement of the S/A.

Problem is that my cases are with Ed-V for the T/S bearing conversion right now, so I have limited means to check for spacing/alignment of S/A so the sprockets line up.

Will post an update

acadian · Aug 26, 2022

Making slow progress, blasted and painted the frame

Came up with what I hope will be a good alternative to the stock swingarm bushing arrangement. Machined top hat bushes that press into the S/A tube, these bear on the end caps which I also machined down. S/A dimensions were necessary to maintain the correct offset, but I'll have to wait a while before I can test it out, action is smooth with no lateral play (the entire assembly gets drawn up against the primary side)

Matt Spencer · Sep 27, 2022

The drive side output shaft looks in bad shape though, threads are pooched, but I'm more worried about the state of the splines. I'm not sure if it is serviceable, my plan was to send the crank and TS cases to EdV in Michigan for the bearing conversion.

Saw recently in a OLD ' Cycle World ' a picture of " Dave Aldana's New A 65 " with its timing cover OFF .

Was a largeish Ball Race in there . ( looked like theyed just run a boring bar through ) Didnt see if it had
a HOLE in the END of the Crank , for the END FEED OILING . Which is said to be a priority . And Annoyingly
I cant re find the picture . ( on a computer thingo ) Figure it may be one of the first to try it ? ? .

DEFINATELY crack test your crank , if it aint no good , you could throw in a Triumph or Norton Crank !
The 170 being 84 stroke a T120 / t140 crank'd have to be intresting .

Matchless · Sep 28, 2022

That's a photo I'd like to see, as I can't see how a largeish (is that a real word?) ball bearing would fit. I recently machined my A65 cases to take the combined INA needle roller/thrust type bearing, & there is only about 0.010" wall left between the bearing bore & the bottom oil pump screw hole. Any larger & not only the screw hole would be lost, but also the feed hole in the oil pump area. Maybe these were a one off set of cases & oil pump.

Martyn.

Matt Spencer · Sep 28, 2022

Ifin When I ' refined ' It , I'll at least copy it to a Email . As the httperisings another THING .

Right . About 2 inch diameter . maybe 2 1/4 . The outer face of the C'case did not look to be welded to produce a rampart .
Seemed to only be bored ( perhaps with a ledge / End - Lateral location . The Immediate impression was ' He's Bored the Case & thrown a Ballrace in .
It wouldnt be less than 1 1/2 . But as we have spent aeons exact sizing from pictures ( usually using a known datum / size and SCALING ,
We are pretty confidant its not less than 2 inch outer diameter , looked like a good olde quality caged ball race . As the other covers wernt there ,
and I didnt think to look for a black dot in the crankshaft end , thats about as far as we can take it , for now .
Was in the tech. / racing section , aft in Cycle World . WHEN did Aldana start with ' Factory ' BSA's ? ( year / month ) To elp better refine the Re Search !

acadian · Sep 29, 2022

More progress, getting close to my goal of having a rolling chasis by fall (just waiting on tires)

Tapered head bearings from SRM

On the blocks with rebuilt QD hub installed

Wheel building

acadian · Oct 3, 2022

Parts back from vapour blasting, the head (thankfully) is in good shape, with decent seats. The "mini" BSA logos at the engine stamp are a nice touch by the factory! Don't think I would have seen them otherwise