Hi , had a dry run today having put new bearings and bushes in the crank cases all going well until I nipped up a couple of boots and then the crank is almost impossible to turn, tried it a few times making sure the busy and bearing are well home but same result. When I stripped it there were no spacers or chip washer on the crank so presume it was a good fit before, any comments would been appreciated. Dave.
Did you drop the barrels on to make sure the cases are going together square?
Hi, no didn't go that far but all the studs are in the left hand case and everything lines up well, the crank turns until I nip up a couple of opposite bolts.
The problem even with a properly set up A65 engine is that there is usually only a few thou of end float and so it doesn't take much to make this disappear because of a bearing that has not seated correctly.
Ideally, you need to measure the end float before you put the cases together and then shim as necessary to leave the specified amount. Out of interest, did you compare the flange thickness of the new bush and the thrust washer with the old ones to check there was no obvious problem?
:) :) :) :)
Was your engine running previously with all the current components. I ask this because There is a difference in the years/casings/crank. I had the same problem (or similar) And the only way around it was to have a couple of thou machined off the cransfaft web I think on the timing side. SRM did mine.
However if it was running with the current parts, then it sounds like an ill fitting bearing, or your present shimming could be wrong.
Let us know please.
Mike 8) 8) 8)
Hi spaceman / Mike, I bought the bike 40 years ago in bits and knew nothing about its history.when I stripped the engine down last year I found a few horrors,one come of was all cast ali the other was fast ali with a steel bottom half, there were gouges on the inside of the crank cases and a split in one case adjacent to the bearing. I had the crack welded up before removing the old bearing to retain the shape. When I stripped the engine the were no spacers, cup washer or thrust washer on the crank but it did turn although I don't recollect how easy or tight it was.having measured it this afternoon as accurately as I was able there doesn't seem to be any difference from the length of the crank and the distance between bush and bearing. The bearing housing is a bit rough particularly where the oil seal fits ,see photo's, I'm thinking could I get these honed and killed to gain the required tolerance. what do you recon. Cheers, Dave.
Should read milled, bl...e.g. Predictive text. :😁
:) :) :) :)
Killed is fine. I kmow how you feel.
Mike 8) 8) 8)
Hi, been messing with this in my head and on the bench and have decided to get some professional machining done. Does anyone know the dimensions of the thrust washer and the cup washer that fit on the crank? Also if I get the crank machined to the correct length for the required drift do I need to put the cup washer and shimes on or just the thrust washer. Cheers Dave.
Hi,
There are 2 different shim cups available, for the roller bearing or the ball bearing. They are pressed and cut to shape from 15-20 thou thick sheet, you are better off buying them for about £5 (I have 2 for the roller bearing if finding difficulty getting them, try Draganfly first).
The thrust washer will also be quite difficult to make cheaply and again would be cheaper to buy new. The best are the Vandervell they have a steel backing, again I have 2 and a solid if you cant source any, (again try Draganfly).
I wouldn't machine the crank the correct length to fit the crankcase. I would recommend investigation into why it is binding. Where in the country are you? perhaps a BSAOC member could visit and help.
Best wishes...
I wonder if it is possible that the two crankcase halves are not matched? For example, if you have a roller bearing RH crankcase and crankshaft but a ball bearing LH crankcase, then the crankshaft will be too long. Presumably, the engine number on the LH crankcase shows it to be at least 1966?
That said, the LH crankcase seems to be in poor condition and something has clearly happened to the engine to cause the damage that is evident. Presumably the roller bearing is still a good interference fit in the LH crankcase?
BSA designed these engines to have adequate axial clearance for the crankshaft requiring it to be shimmed. The fact that there is no real clearance in this engine suggests something is not quite right and may well point to you having a mix of incompatible parts?
Hi Dave,
Spaceman maybe correct, the crankcase image you've shown is for a ball bearing (see alternator stud tappings) therefore no need for a thrust washer. Can you post some images of the other crankcase and crankshaft?
Thanks...
Evening gents, I get the feeling that the engine was assembled haphazardly and when whoever tried to turn it over the damage to the cases occured. I found it in a cellar of a large house in Leamington spa that I was working on and the owner was pleased to see it go if I remember rightly. Spoke to an engineering company today who did the regrind and honning and they thought the same as you have suggested, there's a wrong bit in there somewhere. I live in Hollywood, not the warm one, the wet one just South of birmingham but obviously would be willing to take it all to wherever to get some help.have posted some photo's as requested. Thanks for your help Dave. Ps, some more photos on next post.
Photo's.
Even more photos
Hello Guys, sorry to interrupt. I'm on a different level. I've got a65 casses from 63. Looks just like you with the right part nr on it. Loose stud alternator.
I'm running this for over 35 years now after restaration. Inside there is a 734 crank. (Wide one and balanced )
I'm trying to figure out how they did it.?? Because i have also a smaller crank wich used to match with the casses. How did they managed it. Have they machined the depth of the roller bearing . Can you measure the depth for me? Then i have clue how its possible? So i can have a refferance.
Mine casses doesn't have a thrustwasher , just a roller bearing, 1 shim.
Don't know the history of the bike, bought it when i was 17 years old, now I'm 54.
Sorry for my odd english, Greetz alex
In answer to MITCHELL:
I bow to Bess's greater A65 knowledge and assume he's right about the LH crankcase case being for a ball bearing. I also assume the RH crankcase is designed for the later thrust washer although a close up picture of it and the timing side bush would be helpful confirmation. If both are correct then the cases appear to be mismatched. The consequence of this is that the roller bearing will sit 50 thou to the right of where it should be for a 1966 onwards engine (whose bearing mount was machined outwards by this amount) which probably means the crankshaft is a few 10's of thou too long to fit between the bearings.
However, the crankshaft was also heavily modified in the 1966 onwards engines. In the earlier engines, the crankshaft counterweights were the same thickness but, in the 1966 onward engines, the LH counterweight is 60 thou thicker. It would be interesting to know which crankshaft the engine is currently fitted with?
Assuming it's a later crankshaft, the potential solution to the present problem would be to mill out the roller bearing mount to move it outwards by 50 thou. However, before contemplating doing this, it would be worth measuring up the engine to work out what the current clearance actually is (assumed to be a negative value) and to confirm that the modification will work.
I would be happy to measure up the engine and have a closer look at what you've got. I know the Hollywood area south of Birmingham (I was born in King's Heath) and, if I can persuade my wife to make another visit to Birmingham city centre, I would be happy to pop in and collect the engine.
Hi,
It seems you have an early ball bearing set of casings so no need for a thrust washer. It looks like you may have a later crank which could be the reason you're having an issue.
Can you check your crank, has it got a plug on either end of the sludge trap?
Could you also post an image of the crank in the same orientation I have posted and check the cases have a matching number stamped as image 2?
Best wishes...
Hi Gup,
I have just checked the roller outer cage in the casing, when fitted it is flush with the casing therefore the measurement you want is 13/16".
However:
I "believe" to fit the later crank, the face of the LH case and the oil seal lip needs to be machined to allow the bearing to sit deeper in the primary drive side, making room for the wider crank. BSA also made some mods on the RH case and bush, to make way for the thrust washer.
Best wishes...
Hi,
For anyone following this thread, the crank shim cups.
There is 1 for the ball bearing, 2 different available for the roller bearing (I did say 1 for each). The bearing inner races are now bigger and the bearing carries the same manufactures number. Care maybe needed, the new shim cup has a 65 thou bigger diameter to accommodate the different race. There has been problems where the shims in the cups are tearing, it maybe because the old smaller diameter shims are being used in the larger shim cup?
Best wishes...
Hi Bess, the casing numbers match, if posted some photo's as requested including the old and new bearings although they are different as in one ball the other roller the actual width is the same when fitted in the case it stands proud on the inside by as much as a couple of millimetres. Cheers Dave.
Hi,
Just check to see if the sludge trap has blanking plugs both sides of the crank.
If so, you have all the components for a ball bearing engine and if fitted correctly should spin freely. Worth checking the depth of the bearing recess, it should be 13/16".
Best wishes...
Hi Bess, the sludge trap only has a screw cap on one end, measured the depth of the housing which is exactly 20mms which according to the internet is slightly undersize ( 13/16 = 20.63 mm)
Hi bess and mitchell, I'm following your discusion it does have a lot info for me. Bess, i measured the depth of the bearing casing ; 0,792"- 20,25 mm.
When the outer cage was still in i took Some measurements see pic. The outer cage wasn't flush with the case. Stands 0,157"- 0,4 mm out. So it doesn't seems like they machined the bearing depth?
My case doesn't hold a thrustwasher. See pic.
The Bush has a thin flange mine is 0,100"- 2,55 mm and stands about 0,003" - 0,1 mm above the case. I know there were 2 types off bushes, did they do something on the timingside Perhaps?...
I,m very confused know, mitchell should have the same bearing depth as mine? If that is so, what happend.
Read already the CBS story about the differance of the cranks, small/wide.
Have a good +65 crank, 1 plug crank. Can put it in and i have to overcome 0,590"- 1,5 mm prox.
Self made thick shim for instance. The old TS Bush Can stay in, only needs to make bigger to +0,20."
The 734 crank is now over 0,50"
If Someone have a clue? Please react, I'm also on the dutch BSA forum, but it isn't that lively as here on your forum.
Best wishes from the metric side. ;D ;D
Evening Spaceman, thanks so much for the offer but why on earth anyone would want to come to Birmingham for pleasure I have no idea, well see what transpires through this thread and poss chat later, incidentally where abouts are you? Dave.
Hi,
Check which crank you have with these dimensions G and D:
Mitchell ansered my question already, Can you measure the timing side Bush flange, is it the same as mine? 2,55 mm ?
Totally lost here now.
Thanks bess, gone look on the other crank wich type it is..The crank wich was in was stamped on the web 734.
Gr gup
Hi,
The bearing recess of 20mm sounds okay it needs to be slightly shallow, ensuring the bearing is proud and the crank doesn't foul the casing.
Best wishes..
Hi Bess / Yup. The mist clears..... The measurements on my crank correspond to the post 66 crank, my bikes a 64 with I presume 64 cases. Yup the flange on my bush is approximately 2.5 mm..... Is there anyway this crank can be modified to fit, maybe machining out the housing. 😞
Hi,
In this thread Bill Nelson is aware of your issue and mentioned a place that sorts it out. Worth having a conversation with him or the engineering firm he recommends.
Best wishes...
Hi, of course, will make that call thanks Bess...... and Bill.
Hi Mitchell,
Looking back over your crank images I cannot see a timing slot or hole in your flywheel, it should have one on the later assemblies. I can see the number for calculating the shim size at TDC so guess the flywheel is in the correct orientation. Its worth checking to see if your crank and flywheel is a mix and match, it looks like you have a later crank and an early flywheel. Unfortunately there's a choice of 6 flywheels so it would be prudent to have it balanced on completion.
Have you considered getting the correct crank, I have seen some on the internet, maybe stop these issues, easier and cheaper option?
Hopefully you can now go forward and please can you send some pics on progress? I am interested to see how this turns out.
Best wishes...
:) :) :) :)
I had this problem as I posted earlier. SRM machined mine by X thou to run smoothly. At least I think it was SRM it may have been T&L I cant find the invoice.
Mike 8) 8) 8) 8)
I took Some mesurements, the crank i want to put in is pre 66. Engine is 62. There was a 734 crank in, the same dimensions as post 66. In my case of 62 there was no machining done , i suppose , bearing dept same as bess said. TS flange same as Mitchell.
According to the story off CBS (small cranks/long cranks) it's shouldn't by easy to fit. I'm running around for over 35 years now with that engine.
When i took it apart there was 1 shim 0.010" between roller bearing and crank. It's a strange engine of diverent parts. Primairy cover is from 70, I always strobe the timing. Engine does not have cover for ignition plug in front,
On the timingside i have a cover also from 70 i think, it's with 3 ball lever for clutch.
So the engine does have a sort of history i don't exactly now.
With a solid thick shim prox 1.5 mm between bearing and pre 66 crank, everthing comes in line like primairy drive en so on
Strange Mitchell does have same situation like me, with 734 post 66 crank.and won't fit?.....
One other diverance between my to cranks is the position of the dowel , to mount the stator.
It's few degrees of, looking at the splines of the crank. Position of splines on both cranks are the same so i Can see.
Can only timing ignition by disk i think..?..? So the timing strobe marks are not usefull with the pre 66 crank i think?
Have pic of dowel on both cranks.
What is your opinion about it? Am i wrong??
Gr gup.
Hi Alex,
You didn't say why you want to use a pre 66 crank? From your explanation you are saying the post 66 crank hasn't been altered and fits your cases, the cases are pre 66 showing no signs of alteration. You want to use a pre 66 crank but its 1.5mm too short.
The only thing you have that's different from BSA'S original specification is the roller bearing. Have you tried a ball bearing on the pre 66 crank rather than a roller bearing, I did notice your original roller bearing outer race wasn't lipped (maybe nothing but its worth checking).
If you want to strobe the engine with the pre 66 crank, it is possible to accurately find TDC and scribe new timing marks onto the rotor.
Best wishes...
Hi Bess, i just stept in this discussion When i saw that Mitchell had same engine as mine. I wanted to find out how they did it to put a late crank in a early case.
Let me further explain my problem.
The late crank 734, has some problems. I dismanteld the engine because of oil consumption . I overhold it 30 years ago, and took a peek on the TS end. I had no oil pressure problems. I discoverd some play at the big end , and diceded to act before it's to late.
The TS side is now already over +0.50 , the conrod ends are +0.20. The drive side end i Can slip off the roller bearing with my hands and is no tight fit anymore.
The crank is i think balanced, the flywheel is machined as also the center of the crank, see pictures.
The calculation figures for shimming isn't even visible anymore. The weight between the two cranks is 1.1 kilogram.
If i wanted the late crank in, i need a new TS bush +0.60. I believe it stops at +0.50. The od of TS is now 36,78 mm / 1.448" . Could choose for self made bush, after another regrind. But how far Can you go with this.? And what to do on drive side bearing? For a beter fit. Use a loctite??
Like to use the late crank because he is balanced, but...........
Could get a pre 66 crank, wich has a TS of +0.10 , and big ends +0.20. And a good fit on the drive side for the bearing. Al needs a regrind. Then my old TS bush Can stay in and bored to +0.20". I think this is the cheaper way. The 1.5 mm ? When i read that a shim cup thickness is 0.034"/0,86 mm and a few shims with it , i Can overcome the 1.5 mm/ 0,059". Haven't got a shimcup yet, or make a soliid one? Ring between the bearing.
The bearing wich always was in the engine is a two piece roller bearing, hoffman i believe. Thats what you ment with single lipped bearing ? I looked at a ball bearing, but they have got the same dimensions If i am right. So it's a choice of what to use.
I'm learning more about the engine lately because of the internet, we had only workshop manuals. They also added a oil sensor on the 62 case. Works perfect for over the years, see pic.
It also has a Lightning head on (2 Carls) with a early barrel ( now on +0.60 pistons in good order). The 2 bolts on the back are 3/8" altered on the bottom to 5/16" threads to acomandate the barrel. So its a engine of diverent parts in fact but it runs great.
Originality is one other thing. It also sits in a 1970 Lightning frame.
I bought it in 1986 When was 17 without a drive licence, till now. But now with a licence 8)
Have also a golden flash 1951 under construction for many years for hobby. And a royal enfield interceptor mk2 2021. It runs fantastic but the BSA is more fun.
So what you think?.
Greets alex (gup)
Hi Alex,
You have a nice bike, I can see why you kept it for all those years.
As said, I noticed the roller used on your bike never had a lip on the outer race, BSA specified a bearing with a lip on the post 66 engines. As your crank could move further into the outer bearing race I was thinking maybe that's how the wider crank fitted into the cases.
If you use a deep groove ball race as originally specified you might find the crank doesn't have 1.5mm clearance?
Best wishes...
Hi Alex,
I also noticed you had an issue with the crank and timing side bush with the post 66 crank, the oil supply to the rod bearings could have been reduced. I guess using the correct crank will be a better option.
Could you take the measurements of the pre 66 and post 66 for comparison for me?
Best wishes...
Hello Bess, the crank ran in de same bearing as your picture, i thought it was hofmann but is rhp. I know that original in my case a ball bearing is used. Looking at the specs of the ball bearing i see no diverrance with the roller bearing. I have not a ball bearing for comparison, Then i have to order one.
I was also disturbed that the oil hole in de TS bush was not in center of the oil Groove in the crank. It's always been so and had no oil flow problems, 30 years ago When i overhauled the engine i put in a high delivery oil pump. Cast iron i believe it was an MCA pump.
The center of the oil hole in the bush , doesn't come in the center of the groove but exatly on the side. So only the 1/2 of the oil comes directly in the groove. That's looks me odd.
So, When i am going to use the pre 66 crank (best option i think) and it comes right next to the bearing it comes 1,5 mm to the primairy side, the oil hole and the groove better lines up.
Whats going to happen on the line up of the primary chain. Never had problems with it. But i never checked it If the chainwheel and clutch was inline?
Also took mesurement you ask, see pic.
As you see they are the same, the pre 66 / and late crank..
Took long ago Some mesurements , see pic. The diverance in the cranks is web thicknes. When the pre 66 is against the bearing the primary Will line up, or am i messing what, am i seeing this right.??
I always looked at the TS, as a fixed
point. This means there is prox 1.5 mm clearance between crank and TS bush??
What's your point of view?
Greets alex
I have a pic so you can see how much the big end comes through the bush, now to say , there was no spacer ring between drive pinion and worm drive for oil pump.
Maybe could this be a problem then?
I think??
Hi Alex,
Leaving out the washer between the Crankshaft gear and the oil pump worm is strange, it is 1.9mm thick (the washer is soft and is crushed when used, probably to 1.5mm). Perhaps it has been left out of your engine to line the worm centrally to the oil pump drive. Can you check your engines the TS bush lip thickness again, you are needing a a lip thickness of approximately 0.155" and you stated yours is 0.100"?
The primary sprocket line up is done with shims, pt no. 40-0069.
Image dimensions from an original post 66 bush, the oil holes are drilled at an angle towards the engine.
Best wishes...
Thanks for your reply, things are coming together i think. They left the washer out otherwise the ring came to far out and scored the pomp i believe?
The TS bush is still in the case so i could just prox mesurements. I found my very first TS bush replaced in the 90s. It has the mesurements that you gave me. There are 2 things different with the bush in the case:
1 the oil hole is further towards crank +/- 11mm from the outside. ( start of the hole) .
2 towards the crank the bush is 45 degree in and bush in case isn't. See pic.
I have a thrustwasher ( never used) together with bush ( old) it comes prox 0.155, so your right.
You mean that When i am going to use the pre 66 crank i need another TS bush ?
This pre 66 TS bush must have a thicker flange (lip)? Perhaps i dont know?
Greets alex
Hi Alex,
The early bush pre 66, has a flange of 4.1mm thickness. The post 66 bush has a flange of 2.4mm.
So to get the post 66 large crank in your cases a post 66 bush was used moving the crank to the right. Therefore the thrust of the crank was taken by the bush flange, the oil hole to the shell bearings was partly covered and the con rods were 1.5mm to the right hand side. No too good!
So if you use the pre 66 crank you need to fit a pre 66 bush and a deep groove ball bearing. The primary sprocket will line up okay and don't forget the worm drive washer.
Best wishes...
This complete the story about the long crank. I know now what to do. I must get another TS bush pre 66.
The ring i al ready have.
That's should solve the prox 1.5 mm problem.
And a ball bearing If Needed.
Thanks for info , i started a topic of my bike on the dutch BSA forum one year ago. With the same questions.
You delivered me answers much quicker than the dutch club, pitty!
I Shall start here an topic of my bike soon here, you'll Can folow the progress.
Thanks you all, best wishes
Alex
About your remark over the conrods moved 1.5mm to the right side, i found no evident of scoring on the inside of the piston or conrods.
I realised that a while a go. It was not in central line with cilinders. Nor the cilinders have some sort of damage. There in good Nick, to say.
Strange?
Gr alex
Hi Alex,
That's good news...Best wishes.
Just a quick update, went to the Stafford show today and found what I think was a pre 66 crank £75 plus any machining required. Took contact into and will explore using the existing first by having it or the cases altered. One of the gents on the bsaoc stand is sure he has a pre 66 a65 with the later crank fitted so must be a possibility. Let you know what transpires. Dave.
Well, Mitchel. I'm running around for more than 30 years with a late crank (734) in pre 66 cases. So it's possible.
I thought always it was the original crank, but found out the last year that it isn't.
I don't see anything is altered on the cases.
Only point is that the oilholes in the TS bush doesn't line up exactly with the crank, check this out.
Greetz alex
Good point Alex, will make sure to mention it to engineer. Cheers Dave.