ET: Engine (Twin) Locking Spindles

Albervin

Well Known and Active Forum User
VOC Member
While rebuilding my shabby shadow I find I will need to use some loctite or similar on a spindle or two. Reason being the hole is just a gnats hair too small for a 2 thou oversize but too large for a 1 thou. This is a low cost rebuild OK. Do I use Loctite 620 high temp. or 660? I am leaning to 620 but prepared to listen to those with more experience. As far as I can see the spindles need to be located to allow the cam followers and cams to rotate and do their job. If the spindles are fastened to the steady plate and all moving parts are lubticated with clearances there should be no problem. There are two studs that set the steady plate in position plus the half time pinion so if all other spindles are set at their 0.491 " from the timing face or thereabouts all should work. Or not? The bike was running like the Mallard before I pulled it down; smoke and all. 90mph in 3rd gear was something I had never experienced on a Vincent before.
 

Bill Thomas

Well Known and Active Forum User
VOC Member
While rebuilding my shabby shadow I find I will need to use some loctite or similar on a spindle or two. Reason being the hole is just a gnats hair too small for a 2 thou oversize but too large for a 1 thou. This is a low cost rebuild OK. Do I use Loctite 620 high temp. or 660? I am leaning to 620 but prepared to listen to those with more experience. As far as I can see the spindles need to be located to allow the cam followers and cams to rotate and do their job. If the spindles are fastened to the steady plate and all moving parts are lubticated with clearances there should be no problem. There are two studs that set the steady plate in position plus the half time pinion so if all other spindles are set at their 0.491 " from the timing face or thereabouts all should work. Or not? The bike was running like the Mallard before I pulled it down; smoke and all. 90mph in 3rd gear was something I had never experienced on a Vincent before.
I find the looking bit in the nut a bit too tight, And can shift a spindle, So I just wind the new nut on an old spindle, Just for half a turn to give it a chance. Cheers Bill.
 

Marcus Bowden

VOC Hon. Overseas Representative
VOC Member
Does that apply to fitting main bearings too, as thats what I doing right now and it must be ready for France Saturday, ferry booked , bearings were wrong this morning so now its tomorrow.
 

david bowen

Well Known and Active Forum User
Non-VOC Member
If you look inside early crankcases you will see the main bearings were peened this was done for quickness as hard chroming bearings in those days took weeks to do.
 

Albervin

Well Known and Active Forum User
VOC Member
638 or 648 but you will need a torch if you ever want to remove them again:)
I think the gap is less than 2 thou and I have a bottle of 638 so all systems go. I will chamfer the edges of the spindles though. Maybe a bit more than a chamfer and bell them.
 

medat727

Well Known and Active Forum User
VOC Member
Did this with 638 this past winter on my cam spindle on my racing Comet, after two races this spring I checked and the spindle is loose again. I think that the problem is that 638 is for loose fitting shafts, up to .020” slop, my spindle is a nice slip fit, maybe .001” so I have tried it again with 648 which is designed for tight fitting shafts up to .006”. The other issue that I believe came into play is that when you insert such a tight shaft into a blind hole it acts like a plunger in a syringe and the loctite is pushed out past the shaft as it is inserted. I had the cylinder off as I was replacing the piston with a higher compression version and when I inserted the spindle I was able to make sure that the loctite went all the way through and was able to keep it from running down into the case. Will give it a check after the next two races and report the findings.
 
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