• Welcome to the website of the Vincent H.R.D. Owners Club.

    Should you have any questions relating to the Vincent H.R.D. Owners Club, or Vincent H.R.D. motorcycles in general, please contact Graham Smith, Hon. Editor and Webmaster by calling 07977 001 025 or please CLICK HERE.

    You are unrecognised, and therefore, only have VERY restricted access to the many features of this website.

    If you have previously registered to use this forum, you should log in now. CLICK HERE.

    If you have never registered to use this website before, please CLICK HERE.

E: Engine This is where some of that swarf ends up.

Cyborg

Well Known and Active Website User
VOC Member
That’s a E16 in photo one. Other than the swarf packed into the oil groove, there is one other very obvious “major” problem with the pin.


1F95FC8E-01F9-4E24-8038-B522D60769E1.jpeg5E945F02-4BD5-4F11-83B3-FEF1F67A976D.jpeg
 

oexing

Well Known and Active Website User
VOC Member
Sort of centrifugal fine filter. Unfortunately only limited capacity, a lot less than the oil catch/thrower on Earles fork BMWs. But then,these had no real filter at all, just a sieve. So I wonder if you could prevent that on a Vincent with paper filter cartridges ?

Vic
 

timetraveller

Well Known and Active Website User
VOC Member
That is the reason that I changed from standard sized crank pins years ago. Every time I changed a big end for someone the groove at the end of the crank pin was full of rubbish. If one goes for the much larger crank pin, which used to be made by Alpha, then the feed into the big end is a hole which has to line up with the hole in the timing side flywheel. I prefer the crank pins which are longer over the larger diameter so that part of that larger diameter goes into the flywheel and makes a much stiffer job. A castellated nut is used to tighten things up. Modern filters might prevent some of this and so might some modern oils.
 

oexing

Well Known and Active Website User
VOC Member
Is this a mod that can be done without machining the flywheels ? My guess no ?
When I do new crankpins, pressed type here, I place the small holes in the conrod area at 90 degrees to the rear. That way you get some space in the big pin bore for collecting a substantial amount of centrifugal fine dirt so it takes a higher mileage till unfiltered oil finally gets into the needle bearing . But really I was confident that a paper filter would prevent collecting much dirt past it elsewhere in the circulation ?!?

Vic
P1050481.JPG


P1050484.JPG
 

Cyborg

Well Known and Active Website User
VOC Member
That is the reason that I changed from standard sized crank pins years ago. Every time I changed a big end for someone the groove at the end of the crank pin was full of rubbish. If one goes for the much larger crank pin, which used to be made by Alpha, then the feed into the big end is a hole which has to line up with the hole in the timing side flywheel. I prefer the crank pins which are longer over the larger diameter so that part of that larger diameter goes into the flywheel and makes a much stiffer job. A castellated nut is used to tighten things up. Modern filters might prevent some of this and so might some modern oils.

What makes you think they need to be stiffer?

Here’s the other end of that pin.
05F1880D-CDAB-4570-9429-F08503272EBB.jpeg
 

timetraveller

Well Known and Active Website User
VOC Member
You are correct Vic, The large crankpin does require each flywheel to be machined out about half way through the thickness of the flywheel. Originally these crankpins were developed for racing but once I had seen them I realised that they got round the problem of dirt centrifuging out of the oil and blocking the original annular groove. You will be aware that the original flywheels are quite soft and later experience has shown that if one wants a serious crankshaft for high power output then it is better to use hardened flywheels and to use Picador style push in crankpins. It might well be correct that a modern filter would prevent some of the original problem. Both filters and oils have improved a lot in the last few decades. I remember when if one worked on a car engine the inside of the rocker cover was covered in about 6 m of burnt on/condensed dirt and the sump would have sediment all over the bottom. This no longer seems to happen.
 

timetraveller

Well Known and Active Website User
VOC Member
Reply to #6 above.
Imagine that the larger diameter part of the crank pin had continued half way though the flywheel. The crankpin would not have broken where the one in the photo did. It removes one of the stress concentration areas outwards and into the flywheel. If a Picador type pin is used then there is no change of diameter along the crankpin and hence no stress concentration within it. However, if a soft flywheel is used then there is enough deformation after one pressing in of the crankpin that the interference will be lost for a second fitting. Hence the need for hardened flywheels. Hardened flywheels also remove the need for hardened washers at each end of the crankpin.
 

Bill Thomas

Well Known and Active Website User
VOC Member
You say standard flywheels are soft,
But when I got Tony Maughan to take a 1/4" off the sides of mine ,
He said how hard they were !!, What I had done a few years before,
Was to get George Brown to fit a Big Pin and
while he was doing it get the wheels Polished ! ,
Tony said that's what made it so hard.
 

Cyborg

Well Known and Active Website User
VOC Member
Am I correct in assuming the mills pin goes in (and out) from this side? Never taken one out before. The parts book suggests it goes in from the other side, but doesn’t seem to look that way on the actual crank. (Not the bearing, but factory mills pin)


AACFB678-8950-4CAA-984C-FDB4FD870AEB.jpeg
 
Last edited:

Latest Forum Threads

Can't Find What You Need?

Buyer Beware: Fake or Real?

Top