Lister 12/2 Fuel Pump Pushrod/Cam follower Wheel

[Samo]

The right fuel pump pushrod on my 12/2 has a cam follower wheel that's obviously been stuck for some time, it's worn a decent flat spot. Plus the wheel has quite a bit of play on the axle. Are these repairable? or do you normally source new units. The axle pin doesn't want to come out either, doesn't look tapered. I've tried a couple of heat cycles and some hydraulic pressure.  Info appreciated before I try more force.

cheers,
Samo

[broncodriver99]

Hi Samo,

The fuel pump lifter on my 6/1 is the same way. There are some pics of it in my build thread. The tip of the pin on one end is tapered so it will only go in one way. I was able to disassemble mine pretty easily with a punch and hammer. I have scoured the web and several dealers and the roller is no longer available but the pin is still available from one source. I picked up an Indian lifter and it will work fine. I even tried swapping the wheel and pin over from the Indian lifter but the dimensions are different and will not interchange without modification. The Indian lifter uses a knurl on the pin to hold it into the lifter as opposed to the English original which uses a tapered tip. After a little cleanup and deburring the Indian lifter is decently made and the roller and pin are hardened and ground, I see no reason it will not work properly.

[listard-jp2]

/\ I have to disagree.

In the case of a OEM Lister CS IP cam follower, the pin is parallel, and is retained in position by a straight pattern knurl

The pin can  be difficult to remove as the knurling effectively broaches part of the follower body when it initially assembled, and it will only come out one way due to it having straight pattern knurling on only one end of the pin.
Here is an example on ebay uk:  http://www.ebay.co.uk/itm/LISTER-3-1-2-1-6-1-8-1-12-2-16-2-VA-FUEL-PUMP-TAPPET-PIN-pack-of-2-008-02126x2-/262935648072

I do however agree that the roller is NLA, and Indian parts are not interchangeable with the body of the original Lister cam follower without further modification to the body of the follower, but the complete Indian assembly will fit, in place of the original.

I would also suggest that you pay close attention to the fit of the new Indian item in the cam follower bore, as it is quite common for wear to occur in the cast Iron bore, to such an extent that the housing can require sleeving back to the original size in extreme cases (1" bore if memory serves me correct).

Whilst your at it, what is the condition of the fuel pump cam lobe, as a frozen roller will quickly wear away at the tip of the cam lobe.

The situation you describe is very common to find, due to the marginal lubrication in this area of the engine and the potential for grit ingress, just be thankful you don't have a single cylinder version (as the oil pump cam follower also runs on the same cam lobe), and been non rotational it causes even more wear than the IP roller follower.

[broncodriver99]

Pics.....

Original on the left/bottom. Indian copy on right/top. As you can see the original has a straight pin with a taper on one end(no knurling). Measuring the bore in the tappet one end is .002" smaller to receive the taper. The Indian copy uses the straight spline/knurl setup. Also, just noticed that on the Indian copy the center hole of the roller was drilled .010" off center, the adjusting bolt on top is off center as well, unlike the original where everything is properly centered as expected. Guess I will be tracking down something more usable. There are also some differences in the overall dimensions of the parts. The original measures .9975" and the Indian 1.00". The good thing is with the Indian part being a couple thou oversized it takes up a little of the wear/slack in the bore of the cam cover housing. The original pin is .010" larger than the Indian part, theoretically one could track down an Indian roller and hone it out .010" as the Indian roller does physically fit in the original tappet body but has very little clearance, a few minutes with a file should be all that is needed though.

[38ac]

 As they said repairing the originals is not an option  for those not equipped with machine tools. I have made rollers in the past and pins but usually the Indian part works well enough and costs much less than the machine shop repair. I don't think I have ever seen a good lifter or cam lobe on the #2 side of a twin due to the fact it gets almost zero lubrication

[Samo]

Thanks All,

I'll look for a good second hand / new indian part from the local suppliers. The left one is perfect, right is heavily worn, no doubt due to lack of lubrication as has been poined out.

cheers
Samo

[Samo]

Could I replace the wheel with a through hardened roller bearing?
SKF make some pretty good hardened bearings and rolling speed is pretty slow.

[vdubnut62]

Could I replace the wheel with a through hardened roller bearing?
SKF make some pretty good hardened bearings and rolling speed is pretty slow.

I was thinking the same thing. What about it some of you more "seasoned" Lister  and 'roid owners and mechanics?
Ron.

[Samo]

So I've ordered some through hardened roller bearings. These are 2mm larger in outside diameter, and will press fit onto the roller pin without impinging in the well of the existing follower   - though I need another pin machined so it doesn't have the wear pattern in the existing one...






There's been no comment on this as an approach for repairing the Cam follower, but to my limited knowledge the approach seems sound. Ok it's not the original Lister approach but at this stage unless someone can come up with a convincing argument, or have tried it and failed, I'm going to install these bearings and rebuild  .... 

[broncodriver99]

I would think it very important to have no slack between the cam eccentric, lifter, and fuel pump. Any kind of slack there would probably damage the bearing pretty quickly. The constant loading and unloading, 5-6 times a second, could be a problem but only time will tell.

[vdubnut62]

I would pull the seals off if it was me. Just saying.
Ron.

[EdDee]

Hey guys...

Correct me if I am wrong, but I am sure someone on the forum has gone down this road before.... It worked, but for a short while only, if I remember correctly.... The bearing failed due to the minimal point of contact on the outside of the raceway (The raceway needs a support to stop it going oval, even by a small amount).... Anybody else remember similar, or am I hallucinating again..... Oooh look.... Green bunnies wearing bow-ties!!

Cheers
Ed

[mikenash]

FWIW I reckon the bearing will fail.  Have you ever cut one up or smashed one & seen the hardness/brittleness of the steel of the races?  This isn't what bearings do - their strength is in using an oil film & close tolerances to distribute loads; not in repeated impacts at one spot

Why wouldn't you buy an off-the-shelf Indian part?  If you are concerned for their longevity, buy three of them.  They're cheap & available . . .

Just my $0.02

[Samo]

that's more like the commentary I was expecting! thanks Mike

The question is does the wheel follow the cam or does it get slapped by the cam? That could change my thinking...

The bearing I've chosen are precision bearings and a bit on the tight side at 5 microns clearance, so designed for more slow speed radial force, which is what I'm expecting this environment is.  They are rated at 180kg, but that force won't be in the same place every time, because the bearing will spin with contact on the cam. Given the precision, top and bottom ball bearings will share the radial loading.

Contact area (ball bearing surface) is smaller than original, however friction should be lower....  I'm in two minds about following the advice on seals... maybe drilling some lubrication holes, the concern is these are low oil areas, which is why the units I have seized in the first place. 

If it doesn't work I'll pull them out and go with the Indian copies.... they're not that hard to get to.

Just got the crank out, so not far from the point I start putting it all back together...

Samo

[selmawp]

Hi Amos, my 2 cents worth, drilling holes in the shield very bad idea,    for 30 years I did rebuild water pumps and have dealt with many brgs  and 99% of the time brgs failed because of contamination, and a couple of drops of oil will contaminate the brg.
shielded brgs are designed to operate on there own lubricant, also shielded brgs will let some oil in, so there for I would recommend using rubber shielded brgs. Tony.