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Posted By: AML Victor pushrod/rocker arm question - 09/12/19 5:36 pm
I’ve belatedly begun to get my Victor running after a road-side stoppage in June and I’ve got a few questions.
I replaced an exhaust pushrod that had gotten hammered (shortened) and that seemed to be the extent of the damage.
But now with everything back together I have to screw in the tappet adjuster all the way down to get the 010 clearance, so much so that there is barely any of the adjuster showing above the lock but, which doesn’t seem right.
At TDC both pushrods are at the same height and the tapper adjusters are the same length. The exhaust valve is not stuck open as I can stand on the k/s after a few kicks, so it seems the valves are sealing.

I can only think that the rocker arm has bent. Is that possible?
Any thoughts as I’d rather not pull the rocker off again if I’m missing something obvious.

Adam
This is a 69 B44 exhaust valve. I seem to have quite a few threads left. The head is quite original and the seats have not been ground. only lapping in the new valves.

It would seem to me that bending a rocker would be hard to do. Is the valve the correct length?

Gordo


click to enlarge
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Posted By: gunner Re: Victor pushrod/rocker arm question - 09/12/19 7:11 pm
I would check the push-rods for straightness by removing them from the head, once out, the hardened-end caps can be pulled off and the bare push-rods checked for straightness by rolling them on a flat surface.

If the push-rods are straight then its possible to fit a hardened washer under the cap to take up any slack, assuming this isn't too much.

Alternately you can have slightly longer push-rods made up by someone who has access to a lathe.

There is no way I would bend a rocker !
Posted By: AML Re: Victor pushrod/rocker arm question - 09/12/19 8:17 pm
I bought a new pushrod from Peter at BSA unit Singles, and it and the intake pushrod are both straight and true. The damaged pushrod I removed is now about 8 inches long, as opposed to the normal 8.25”.
I’ve attached pix of both the intake and exhaust tappers and I don’t remember there being much difference between them before this.
I know I could probably just use a longer 8-3/8” square barrel pushrod but I think something else must be going on.
I wasn’t thinking of bending the rocker, I thought perhaps it could have been bent during running when the pushrod shortened?
Adam

Intake
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Exhaust
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I note that Rupert Ratio book shows the B44 pushrod at 8 5/16 inches and only the B50 has a longer pushrod at 8 7/16. There is no mention of the round and square barrel B44s having different pushrods.

Gordo
Posted By: AML Re: Victor pushrod/rocker arm question - 09/13/19 1:01 am
Yes, I noted RR lists only one length, but there’s a difference in part numbers between the round and square barrel pushrods and BSA unit Singes and Baxter among others list different lengths (although they don’t agree) for the pushrods.
AML: Thanks for the info, as always this forum is better than most references.

Gordo
Posted By: kommando Re: Victor pushrod/rocker arm question - 09/13/19 6:29 am
From the B50 site

41-0028 B40 7 11/16"
41-0592 B44 Round Jug 8 1/4"
41-0590 B44 Round GP 8" 1966-67 sand cast barrel
41-0790 B44 Square jug 8 3/8"

40-0100 C15 7 5/16"
40-1021 B25 Ex 6 7/8' aka 70-8053
40-1010 B25 IN 6 15/16" aka 70-8055

71-1620 B50 8 19/32"

The GP barrel was shorter than the round barrel to get the 11.4 comp ratio so the pushrods would have been shorter than the 8.25" of the round barrel. You have to be careful with the round barrel as some were GP length but had a spacer under the barrel to get the 9.4 comp ratio.
Posted By: AML Re: Victor pushrod/rocker arm question - 09/13/19 1:17 pm
Thanks kommando do for all the info.
But my real question seems to have gotten lost:
both pushrods are the correct length, are straight and of equal length, yet the exhaust rocker tappet/pushrod clearance seems to have expanded. (I need to screw the tappet into the rocker arm much further)
Given that my previous pushrod got hammered/shortened I was worried something else (the exhaust rocker arm) also was damaged/bent.
It was the only thing I could think of and was eliciting thoughts before I pull the rocker box again.
Adam
Posted By: kommando Re: Victor pushrod/rocker arm question - 09/13/19 1:23 pm
I can't answer that other than to say tappets do lose their stellite foot so you need to check for that by checking that both com followers are at the same height.
Posted By: Peter_Joe Re: Victor pushrod/rocker arm question - 09/13/19 3:20 pm
Many years ago, back in the 1970's, the exhaust push rod on my 441 Shooting Star got hammered to where the push rod jumped out of the tappet and rode on the engine case. The amazing thing is that the engine still ran (just barely) and I was able to limp the bike home. What I discovered was that the exhaust tappet's forward foot simply broke off. Somehow this caused the push rod to get hammered.

Apparently this is not that uncommon of a problem because on the BSA B50 engines the tappet's foot is made of thicker material. Maybe the B50 tappets can be fitted to the 441 engines.


Peter Joe
Posted By: kommando Re: Victor pushrod/rocker arm question - 09/13/19 4:00 pm
Quote
Maybe the B50 tappets can be fitted to the 441 engines.


Yes they can.
Posted By: chaterlea25 Re: Victor pushrod/rocker arm question - 09/13/19 9:15 pm
Hi Adam,
Have you checked the cam and followers?
Damaged or worn parts would punish the pushrod as the clearance increased

John
Posted By: AML Re: Victor pushrod/rocker arm question - 09/13/19 9:24 pm
I’ll be having the inner timing cover off to check, hopefully in a day or two.
I’ll report back
Thanks to all
Adam
Posted By: Ignoramus Re: Victor pushrod/rocker arm question - 09/14/19 10:29 pm
Originally Posted by chaterlea25
Hi Adam,
Have you checked the cam and followers?
Damaged or worn parts would punish the pushrod as the clearance increased

John


that would also be what i would do ......but first see if you can measure how much lift you are getting off the cam as it is.....
Posted By: AML Re: Victor pushrod/rocker arm question - 09/15/19 10:36 pm
I had a chance to open things up this morning. The cam is not worn (the lobes are of almost equal height) but it seems excessively pitted. The followers are ok-ish; they’re not too worn but I think I’m going t replace all.
But these parts don’t seem to be the cause of my problem.
[Linked Image from i.postimg.cc]
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[Linked Image from i.postimg.cc]
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Posted By: kommando Re: Victor pushrod/rocker arm question - 09/16/19 7:51 am
Could be the angle but the followers look different lengths.
Posted By: AML Re: Victor pushrod/rocker arm question - 09/16/19 1:36 pm
It’s just an optical illusion. They’re both of equal length (well, one is 0.2mm longer)
Posted By: Dave Martin Re: Victor pushrod/rocker arm question - 09/17/19 10:23 pm
Have you had a look at the rockers yet? has, one of the little ball end thingys (they probably have a proper name) that locate in the tops of the push rods been hammered up into the rocker arm by any chance?
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