Lifter and rocker wear
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Re: Lifter and rocker wear
With the lifters out it is easy to examine the cam. Usually the cam is OK in my limited experience with the /5 and /6. I don't know about later models, or after these 40 years.
Ask the Indians what happens when you don't control immigration.
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Re: Lifter and rocker wear
Damn. That would certainly solve any "flush with cash" problem.chasbmw wrote:If you were feeling very flush with cash then MI have these lightweight followers
http://www.motoren-israel.com/product_i ... m-4pc.html
Charles
MS - out
- Airbear
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- Location: Oz, lower right hand side, in a bit, just over the lumpy part.
Re: Lifter and rocker wear
Thanks to all for the replies.
My current thinking is that the lifters can remain - they don't look any worse than they did 40k kms ago when I was in there last. I've had a good look at the cam lobes using a bright light and rotating the cam, and they appear to be undamaged.
For the rockers:
German ebay has a good selection of used sets from later models at reasonable prices. If I can find good ones for the 76 to 84 they will fit straight on. There are many more available for the '85 on, but that would involve some machining to the heads to fit them. I'll do some more research on that option.
The other matter is what has happened to one of the valve ends - the one that has been pounded by the worst rocker pad. On that rocker pad the hard casing has a crack in it and this has chewed the end of the valve stem. The others show the characteristic concentric marks with slight denting marks. I'm wondering whether it is possible to clean up all the valve ends somehow, so they don't damage the rocker pads on the replacement rockers. I have yet to pull the valves to check guides, so I'll hold off on that matter for now.
Thanks again for the thoughtful responses. I'll keep you informed as things proceed.
My current thinking is that the lifters can remain - they don't look any worse than they did 40k kms ago when I was in there last. I've had a good look at the cam lobes using a bright light and rotating the cam, and they appear to be undamaged.
For the rockers:
German ebay has a good selection of used sets from later models at reasonable prices. If I can find good ones for the 76 to 84 they will fit straight on. There are many more available for the '85 on, but that would involve some machining to the heads to fit them. I'll do some more research on that option.
The other matter is what has happened to one of the valve ends - the one that has been pounded by the worst rocker pad. On that rocker pad the hard casing has a crack in it and this has chewed the end of the valve stem. The others show the characteristic concentric marks with slight denting marks. I'm wondering whether it is possible to clean up all the valve ends somehow, so they don't damage the rocker pads on the replacement rockers. I have yet to pull the valves to check guides, so I'll hold off on that matter for now.
Thanks again for the thoughtful responses. I'll keep you informed as things proceed.
Charlie
and Brunhilde - 1974 R90/6

Graduate, Wallace and Gromit School of Engineering and Design (Pending)
and Brunhilde - 1974 R90/6

Graduate, Wallace and Gromit School of Engineering and Design (Pending)
- George Ryals
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Re: Lifter and rocker wear
Any auto shop that does valve jobs has the equipment to dress thw valve stem ends.
Smile it's contagious!
'74 R90S, '67 /2 Conv w/sc, '66 R50/2
'74 Harley FXE, '72 Harley FLH w/HD sc
'69 BSA 441 Victor Special, '74 R90/6 Basket case
'85 R80RT wreck for parts
'74 R90S, '67 /2 Conv w/sc, '66 R50/2
'74 Harley FXE, '72 Harley FLH w/HD sc
'69 BSA 441 Victor Special, '74 R90/6 Basket case
'85 R80RT wreck for parts
- Airbear
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Re: Lifter and rocker wear
Great, thanks George. That sounds easier than trying to do it myself with carpenter's tools. Grin.George Ryals wrote:Any auto shop that does valve jobs has the equipment to dress thw valve stem ends.
Charlie
and Brunhilde - 1974 R90/6

Graduate, Wallace and Gromit School of Engineering and Design (Pending)
and Brunhilde - 1974 R90/6

Graduate, Wallace and Gromit School of Engineering and Design (Pending)
Re: Lifter and rocker wear
Used valve gear from 76 on can be obtained for less than $50.00 on eBay. After 76 the hardening is way better.
I upgraded my 75 rockers with early 80's gear. They bolted right on. Switch to the later style push rods while you're at it....way lighter.
I upgraded my 75 rockers with early 80's gear. They bolted right on. Switch to the later style push rods while you're at it....way lighter.
Bellingham, WA USA
1975 BMW R90/6
1975 BMW 2002
1971 VW Westfalia
1985 VW Vanagon
http://advrider.com/index.php?threads/b ... s.1074183/
1975 BMW R90/6
1975 BMW 2002
1971 VW Westfalia
1985 VW Vanagon
http://advrider.com/index.php?threads/b ... s.1074183/
- Airbear
- Posts: 2887
- Joined: Tue Aug 03, 2010 10:02 am
- Location: Oz, lower right hand side, in a bit, just over the lumpy part.
Re: Lifter and rocker wear
Thanks Matt. That is the way I'm heading - got my eye on what looks like a good used set of 76 - 84 rockers.
I continued dismantling and cleaning parts today. This is the tip of the valve that was being hammered by that nasty rocker pad:

It took a bit of careful filing to permit removal. Guides are still fine, and I've got a good replacement valve. A useful lesson for me. In future I'll avoid taking such shortcuts - I knew the rockers were crap back in 2008. On the bright side, at least there are no stripped studs.
I continued dismantling and cleaning parts today. This is the tip of the valve that was being hammered by that nasty rocker pad:

It took a bit of careful filing to permit removal. Guides are still fine, and I've got a good replacement valve. A useful lesson for me. In future I'll avoid taking such shortcuts - I knew the rockers were crap back in 2008. On the bright side, at least there are no stripped studs.
Charlie
and Brunhilde - 1974 R90/6

Graduate, Wallace and Gromit School of Engineering and Design (Pending)
and Brunhilde - 1974 R90/6

Graduate, Wallace and Gromit School of Engineering and Design (Pending)
Re: Lifter and rocker wear
Good news on the studs Charlie.
4 rockers, shafts, bearings, and blocks have been going for just under $100 on ebay. Not bad.
4 rockers, shafts, bearings, and blocks have been going for just under $100 on ebay. Not bad.
Lord of the Bings
- hools100RS
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- Location: Central Goldfields, Victoria, AUS.
Re: Lifter and rocker wear
Hi Charlie, for what it's worth a friend had the tips of his rockers built up by a local welder using stellite rods and had them carefully re profiled using a good rocker as a pattern. They're still in his bike and have covered many thousands of trouble free kms. Replacement lifters look to be on the cards though. E bay is also a good bet. Good luck with it!! hools.
- Airbear
- Posts: 2887
- Joined: Tue Aug 03, 2010 10:02 am
- Location: Oz, lower right hand side, in a bit, just over the lumpy part.
Re: Lifter and rocker wear
Thanks Hools. Good to know. Pretty sure I'm onto some good rockers.
I am getting worried about the lifters, but good ones seem hard to find. I could just assume that because of the large surface area, the abundant oil film and the cam lobes being in such good condition, that the old ones might be just fine.
Being a cheap bastard AND paranoid can be tricky sometimes.
I am getting worried about the lifters, but good ones seem hard to find. I could just assume that because of the large surface area, the abundant oil film and the cam lobes being in such good condition, that the old ones might be just fine.
Being a cheap bastard AND paranoid can be tricky sometimes.
Charlie
and Brunhilde - 1974 R90/6

Graduate, Wallace and Gromit School of Engineering and Design (Pending)
and Brunhilde - 1974 R90/6

Graduate, Wallace and Gromit School of Engineering and Design (Pending)