Rocker Thrust Bearing Mod

[Julio A.]

My valves needed some TLC. I bought new pushrods shafts, valves, springs, seals and seats. and I saw this. I though I might as well get them since I'm doing the valves anyway.



All I know  is that you'll need to shorter the rockers a bit, and just install one thrust bearing per rocker at the top.
Does anybody have any experience with these?

[tunnelrider]

They would be pretty good I reckon, especially on your pre '85 rockers with no plastic bush.  They'd probably make things noticeably quieter and any reduction of that waste axial friction of the rocker arm up the shaft and stopping on the supports by the thrust bearings must give increased efficiency of the pushrods I guess equals more horsepower at the wheel hopefully
But first time I've seen them so can't comment on how good they actually work Julio.. Good score I think, just have to get the rocker body shortened though as you said. I guess an engine machining shop will do that easily enough.

[Tony Smith]

I first saw these in around 1981, they were marketed by Luftmeister which should tell you everything you need to know.

Somewhere I still have my copy of an absolute "classic' Luftmeister catalogue where on one page the tout the virtue of their (very expensive) electronic fuel injection kit for airheads, whilst on the very next page they had their carb conversion kit for K bikes. Both advertisements were of the same formula - "Replace your unreliable (Carbs/Injection system) with our "new and improved" (Carb / injection system) , gain extra power, get better fuel economy, let us have a good feel of your wallet......


To my shame, and in spite of knowing that luftmeister are/were snake oil salesmen, I bought the Torrington bearing rocker kit (my excuse is I was much younger then and I wanted to believe).

The long and short is that yes you need to have an amount machined off both ends of your rocker to provide fitting clearance for two hardened washers and (if you can be bothered to use it) a hard plastic bush.

Unless you are VERY lucky you will destroy at least a couple of the existing needle roller bearing "housings" and have to fit new ones (my record with these is not good I think I have broken around 50%of my attempted installs - but then I haven't replaced one for more then 30 years so hopefully I might be smarter now).

When you have it all done you re-assemble the rockers and use the "two sockets method" to supply pretension and if you are lucky the former faint "tick -tick" of happy BMW rockers moving laterally on their shafts is replaced by the "rustle-rustle" of torrington bearings doing their thing.

Save yourself money and ignore the "tick-tick", but if you really must "improve" your engine-  a set of post 1985 rockers and pillow blocks will cost less than the torrington kit and will frankly do a better job.


I can confirm that the post 1985 rockers can be retrofitted to earlier heads and have done so on the wife's R65/80 which has a 1987 R80 engine fitted. Two years ago I sadly had to destroy the original heads to get the header pipes out - i had new valves fitted to an earlier pair of cylinder heads and after removing the old style rocker "pillows" was able to fit the later model rockers to them.

The late model rockers btw are silent when set up correctly.

[Bob_Roller]

There are shims available from BMW, to place between the rocker arm and support block at the end .

Item # 17, they come in various thicknesses .

http://www.realoem.com/bmw/enUS/showparts?id=0364-USA-09-1980-248-BMW-R65&diagId=11_1698


I put some in my '81 R65 about 24 years ago, it did quiet the ticking sound, but airheads have been making this noise for over 90 years, it's just it's character !!!

[Tony Smith]

There are shims available from BMW, to place between the rocker arm and support block at the end .

Item # 17, they come in various thicknesses .

http://www.realoem.com/bmw/enUS/showparts?id=0364-USA-09-1980-248-BMW-R65&diagId=11_1698

The parts in  the link above are the post 1987 rockers etc. For pre 87 the approved method is to use two largish sockets and a 'C" clamp to restrict the up and down movement of the rockers whilst tensioning the head bolts. You cant do that with the post 1987 heads as the rocker "pillow blocks" are positively located in the head, the earlier ones have a little "wriggle room".

[mrclubike]

The needle thrust  bearings are a solution without a problem
All you need are standard round shims to put on the bottom of the rocker shaft
It looks like Bob has used the ones for  the later rockers and they  should work  just get the thinner ones
This is what I used and they have been in for over 20000 miles and are showing no wear at all
You still need to squeeze in the shaft support as Tony explains 

[tunnelrider]

my excuse is I was much younger then and I wanted to believe

Guess I'm still in this age Tony    Good reply, you've used them.  So a 'rustle rustle' instead of a 'tick tick', yeah that's not quite the typical airhead sound..  Did you notice a difference in performance with the Torrington bearings Tony?

The late model rockers btw are silent when set up correctly.
                   

Silentish!

[Julio A.]

I went ahead and bought the bearings. As well as some nice new rocker shafts as I found mine pitted. I just hope I don't blow something up.

[Bob_Roller]

Is there any mention of what kind of cold clearance you need to have with this ' assembly ' and the blocks at each end .

[Tony Smith]

  Did you notice a difference in performance with the Torrington bearings Tony?

                   

None whatsoever....

[Tony Smith]

Is there any mention of what kind of cold clearance you need to have with this ' assembly ' and the blocks at each end .

Of course there isn't - you are left with the need for the same clearance as the standard rocker - enough so you can see oil being squeezed out, but not enough to hear a "click".

I'm sorry but the entire thing is complete snake oil. If for any reason the running clearance cannot be sufficiently closed up on pre-1987 rockers by the "C" clamp and two sockets method, then either the shims form the post 1987 rockers (or cheaper non-BMW part alternatives) can be used.

When I rebuild the R100 engine in the next little while I intend using the 1987 rocker set I was lucky enough to purchase cheaply and consign the evidence of my early 1980s foolishness to the dustbin of history. (Well the real reason is that the hard facing is worn through on the old rockers and they have already been re-profiled and re-hardened twice and I do not think that there is enough metal left for a 3rd go-round).

[Tony Smith]

I went ahead and bought the bearings. As well as some nice new rocker shafts as I found mine pitted. I just hope I don't blow something up.

There is no reason at all that you should blow anything up - check the oil hole orientation on the shafts and you cannot go wrong.
 
You do however have an interesting little task in front of you. If your old shafts were pitted, then your rocker bearings are in need of replacement, they are expensive little suckers too. 

Hopefully your Torrington bearing kit will tell you how much needs to be machined off te ends of the rockers to provide clearance for the beatings, shims and spacers, if not your will need to give the whole kit to your machinist so that they can measure it and work it out for themselves.

In all seriousness, if the seller will accept returns, send the damm things back, they will not provide any improvement in performance or service life whilst providing another thing to check and adjust.
 
If you are going to change the rocker bearings yourself you need a biggish bench vice, a piece of steel bar turned to the same diameter as the rocker shaft and some thin sleeves (preferably hardened) for pressing the old bearings out and the new ones in. Go slow and use white lead to lubricate the new bearing shells being pressed in. Also the end walls of the bearings are way to thin and fragile to tolerate being pressed in whist unsupported, you must put all the rollers in so that  both ends of the housing share the load.

Lastly, when you buy your bearings, make sure the supplier has more in stock, you are probably going to be buying a couple more when you break them during assembly.

Lastly, best of luck.

[mrclubike]

Tony knows what he is talking about
Listen to him and save yourself some hassle

[Tony Smith]

Tony knows what he is talking about
Listen to him and save yourself some hassle

And now i'd like to ask you a question to save myself some hassle. I have bought new Shinko tires for my R65 and intend to run them tubeless. The front shoudn't be a problem as it is a K100 rim and was tubeless ab-initio, but I a curious as to the length needed for the standard R65 rear rim.

Ideally I want 90 degree fittings to solve the no.1 annoyance with snowflakes - do you have any dimensions, brand names etc that will help me?

[mrclubike]

Here is the thread that i posted when i was switching over
It is titled
Getting a Pilit Activ to seat on a snow flake
I am running straight stems
They are on the long side but they have been working good


http://www.bmwr65.org/YaBB2.612/cgi-bin/yabb2/YaBB.pl?num=1441765743">http://www.bmwr65.org/YaBB2.612/cgi-bin/yabb2/YaBB.pl?num=1441765743</a