Rocker Arm Setup

[carguytroy]

Alright. I’ve been messing with the rocker arm set up/geometry on my engine build. Having some troubles. Questions:

I opted for the CB Performance solid shafts with the elephant foot adjusters. Are they supposed to line up center of the valve looking at them from the adjuster/pushrod tubes. Straight on. or sit off to one side or the other? And do I run the adjusters all the way up and turn them in so much or what’s a good starting point to have the adjuster at?

Shimming. I’ve shimmed the shafts up to .150 and I’m close to level which is what I understand I’m going for. The pushrod side of the rocker needed to go up. Too much shim? Or is this fairly normal?

Any other tips you can throw my way?

I know I ask a lot of questions on here. I really appreciate the help.

[bugguy1967]

This gets asked once a week. Grind the rockers back so you can turn them back more.

https://www.thesamba.com/vw/classifieds/detail.php?id=1925154
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"A petrol engine can start readily, run smoothly and give every appearance of being in good order, without necessarily being in good tune." - Colin Campbell, "The Sportscar Engine"

[carguytroy]

I just purchased new CB rockers and shafts. ????

[jimmyhoffa]

True- and they'll hold together as advertised shimmed out a bunch... even with sub optimal geometry.

BUT like most things, new does not equal optimal. New equals functional. If you make the rockers so you can retract the elephant feet deeper then the geometry will make sense.


I wrote you a little rhyme on the matter:

If you want it done right, you gotta lower that shim height.
Just send em' to Tabari, you won't be sorry.
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1974 Chenowth 2RL #1244 Street Legal
My other car isn't ridiculous.

[txoval]

Read here:

https://www.thesamba.com/vw/forum/viewtopic.php?t=751867

Only three threads away from yours

[carguytroy]

Sounds like I need to either buy another set from Tabari or send mine out there. Quicker is better at this point. Whichever is faster. I’m on!

[jeffrey8164]

Link

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Volkswagen!
Turning owners into mechanics since 1938.

“Let he that is without oil throw the first rod”
(Compression 8.7:1)

[mark tucker]

he is clueless.no I wont argue the point.

[Shane Tuttle]

[Dan Ruddock]

[clonebug]

I took about .070" off the bottom of my stock rockers and added .130" shim under the rockers while using CB's Swivel Feet adjusters with solid shafts. I didn't want to buy new pushrods at the time since I was running a W-100 cam.
I spent a lot of time working out the geometry and I came up with the best scenario I could with what I had.
I ran it that way for at least 12,000 miles and it showed no ill effects.
Just because it ain't the way some say doesn't mean it won't work.

Get the half lift as close as you can and you will be fine.

I also ran a W-100 with 1.38 ratio rockers giving me .526" lift and I used 10.630" long .035" thick steel pushrods for a season using the outside spring of the CB 650 springs.... and the cam, lifters, chinese rockers, lash caps and valves were in perfect condition.

I now have the same upper valve train but switched to a FK-42 cam that's designed for 1.4 rockers....not because I had to but to try to move the peak power up to 5000-5500 instead of 4700-4800 rpm.
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[modok]

.150 worth of shims can be needed to get "90 at half lift" with a stock camshaft.
the more lift, the less shims needed

The center of the ball joint hould be positioned where the tip of the stock screw used to be.
This requires grinding the rockers to allow it to be backed out that far.
If the adjuster is EXTENDED farther out of the rocker from NOT doing that, you are making a variable ratio rocker with higher ratio closed and lower ratio open. is that good or bad? IMO, worse. IMO it is better to be constant ratio or slightly progressive.
Most people don't understand enough to have an opinion on that, which makes it hard to discuss.
but a WIDE survey of people doing it one way or another randomly, seems to show that a progressive ratio does work better.

[carguytroy]

I'm going to have these rockers worked over and go from there. I would start grinding on them myself, but I've never done it and I don't trust my lack of knowledge and experience on this one. Normally...I would have at it. But probably not the way to go here.

[txoval]

T will hook you up if you send them to him. His work is excellent and great to work with

[carguytroy]

Got the rockers back. Look good! Now to put them together. Questions. When setting these up do I want the adjuster aligned to the right a bit or dead center of the valve when starting out? Meaning before the rocker starts to push the valve.

[modok]

They were originally about 1mm off center toward the pushrod.

I noticed CB's latest reproduction stock rockers seemed like they were centered.

Not a big deal, whichever way works out best.

[GARRICK.CLARK]

I'm with Clone bug and Modok on this subject

[mark tucker]

either way, but if you have extra lift&ratio you may have pushrod to tube cleance issues so...you can sometimes offset the adjuster some to get the clearance you need. be sure to set the rocker side play between .002&.004" for quiet operation.I use lash caps on all my builds and have for well over 40 years with zero issues.I wont use a tight fitting lash cap. for the guys that seem to have issues with lashcaps comming off...it's not the lash caps fault.it's the builder or drivers fault.unless it got leened out real bad...still not the lash caps fault in any way.

[carguytroy]

[oldgit]