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Post by 71XS1B on Apr 15, 2007 14:35:13 GMT -5
I suspect that the reason for the shims is to compensate for the increased length of the adjuster - nothing to do with the geometery. Tony I think, but Im not 100% certain, that the shims fit under the towers that mount the rocker arm shafts on VW's in order to alter the rocker arm shaft height, and thus, the geometry of the valve actuation. I'm really anxious to see how it goes with yours and mashermoto's modification... Dan  |
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Post by tony101bikes on Apr 15, 2007 15:33:04 GMT -5
Dan
I'm sure that you're right about them going under the towers but if you need to cater for a longer adjuster in a VW you get three options.
Grind away the rocker which preserves the geometery.
Shorten the pushrods which radically changes it.
Shim the towers which only changes it a bit.
I suspect that option three is easier and a better compromise.
I'm now regretting starting this thread. I'll guarantee that I'll wake up at 3am with a different opinion. Don't you wish you'd paid attention during those geometery lessons?
Tony
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jack
Junior Member
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Post by jack on Apr 15, 2007 19:33:49 GMT -5
So what's the consensus of preference here,VW,Porsche or Berg? I don't mind paying for better quality.................Jack
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Post by tony101bikes on Apr 17, 2007 14:06:36 GMT -5
Got my adjusters through today. On a dry run with a Shell #1 cam, I managed to get stock clearances without grinding the rockers at all! The slotted and seems to clear the covers without shortening. I think that I'll take a polish off the bottom face of the rocker with a flap wheel in the angle grinder just to make sure.
Has anybody else got this far yet?
Tony
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Post by mashermoto on Apr 17, 2007 18:09:42 GMT -5
Haven't got that far yet Tony.
No grinding on the rocker? How close is it?
Got pictures?
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Post by 5twins on Apr 17, 2007 18:22:07 GMT -5
I looked up those "Berg" adjusters - $15 each - ouch!
If these things really will fit with no grinding of the rocker and no shortening of the adjuster, then I think I would go with the allen head style.
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Post by mashermoto on Apr 17, 2007 18:28:59 GMT -5
No doubt about the allen style if not necessary to grind on the adjuster end. The allen style are cheaper too  |
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Post by 71XS1B on Apr 17, 2007 18:56:52 GMT -5
Hi Tony, Great news about possibly not needing to trim the rockers! Which adjusters did you finally end up going with? Zim's, CB Performance, Berg? Are they the slotted or socket-type adjusters. Posts some pictures, if you can. Cheers, Dan |
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jack
Junior Member
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Post by jack on Apr 17, 2007 20:20:38 GMT -5
The shell cam will give more clearance cuz the base circle was reground on a stock cam you might have to modify the stock rockers...............Jack
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Post by tony101bikes on Apr 18, 2007 12:10:34 GMT -5
 Jack Sorry but I pulled it apart again and sent the cover for blasting. This is one of the inlet rockers which I set to the right clearance and then removed without touching the setting. This rocker has not been ground away at all. I would suggest taking 1mm or so off them just to make sure there's enough scope for adjustment in the future. Hope the picture comes out ok. Is there any difference in early / later rocker type dimensions? Tony |
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Post by 5twins on Apr 18, 2007 12:48:47 GMT -5
After giving this some thought, I don't think we would need as much grinding as we thought .....  It seems to me that only the lower front part of the rocker would need some grinding. The "foot" would pivot in the direction of the arrow when the rocker rotated down, right? This way, we wouldn't need to grind into that stiffening rib at the lower rear. |
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Post by tony101bikes on Apr 18, 2007 14:00:59 GMT -5
Funnily enough, I've just been out and done one as suggested. I'm just not as good with IT ............. Not bad with an angle grinder though! I've now shortened by 1/8th of and inch and recut the slot with a Dremel. The ones I got are Empi parts from Anaheim.
Tony
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Post by mashermoto on Apr 26, 2007 9:18:33 GMT -5
So...what was the verdict on the best way to grind the rocker?
Maybe just a milimeter or two off the bottom, and then a couple of milimeters off the front edge like shown in 5Twins photo?
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Post by tomterrific on Apr 26, 2007 11:20:15 GMT -5
I looked at the 5-twins pic above and verified what I thought might be the way to grind/modify the rocker tip. The elephant foot has sort of a truncated cone shape so really all that is needed for more clearance is to use a large drill bit or ball stone to relieve the area around the elephant foot on the rocker. This leaves the original strength of the rocker but grinding a tip straight off doesn't really weaken the rocker much.
The depressed Allen hex type adjusters are lighter than the slotted type due to the hole. The screwdriver type are lighter than the stock square tip type.
The elephants foot can be thought of as a bucket with a rotating ball in it. Always pre oil these before installing them. The foot fills like a bucket in operation and not only lubes the ball but cushions the valve action ever so slightly. I wish I could find these for my Triumph.
Tom Graham
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Post by 5twins on Apr 26, 2007 15:24:55 GMT -5
I like that large drill bit idea, Tom. I think I'll do that plus grind a little off the front. What concerns me is not being able to back that elephants foot adjuster out enough during assembly/disassembly of the head so it won't contact the cam. One cylinder is always fine at TDC because both rockers are loose, but the other one is part way through the exhaust (intake?) stroke and one valve is partly open. When I disassembled mine, I was able to loosen all 4 stock adjusters way up so none were contacting the cam. I'm not saying it can't be done but I just think it would be a bitch trying to bolt the top cover on while one of the rockers was trying to force a valve open.
Tony, you got the Porsche adjusters, right? How long are they? I ordered the allen VW ones from PJ's link. I'll report on length and mods needed when I get them.
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