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Cal-look/High Performance => Cal-look => Topic started by: alex d on March 27, 2008, 11:31:08 am



Title: Rocker sideplay, how much is too much?
Post by: alex d on March 27, 2008, 11:31:08 am
I was going to do rocker geometry, and after discovering that those CB Perf. cro-moly head studs are way too long for a non-stroker (they hit the rockers!)and shortening them, I layed the rocker assembly on the head and noticed that rockers have lots of sideplay, didn't measure it but it sure felt like an awful lot, they are Scat pro-street 1,25s, brand new. How much sideplay would be acceptable? And how do I reduce it?


Title: Re: Rocker sideplay, how much is too much?
Post by: richie on March 27, 2008, 17:36:55 pm
I was going to do rocker geometry, and after discovering that those CB Perf. cro-moly head studs are way too long for a non-stroker (they hit the rockers!)and shortening them, I layed the rocker assembly on the head and noticed that rockers have lots of sideplay, didn't measure it but it sure felt like an awful lot, they are Scat pro-street 1,25s, brand new. How much sideplay would be acceptable? And how do I reduce it?

You can get different thickness shims to allow you to tighten it up,Scat sell them,i really do it through feel,tight enough so no noticable side play but just loose enough not to bind,cheers richie,uk


Title: Re: Rocker sideplay, how much is too much?
Post by: John Rayburn on March 27, 2008, 18:02:10 pm
I set mine like the feel on a valve adjustment. Not quite zero. Just enough movement so stuff is nice and free.


Title: Re: Rocker sideplay, how much is too much?
Post by: Jim Ratto on March 27, 2008, 18:05:02 pm
Me too, I try to set up like .002"-.003", and usually have to sand sides of rocker stands or aluminum end caps to get them "just rght"

Make sure you test them before you lay them on over pushrods, and make sure you torque to head, as the clearances will pinch after being torqued.

It's a "feel" thing  ;D


Title: Re: Rocker sideplay, how much is too much?
Post by: Harry/FDK on March 27, 2008, 19:16:36 pm
And NEVER use the wavy or spring washers.


Title: Re: Rocker sideplay, how much is too much?
Post by: alex d on March 27, 2008, 19:19:31 pm
thanks guys, so, can I use the shims most vendors sell for stock style shafts or do I have to use the scat ones, which no one sells around here BTW  >:(



Title: Re: Rocker sideplay, how much is too much?
Post by: Jim Ratto on March 27, 2008, 19:33:08 pm
I think Scat's are a different (larger) diameter than VW ones.... :-\


Title: Re: Rocker sideplay, how much is too much?
Post by: richie on March 27, 2008, 20:09:39 pm
thanks guys, so, can I use the shims most vendors sell for stock style shafts or do I have to use the scat ones, which no one sells around here BTW  >:(



Scat uses 2 different sizes,1 size for the swivel feet style and another for the Pro rockers,CBs are different again etc,you will need to measure yours and compare them to standard,where are you in the world?am sure we could find a way to get you some if you cant find any locally :)

cheers richie,uk


Title: Re: Rocker sideplay, how much is too much?
Post by: alex d on March 27, 2008, 21:41:25 pm
they are the swivel feet ones, tomorrow I'll measure the shafts to see, richie, I'm in Spain, I checked with my usual supplier and they don't carry them


Title: Re: Rocker sideplay, how much is too much?
Post by: alex d on March 31, 2008, 08:54:28 am
well, I spent all friday afternoon playing with my rockers, it turns out they use the stock shaft size, so I disassembled the rocker assemblies from my old (junk) 1200, and took the shims (no, not the wawy washers) and after something like 400 tries I found a combination of shims which gave it that  "right" feel, now I got to do the other head!


Title: Re: Rocker sideplay, how much is too much?
Post by: Jim Ratto on April 03, 2008, 18:55:00 pm
well, I spent all friday afternoon playing with my rockers, it turns out they use the stock shaft size, so I disassembled the rocker assemblies from my old (junk) 1200, and took the shims (no, not the wawy washers) and after something like 400 tries I found a combination of shims which gave it that  "right" feel, now I got to do the other head!

Cool glad you got it worked out. I disassembled mine last night, as I was never quite happy with the way my 1.25 Scat's (skuffer tip type) were set up originally. After some shuffling of shims and some light filing and polishing of rocker-shaft-stands, I got them all set in with about .002" end play, nice and quiet. Nice to have two genuine VW cylinder heads to use as mockup models if you run VW heads on your motor.


Title: Re: Rocker sideplay, how much is too much?
Post by: alex d on April 30, 2008, 11:03:30 am
oh, well yesterday I was finishing the rocker geometry, when I was taking off the rocker assembly to change the shims it fell to the ground!  :o
one of the balls of the swivel feet fell altogether (at least it didn't get lost), I put it back in place (didn't take much force at all), it seems to move ok without binding, but how do I know it wont self-destruct at 6000rpm? What would you guys do?


Title: Re: Rocker sideplay, how much is too much?
Post by: Jim Ratto on April 30, 2008, 17:32:41 pm
oh, well yesterday I was finishing the rocker geometry, when I was taking off the rocker assembly to change the shims it fell to the ground!  :o
one of the balls of the swivel feet fell altogether (at least it didn't get lost), I put it back in place (didn't take much force at all), it seems to move ok without binding, but how do I know it wont self-destruct at 6000rpm? What would you guys do?

if you are using the swivel ball type (face that contacts stem is a ball with a flat on it), I would consider getting rid of those and getting a set of Porsche 911 adjusters, also known as "elephant feet." The Porsche part number is 901 105 370 02. The advantage is that the swivel ball type can mash up your stems or retainers if the ball rolls over in screw. The Porsche type can't do this.




Title: Re: Rocker sideplay, how much is too much?
Post by: alex d on May 02, 2008, 11:05:45 am
thanks for your insight Jim, I've heard other horror stories of the courier type adjusters (and some praise too), but as I don't want to risk the engine for this stupid part I bit the bullet and have ordered the 911 adjusters, coincidently I had some credit in my customer account in a US supplier which was nearly the price for the 911 adjuster set... ;D
now to wait for the postman  ::)


Title: Re: Rocker sideplay, how much is too much?
Post by: Jim Ratto on May 02, 2008, 19:45:32 pm
thanks for your insight Jim, I've heard other horror stories of the courier type adjusters (and some praise too), but as I don't want to risk the engine for this stupid part I bit the bullet and have ordered the 911 adjusters, coincidently I had some credit in my customer account in a US supplier which was nearly the price for the 911 adjuster set... ;D
now to wait for the postman  ::)

good job! make sure you soak them in a bowl of good engine oil overnight before you install them. Watch backside of foot against rockers too.
You'll be much happier adjusting valves with those 911 screws!  :)

Jim


Title: Re: Rocker sideplay, how much is too much?
Post by: alex d on May 16, 2008, 08:32:23 am
adjusters arrived yesterday, I played a bit with them, it seems I have quite decent rocker geometry, I'll probably grind a bit more off the rockers though