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Cal-look/High Performance => Technical stuff => Topic started by: leec on October 16, 2016, 22:54:24 pm



Title: Genuine VW 1.25:1 rocker arms
Post by: leec on October 16, 2016, 22:54:24 pm
Hi guys,
Anyone know the part number or markings on the actual rocker arms of Genuine VW 1.25:1 rockers

Picked up a set on bolt up rocker shafts at a swap meet and just wondered if I got lucky :)

Lee


Title: Re: Genuine VW 1.25:1 rocker arms
Post by: Bruce on October 17, 2016, 04:20:55 am
The forgings are exactly the same as stock 1.1 rockers, so there are no identifying marks.
Look at the part where the pushrod seats.  If the location is centered to the forging, you have stock rockers.  If it is offset way closer to the rocker shaft, you have 1.25s.  Post a close-up pic to be certain.


Title: Re: Genuine VW 1.25:1 rocker arms
Post by: Felix/DFL on October 20, 2016, 14:17:38 pm
To my knowlege there are no 1,25 rockers made by vw.
1.0 / 1.10 / 1.15 were available that's it.

There often comes up the mystery that wbx had 1,25 but that's not true to what i learned...
1,25 only on aftermarket parts.
You could measure the ratio in an old head, clamped with two meassuring clocks.
Greetz


Title: Re: Genuine VW 1.25:1 rocker arms
Post by: leec on October 20, 2016, 14:22:58 pm
To my knowlege there are no 1,25 rockers made by vw.
1.0 / 1.10 / 1.15 were available that's it.

There often comes up the mystery that wbx had 1,25 but that's not true to what i learned...
1,25 only on aftermarket parts.
You could measure the ratio in an old head, clamped with two meassuring clocks.
Greetz

My understanding was the VW sp2 had them fitted as standard
Lee


Title: Re: Genuine VW 1.25:1 rocker arms
Post by: Bruce on October 21, 2016, 06:58:06 am
To my knowlege there are no 1,25 rockers made by vw.
The rockers I described above are made from genuine VW forgings. VW and Audi logos.
1.0 / 1.10 / 1.15 were available that's it.
What came with a 1.15:1 rocker?


Title: Re: Genuine VW 1.25:1 rocker arms
Post by: Felix/DFL on October 21, 2016, 08:09:43 am
To my knowlege there are no 1,25 rockers made by vw.
The rockers I described above are made from genuine VW forgings. VW and Audi logos.
1.0 / 1.10 / 1.15 were available that's it.
What came with a 1.15:1 rocker?

Hi bruce,
1,15 came with all 1600ccm.
I even thought for long that i had 1,25 in my 1776, they have vw and audi logos on it and were sold to me as wbx rockers 1,25 and look offset to others. Then i measured them and many others i had laying around for my next build. Suprise,suprise they only had 1,15-1,16 many other came out at 1,1-1,12...
I even got the info after that from some german engineheads that there are no oem 1,25.

Have you measured your rockers?
Maybe my info is wrong and i had no luck with the rockers i bought, would like to hear/see that but I have not much hope...


Title: Re: Genuine VW 1.25:1 rocker arms
Post by: Bruce on October 22, 2016, 17:20:44 pm
AFAIK, a waterboxer used a 9mm adjusting screw.  Correct?

The 1.25s I have use traditional 8mm screws. I believe CB was importing these from Brazil.  It wasn't clear if they were machined to the higher ratio by VW, or if another co was getting raw forgings and machining them "wrong".


Title: Re: Genuine VW 1.25:1 rocker arms
Post by: Jim Ratto on October 25, 2016, 00:35:09 am
DH 1.9 waterboxer rocker is 025 109 405C and uses 9mm adjusting screw (thru 1985MY in US)

MV 2.1 waterboxer rocker is 025 109 405A and uses 10mm adjusting screw (1986-91MY in US)

Both engines use 272mm long pushrod, 025 109 301

I wonder what the big slug of 10mm adjusting screw does to valvetrain harmonics at high rpm ?


Title: Re: Genuine VW 1.25:1 rocker arms
Post by: Bruce on October 25, 2016, 06:59:07 am
And now with pictures!
The forging is the 2 line 1600cc rocker and they've machined the socket for the pushrod as close to the rocker shaft as possible in order to get the maximum ratio.

[attachment=1]
[attachment=2]
[attachment=3]

CB advertised them as genuine VW from Brazil and sold them for decades.  On their current web site they have a new forging to replace this.  They say it's a "better" forging.  My bet is that their supply dried up.


Title: Re: Genuine VW 1.25:1 rocker arms
Post by: modnrod on October 25, 2016, 10:17:16 am

I wonder what the big slug of 10mm adjusting screw does to valvetrain harmonics at high rpm ?


Gday Jim.

My guess on that is very little.
I have a set of late 9mm rockers which I drilled out and tapped to then take 10mm adjusters from a Kombi 2L (Type 4 to you guys?), and their was negligible difference in the weights on the nose, I did measure it but only remember it was enough for me to discount it for the real world.

New strong OEM rockers, new strong OEM adjusters with wide feet, it's all good really.
 :)


Title: Re: Genuine VW 1.25:1 rocker arms
Post by: leec on October 25, 2016, 10:18:29 am
Thanks Bruce,
They are the exact ones I bought and described in my original post

Lee


Title: Re: Genuine VW 1.25:1 rocker arms
Post by: besserwisser on November 08, 2016, 23:45:33 pm
I have tried those so called redrilled original rockers and they all came out to 1.15:1 and the camshaft from CB was missing 1mm lift on the cam so I went with CB 1.3:1 rockers and got the lift I was aiming for. The only sort of original look rockers that give 1.25:1 is the Scat.


Title: Re: Genuine VW 1.25:1 rocker arms
Post by: Bruce on November 12, 2016, 21:57:05 pm
The ones in my photo are not "redrilled originals".


Title: Re: Genuine VW 1.25:1 rocker arms
Post by: Felix/DFL on November 14, 2016, 13:00:26 pm
Very interesting info`s, so there were OEM 1,25 rockers but not in the old world.
Or let`s say they were made out of OEM castings and drilled to different specs.  ;)
I will check my rockers that I measured were the hole for the socket sits.

So the way to go is with Scat for the true 1,25 ratio, thank`s for the info!


Title: Re: Genuine VW 1.25:1 rocker arms
Post by: JayUK on December 20, 2020, 22:35:16 pm
Sorry to bring this back from the dead, but I have just gone to replace what I thought was stock VW in my type one with Scat 1.25:1. When I took them out and laid them side by side, they are identical dimensions.

Exactly the same as the pics that were posted. I will try and upload a couple of pics. 

Jay


Title: Re: Genuine VW 1.25:1 rocker arms
Post by: Flc on December 21, 2020, 08:28:07 am
Those look like stock ratio, the pushrod location looks to be central in the pad. The ratio ones have the drilling closer to the shaft, clearly offset. The new ones you have are machine offset at the shaft mounting point, to lower the whole game in the head. (twist the mount pad 180 deg and you will see the offset) this is done to allow better centralisation of the pushrod in the tube. If you come across pushrod with a shinny polished area around half inch down this will have been rubbing on the pushrod tube(usually causing a leak) hope this makes sense (it's early)


Title: Re: Genuine VW 1.25:1 rocker arms
Post by: JayUK on December 22, 2020, 23:48:04 pm
Thanks for the info. It definitely makes sense. I was slightly confused when I compared both sets 

I just have to wait for the shims and the shorter push rods through the post mow so I can fit them. I stupidly thought they would fit without any issue.

Thanks again for the info.


Title: Re: Genuine VW 1.25:1 rocker arms
Post by: Flc on December 23, 2020, 12:33:06 pm
I do a full dry build set up to try the geometry. I've found that the new type (adjuster at p rod) have required the mounting pads lowering to reduce height rather than spacers I machine the cheaper part (the rocker shaft pad not the head) . If your not familiar with this type of rocker have a look here. https://youtu.be/eTWXzYWieeg
Simplest explanation I could find.