Valve train rebuild

[op3]

Hi All...
Questions on valve train rebuilding.. Ron Wilson's book recommends to use Swivel foot adjusting screws. While PP recommends just replacing them w/ stockers.. any advice there? Anything else i should be wary of while reassembling the rocker assembly?
Thanks
Chris

[Dave at Pelican Parts]

The swivel-foot ones are good--if. That is, if you get good-quality ones, and if you set the valve-train geometry after you install them.

I don't know of any good swivel-foot setups for the 73+ rocker arms (with the M10 adjustment screws). The 911 swivels can be used on the 70-72 ones, but some machining has to be done to the upper end of the rockers, and/or the rocker stands have to be shimmed out, and/or the pushrod lengths adjusted.

It is simpler just to use stock ones. The swivel-foot guys are better (they should hold an adjustment longer and put less stress on the valve tips), but it is more complex to set them up correctly.

--DD

[op3]

Thanks Dave..
Guess I'll wait till next time to mess w/ swivel feet and ratio rockers.. Question then, is there any difference in other Type 4 valvetrains (i.e.: 1.7, 1.8, 2.0 and bus?), seems they would have to be the same since all pushrods/tubes are same length for a T.IV. I'd like to scavenge parts from the other assemblies that i have, if need be. Does anyone have a link to a good VW valves page? PP only has info on valve adjustments, that i saw...
Thanks
Chris

[Dave at Pelican Parts]

The very early 70s had pushrod tubes that were a different diameter on the outer end.

The later Buses (don't remember the year, sorry) had hydraulic lifters, and used different pushrods as a result.

Not sure about the other valve train components, except that the hydraulic-lifter-equipped Bus motors used solid spacers in between the rocker arms, rather than the springs that the solid-lifter-equipped motors did. (Though it's an easy retrofit, so that's not a certain way to tell...)

For a broader spectrum of T-IV info, check: http://www.tunacan.net/t4/reference/cylhead.htm

--DD

[Jake Raby]

Rocker arm geometry is one of the hardest parts of engine assembly!!

The swivel feet are good for the valve guides, as they widen the pressures being exerted from zero, to half and full lift evenly.

Every engie we build, with more than a stock cam, gets real 911 valve adjuster screws, and about 3/4 of a day to set up the geometry. It is very important when setting rocker geometry to make 100% sure you are getting the max lift from the cam, the pushrod length can play with the ratio, at the rocker, and cheat lift from you very easily.

The valves, valve guides, and entire engine benefit from a properly set up valave train...These parts can kill, and I can vouch for that..

[op3]

Well, thanks jake.. now i'm getting worried.. to thicken the plot.. how do i know which rocker arms go to which pushrod? when i bought the heads the valve trains were all disasemmbled and in one bag..

rocker arm part #'s:
(3) 7R 55
(1) 7R 6(4?)
(1)46 J7
(1)45 J7
(1)46 H4 (more similar to the 7R 55's)
(1)46 H6

Any ideas? Thanks..
Chris

[This message has been edited by op3 (edited 06-05-2001).]

[op3]

Well.. I guess not to worry.. did some test fitting and it looks like i've found which ones go to which...