oilpressure valves: which one is correct?

[nicolas]

as the title says, which pressure valve goes in what case?

as far as i can say i hear contradicting answers about the dualpressure cases. some say that you need two non-grooved plugs (and that seems to be correct up to 72 in my books), but if i look at my aftermarket set with stronger springs it has a grooved one for the pulley-side... and indeed some people and info i found say to use those.

why? what is best? and while we are at it are the stiffer springs that much better in a street car?

[K-Roc]

I have never found anyone who knows for sure....

I always use the non grooved ones in both spots on dual ports. And the grooved one on Single ports.

I would love to hear how or why the H.P. relief valve kits have one of each as well!

[nicolas]

yep, it seems to be one of 'those' mysteries... 

if someone knows, please do share.

[Bruce]

Every virgin 1600 dual relief engine I've taken apart had the short non-grooved plunger in it.

If you look carefully in your orange Bentley manual, they show both! (P38 & 39)

[neil68]

Ditto.  In 35 years, every German OEM case I've seen came with solid valves in both relief holes...and that's what I always use.  Also, the OEM hardware kits available up until a few years ago also came with two solid relief valves.

[nicolas]

thanks, non-grooved it is then!

 

But what about uprated (aftermarket) springs. i could see some benefits, but also some drawbacks as valves opening or closing later...

[Harry/FDK]

To make things even more complicated. John from Aircooled.Net states that the springs in the OEM hardware sets have the wrong tension. So, what would be the "right" tension then...

(I just use the springs and non-grooved plungers that come with the OEM kit).

[Bruce]

I use the springs VW put in there 35 years ago.

[jr59]

to Answer about the aftermarket oil ressure regulator kit,the worth thing are the piston themselves which are out of the original OD .In most case there are smaller than the VW original OD! thus the leak is more important between piston and wall!
For the springs the "higher pressure" ones have...too much (particulally on the pressure side) tension ( with new case and classic oil used you can reach very (too much) pressure ).And finally,most of the time if you have an oil pressure issue, look inside dthe case  as this device will not cure the problem at all!
those sold as EOM are not so bad, in fact.
NOrmally solid valves is use in all the dual pressure case.The "legend" is that grooved piston is use in heavy duty/hot weather engine...but I really couldn't check in real life!!