Valve adjustment on 69 Volkswagen question

[Buick35]

I have two books with conflicting answers on valve adjustment.I have a Chilton's that says adjust them to .004 and a how to rebuild a Volkswagen engine by Tom Wilson that says to set them at .006 which I did.I plan on checking them again anyway but which one is right? Thanks.

[Str8-8-Dave]

The looser (0.006) is safer.  The tighter (0.004) might be a bit quieter but if it turns out to be too tight, expect valve and seat damage due to burning AND loss of power if valves don't close all the way.  If it were me, I would go 0.006 keeping in mind if a few thousandths loose is harmless to the valve train.  Air cooled Volkswagen motors can get pretty hot in stop and go summer traffic.  They don't make gobs of power so you can't afford to lose any.  

 

I rode BMW air cooled opposed twin motorcycles for many years and ALWAYS erred on the loose side with valve lash, especially exhaust valve lash.  

[Frank DuVal]

Do it cold, overnight cold.

 

Is the sticker missing from the fan shroud?

 

JBugs agrees with .006:

 

https://www.jbugs.com/VW-Tech-Article-Valve-Adjustment.html

 

Did you check the bible from back then by John Muir? 🤣 (you have to be over 50 to understand this, but they are still available, even in Kindle form)

[NailheadBob]

VW Beetle official service manual agrees with @Frank DuVal and JBugs Cold engine (.006") on both intake and exhaust valves.

 

Bob

[Buick35]

Thanks for the information,I'll have to get the sticker for the fan shroud.

[Rusty_OToole]

For a time the VW company recommended .004 then later changed to .006.  I believe .004 was best except under severe service or high heat conditions when the lash would tighten up too much due to heat.

 

Dodge did something similar, on slant six engines they recommended .010 on the intake valves and .020 on the exhaust for cars, and .012 and .024 for trucks, presumably because truck engines work harder and develop more heat in the valve area.

 

I would use .006 in your case as your Ghia is heavier than a bug, and a hopped up motor may run hotter than a stocker, especially if you live in a hot climate.

Edited June 8, 2023 by Rusty_OToole (see edit history)

[Rusty_OToole]

On the subject of valve adjustments. They are supposed to be done every 4000 miles. A bit of a nuisance but can be made easier. Clean the valve cover and glue the cork gasket into the valve cover with a bead of silicone then press it against a flat surface. Let the valve covers set while you adjust the valves. When you put the covers on coat the gasket with oil or grease so it does not stick to the head. Next time, the cover will come off easily and not damage the gasket. Do this and you don't have to replace the gaskets every time. Pry the bail up to free the cover and snap it back down again when you are done.

[Pfeil]

There was a specification change somewhere in the late 60's early 70's. At that point in time, I was a VW line mechanic and a little later a Unit repair mechanic. Unit repair consisted of rebuilding engines and transaxles.

The reason for the change from .004 to .006. The lash setting was a cold setting. People would bring a car in for service and expect the car to be ready in a few hours. Well, we could never get the engines cool enough for a proper valve adjustment. The folks running the U.S., VOA and the national technical schools came up with an answer. They came up with a blower system that would reverse or back flow in the opposite direction to cool the engine down. This worked somewhat; however, you can imagine several techs all trying to use a couple of blowers that were allocated to a dealership. That's when the edict came down specifying .006.

As most VW and Porsche people at the time know valve adjustments are crucial in the longevity of those engines. Valve adjustment requirements are every 3,000 miles and oil changes are every 1,500 miles. Those engines and like all aircraft air cooled piston engines like straight weight oil. Anyroad, if you have a overnight or stone-cold engine .004 is perfectly fine. If you adjust to .006 you just gain a little more noise and loose a small amount of lift and duration(=hp) from the camshaft.

 

 

[californiamilleghia]

my friend has one of the blower systems if you just need to have one .....

 

We have always done .006 for a stock motor , 

 

But I believe if you have steel aftermarket push rods  it is not the same.

[NailheadBob]

@californiamilleghia please could you post photo of blower?

 

Bob

[californiamilleghia]

On 6/10/2023 at 12:10 PM, NailheadBob said:

@californiamilleghia please could you post photo of blower?

 

Bob

if he brings it to the next Pomona swap meet I will take a picture , cheers