Valve adjustment with swivel foot adjusters Options

[Geezer914]

When adjusting valves with swivel foot adjusters, are you adjusting them with "0" lash or .004 that Porsche recommends? My thinking "0" lash does not allow for heat expansion and the valves will not fully seat. (IMG:style_emoticons/default/popcorn[1].gif)

[914werke]

What pushrods do you have installed?

[Geezer914]

Chrome molly from the Type 4 store. Engine is a 2056 build.

[VaccaRabite]

If you have steel cut to length pushrods you can adjust your adjusters to 0 lash.
If you have aluminum push rods you need to follow the factory specs.

It has NOTHING to do with swivel foot or not. It has everything to do with the expansion rate of the pushrods VS the expansion rate of your cylinders.

Elephant foot adjusters expand the contact patch of the adjuster and (in theory) keep the adjuster from wearing away. They usually are not used in otherwise stock builds, and using inferior swivel foot adjusters (ie - most of them) will eventually be the cause of failure in your engine. Therefore, unless you are building an engine with upgraded valvetrain, and steel custom pushrods the cost of the good swivel foot adjusters ($20 per adjuster) usually isn't warranted.

But valve lash has noting to do with the adjusters and everything to do with the push rods.

Zach

[Geezer914]

So you are saying chrome moly pushrods don't expand? Every solid lifter engine I have owned specified a valve lash?

[GregAmy]

So you are saying chrome moly pushrods don't expand?

Chromoly pushrods expansion is comparable (actually, slightly less) than that of the head/cylinder stack expansion, thus no cold valve clearance is needed.

Aluminum (stock) pushrods expand more than that of the head/cylinder stack expansion, thus need cold valve clearance so the valves aren't being held open after the engine heats up.

If you disagree, then assuage your concerns by following the factory specifications. Worse thing you'll experience is noise and a slight (negligable) performance decrease.

[Superhawk996]

(IMG:style_emoticons/default/agree.gif)

Ya' all also forgot that the rockers sit on top of a chunk of aluminum that also expands outward (rocker arm axis getting further from case centerline). That thermal expansion is proportional to change in temperature and has a much higher operating temp (300F or so) than the case, or chromemoly pushrods.

Bottome line: you're picking up operating clearance to chromemoly pushrods as the head expands too.

[Geezer914]

Thanks to all for the clarification. "0" lash it is.

[GregAmy]

BTW, my "zero lash" isn't really 0, it's just as tight as I can make it while still feeling/hearing a little "give".

Makes me feel a tad better.

[Superhawk996]

So you are saying chrome moly pushrods don't expand? Every solid lifter engine I have owned specified a valve lash?

Not trying to beat you up on this. Just wanted to post the why . . . which you already got.

Over the years, the biggest mistakes I've seen associated with any type of air cooled engine is to associate them with generic water pumpers.

So many things are different about cooling with air (and oil) vs. water cooled lumps of cast iron that were so prevalent back in the good ole' days.

Ignorance of these differences is why so many pulled the cooling vanes and thermostat thinking that would result it better cooling - never bothering to see that that they had taken air away from the critical oil cooler.

Same kind of thing with lugging engines. Many VW's have died early due to "Luggers". Invariably they had a well meaning friend or relative that told them reving an engine shortens engine life. But what they didn't realize is that air cooling needs air to cool with. And . . . that air is moved by a fan directly or indirectly tied to the crankshaft. So too few Rev's = poor cooling and shortned life.

Or they get freaked out by all the normal operational noises that are so much easier to hear on an air cooled engine.


But all those unique things are why I (IMG:style_emoticons/default/wub.gif) air cooled 914's! They were truly different.

[73-914]

For the same reasons , I always cut to the front of stopped traffic on my motorcycle. Got to keep the air flow up for cooling

[Geezer914]

Adjusted the valves, what a pain in the ass! could not reach the push rods to see if they spin so I adjusted them so I could feel just a hair of movement in the rocker arm.

[VaccaRabite]

BTW, my "zero lash" isn't really 0, it's just as tight as I can make it while still feeling/hearing a little "give".

Makes me feel a tad better.

I do mine with my finger. No wrench or screwdriver. Twist them in with my fingers till they JUST touch the valve stem. I usually end up backing them off and in a few times to make sure I get the feel right for that cylinder. Then I use the stubby screwdriver to make sure the adjuster won't move when I snug down the jam nuts.

Zach

[Geezer914]

I did mine the same way as Zach, finger tight just touching the valve stem.

[Highland]

with aluminum pushrods should the exhaust be .008 with SS valves or is .008 only for sodium filled valves? This is for a 2056cc with 2L heads.