TheSamba.com :: View topic

Wed Jun 08, 2011 7:44 am

Can I adjust the valves when the engine is still warm? If so what setting? 1972 Beetle 1600cc. Many thanks.

Wed Jun 08, 2011 9:16 am

sure it can be done but wont be acurate wait till you can do it when its cold so it is uniform..

Wed Jun 08, 2011 9:23 am

Do it when the engine is cold, why second guess it?

Wed Jun 08, 2011 9:33 am

I am not so sure that adjusting while cold is the real answer - although 99% of the vw hobbyists and mechanics claim that.
---------------------------------
I think you’re on to something
------------------------------------
Each piece of metal expands at a different rate and value and the car performs at 200 or when it is hot so the best would be to adjust while hot.
I am sure that the lash is much less but how much less could easily be accomplished by adjusting at 004 when cold then run it until it is hot them measure it - I t might come down almost to zero but all VW's clash even after hot .
Then run hot to same temp and adjust hot. Out of sight ! ! ! ! ! ! !

Wow -- boy will the knuckledgragon purists appear on this one - along with some others that seem to believe that everything should be done like the factory in 1939. I have never heard of a mechanical engineer on this site – maybe one will show up.
Argue it up boys and girls PhD here in Mathematics

Wed Jun 08, 2011 10:01 am

I have checked valves hot before - but only in certain circumstances - valves that are unusually noisy when warmed up and also when I suspect a valve of having tightened down to zero clearance. However I only ever alter them hot if they are way off and then I'll check them the next chance I get cold to see what they read then. And it's not very fun to do hot - you best wear cloth gloves to avoid getting burned.

Wed Jun 08, 2011 10:36 am

The problem I see with adjusting valves on a hot engine is that everything starts cooling down the moment the engine is shut down. As it cools down those critical dimensions are changing. So the "correct" clearance for the first valve you do is different from the last valve.

Max

Wed Jun 08, 2011 10:49 am

Although I don't think many could argue that the "correct" way, or "book" way is with the engine dead cold, wouldn't there be some convention to adjusting them warm?

I'm thinking of back in the day when you'd take your car to a mechanic for a service. Certainly they didn't wait overnight to adjust the valves, would they? (before my time).

I think this is surely one of those issues where the best practice is to adjust on a cold engine because of the nature of the metal parts and the changes in dimensions with heat (no argument there). But I'd like to know what the "real world" method was back when these VW's where everyplace. We need the old-school mechanic to speak up and say what they really did.

Wed Jun 08, 2011 11:01 am

My understanding is you would set them to zero or a "loose zero".

Here's an old thread I found:
http://www.thesamba.com/vw/forum/viewtopic.php?t=198453

I know one of my friends was having trouble on a trip and he wanted to check the valves. I recall he reset a few to zero when hot and he didn't blow up the engine on the rest of the trip.

Quote: I'm thinking of back in the day when you'd take your car to a mechanic for a service. Certainly they didn't wait overnight to adjust the valves, would they? (before my time).
My understanding is they ran a fan against the heads to cool it down.
Reference:
http://www.thesamba.com/vw/forum/viewtopic.php?p=89277#89277

I took a quick look in my shop manual and it says the oil needs to be below 122F so not dead cold but pretty cool.

Wed Jun 08, 2011 11:31 am

Valve adjustment is a 2 day process for me. I hate valve adjustment, it's like being a women and having a period every 90 days.

Day 1 - Drive home from work and let it sit overnight.

Day 2. Drive other vehicle to work and come home and adjust valves.

It takes me about an hour because I take my time and clean up the mess and put my tools away. I know some of you can do it in 5 minutes. My OCD kicks in and it takes about 10 minutes per cylinder. Partially because I have to get out and rotate the engine to the proper cylinder. I go counter clockwise. But really I dont think it saves any time at all. It takes the same amount of time to crawl under the left side as it does the right side.

I think VW intially recommend .004 for the exhaust at .006 for the intake? Or is that backwards. Unless your a lazy america and just set everything at .006

But a proper adjustment sure can bring a little vw back to life.

Wed Jun 08, 2011 12:00 pm

I bought a new one is 70 - took it in to the little VW shop on Monroe in Spokane for an oil change and valve adjust - I had owned the car about 3 months and knew nothing - picked it up in about 2 hours - remember it like it was yesterday, the guy smoked cigars real husky and had a great sense of humor -- cussed like crazy and told some women stories.

Thanks for reminding me of that -- zero lash at 122 degrees ! ! ! ! ! ???

I will guess at that temp -- and try it

Can anyone tell me of the most reliable oil temp gage on the market - I am always worried about my engine temp !
Jerry

Wed Jun 08, 2011 12:24 pm

Quote: Thanks for reminding me of that -- zero lash at 122 degrees ! ! ! ! ! ???

I will guess at that temp -- and try it

Someone told me once that the hottest temp someone can hold their hand on is 150 deg. Hotter than that and you can't hold your hand on it. I don't know if I believe it or not...but that's what I heard once.

So 122 deg would be hot...but you could hold your hand on it and not have to take it off.

I don't really know that I believe this, and everyone must be different, but maybe that helps with your guessing.

Wed Jun 08, 2011 12:51 pm

Actually, even at "hot" (with stock pushrods,) I look for at least a small amount of valve clearance.

Wed Jun 08, 2011 12:52 pm

the cold adjustment is the recommended procedure for other motors as well not just vw. and the reason is for it to be uniform .like the other member posted regarding the temp cooling soon as the engine is off by time you to your last valve setting the temp is different, but to give input on the situation i remember on my toyota 22r if this was done on a warm engine it requied a difference of .002 . this would be less of a problem on a vw because you could have the engine warmed up, do the #1 and 2 valves button it up, start the car for a minute then do the the other side.

Wed Jun 08, 2011 1:31 pm

My MG valves are adjusted hot...which I always thought was strange. As noted above, "hot" or "warm" is different things to different people, but sitting overnight cold is more likely to be the same for everyone.

MG people are always confused on what is hot enough to adjust the valves. There are cold settings too, but everyone in the MG world says the only wau to do it is hot. (It's kind of opposite from VW). But adjusting the MG valves is 10 times easier than the VW's and can be done in about a minute or two...so the cooling down issue isn't a big deal.

Wed Jun 08, 2011 1:51 pm

When I am in my driveway working with tools here in the great Phony and it is over 100 outside in the sun
You cannot use the tool !

So the fingers will get a little toasty trying to slide the gauge unless a little cool down happens

Wed Jun 08, 2011 2:48 pm

Many thanks for the important replies. Bottom line is I'll drive less than 15 minutes to where the valve adjustment will take place-so after a couple hours of cooling, I'll set them at .004-0.005 and then road test. If AOK then all is well-if not,I'll workout a cold adjust according to the majority opinions!
So thank you all again. I'll try to report results of a "warm adjust"!!

Wed Jun 08, 2011 2:49 pm

Off the top of my head the only two cars I can remember cold adjustment is subaru and volkswagen ac.All the japanesse cars I have seen are hot .We used to get them in the morning and let them sit, they're the last cars we worked on if it was a valve adjust cold . If I remember and I have not been actively working as a professional mechanic in 20 years but I do seem to remember this tidbit. On vertical motors especially ohc motors the expansion rate when hot is not even close to horizontal motors also most over head cams are hot cuz the expansion rate is equal among parts .As for losing heat from first to last .My 22re race engine is done at operating temps on the valve adjust .Even when we run the valves twice, as in check then recheck even cooled down during adjustment process it does not change. .Umm correct me if I am wrong but from reading here .The vw engine expands and actually gets much wider when it gets hot so if you set the valves hot to 0 or no clearance. Then if it cooled off it would contract possibly holding the valves open when cooled causing a big problem .If you new the exact expansion rate in thousands of an inch you could adjust cold or hot just by knowing the specs .We have them for the 22 re race motor but rarely between racers could we get it stone cold so the hot spec is what we use . .In a perfect world all things being equal the expansion rates would be equal .. Now to test this theory almost all vw air-cooled I have seen are very silent valve wise when cold then clatter little or some a lot when hot .Well check me if Im wrong but the clatter is cuz the clearance gets wider when its hot.I have no idea what the gain in clearance is but some one could test by checking cold then heat your motor up and see what the difference is but damn that close to a heater box or j tube no thanks that sucker gets hotttttt.. JEFF

Wed Jun 08, 2011 3:52 pm

hmmmm
got your point !

Wed Jun 08, 2011 4:10 pm

:) As a former VW mechanic have done my share of valve adjustments both HOT and COLD.

Ont thing that people are NOT aware of is that the valve adjust screw takes a beating and is always rotating the valve in the process.

You can adjust the valves...drive a couple miles and return to check the adjustment which has CHANGED a little. So what is the big deal of being .001 difference in the adjustment. This will change as the car is being driven (verified on my own car).

Steve

Wed Jun 08, 2011 4:52 pm

HRVW, I see your point and that was what our race motor builder said to us on the 22 re motor .I just replaced my adjuster screws and after a thousand miles or so it seems alittle loud .I imagine maybe a break in period or maybe just a thousand miles .I had had some trouble in the past with the adjustment so I changed out to og setoff screws and nuts I got nos from some one .Some were on here I read that the cheap ones go south in a hurry .And I also tried empi swivels but no matter what could not get the geometry correct and they drove me nuts .