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Tue Oct 27, 2020 2:50 pm

so this was brought up in another thread and i wanted to see if someone can give a more detailed method to do it on a vw? i did google it but most was about v8's, which gave me the jist of it, but like i said, wanted more vw specific info.
thanks

Tue Oct 27, 2020 3:19 pm

I'm curious also. Makes since, I dont see any vw specific differences. We still use our chromo/aluminum pushrod specs, its just a method of getting to a safe and sure base circle.

"Starting with cylinder No. 1 (usually the head that is farthest forward on the block is No. 1) with the valve cover off, rotate the engine until the exhaust lifter begins to move upward. This is the point at which the exhaust valve is opening (EO), meaning the piston is through with the power stroke, and it's about to begin the exhaust stroke. At this point, the intake valve is closed and the lifter is on the base circle of the camshaft and can be adjusted. To adjust lash with hydraulic lifters, simply grab the pushrod and back off the rocker-arm adjusting nut until you feel play between the pushrod and the rocker arm. Turn the rocker arm adjusting nut while rotating the pushrod until there is no more play between the pushrod and the rocker arm, then tighten the adjusting nut one half turn. That's it, you're done. To adjust the exhaust lash, turn the engine over until the exhaust valve has completed its lift cycle and the intake valve begins to close (IC). Now, the exhaust lifter is on the base circle because the piston is finishing the intake stroke and about to begin compression. Set the lash on the exhaust valve and you're done. This needs to be done for each cylinder."

https://www.hotrod.com/articles/ccrp-0702-camshaft/

Tue Oct 27, 2020 3:29 pm

This method is simple to me, but others may disagree...

You can start at any cylinder and don’t need to worry about timing marks or where the rotor is pointed...just have to rotate the engine in its normal operating direction (clockwise).

Then watch the valves...exhaust valve opens about an 1/8”, adjust the intake valve...rotate watching the intake valve now open and close. When about 1/4” from closing adjust the exhaust valve. As you watch the valves, you’ll notice the other valve movements and can adjust them as well, but doing one cylinder at a time is okay too. It’s that simple

Tue Oct 27, 2020 4:12 pm

txoval wrote: This method is simple to me, but others may disagree...

You can start at any cylinder and don’t need to worry about timing marks or where the rotor is pointed...just have to rotate the engine in its normal operating direction (clockwise).

Then watch the valves...exhaust valve opens about an 1/8”, adjust the intake valve...rotate watching the intake valve now open and close. When about 1/4” from closing adjust the exhaust valve. As you watch the valves, you’ll notice the other valve movements and can adjust them as well, but doing one cylinder at a time is okay too. It’s that simple

Yes....it is simple and it is good.......but it's also not 100% on every cam....because tbe flanks coming off the base circle are not exactly the same from cam to cam or lobe to lobe.

I will say the "metbod" is there....but gou may have to move a little more or less to make sure you are at the bottom of the base circle.

And.....if you do....again depending on the cam.....once you set it with this method.....you will find that if you go back to the standard method ....both valves closed at TDC for the cylinder....rotating backward and adjusting both I and E on 1, 2, 3 and 4 in order............you will find that it no longer is .006".

It is like this on stock type 4 cams. Ray

Tue Oct 27, 2020 6:43 pm

I used this method for the first time recently after reading about it on here.

I first set the valves as I normally would with the cylinder at TDC 1, rolled it backward to 2, 3 and 4 and set them all.

I then used a remote starter button to crank the engine over until the Exhaust is starting to open and checked the intake valve clearance. I then used the remote start button to bump the engine over till the intake is closing and adjust the exhaust valve clearance.

I found that the 15 degrees before or after is a bit hard to get exact but it was easy to get close enough. The valve spring pressure sort of pushes the engine around a bit.

With this method only one cylinder needed to be adjusted vs the TDC method and that difference was really small. I am using steel push rods adjusted for a loose zero for the record.

I don't notice any difference in valve train noise at first startup or after running for a while, but I did think it was fun.

Wed Oct 28, 2020 6:04 pm

Are we reinventing the wheel here??

Thu Oct 29, 2020 1:16 am

I've never liked it on VWs, often the clearance changes. At least for me.

Thu Oct 29, 2020 7:19 am

I have done it both ways and can’t really see a difference.

Thu Oct 29, 2020 8:05 am

FreeBug wrote: I've never liked it on VWs, often the clearance changes. At least for me.

I have had "some" of the same experience. Again, mine is all type 4.....and there are some cam lobe shape differences between types 4 and 1.

In my experience, I would not quite call it "changed".....more like very hard to hit the same exact position twice. I finally fixed that when I was using this method....by putting exact marks for each valve position with permanent marker in the timing "V" notch of the fan housing.....blue for intake and red for exhaust.

Why?
.....because I found with the stock cam (and very slightly worse/different on the Web #73)....when you go by "exhaust just starting to open with intake closed".......and set your .006" clearance.......further rotation......would then show that the lash would GROW....out to as much as 0.010" to 0.012" :shock: ......which means you were not on the base circle. You were on the flank between lobe and base circle.

I did find.....that adjusting with a VARIATION of the EOIC method works well. That is to use the EOIC method to get you to the right "zone".....close up the lash to "0"....and rotate the engine a bit in both directions. If one opens the lash back up.....you are moving in the right direction. Close the lash again and continue until movement in that direction no longer opens the lash.

That means you are on the base circle. Then adjust lash correctly.

When I adjust valves.....I have the wheel off the ground on one side.....trans in 3rd gear.....and just rotate the wheel to make fine rotation adjustments. Once you remember which way you need to rotate from the EOIC spot.....there is no playing around to do.

As I noted.....I ended up just marking the fan pulley. So I just pop the distributor cap off....watch the rotor position while I push the wheel with my foot to rotate the engine....and when the rotor is pointing at the correct cylinder.....and the correct mark comes into the V notch.....Im there.....at the base circle. Just adjust and move to the next valve.

Does this method help? Well....I would never say that I considered my valves to havd any excessive noise. With solid lifters......once I went to solid rocker spacers, less sloppy than factory stock geometry and Porsche swivel feet.....my rockers were damn quiet.

So.....no noticable difference in noise. But....since all of my cars are D-jet injection....which is VERY sensitive to excessive lash in valve adjustment.....yes.....it makes a difference.

Also I check and adjust my valves hot. A .006" cold lash setting translates to about .003" when fully warmed up and about .002" to .0025" when raging hot in 100° ambient weather.

I set them hot with this method to .003"

A combination of the slightly modified EOIC method and hot adjusting will also show you which valves (or it may be the pushrod, rocker, rocker shaft, lifter, swivel foot or a combination several)......has more or less expansion. .....and needs a very slightly different adjustment to make the exact same lash when hot.

And....with D-jet....setting lash this finely makes a noticable difference in idle quality. Ray

Thu Oct 29, 2020 8:10 am

People with time on their hands will devise busy work and alternate methods. If you like it and it works all good.

Thu Oct 29, 2020 8:29 am

jeffrey8164 wrote: Are we reinventing the wheel here??
I think so.
The overlap + 1/8" is good as such. But, you cannot be sure that that is actually the lowest point of the cam. So, if you want to go "tight" on the adjustments you need to figure out where the lowest point is on your cam. This point is grind specific, so you cannot use a generic position for all cam in the range.
Next, it will not always be possible to get best results this way, because if the cam in ground inaccurate (and that happens a lot especially from some suppliers) You will have to run larger lash in order to make the cam clear at all cylinders. - Normally an ACVW engine is quite forgiving because it stretches so much during warm up, but if you go really tight on the lash it happens every once in a while that an engine does´nt run right. Then you loosen the lash a tad bit and the engine runs better.

Thu Oct 29, 2020 8:37 am

jeffrey8164 wrote: Are we reinventing the wheel here??

YES....

Thu Oct 29, 2020 10:50 am

the engine does not know if it is a vw or v8. Ive seen many vw owners as well as v8 owners that havent a clue about anything related to their cars or engines at all but think they do.and yes cant tell when it has one or more dead holes and drives them like that. opening the ex 1/8" will do very little to offset the other banks pressure.but it may put you in the right aera of the lobe for a better adjustment. but some people dont care if they are adjusted or not as long as they think they are. eieio

Thu Oct 29, 2020 11:56 am

I have been watching this post for a while. Laying low.
Only adding tiny bits here and there..

I must speak now:

I don't really follow the logic of this alternate "EOIC" method for adjusting valves.
It seems confusing and overly complicated to me.
mind you, I set ALOT of valves.

I try to understand the logic given, but it just doesn't make sense to me. Who cares what the lash on the intake is doing while the exh is opening. The cylinder pressure is low at that point.

The traditional way of setting valves is to park the motor at TDC (firing).
From what I know of a 4 stroke engine, this is the point in cycle where having the correct lash matters the most.
At TDC, cylinder pressure is highest as the spark has already fired and the burn is starting to build pressure in the chamber for the power stroke.
Having both valves close (with correct lash) at that moment is most important. After the power stroke is over, then the lash can do whatever and it won't have an impact on performance.

Cam duration and ramp design can play havoc in any alternate method of valve adjustment.
The FK-87 cam comes to mind. It has such as long soft ramp from .050" to .000", it seems to go on forever before closing all the way. EOIC would get you in trouble real fast with that cam.

One thing you can always say for sure, is that at TDC firing, both valve should be shut.. No confusion there..

Thu Oct 29, 2020 12:24 pm

Ohio Tom wrote: I have been watching this post for a while. Laying low.
Only adding tiny bits here and there..

I must speak now:

I don't really follow the logic of this alternate "EOIC" method for adjusting valves.
It seems confusing and overly complicated to me.
mind you, I set ALOT of valves.

I try to understand the logic given, but it just doesn't make sense to me. Who cares what the lash on the intake is doing while the exh is opening. The cylinder pressure is low at that point.

The traditional way of setting valves is to park the motor at TDC (firing).
From what I know of a 4 stroke engine, this is the point in cycle where having the correct lash matters the most.
At TDC, cylinder pressure is highest as the spark has already fired and the burn is starting to build pressure in the chamber for the power stroke.
Having both valves close (with correct lash) at that moment is most important. After the power stroke is over, then the lash can do whatever and it won't have an impact on performance.

Yes...when I first started working on engines...and my first car was a VW 411....the method you described is what I originally learned. Set it TDC for each cylinder you are working on....and both valves are closed....and close enough (so I was told). Then simply turn the engine backwards to the next cylinder. On a VW this lest you go 1,2,3,4 for adjusting order. Simple and convenient.

However....as I started doing tighter fuel tuning than the sloppy level the factory set the engines with.....I found this was not exact on each cylinder.....and as I noted.....on type 4 stock cams...this meant that the .006" was not set on the actual base circle. Your real lash is typically about .008". And....it was pretty close on each cylinder with this method....but was not .006"...unless you measure it at TDC....because you are not on the base circle. You are just up the flan from base circle on most type 4 cams.

After finding this out....I had to ask......did VW "actually" want .008"? Meaning.....did they KNOW the real lash was .008" (in some cases up to .010") when they told you to set it at TDC....and were they just saying .006" at TDC to give a simple method?

Why does this make a difference? On a carbed VW...probably doesn't. On D-jet injected engines....it makes a difference because there is enough variation mainly at idle to cause minor vacuum signature variation....because there is injection timing at stake with relation to valve open event....and it all affects the manifold pressure sensor which is VERY sensitive and it both fuel baseline and enrichment control. Variations as low as 0.25 inches of vacuum are easily sensed and reacted to via pulsewidth changes.

Minor changes at idle change signature further....causing another reaction in pulsewidth....etc...etc. Its a cascade reaction that causes highly variable idle.
Just cleaning up valve adjustment can get rid of it.

Now....why others use EOIC?....I had no idea it made any difference at all with stock cams with carbs. I found no differences using it.

Until.....I used a non-stock cam that had different overlap and different lobe profiles. Thats when I found that the normal TDC and both valves method....simply did not get the valves very close at all. TDC was too far up the flank from base circle.

Using EOIC....made it much closer. Ray

Thu Oct 29, 2020 2:07 pm

And how much of is cam flex, with heavy springs?

Fri Oct 30, 2020 7:46 am

if any way of adjusting the valves confuzes you you probably arnt getting them right and should take the car to somebody that isant confuzed by possiably the smiplest car ever produced. also just because you cant "see" it or it isant "logickel" to you dont mean you understand any of it.and thats ok. go look at the akerman angle and see if you can see it..or how to set it?or why it is. why is a counter weighted crank beter than a non counter weighted when both are balanced? why does the IR system work better than a single? why do vw people think building a vw is not the same as anything else?oh never mind.I think I already know.

Fri Oct 30, 2020 8:07 am

Ohio Tom wrote: jeffrey8164 wrote: Are we reinventing the wheel here??

YES....

New Math

Fri Oct 30, 2020 8:10 am

Have a friend in my Whatsapp group that's running a FK87 or 89. He tried the method that I explained to him, then went back and checked using the traditional method. All valves were .004" tighter.

Fri Oct 30, 2020 8:23 am

Yes.
As I said, it is cam specific.