Backside valve adjustment

[david.avrahami@]

1987 carrera, I am about to start doing the BACKSIDE valve adjustment for the first time...kind of worried...
I am not clear on where EXACTLY do you insert the 2 FEELER GAUGES at the other end of the rocker arm?. I looked at the pictures provided by the technical report in Pelican parts...the white feeler gauge showing seems to be inside the cave...how did it get there? Is it a straight insertion FROM OUTSIDE THE CAVE?
I intend to do the UPPER valves from the engine compartment NOT from under the car and the exhaust valves from the side by removing the wheels. does anyone has a clear picture of the upper valves insertion? preferably with the feeler gauge inserted?
Your help is much appreciated.

[Ronnie's.930]

The only way you are going to be able to do the intake valves from the top is by severly bending the feeler blades - I tried this and it does not work well at all. The easiest way by far is to measure the intake lash from below and the exhaust from above. If you look closely at this you will see that there is essentially a straight shot to each cam lobe this way.

By the way, you are going to insert the feeler blades between the appropriate cam lobe and the rocker arm pad that rides on it.

[david.avrahami@]

BUT the view from below is blocked...do I need to remove some body part?

[Ronnie's.930]

I guess your car and mine are very different from below (I have a 1987 930) as nothing at all blocked my view. I moved the wastegate aside for the sake of convenience, but could have left it there.

[HelmetHead]

The feelers are measuring a "go/no-go" tolerance between the camshaft lobe and the rocker arm. The adjustment screws for each valve are on the opposite end of the rocker arm from where the backside measurement is made. To measure the intake valve clearance, you must measure the cam to rocker spacing and to get to that you must be under the car...helps to have a buddy making the go/no go determination while you are adjusting the screw/nut. Hope this helps

[david.avrahami@]

yes...they are different ...I do have 12" feeler gauges from our host and they are quite flexible and can be curved ...I was hoping that some one can have a picture or a more detailed visual explanation.

[K Sykes]

Originally Posted by david.avrahami@

BUT the view from below is blocked...do I need to remove some body part?

Do you have the lower valve cover off? If so, it's actually easier to see the intake valves from below than the exhaust from above. Also, on the driver's side, the cat is in the way. The way to find where the "foot" of the rocker arm is to look just to the side of the rocker shaft for the side you are on - meaning if you are under the car, find the exhaust rocker and look right next to it for the cam lobe for the intake and you should be able to see the foot of the rocker - that's where your feeler goes. A headlamp helps.

[K Sykes]

Originally Posted by david.avrahami@

yes...they are different ...I do have 12" feeler gauges from our host and they are quite flexible and can be curved ...I was hoping that some one can have a picture or a more detailed visual explanation.

Also - I use a popsicle stick with the go feeler on one side and the no go on the other - I used green and red shrink wrap to make it easy to know which is which. You only need about 2 inches past the end of the popsicle stick. I think more would be hard to handle and too floppy.

[david.avrahami@]

both of you guys have 930's and have a clear view from below...I have a carrera and the view is blocked...I thought this method was the easier one.

[K Sykes]

Not sure what is blocking your view - can you take a pic? I have an SC, not a 930. While the displacement is different, it's a very similar motor, particularly on the bottom.

[david.avrahami@]

The 930 was meant for the first 2 answers that have a 1987 turbo...
The upper valve covers and lower ones are separated by a metal floor so when you open the engine compartment and look down on both sides of the engine, you can not see the lower valve covers and vice versa...that is why I have to do it from above and from below...

[david.avrahami@]

maybe when you remove the valve covers upper and lower you have a view of upper stem from below...since I never did it before, I am only speculating
Sorry for the confusion.

[K Sykes]

Exactly - wasn't tracking with you. Yes you measure the upper valves from below and vice versa. But you do the actual adjustment on the other side. Meaning put your "Go" feeler between the foot of the rocker and the cam from below (for the intake valve). Assuming it fits, try the "no go", if it doesn't go, the valve is good. If not, the valve needs to be adjusted. Put your "go" gauge in the same spot and go to the top of the engine. Adjust the intake valve to be just snug with the "go" gauge in the gap. Go back under the car and try and pull the go out. It should be a tight pull, but not really tight. Double check by trying the "no go" gauge and if it won't go, you are done.

I wish I had taken some pics, I just did mine saturday.

[K Sykes]

Originally Posted by david.avrahami@

maybe when you remove the valve covers upper and lower you have a view of upper stem from below...since I never did it before, I am only speculating
Sorry for the confusion.

Yes - that's exactly what you need to do - it is impossible to do without removing both valve covers.

[FL911SC]

I am following this since I hope to use this method for my next adjustment. Am I to understand that the "engine tin" does NOT have to be removed? That the access is made by having the upper and lower valve covers off at the same time on the respective sides? I had assumed (dangerous word) that one would remove all four valve covers before starting any adjustments, so I would like to understand that is all that is needed (i.e. the engine tin doesn't need to come off)
Thanks!

[david.avrahami@]

Thanks...now I understand...so what it boils down to is that it is quite difficult to do the go/no go on the upper valves from above...because the feeler has to be curved to be able to be inserted...

[K Sykes]

Some people take the tin out, and find it's a bit easier. Personally, I find removing the tin is a pita and it's a tough reach to the adjustments from the "wrong side". I did both sides on Saturday in about 45 min, tin in.

[david.avrahami@]

I can not answer you FL911SC...I am just hoping that this is the case...
maybe someone with more experience can answer that for both of us

[david.avrahami@]

Thanks K SYKES...NOW IT IS CONFIRMED!

[Ronnie's.930]

Originally Posted by FL911SC

I am following this since I hope to use this method for my next adjustment. Am I to understand that the "engine tin" does NOT have to be removed? That the access is made by having the upper and lower valve covers off at the same time on the respective sides? I had assumed (dangerous word) that one would remove all four valve covers before starting any adjustments, so I would like to understand that is all that is needed (i.e. the engine tin doesn't need to come off)
Thanks!

Correct, the engine tin does NOT have to be removed. I don't understand how removing it would be beneficial, but I know that some people do remove it.

And yes, you can only see what you need to see, and have access to the cam lobes, by having both upper and lower valve covers off, at the same time, on the side you are working on.