I have two feeler gauge "sets". One with the 0.003 blade pulled out and one with the 0.0025 blade out, so it is easy to test go-no go. The length of blade on the normal feeler gauge set works just fine. A longer blade might actually cause problems with being too "floppy". I bought my feeler gauges at a basic auto parts store. Note that not all sets come with a 0.0025 gauge. I should have been more diligent and taken some pictures while using the Go-NoGo method. I will be starting the valve adjustment on the 90 C4 perhaps this weekend.

 

After reading thru this entire thread, I have a couple of questions. I would think the dial indicator to be the most accurate, however, Ricardo verified the gap using a regular feeler gauge and discovered a couple of valves were still out of spec. So, is the dial indicator the most accurate? Or, do you need to still double check the spec after using the indicator? When I adjusted my valves, I used a regular feeler gauge, which was a real PITA!!!

Is the best method a combination of the feeler gauge and the dial indicator? I would hope the dial indicator would be the best and most accurate method without having to rely on the feeler gauge. Thoughts?

Steve

BTW - I tried the back side method (go-no go) but could not get the gauge under the cam follower, so I gave up and used the regular feeler gauge method.

 

You really need to have a good dial indicator setup to use it properly. Also on my dial indicator every tick mark is 1/10,000 of an inch. You sneeze and the dial moves. You find out that even the side to side play in the rocker will move the needle.

I have yet to try the backside method but will do so sometime in February on another 964. I'm curious to see how that will work out as that is go / no-go. Until I get through that experience I will use the dial and follow up with the feeler gage as a double check. Don't know how I screwed up cylinder number two as just by hand I could tell it was set too large. You can rotate the rocker back and forth with you hand a very quickly get a feel for what decent gap feels like. The dial indicator just keeps you from going crazy and guessing about your technique and feel.

 

Just finished adjusting my valves using the backside method and was able to get them squared away very easily. Well, except for the lockdown nut on #5 which didn't want to spin freely on the adjuster. Had to work it up and down the stud a few times with some PB blaster, but still was dragging a bit... PITA. Every time when I would get the clearance perfect and try to tighten the locknut, it would turn the adjuster.

Aaaaanyway... otherwise it's a great method. Big timesaver.

 

Great thread & pictures Ricardo, and very timely as I am just doing my valves as we speak.
I am not trying to be **** here, but since we are working with 1/10000" accuracy when checking with the dial indicator, 0.003937 is the correct clearance not 0.004", so I have been shooting for 0.00395. I know it is a very small difference, but why not aim for perfection?

 

Trust me on this Steen, you hit .0039 to 0.0041 and you will be very happy after your adjustment is done. I keep having to go back and forth because I hated being at .0038 or 0.0042, crazy!

 

Yes I know, I was playing around with it today and it is just about impossible to get right on the money, but fun trying.
This is my first valve adjustment on the Porsche, I bought the tool/feeler gauge, but have a tough time getting the right feel, the "back side" way seems a lot better an then check with the dial. Again, thanks for taking the time to post the DIY.

 

I just started my first pCar valve job. Tonight I got the car up and the lower tins removed. I had some issues with the tin bolt up behind the g-pipe. The nut that is attached to the back tin had broken free, I had to jam a wrench in ther to hold it.

Also, what is up with the old foam on the lower tins? It has totally broken down, I am thinking about just ripping it off. All my exhaust parts are ceramic coated, the g-pipe and 200 cell cat are not even close to the lower tins.

 

I had to rip off and clean the foam behind the plastic encapsulation pieces. I am eager to use the back side method as the initial check on my next valve job.

 

Is my feeler gauge suppose to look like this?


Was it a good idea that I ordered spare blades, none of which are bent like this?

 

I've done multiple valve settings... and yes, your feeler gauge will always need a little tweaking to get it at the right angle to insert between the valve stem and the adjuster. That is always why you buy extra blades... they get bent trying to get them inserted or when pulling them out. They should go in easy....but always don't .

 

Oh okay, just making sure. That pic is brand new, straight out of the PelicanParts packaging.

 

How sensitive are the valve adjustments to the TDC and 2 other markings on the crank? I'm asking because I went through the valve last night and I'd often find myself taking the notch slightly past the centerline on the block as I spun it around, 120° at a time, and the engine's compression worked against me.

 

I like to get it exactly dead on, but that is just my anality. I did go past the mark a couple of times, so I backed it up and then back in line, making sure the slack is out of the chain.

 

Alright. I will go through them again tonight and be really keep on hitting the marks.

I did Round 1 last night and started Round 2 (re-check) on the 1-3 bank (240° at a time), noting I'm going to have to go back to #1 for readjustment.

I elected to do backside method after trying the traditional method on a couple of cylinders and feeling like I was doing guesswork.