RicardoD

I think I will clean it out. The flaking seems to be in the gasket groves and metal clamping surfaces. In the pockets the coating seems fine.

911porschefan

I was also thinking about sandblasting and powdercoating the covers but am worried the aluminum is too thin. How did they turn out? Is there anything else that can be done.

mrmandmman

I sandblasted mine and sprayed with ceramic paint. Then baked in the oven to cure.

RicardoD

Ok, gentlemen, the plot thickens... Today, I received my dial indicator and Z-block because I think this 0.1mm shim feel is a crappy way to do this. I think its very clear using the Tom Bennett's 36 degree screwdriver is more accurate.

Springer3 in this excellent post pretty much nailed it for me.

I did try using the shim on lower cylinder 1 valve and ran into all the trouble everyone else has at first, couldn't slide in the feeler gage, and then upon completely loosening valve and tightening down on the feeler gage you get into that subjective "how tight should the shim feel be" territory. To me it felt like the shim approach left more gap than using the 36 degree screwdriver but there is only one way to tell exactly-> DIAL INDICATOR!

Springer3 makes the excellent point that its totally worth it to invest in a Z-block, $36 at Pelican, and a dial indicator with the appropriate resolution to eliminate any guesswork on the valves where the dial approach is possible.

Reference for those of you just starting to look into what a valve adjustment is:
- valve adjustment screw to valve gap is to be set to 0.1mm (0.0039")
- you can buy a 0.1mm shim to set the gap
- the valve adjustment screw has 1mm pitch which means 1 revolution of the screw produces 1mm of linear travel, therefore 1/10th of a revolution = 0.1mm or 36 degrees (360 degrees divided by 10).
- Tom Bennett's valve adjustment screwdrive to help you turn it exactly 36 degrees http://obd1interface.com/valve-adjusting-screwdriver/



- Z block at Pelican is PEL-TOL-P207
- Just Google "Porsche 911 Valve Adjustment" and the first hit is the excellent explanation from Pelican: http://www.pelicanparts.com/techarti...lve_adjust.htm


A picture of my dial indicator is below, each mark on the large dial is 0.0001" so 39 of those tick marks on the dial will be exactly 0.0039" (0.1mm).

Once I figure out how to set this up on my car I will photograph and explain it to everyone.

FeralComprehension

Mine are magnesium, and it's not too thin. It was a total ***** to get the coating and it's.... primer? out of the corners, however- there were multiple iterations of blast, inspect, dental pick.

Turned out fine, so far at least. I did it in August and probably won't look inside again until the middle of next year or so.

chris951

I did my valve adjustment a couple of weeks ago and plugs. It wasn't that bad. My valve covers look like crap, but I put them back on. I broke off one of the 10mm bolts that hold the upper engine tin on to the head. I tried to use a bolt extractor and it broke off as well, so that part is fubar. I broke off some of those speed nuts and just bought new ones at autozone. The valve adjustment kit from Pelican Parts and it worked out great.

Rocket Rob

Ricardo - I have the z-block and need a dial indicator. Pelican's is NLA. Can you give me a link as to where you found yours on eBay? I want to be sure I get the right one.

RicardoD

11)Now its time to access the upper valves
12)Remove the engine tins (10mm socket for the bolts) in the order shown in the photo, do the same for the other side which is easier. Note: your are removing the 10mm bolts, not the nuts which are welded to the tin.
13)The lower spark plug wires are routed through this tins, its straightforward to remove the spark plug grommet and push each wire through the tin opening. The tins are now free to be clean and refinished if you want as necessary.
14)Remove the 6 10mm nuts from the valve covers. Use a screwdriver to gently pry it open and then it can be removed easily by hand.

RicardoD

Great reference procedure is here:
http://www.pelicanparts.com/techarti...lve_adjust.htm

Now its time to adjust the valves, but first we must put cylinder #1 at top dead center (TDC) such that both valves are closed and intake and exhaust valve can bet set to 0.1mm (0.0039") gap. You do this by rotating the alternator pulley

15)Before we start rotating the crankshaft, remove the upper distributor caps, two large phillips head screws hold it in place. We are doing this so we can really confirm cylinder #1 is at TDC when the correct marks are lined up on the crankshaft pulley.

16)You have to rotate the crankshaft pulley by using the triple square tool (which was conveniently missing from my toolkit) or use 24mm wrench in your car's toolkit to turn engine fan pulley nut CLOCKWISE. When I did this the fan belt slipped. You need more tension on the fan pulley. I used a Quick Grip clamp (photo below) below to "squeeze" the belt underneath the pulley. Now when I turned the 24mm engine fan nut clockwise the lower crankshaft pulley spun as well. The clamp slips after about a 1/4 turn, and then you reset the clamp and the wrench and keep on turning until you get the marks you need to line up.

17)Line up the TDC "Z1" mark with the mark on the case centerline (see photo below)

18)Check the the distributor rotor underneath the distributor cap is pointing to notch that indicates TDC for cylinder #1 (see photo below). If the opposite end of the rotor is pointing to the notch, then you need to rotate the crankshaft another 360 degrees. Its the combination of the Z1 mark alignment AND dist rotor position that confirms you are at cylinder #1.

RicardoD

At this point you are now ready to adjust the valves of Cylinder #1 on your car and set the gap to 0.1mm (0.0039").



I actually used a combination of 3 tools to do this:

1)Tom Bennett's VAS-911 36 Degree Valve Adjustment Screwdriver
- full disclosure: Tom and I partnered to sell the OBD1 kits I put together but the screwdriver tool is his and his alone, thanks Tom!
2)The 0.1mm shim gap tool via Pelican Parts PEL-TOL-P207
- Tom also has an excellent video on his website on how to use the screwdriver tool and the 0.1mm shim tool to set the gap.
3)A dial indicator & Z-block which, at least on Rennlist, there is very little information available, but just enough (thank you Springer3) to get me pointed in the right direction

When I started this I quickly ran into that issue of "feel" with the 0.1mm shim. First I was unable to get the shim in the gap (at that point not realizing that was because the gap was too small). So I completely opened up the gap, slid in the shim, and tightened down on the shim with the screwdriver, and then locked the adjustment nut. Having never done this before it was hard to tell how if I had it properly gapped, if I had enough resistance while pulling out the shim.

So that's when I ordered the dial indicator and Z-block. I wanted to have actual measurements to correspond with the feel of the shim, or the technique with the screwdriver. (I am a mechanical engineer used to having all kinds of data at my disposal to make informed decisions, of course with corporate backing to buy my tools!)

The technique I am using here is to set the dial indicator on the adjustment screw with the rocker arm pushed such that the 0.1mm gap to the valve is closed to zero (you rock it closed, which means the gap is on the cam side now). The dial indicator actually helps to push down on the rocker arm and close the gap. The Z-block is used to rigidly clamp the dial indicator into position using the nearest valve cover stud. You then turn the dial indicator markings so this represents 0.0" of displacement. Then using my hand I would push on the rocker arm against the cam and then see how far "open" the gap would be on the dial indicator. (see photos below for the sequence)

The dial indicator I purchased has very good resolution, each tick mark on the dial is 1/10,000 of an inch. I wanted something that fine so that 39/10,000 of an inch would actually move the dial a good amount. Using this technique to set the gap on each cylinder and I think I was able to hit the desired gap of 0.1mm (0.0039") within 5% each time. This all sounds great but in my next post I will write about the problems I ran into with this method.

RicardoD

Using my dial indicator technique here are some issues I ran into with the various tools:

- using the shim tool alone at first I would consistently set the gap too big, 0.12-0.15mm, but then I would adjust and when I would hit the 0.11mm range I started to get the feel for the drag you should feel with the shim

- Using Tom's VAS-911 screwdriver alone would consistently set the gap too small, around 0.078mm. So I thought "that jerk Tom" screwed up this the manufacture of his screwdriver. I double checked with some templates and determined his tool is dead nuts at 36 degrees, scary (great job Tom). So either there is an error in my method or the pitch of the valve adjustment screw is smaller than 1mm per revolution. I would like to check one but didn't want to remove it from my car. If anyone has an extra valve adjustment screw for me to measure please PM me.

- The sensitivity of the indicator is such that the left/right play of the rocker can affect the measurement, you need to make sure the dial indicator measurements are repeatable. A flat tip on the dial indicator or a very rounded tip helped. I was able to confirm with the feeler gage that when I hit 0.1mm on the gage I could slip in the shim tool and get the rught feel of resistance. (I played around forever on cylinder #1 until I felt I developed confidence in my approach using all the tools)

- Tom's tool is extremely useful in that it allowed me to visually perform minute adjustments in screw rotation to dial in the gap to within 5% of 0.1mm. My final technique is to use the dial indicator and Tom's tool only. I abandoned the shim tool and only used it for a sanity check in the beginning and for the #3 lower valve. In between measurement I would swing the Z-block and indicator out of the way, make my fine tuning adjustment and re-measure, some valves took me forever as I kept overshooting in each direction as I was obsessing on hitting 0.1mm almost exactly.

- After Cylinder #1 was complete I was able to measure first if any valve needed adjustment. Several were spot on and needed no adjustment (it got to the point where I could rock the rocker with my fingers and could just feel if it was close or not) some were at almost zero gap and some were way too large, so I am very glad I adjusted the valves all back into spec.

- You can not do Cylinder #3 lower valve with the dial as the flange for the CAT gets in the way, fortunately, that is the easiest valve to use the feeler gage, and I was confident in my feeler gage technique by then to do that one by feel.

- The Pelican Z block is not exactly perfect for this application, I was already thinking in my head how to make a better one. You will also need an assortment of dial indicator plunger tips, as the lower valves require a shorter tip, and the upper valves require a longer tip. For dreaded upper #6 cylinder valve I actually made a custom tip because the power steering pump prevents you from centering the dial exactly over the adjustment screw.

- Overall, I really enjoyed doing this, and mechanically bonding with my engine (I think my fellow gear heads know what I mean). I think next time I can do this about 4 times faster. My car really needed the adjustment as well (Cylinder #4 had no gap)

UPDATE: Always, always confirm the valve gap with the feeler gage when finished. I screwed up my valve adjustment and had to repeat the process and found cylinder #2 was way off, too large, engine sounded horrible. Do not repeat my mistake and simply double check with the feeler gage at each valve.

RicardoD

To finish up on the procedure part

19)Adjust the upper and lower valve for Cylinder #1
20)Turn the crankshaft 120 degrees to the next mark on the crankshaft pulley and align that with the mark on the case (this one won't have the Z1 mark), then set the valve gaps for Cylinder #6
21)Turn the crankshaft another 120 degrees to the next mark, and adjust the valves for #2
22) Turn... adjust #4, Turn... adjust #3, Turn... adjust #5
23) You should clean and change out the valve cover gaskets
24) Its 7ft-lbs for the valve cover nuts

hawk911

very nice write up Ricardo! Looks like all that time at Motorola was well spent.

RicardoD

I am not too proud to admit that I screwed up my valve job. When I finally fired up the car this weekend the engine sounded horrible. Even my wife could tell something is wrong as the engine did not sound like it did. I had to go back in and re-check all the valves. I went from the world's slowest valve job to one in 3 to 4 hours. It's amazing how fast you can work when you know exactly what you are doing and all the hardware is fresh. I discovered the lower cylinder #2 valve was set way too large, I touched up upper #4 but everything else was spot on. Don't know what happened but I now know to double check every valve with the feeler gage, whether you use a dial or not. I updated my procedure to reflect that and I would go so far as to say the dial can be used to "dial-in" your feel with the shim and then use that on the later valves.

Started the car after the second valve check and engine purrs like a kitten now.


Anyway, my 60k maintenance is done and my car is running great. Here is a goofy picture I took after my two month deep dive into my car was complete!

B. Elliott

Congrats Ricardo! Glad to hear she's running great now.

You definitely look happy!