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Gruppe IB
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About carrpet

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  • Location
  • Interests
    Porsche engineering, Salmon Fishing, Golf

Previous Fields

  • Current 911
    1989 930.66 Convertible G50, K27 7200, Fabspeed LN Intercooler, E-wur Microsquirt, Fabspeed twin pipe exhaust, Tial P46 wastegate, Classic Retrofit CDI+ & Fuse board owner since 1997
  • Daily Driver
    Porsche Taycan
  • Day Job?
  • Drink?
    Bordeaux, St. Julien, Talbot

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  1. Spurred on by MobyDick, and having done all of my homework on all aspects of valve adjustment, I decided to give it a go. I have a pit in the garage and I had listened to the engine running from underneath the car and I could hear that I had at least one exhaust valve that needed adjusting on the drivers side (cylinder 5 or 6). I also had some evidence of rocker shaft weeping oil at both front ends. The last time my valve clearances were adjusted was round about 20 years ago (approx 10,000 miles) by Merlin Porsche in Nottingham. My main guide was the Pelican 911 valve adjustment guide which appears identical to the 101 projects guide. As it happened, I didn't attempt and work on rocker shafts for two reasons. The evidence of leaks was minimal and this looks extremely challenging in-car. I can't see that there is enough space to get even the smallest torque wrench in there and there is a lot of scope for damaging the female allen headed adjusters at both ends of each rocker shaft. I borrowed the Kirk Tool from Les and made myself a 0.1mm feeler gauge to keep all options open. I even dug out my old SPQR valve clearance adjuster which does the same as the Kirk tool it is just a case of backing off by 4 clicks each click being 1 thou. I decided to purchase a Stomski because I liked the idea of using a dial gauge rather than using feeler gauges as the definitive check. Even using the Kirk Tool I'd probably still need to validate with a feeler gauge (if I didn't have the Stomski and dial gauge). I also wanted to know how far each valve was out of adjustment before I made any adjustments. I purchased the Stomski from Pelican Parts which arrived in record time even though I only paid for the cheapest (16$ ish) for postage. I was lucky and haven't been charged import tax. I bought a Katsu digital dial gauge on Amazon for £17.50 which is great value. I wasn't expecting to be able to use the Katsu dial gauge (Bezel size 52mm) on all of the valves because of access, particularly on a 930 which has a very cluttered engine compartment on both sides. However I was wrong. I was able to get to all 12 rockers. I had to fabricate an interference fit carbon fibre sleeve for the dial gauge to fit perfectly in the Stomski to replace the clip used by MobyDick. I acquired the lower valve cover gaskets with the silicone bead and Reinz upper gaskets. I bought the set of nuts and washers purpose designed for the rocker cover job. After dropping the oil out (which was due) I decided to have a go at the exhaust valves on the driver's side first. Access was easiest underneath (from the pit) and I had heard clearly excessive tappet noise there. I also decided to do one valve cover at a time which you can do by rotating the crankshaft 240 degrees at a time. Initially I only removed the distributor cap in the engine bay so that I could be sure I was on No.1 cylinder at the start of the process. I even left the plugs in. I used a 24mm ring spanner on the alternator nut to rotate the engine clockwise. I had to apply extra tension to the left had side of the fan belt with my left hand to prevent slippage but that worked fine. So having got to the timing mark for No.1 cylinder (confirmed by the rotor arm) I rotated the crankshaft the 120 degree timing mark to bring No.6 up for adjustment. There is a great photo from Pelican which illustrates this perfectly. However the 930 looks nothing the picture because there is a guard/heat shield which shrouds the 2 crankshaft pulleys (one for the A/C compressor). I used white paint to highlight Z1, 120 and 240 degree timing marks on the fan belt pulley circumference which are just visible when viewed from directly above. Having set the pulley on 120 degrees it was able to get in the pit and check out No.6 exhaust valve. I used a cable tie to hold 2 large oil hoses to one side. I checked by hand and it was obvious that No.6 had much more than 0.1mm clearance. I attached the Stomski for it's virgin run and it read No.6 exhaust at 0.17mm ie 70% out which was consistent with my intuitive assessment of tappet noise. I was able to get a reproducible 0.10mm reading following adjustment. Like MobyDick, I completed the exhaust valves on the driver side first (6,5,4) and replaced the rocker cover then moved onto the passenger's side exhaust valves. I had to remove my TIAL turbo bypass valve which is stainless mounted on a stainless steel exhaust flange with stainless allen head bolts so it is a 5 minute job including removing the two pressure hoses. Again I adjusted the 3 passenger side exhaust valves then replaced the rocker cover torqued to 10.8NM using a centre out pattern. Inside the engine bay was another matter. I had to remove the A/C compressor, Fabspeed Intercooler, boost recirculation pipe, original air filter housing to access the upper valve covers. As a 930 owner you get quite used to removing this lot to get at spark plugs etc. I worked on the drivers side first and found it easier than I expected then moved onto the passenger side. Inlet No.2 was the only valve which didn't need adjusting. All the other valves were at least 0.02mm out. No.3 inlet was furthest out at 0.22mm (0.12mm out). No.1 inlet was the hardest to work on of the lot because of tight access. No.1 is right at the back of the passenger side tucked under wiring/ducting and it's more difficult to get your hands in at the right angle. Car started well from cold. Valve noise significantly reduced. Tick-over was noticeably smoother. Pouring with rain so no opportunity to drive the car yet but all looks very promising ! Observations The Stomski tool is just a purpose designed adjustable dial gauge bracket but it is rock solid and enables reproducible dial gauge readings in tight spaces. After measuring and adjusting the first few valves it became clear that it is possible to learn what an out of adjustment valve gap sounds and feels like. I got better at guessing how big the gap was and what angle to set the adjuster to correct it. Using improving with learning, trial and error, I was able to get a reading of 0.10mm on every valve setting and did not accept + or - 0.1mm. I got much quicker as I gained more experience. The level of reproducibility with the Stomski / Katsu dial gauge is very high which gives a lot of confidence that the adjustment is right Being able to measure before and after adjustment was invaluable for me to see how far the valve clearances were "out" in the first place. Before adjusting the valve clearance the lock nut has to be slackened off. When re-tightening the lock nut there is drag which rotates the valve adjuster and closes the valve clearance. This in my experience is impossible to prevent and has to be compensated for. A full rotation (360 degrees) of the adjuster gives 1mm valve clearance adjustment. Therefore we are looking for 36 degrees of rotation for 0.1mm valve clearance. A better design might be to have a finer thread on the adjuster (2 rotations or 720 degrees rotation for 1mm adjustment) and a female allen headed adjuster to give more leverage to prevent inadvertent rotation during the locking process ? My valve clearances were a long way out of adjustment so it will be interesting to see what impact this has on engine performance and efficiency (the car has done 42 k miles) I hope this helps anyone thinking about adjusting their valve clearances. I would set aside a at least a couple of days to do the complete job but it is doable and I commend the Stomski / Dial gauge solution. I am also happy to help if needed !
  2. Hi Matthew Thanks for the input Can you expand on your "in-car" experience with the Stomski. Did you use a standard size Dial Gauge ? What diameter bezel ? Peter
  3. Rotating the crankshaft 240 degrees at a time to enable adjustments to be made on one side at a time makes a lot of sense since the geography of engine "obstacles" is very side specific. Could you have used the small analogue gauge on all of the valves ?
  4. Hi MobyDick Thanks for that. Can you explain the role of the clip. Is there not enough adjustment in the screw adjuster to close the gap on the diameter of the dial gauge "shank" Peter
  5. Great input thanks. Will take a look. Had heard of these but never seen them
  6. Thanks that is one of my questions answered about standard lower gaskets. Much appreciated! Order in the post !
  7. Good choice I think. The issue with the 100% silicone ones appears to be having the confidence to use so little torque to tighten them down !
  8. I see the lower gasket with the silicone bead are available from Type 911. MobyDick reported using these successfully after valve adjustment.
  9. Thanks for the links Ian, I am quite keen to use the Stomski with Dial Gauge to measure the gap before and after adjustment instead of using a feeler gauge and use the Kirk Tool to make the adjustment (36 degrees) anti-clockwise rotation. There appears to be a big difference between using the Stomski with the engine-in versus engine-out. With the engine in-car, with space and access being limited, the size of the dial gauge bezel is key and needs to be 35mm or less. There is no detail in MobyDicks post so I hope he might respond to this and give me a few more details. Would be great to borrow Les's "Kirk" Tool if still available as a loaner. Would also be keen to loan a Stomski if possible ? Thoughts would be welcome !
  10. Hi All, There appear to be a number of options for gaskets Standard gasket without a silicone bead Standard gasket with a silicone bead (lower only) 100% Silicone from USA which are claimed to be re-usable Graphite which are claimed to be reusable I understand the Porsche Original are standard gasket material with a silicone bead (lower only). Any thoughts would be appreciated Peter
  11. Has anyone any experience of using the Stomski Racing Valve Clearance tool, in-car, which works with a small dial gauge ? It is not a clearance adjuster tool (like the Kirk tool) as such but it enables accurate measurement of valve clearances before and after adjustment ? Peter
  12. I have a Tial F46P wastegate on my 930 and it is a wonderful piece of engineering. Spring selection can be a challenge ! FYI - I also use an AEM Tru-Boost X boost controller which Tial recommended to me to tightly control maximum boost. I can provide more details if anyone is interested. There are 2 basic body types and only one of these fits the Porsche 930 standard exhaust. The P variant has trimmed of cooling fins the standard F46 variant has circular cooling fins which interfere with the standard 930 exhaust. This item on sale is and F46P body with WG46 304L stainless steel flanges (which I did not need for my installation on a standard 930 exhaust) and in my view is very good value at £300 !!
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