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Join Date: Apr 2006
Location: northeast
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Grady, is it possible that you could snap a photo of the cam timing tools you use and made to do timing your way.
I think I can envision correctly what you procedure is and the tooling you crafted and use, however, a picture is worth a thousand words and your pictures and words are worth a ga zillion words to me and probably most here also!!

Thanks in advance Grady if you are able to post some pictures here.

Take care!
Bob

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Old 09-30-2007, 08:54 AM
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I finished up the ride side this afternoon.

I found that not only is the oil important, but keeping the chain extremely tight (more than you think you should) will also help out a whole lot. Luckily I found two mechanical chain tensioners online for cheap. They made this process so much easier.

On the right side instead of having to over compensate (choose a higher value) than the left side, I had to under compensate (a lower number than I wanted). It ended up being so spot on that I only had to go down one degree (started at 1.69 and achieved 1.70).

The crazy thing is, I put the guage back over on the left side and the timing actually changed a degree to 1.70 which worked out perfect!

I will be sure to check all the timing again after the chain tensioners go in.

Thanks again for everyone who gave thier input. I do hope this thread will help out others just like it did for me!
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John A.
1979 Porsche 930: 3.4L, SC cams, Twin plug, Leask WUR, Custom SSI turbo exhaust, Tial WG, K27HFS, and we can't forget the Zork (short lived depending on my homeowners assoc.)
05 Boxster S: For the Track.
06 Dodge Ram 2500 Power Wagon: Tow Vehicle
Old 09-30-2007, 01:58 PM
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AngM018, what & where did you get the two mechanical chain tensioners? I need to buy two also for a rebuild.
Thanks!
Bob
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Old 09-30-2007, 02:47 PM
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picked them up on evilbay. I have been religiously watching ebay for Porsche parts/tools since january, and this was the only set I have seen. I dont think they are too expensive to buy new, but well worth the cost.
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John A.
1979 Porsche 930: 3.4L, SC cams, Twin plug, Leask WUR, Custom SSI turbo exhaust, Tial WG, K27HFS, and we can't forget the Zork (short lived depending on my homeowners assoc.)
05 Boxster S: For the Track.
06 Dodge Ram 2500 Power Wagon: Tow Vehicle
Old 09-30-2007, 04:25 PM
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Thanks John! Can you post a picture of these mech tensioners? Do you know if Pelican sells these or where they can be bought?

Thanks alot!
Bob
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Old 10-01-2007, 04:03 AM
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Here's what mine look like. They are from Pacific Designs Inc.




Here is what our host sells. These one's look better made than mine, but its not like they will actually be left in the engine, so I doubt it would really matter.



Part #: STROMSKI-SR011
Price: $82.00 for the pair
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John A.
1979 Porsche 930: 3.4L, SC cams, Twin plug, Leask WUR, Custom SSI turbo exhaust, Tial WG, K27HFS, and we can't forget the Zork (short lived depending on my homeowners assoc.)
05 Boxster S: For the Track.
06 Dodge Ram 2500 Power Wagon: Tow Vehicle
Old 10-01-2007, 10:18 AM
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thank you John!
Bob
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Old 10-01-2007, 10:59 AM
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I'm a bit late to the thread, but perhaps not too late...
There is considerable play between the pin, the sprocket and the nothc in the drive flange. This fact accounts for the movement observed by some posters while tightening the cam nut or bolt. Keeping the mechanism loaded in one direction while changing the setting and tightening fasteners minimises this effect.
FWIW, my procedure for timing the cams:

Preliminaries: Initially set the cams slightly advanced (keyway slightly to left of vertical). Not too much or with hot cams/high compression/tall pistons you'll get interference. Have all rockers installed and all valves adjusted. It does make a difference. Torque both cam nuts/bolts every time. It also makes a difference. Install mechanical tensioners. If unavailable, use C-clamps to pull the idler to the chain case. Tension chains tight, but not dead tight. Install degree wheel and determine TDC with dead stop method. Pulley works, but could be off. Install and zero indicator, obviously Lubricate the threads and surfaces that slide (side of the nut, under head of bolt) with a moly lube. Porsche are even very specific which lube is approved, but I use what comes with the ATP rod bolts or CV joint grease.

Procedure: Turn crank to desired lift. Long handled wrench on pulley nut works well. Crank will be beyond TDC. Holding the crank with the wrench, loosen the nut/bolt and slowly turn crank back to unload the pin, move pin to next hole until it slides in. Reverse direction on crank and keep pressure on while torquing the nut/bolt. Turn back until the indicator is at 0, then forward to desired lift as before. Repeat until as close to spec as possible. Final check by turning forward a whole cycle. My goal is to get within at least .05 mm. Advanced cam is better than retarded. Finally, if in doubt, check piston to valve clearance by threading a wide nut on a valve cover stud and using a prybar repeatedly push the valve open to feel the play while slowly turning the crank past TDC. 0.020 in with stock valve springs. At .010 you can usually hear contact noise at around 6.5 G due to float.

Couple hints: There should be no axial play between the cam and the sprocket.
When using a nut, be careful that the huge wavy washer is centered. The hole in it is large enough to allow it to get caught on the lip of the sprocket. Result: The nut, while torqued, will come loose.

Has worked well for me. I'm sure there are other methods which work just as well. I'm not preaching gospel.
Old 10-01-2007, 07:17 PM
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I pulled the right side cam tower and replaced it due to a rocker shaft boss failure. I left the left side completely buttoned up... haven't touched the cam or anything. I'm now at a point where I'm ready to re-insert the right side cam, rockers, shafts, etc and time it. Most of you guys have pulled both sides and are starting from scratch with the left cam, then the right, etc. Am I ahead of the game because I didn't touch the left side? Or, do I need to re-time both sides. What's the procedure in my case where only the right side needs to be timed?

Thanks.

-Troy
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Old 06-17-2008, 10:13 AM
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Here's what I'd do:

Install your dial gauge on the left bank/#1. Ensure left-side chain is tensioned up, or clamp the idler arm to the top of the chain housing to tighten the chain. With your rockers backed off on the right bank (don't want to ding a valve while messing around over on the left bank), turn the engine to Z1/TDC overlap on #1. Take a reading of the cam timing on the left bank. Ensure both that you can repeat the measurement (by turning the engine thru 720' a couple times) and that the measurement is within specs. Now time the right bank as closely as possible to the reading you took on the left. Don't sweat it if you use different techniques to tension the chain left vs. right; on the stock DME cam a minor variance is not going to have any impact.

Most first-timers seem to get confused about the orientation of the cams during the timing process. Here's a way to improve the process above if it makes sense to you. With both chain covers off, turn the engine to Z1 and make sure the dot or '911' (or other PN stamping on the snout of the cam) on the left-side cam is pointing up. If pointing down, turn the crank through another 360. Now turn the right-side cam by hand (with rockers backed off) to the same orientation - markings up, so it is the same as the left. Now keep this rough timing by pinning the cam to the sprocket with the dowel pin and hand-torquing the bolt. While taking measurements on the left, the right will stay rough-timed. After finishing taking measurements on the left, set your dial gauge on the right and turn through 360 on the crank. You'll be on-cam on the right bank/#4, and ready to fine-tune timing.

Exercise extreme caution with the woodruff key and dowel pin, they WILL throw themselves down the chain case at the slightest opportunity. Often a good idea to stuff a clean shop towel down there. Saved my bacon on my latest build.

Is your left-side cam housing ok? Hate to see you going through this again in a few months on the left bank.
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Old 06-17-2008, 10:36 AM
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Thanks Dave! Great advice... and that doesn't sound bad at all. I've been dreading the cam timing part of this job.

I had been chasing an oil leak on that right side for some time, ended up putting RSR seals in there and, I think, over-torqued the sleeves causing the boss failure. The left side looks good, although I am gonna go back in and re-torque everything to spec just to make sure. Was real lucky I didn't do a ton of damage.

-Troy

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Old 06-17-2008, 11:13 AM
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