John Speake

Hi Hammer, the PEMs should have starting files installed (S4) and labelled LH and EZK.

If not, using the ST2, go to File>New and then select the required EZK file.

Mike Simard

Yes, I thought about the ATI and remember that they are very accurate and not easy to put on backward like stock!

What about the timing light? What does it say?

6.0-928S

I was inside the car cranking it. My tech friend was working the lite. He said it was ok. But if the cam/valve timing was off how could I have 195-205 lbs of compression?

Hammer

GregBBRD

If the cams are factory cast iron cams, Porken's tooling will get the cam timing very, very close. With compression numbers that close, I doubt that is your problem.

Start with the basics. Make sure that #1 piston reaches TDC at the same time the damper reaches TDC and make sure that the cam marks are lined up.

The ignition rotors can go on different ways....make sure that the tips of the rotors are pointed to the driver's side of the car, when the engine is at TDC and the cam marks are lined up (There are two cast "nubs" on the cam gears that the "tips" of the rotors must go between.)

6.0-928S

Thanks for replying Greg. The cams are from Phil Threshie reground by Delta cams. The cam gear nubs are visible in the sight holes at TDC. Both rotors point to approx 3 o'clock.

Hammer

atb

Is it possible to cross-install the intake cams, and if it is would it cause a cam timing problem or are they identical to begin with?

Mike Simard

This may not apply but if everything is correct it's still possible to have spark timing scatter during cranking speeds because of errors from the mag or hall sensors, at least on a Motec anyway under certain conditions like bad sync sensor wiring.

I don't know if this can happen with the stock ign setup though. I know nothing about stock other than the fact that the sync sensor isn't needed but lack of it will retard the timing a small amount, right?

BTW, it's good to hear from you again!

6.0-928S

Thanks Mike! It's good to be 'back' although I still need some follow up eye surgery, at least I'm not blind. But I still can't see well enough to use a dial indicator or see the timing marks. That's why I had to hire a Porsche tech to help me. We're going to recheck the hall sensor & trigger wheel this week.

Regards, Hammer

WallyP

It would be interesting to see which cylinders are backfiring. If only two, I'd bet on misrouted plug wires. If all of them, I would be suspicious of the flywheel.

If you pull plug wires, make sure that they are grounded, perhaps by laying old plugs on the engine. The voltage is high enough to destroy coils, caps, rotors and wires - that voltage will make it to ground somewhere!

6.0-928S

I had downloaded & printed the procedure for timing the cams with a dial indicator a few years ago when I built the motor but I can't find the papers or the website. Can anyone tell me where I can get it back again?

Thanks, Hammer

Strosek Ultra

This might help.
http://www.burtonpower.com/tuning-gu...ng-timing.html
http://www.iskycams.com/degreeing.php

Ake

WallyP

Of course the procedure is in the Workshop Manual, but here are three videos that might help.

jcorenman

The problem with the WSM procedure is that these aren't stock cams. Setting them properly would require degreeing the lobes, finding the centers and setting those where you want them. BUt as Greg said, if they are reground from factory cams then Ken's cam tools will gt you very close, and much more easily.

But if the cams were very far off them the compression numbers would be wonky, and they are not. They might need a small tweak left-to-right but I don't see how cams can be the current problem.

It sure sounds like spark timing. The damper is fully-degreed, would it make sense to check each plug wire with a timing-light? At cranking, you should see a stable spark somewhere around 10-12 degrees before that cyl's TDC. That would verify plug-wiring as well as flywheel (crank reference) and the EZK.

Hammer, if you want to send me your PEM's I can check them and make sure that they are loaded properly. I'll PM my address.

Cheers, Jim

GregBBRD

This may be obscure....

I've had a couple of vehicles that "fired" the right hand side of the engine, when the left hand side should have been firing. This makes them backfire, badly. I simply "swapped" the white and green trigger wires, inside the car, that sent the signals to each side of the engine and these vehicles were fixed.

I never "bothered" to figure out what was going wrong. Probably some sort of a problem inside the brain that triggered the two sides at the wrong time?

If you think everything is good (and it sounds like it is) you might give this a quick try. It's very easy to do.

6.0-928S

Thanks Greg. I'll try that. Can't make it worse........I hope Do you mean you switched them where they enter the EZK at the plug?