Stroker timing problem
Three Wheelin'
Joined: Aug 2006
Posts: 1,765
Likes: 3
From: Atlanta
Mike, the damper is the ATI Super Damper we got together on remember? The flywheel was used & I didn't modify it.
I guess I'll have to pull the cam covers & do the dial indicator again.
John, I get no spark with the ST II PEMs installed. I had to put the OE chips back in.
Thanks, Hammer
I guess I'll have to pull the cam covers & do the dial indicator again.
John, I get no spark with the ST II PEMs installed. I had to put the OE chips back in.
Thanks, Hammer
What about the timing light? What does it say?
Thread Starter
Rennlist Member
Joined: Nov 2004
Posts: 951
Likes: 2
From: Conshohocken,Pa.
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
Hammer
Former Vendor
Joined: Feb 2005
Posts: 15,228
Likes: 2,529
From: Anaheim
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.)
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.)
Thread Starter
Rennlist Member
Joined: Nov 2004
Posts: 951
Likes: 2
From: Conshohocken,Pa.
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.)
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.)
Hammer
Three Wheelin'
Joined: Aug 2006
Posts: 1,765
Likes: 3
From: Atlanta
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!
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!
Thread Starter
Rennlist Member
Joined: Nov 2004
Posts: 951
Likes: 2
From: Conshohocken,Pa.
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!
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!
Regards, Hammer
Rennlist Stories
The Best Porsche Posts for Porsche Enthusiasts
Porsche Reveals Coupe Variant of the Electric Cayenne With a Fresh Look
Verdad Gallardo
10 Porsche Colors That Have More Personality Than Most People
Verdad Gallardo
Guntherwerks' Final Speedster Creation Is the Ultimate Porsche Restomod
Verdad Gallardo
10 Reasons I Hate Going to the Porsche Dealership (& the 1 Reason I Stay)
Joe Kucinski
Porsche Shakes Up The Nürburgring Lap Record Table Once Again
Verdad Gallardo
6 Ways the Porsche 911 GT3 S/C Redefines Performance
Joe Kucinski
10 Wildest Homologation Specials Porsche Ever Sold
Verdad Gallardo
Super Rare RUF BTR III Comes Out of Hibernation, Looking For a New Home
Verdad Gallardo
10 Porsche Opinions That Can Start a Fight
Joe Kucinski
Rennlist Member
Rennlist Site Sponsor
Joined: Jun 2001
Posts: 6,469
Likes: 13
From: Ball Ground, GA
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!
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!
Thread Starter
Rennlist Member
Joined: Nov 2004
Posts: 951
Likes: 2
From: Conshohocken,Pa.
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
Thanks, Hammer
Rennlist Member
Joined: Feb 2011
Posts: 2,343
Likes: 699
From: Mostly in my workshop located in Sweden.
Rennlist Member
Joined: Jan 2008
Posts: 4,077
Likes: 331
From: Friday Harbor, WA
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
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
Former Vendor
Joined: Feb 2005
Posts: 15,228
Likes: 2,529
From: Anaheim
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.
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.
Thread Starter
Rennlist Member
Joined: Nov 2004
Posts: 951
Likes: 2
From: Conshohocken,Pa.
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.
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.
Do you mean you switched them where they enter the EZK at the plug?