Anyone know the symptoms of an incorrectly degreed cam?
06-20-2008, 12:40 AM
#1
Anyone know the symptoms of an incorrectly degreed cam? UPDATE!
It's running on all 8 now! I'm having trouble keeping it straight on the road now.Lol....
Thanks to everyone that offered input.
My new motor is driving me nuts! It feels like it's running on 6 cylinders, powerwise. Fouls plugs quickly, hard to start, ugh...Except for the PCM, I've replaced everything that could have a role in this behavior. I'm beginning to suspect my engine builder installed the cam waaay retarded. Any of you guys seen or owned a car with a cam pretty far off in the degree?
Thanks,
Dave
It's running on all 8 now! I'm having trouble keeping it straight on the road now.Lol....
Thanks to everyone that offered input.
My new motor is driving me nuts! It feels like it's running on 6 cylinders, powerwise. Fouls plugs quickly, hard to start, ugh...Except for the PCM, I've replaced everything that could have a role in this behavior. I'm beginning to suspect my engine builder installed the cam waaay retarded. Any of you guys seen or owned a car with a cam pretty far off in the degree?
Thanks,
Dave
Last edited by mightyquickz28; 07-08-2008 at 06:09 PM.
06-21-2008, 12:15 AM
#2
If it's "pretty far off," there won't be adequate piston-to-valve clearance on either the intake or the exhaust side. Some of the motors I put together for Stock Eliminator have a window of two or three degrees in either direction before things get really ugly. If it's retarded, the exhaust valves get closer to the piston. If it's advanced, the intake valves get closer.
06-21-2008, 02:32 AM
#3
I have a turbo engine with dished pistons so perhaps there's extra room to prevent contact?
Here's a snip from a online magazine regarding a cam install they diagnosed as having the cam installed 'retarded'. At the beginning of the article, they stated, "Fuel adjustments and ignition timing changes couldn't cure these sooty plugs. We suspected the engine had been degreed incorrectly." and a picture of the plug was provided. My symptoms matched these.
Fouled plugs, lack of power, hard restarts, and a roasting intake manifold with normal water temperature. All of the above were symptoms that lead us to believe that the cam in our 460 had been degreed incorrectly. Specifically, we theorized that it may have been installed retarded based on the symptoms listed above. Retarding a cam is often performed to increase top end power at the expense of low end torque. Not a good condition for street use.
When a cam is retarded too far, a number of problems will arise due to the valve events all taking place too late. When an intake valve opens too late, the initial amount of air and fuel drawn into the chamber is reduced and exhaust gasses will not be effectively purged from the chamber. When an exhaust valve closes too late it can allow spent exhaust gases to enter the intake port. This is also called reversion.
Here's a snip from a online magazine regarding a cam install they diagnosed as having the cam installed 'retarded'. At the beginning of the article, they stated, "Fuel adjustments and ignition timing changes couldn't cure these sooty plugs. We suspected the engine had been degreed incorrectly." and a picture of the plug was provided. My symptoms matched these.
Fouled plugs, lack of power, hard restarts, and a roasting intake manifold with normal water temperature. All of the above were symptoms that lead us to believe that the cam in our 460 had been degreed incorrectly. Specifically, we theorized that it may have been installed retarded based on the symptoms listed above. Retarding a cam is often performed to increase top end power at the expense of low end torque. Not a good condition for street use.
When a cam is retarded too far, a number of problems will arise due to the valve events all taking place too late. When an intake valve opens too late, the initial amount of air and fuel drawn into the chamber is reduced and exhaust gasses will not be effectively purged from the chamber. When an exhaust valve closes too late it can allow spent exhaust gases to enter the intake port. This is also called reversion.
If it's "pretty far off," there won't be adequate piston-to-valve clearance on either the intake or the exhaust side. Some of the motors I put together for Stock Eliminator have a window of two or three degrees in either direction before things get really ugly. If it's retarded, the exhaust valves get closer to the piston. If it's advanced, the intake valves get closer.
06-26-2008, 11:30 PM
#4
Update. After reading SEVERAL accounts where people reported a timing set off a tooth could make a car run like mine has been, I pulled the timing cover off and had a look. I must mention that this engine has a custom and expensive turbo cam spec'd out by Bret Bauer and that it had specific information for degreeing the cam. When I provided all the information to my engine builder (gave him the cam card) he went after it and afterwards, stated he had to move it 2 degrees ( I don't remember now if it was 2 deg advance or 2 degrees retarded) to get the Intake Center Line method to line up. I thought, "Great! He's thorough!". Well, after all the stuff I've replaced and checked, I decided it HAD to be the cam phasing so I pulled off the timing cover. Only to see it's dot to dot. WTF?.... Add to that, the timing cover bolts were all finger tight. Now it looks like I've got to get a degree kit and check it out for sure myself.
06-28-2008, 09:44 AM
#5
Found my cam specs. Going to pick up the cam degree kit plus the nut you put on the crank to turn it over. I have to wait till about noon today to meet the guy (Fbody Buddy of course! The best guys/girls on the planet!) to pick up his kit, accessories. I did a little more research (prompted by fellow LS1Tech'r Chuck Norton. Thanks Chuck!) and found that not only did my engine builder not adv/retard the cam 2 degrees as he'd stated, the timing set (CLO-9-3145) doesn't even have a provision for just 2 degrees. It has 3 keyways. 4 degrees Advanced, "Standard/Dot-to-Dot" and 4 degrees Retarded. (For those in Rio Linda, that means you can't *just* add/subtract 2 degrees with this timing set). Something stinks here (and it's not just that shirt I've been wearing while under the car) Using the ICL (Intake CenterLine method) the cam should show a 112 ICL if it's degreed properly.
06-30-2008, 10:14 AM
#6
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Found my cam specs. Going to pick up the cam degree kit plus the nut you put on the crank to turn it over. I have to wait till about noon today to meet the guy (Fbody Buddy of course! The best guys/girls on the planet!) to pick up his kit, accessories. I did a little more research (prompted by fellow LS1Tech'r Chuck Norton. Thanks Chuck!) and found that not only did my engine builder not adv/retard the cam 2 degrees as he'd stated, the timing set (CLO-9-3145) doesn't even have a provision for just 2 degrees. It has 3 keyways. 4 degrees Advanced, "Standard/Dot-to-Dot" and 4 degrees Retarded. (For those in Rio Linda, that means you can't *just* add/subtract 2 degrees with this timing set). Something stinks here (and it's not just that shirt I've been wearing while under the car) Using the ICL (Intake CenterLine method) the cam should show a 112 ICL if it's degreed properly.
06-30-2008, 10:42 AM
#7
I checked. No offset bushing, no offset woodruff key. I did check the Intake Center line with a CompCams cam degree kit. It's spot on at 112 ICL.
Further investigation points to wiring issues. I'm in pursuit of a new wiring harness and I have found a guy with one. I setup the ignition to monitor spark on each cylinder. The LTCC diagnostics continue to show a undependable signal from both the old and the new opti (even using a new opti pigtail) The sparks on every cylinder are erratic. It might spark 5 times in a row then fail to spark on the next 1 or more, then resume, then stop. This explains why it runs like crap, back fires and fouls the plugs.
Further investigation points to wiring issues. I'm in pursuit of a new wiring harness and I have found a guy with one. I setup the ignition to monitor spark on each cylinder. The LTCC diagnostics continue to show a undependable signal from both the old and the new opti (even using a new opti pigtail) The sparks on every cylinder are erratic. It might spark 5 times in a row then fail to spark on the next 1 or more, then resume, then stop. This explains why it runs like crap, back fires and fouls the plugs.
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07-03-2008, 09:16 PM
#8
Well... Just put a new stock coil ($37) and Ignition Control Module ($71) and a set of stock Duralast/Autozone Plug wires ($35) on the car and just the 'old' opti to spin/generate the spark signal. What? No spark? Wait, what's that noise? The old opti is making a bunch of Chattering noises inside. Then I remember, "Oh, that's right. This is that piece of crap non-functioning(the high voltage part) Opti of someone elses that HPE gave me when they screwed me over on that roller cam motor". So, I just put 3 plug wires with plugs on them onto the New Summit Opti bolted to the engine. I spun it over. What? No spark?.. Oh wait (sheepish grin) I forgot to hook up the harness to the engines opti. Hooked it up, said a prayer, spun the engine. Hot damn! Sparks! And evenly timed too (at least it seems so at this point). I'm going to put the sparkplugs in the heads, route the plug wires as best I can around the Hotsides Log manifolds and once everything is connected to the point I can start it (no waterpump, etc is hooked while I'm in diagnostic mode here) I'll fire her up. I sure hope I'm greated by a V8 running on all 8 for a change. 
07-06-2008, 08:16 PM
#12
Either I have compound problems or someone in Jamaica has a voodoo doll of me and is having at it. With the opti, it runs 'better' but still not on all 8. I took it out for a drive this morning. It's substantially better but not good. As I drove it right back into the garage, I got to thinking about the ways to isolate which cylinder(s) were not participating in the party. I decided to start it up, let her idle, and I'd pull the injector clips, one by one, and see if it made a difference in the idle quality. I started on cylinder #1 and went down the entire drivers side. Each unclipping made the engine really labor down and almost die until I'd reclip it. Then I went to the passenger side and unclipped cylinder #2. Hey..! No change. I clipped it back and off again. Absolutely no change in the idle. I went further and unclipped cylinder #4. Wth? No change with this one either. I could leave BOTH cylinder 2 and cylinder 4 unhooked and it made zero difference. I hooked them back up and unclipped #6. Once again, the engine was really straining to stay alive until I reclipped the injector. Same with cylinder #8. So,... it appears it's something with cylinders 2 & 4. I reasoned, either they're not getting fuel or it's not sparking. I put a timing light on all the cylinders, just to be thorough. All 8 are firing fine. I pulled the fuel rails off and pulled the injectors(this must be like the 6th or 8th time this week) and examined them and the holes they sat in. All clear. I checked the injector harnesses with my voltmeter on cylinders 2, 4 and 6. They all match. 12v on one side and .37 on the other. This is key on , engine off. I tried to get a NOID light from Autozone and O'Reillys. The guys there are like, "A what light?!". Oh well, I'll see if I can find one tomorrow. I'd hoped there was a DIY or Homemade site on the net on how to make one but no luck.
07-08-2008, 06:49 PM
#15
No. The original problem *appears* to be something with the LTCC box. When TurboBob gets back to me on when/where I can ship it to him for a review, I'll know if that's it. The next thing was just battle fatigue I suppose. I was spending so much time under/over/infront of the car and up till 2:30am somenights, I inadvertantly swapped plug wires #2 and #4 when I swapped over to the new stock ignition components. Stevieturbo mentioned checking them again. I did when I got home from work today. I almost smacked my head hard on the front sway bar when I tugged on #2 plug wire with my left hand and I saw the opti boot on #4 wiggle. I was elated and pissed at the same time. But driving it a few minutes ago made all of the strife of the past month or so just fade into tire smoke...
