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Shouldn't be too bad, really. In order to check cam timing with the heads on, you'll first have to find tdcof the number 1 cylinder. Here's how we'll do it. Pull the balancer off and bolt up your degree wheel. Pull off the intake and exhaust rockers of the number 1 cylinder. If you leave them on, there's a chance that the valves will hit the piston stop while you're turning the engine (by hand) and bend the valves. Make a pointer out of a coat hanger or welding rod and point it anywhere on the degree wheel. With the piston stop in the hole, turn the engine over by hand slowly clockwise until it hits the piston stop. Write down the number that the pointer is pointing to on the degree wheel. Now, rotate the engine the counter clockwise until the piston hits the stop and write down that number. Now, split the difference between those two numbers and that's tdc. Example, if you first number is 10 and your second number is 6, tdc would be at 8. Make sense. Next, take out the piston stop and rotate the engine to the number you came up with (In our example it would be "8.") Now, you're at tdc. Next, adjust the pointer to point at TDC on the degree wheel. Here's where there's going to have to be some "sloppy" engineering. Rotate the engine counter clockwise a little bit, maybe 40 degrees or so. you need to stick something down the pushrod hole that will stay centered in the pushrod hole and on the lifter while the lifter moves up and down. Once that's accomplished, put a dial indicator on the top of the tool you made that's sitting on the lifter and rotate the engine clockwise. You should see the lifter coming up and the dial indicator changing. This will make sure your tool works. Rotate the engine back counter clockwise so the indicator is not moving anymore and set the indicator to zero. You'll have to go to the cam card to find a spec. Some cams are degreed at the lobe centerline and some are degreed by the intake closing point. So lets say you're going to use the intake lobe centerline. Rotate the engine clockwise until the dial indicator goes to .050 lift. Record this number that the pointer is pointing to on the degree wheel. Keep rotating the engine in the same direction. the indicator will change directions and start coming back down and eventually stop moving (the cam is on the base circle). Rotate the engine counter clockwise until the indicator reads .050 and record this number. Just as you did finding tdc, split the difference between the two numbers and this is your lobe centerline. Compare your number to the lobe centerline number on the card and this will tell you if you're advanced or retarded. I had a custom ground cam in an engine done by a very well known cam grinder and it was off 9 degrees. Too many variables between the dowel pin, timing set, crank keyway etc. As you know it's important to make sure the cam is where it needs to be if you expect it to perform like it should. Hope this helps and wasn't meant to be demeaning by any means. Good luck. Keep us posted.
I just grabbed the harbor freight dial indicator setup and put it on the push rod. Technically your suppose to use a solid lifter, but I think this can get your pretty darn close. You also don't need to worry about the valve springs doing it this way.
1.) Pull the timing cover and accessories.
2.) Install the degree wheel/pointer and Use the piston stop tool to find TDC
3.) check the intake and exh valve degrees at .050 and see how close they are to the cam card.
The ISKY cam cards are a little fruity and confusing if they use negative numbers. "-2" BTDC is really "2" ATDC. That threw me off a bit.
Last edited by Forcefed86; 11-03-2014 at 10:01 PM.
If the cam is excessively retarded, the engine will be way done on power. This should be indicated by low cranking compression though. I picked up over 30psi of cranking compression. If Matt's friends engine indicated healthy cranking compression, I'm thinking something else must be wrong. I'd look to the trans/converter. I believe jarrett said 170-180 was healthy on the 6.0. I went from 160 to 195ish on my cranking comp. (10:1 5.3)
Originally Posted by 69-chvl
Wouldn't cam timing just alter the power curve either up or down vs changing peak power?
To a point... but it's not linear. My isky 215/215 @ 112 cam was installed 6.5* retarded from the cam card spec. This was dot to dot on my aftermarket timing set. (didn't originally degree the cam)
I had thought it was a cam grind issue so Jarrett sent me the smaller 212/212 @112 cam. With the adjustable timing set I degreed in the cam .5* retarded from the card. (took 8* of advance on the timing set to do this) The car picked up 15mph at the same boost levels and gained a ton of cranking compression.
When Jarrett got my old 215/215 cam back he said he tested it and it was perfect. We think my crank key way was off on my engine. This was later confirmed when I installed the same 212/212 cam on my 4.8 with the same aftermarket timing set and it required almost no advance, where the 5.3 required a 8* of advance to get close to the card.
Last edited by Forcefed86; 11-04-2014 at 11:36 AM.
my stock 5.3 with the same turbo, cleared 515whp on 9psi and 87 turbine
Didn't we go with the triple 12 in that one Matt? If so it can still make good power in straight up or 1 deg advanced to 1 deg retarded in a 6.0L 111~113 Intake center line. The 218 cam likes to be in 1.5~2 deg advanced. 110~110.5 Intake center line.
Originally Posted by Forcefed86
If the cam is excessively retarded, the engine will be way done on power. This should be indicated by low cranking compression though. I picked up over 30psi of cranking compression. If Matt's friends engine indicated healthy cranking compression, I'm thinking something else must be wrong. I'd look to the trans/converter. I believe jarrett said 170-180 was healthy on the 6.0. I went from 160 to 195ish on my cranking comp. (10:1 5.3)
To a point... but it's not linear. My isky 215/215 @ 112 cam was installed 6.5* retarded from the cam card spec. This was dot to dot on my aftermarket timing set. (didn't originally degree the cam)
I had thought it was a cam grind issue so Jarrett sent me the smaller 212/212 @112 cam. With the adjustable timing set I degreed in the cam .5* retarded from the card. (took 8* of advance on the timing set to do this) The car picked up 12mph at the same boost levels and gained a ton of cranking compression.
When Jarrett got my old 215/215 cam back he said he tested it and it was perfect. We think my crank key way was off on my engine. This was later confirmed when I installed the same 212/212 cam on my 4.8 with the same aftermarket timing set and it required almost no advance, where the 5.3 required a 8* of advance to get close to the card.
You would think these Ls engines would be really consistent but I have found a few way out of whack. My cam test engine happens to be a 2008 6.2L and was VVT but cams check really close in it.
I need to do this as well, I have the isky 218 cam also. I put a meth kit on it and turned it up to 15psi and it won't even spin the drag radials on the street. Just feels way underpowered for 15 pounds on a 10.1 engine
I need to do this as well, I have the isky 218 cam also. I put a meth kit on it and turned it up to 15psi and it won't even spin the drag radials on the street. Just feels way underpowered for 15 pounds on a 10.1 engine
What is the timing and air fuel ratio with the meth spraying? The easiest test and a big clue to if cam is retarded is a cranking compression test. FWIW my car will dead hook on the street on a good road with anything below 20 psi from 20 mph up. And 22 psi 40 mph and up. At 15 psi and conservative timing a 5.3 would never spin the tires in my car once it was rolling.
Ok that's good to know, I will do a cranking comp test first. What have you seen for cranking psi numbers on a L33 engine with this cam? It builds boost fast and can footbbrake 7psi by 3,200rpm no problem so it seems as everything else is doing its job.
Matt do you have another engine to try? Maybe the Trans is sucking away power. Fwiw my car dyno'd at 460 rwhp (5.3 at 16psi) and ran 134.4 at 3500 lbs.
Damn. yeah 460whp on 17psi is really low. I honestly don't think cam timing is going to be the magic trick to fix this.
If the cranking compression is way down I could see it. I went from trapping 139 @ 21lbs to 154 @ 21lbs with basically a smaller version of the same cam degree'd in properly. 215/215 isky to the next lobe size down...212/212.
The cam needs to be in the right spot! I agree with ForceFed86, it could definitely be the problem. At least after you degree it, you'll kniwnits on the right spot.
11-03-2014, 04:09 PM
cam timing experts come inside 
