correct cam timing, second opinion please *pics*

[grimreaper]

hey guys can any one that has replaced the timing belt or anything else that has required the timing to be reset tell me if this is on the dot or do i need to play with it more?

if you look, the left cam gear is a hair to the right of the mark on the cover and the right one is actually spot on. The left gear tooth with the timing mark hits the right half of the timing mark on the back cover to be specific. like a 50/50 line up
it looks to me as though i can not move it forward or back a notch as it will defiantly be out of timing. is this good or what?

my hemi goes +/- 13 degrees with one notch, dont think the 7m is this drastic but dont feel like doing this twice!
yes im anal or a perfectionist about this stuff, i dont think there is any other way to be when messing with the sup

 

[grimreaper]

more

 

[Piratetip]

Looks good to me. You would definitely tell if it was out of timing, what you are showing is +-1/2 a degree.
Have you had the head machined?

 

[grimreaper]

head is brand new with a full head job along with block decked etc etc by the previous owner. how ever im sure to prep it for the metal hg it might have been decked a bit. what would machining do?

 

[Slow66]

what would machining do?

It'll drop the head (and therefore the cams and gears) down ever so slightly. Since the crank cant move, and the belt is the same, the minor change in height is taken up by the cams turning slightly. This is where adjustable gears come in handy

 

[grimreaper]

interesting. good to know! adjustable cam gears worth it to correct that hair line movement of the gears?

 

[Rennat]

not for that minute amount.... dont stress it.

 

[Slow66]

Meh, depends on how modded you are and how serious you are about every last hp/ or your torque curve.

 

[jdub]

Looking at post #2, left two pics...both gears look slightly to the right of the back plate index mark.

Where is your crank damper index pointing?

Did you confirm #1 piston at TDC? Remove the plug and put a small dia wooden dowel in the hole. Move the crank damper in both directions until the dowel is at peak height...the damper index *should* be pointing at zero when this occurs.

 

[Slow66]

He put in a pic of his damper @ 0*. The problem I see with the dowel method is that theres a couple degrees where you wouldnt be able to tell by eye where the exact TDC is. IMHO the only real way to find true TDC is with a piston stop and a degree wheel...especially with these types of dampers as I'm sure you know. Just my .02...

 

[jdub]

That is true...a bit of a gumby method to be sure, but you can look at the damper index where it peaks on the way up and keep rotating the damper till it starts down. In the middle is a good estimate.

Ahhh see the pic now...could be the angles, but the damper index looks like it's to the left of the Zero.

 

[grimreaper]

i wish i knew how to read a degree wheel, or had one for that matter. but for now, its good ole oem markings

ill double check that crank pulley marker to timing plate to tdc on #1. maybe i can drop the belt and get enough to line them up a bit closer. oh and come to think of i lined the groove in cp with groove pointing to 0 on timing cover. dead center 0 per markings

 

[jdub]

What the dowel trick will tell you is if your damper is significantly out of phase...i.e. the rubber's twisted up internally.

 

[grimreaper]

cool good to know! almost want to go do it now dampner looks good but im guessing if its fubar it wouldnt be that visible.

on a side note the keyways and woodruffs were PERFECT! along with the belt, and tensioner. i finally feel good about romping on her now. everything else to this point has been top notch (minus the cam, pump and FMS that were all leaking a bit).

 

[Piratetip]

Are you using a new belt, if so what brand?

 

[grimreaper]

no, its an oem belt, no signs of wear on it at all (motor was said to be rebuilt 3-4000 miles ago so assuming it was replaced then). you thinking another (new) one will tighten up more? this one was very tight to get on the last cam gear, had to slide the belt nearly off the other one to get it to go on both at the same time with tensioner all the way to the left

 

[ForcedTorque]

Question since I'm learning, and will be trying to correct my timing today myself. It was said that what was shown represented about a 1/2 degree. Can we not make 15 degrees of adjustment through the CPS? Is a 1/2 degree a critical problem?

 

[Jaguar_5]

Question since I'm learning, and will be trying to correct my timing today myself. It was said that what was shown represented about a 1/2 degree. Can we not make 15 degrees of adjustment through the CPS? Is a 1/2 degree a critical problem?

The CPS controls ignition timing

The cam gears control valve timing, so you're not adjusting the same thing!

 

[trydrew]

Isn't it possible to match up the center hole in the cam with one of the side holes on the gear to achieve ~+/- 5* valve timing? It appears that way to me.

In this case though it doesn't matter, as his isn't off that far.

 

[grimreaper]

i would be VERY careful with cam timing, to much one way or the other and you get the famous "TINK" of piston to valve contact. if your lucky, it occurs when you rotate the motor by hand and not upon first start up

i was thinking the same thing with the extra dowel holes. but id like to know how much exactly each is worth and what type of valve clearance issues it can cause before messing with it.

jdub, #1 TDC is exactly in line with the mark on the crank pulley. if its off, its on a level that i can not tell by looking at it. soo im guessing from other input the slight decking of the head is the main reason for the slight advance in the exhaust cam. car runs like a champ, forgot how quick i can get to 100mph under part throttle.