i searched on this topic, but diden't really get a solid answer. basically, i have an LS motor, milled head by 20thou. i just started it up, and the motor is running ruff, because i need to time it. cam gears lined up so i'm pretty sure i'm not off a tooth, but the exhaust cam gear pointed straight up, and the intake camgear was off to the right a bit at TDC.

i tried to move the distributer to adjust some timing, but the best way i could get the motor to run somewhat smooth was to move it all the way back toward the firewall (advancing it i beleive?) how do i go about this? my one plan is to put the motor at TDC, put the pins into the cams locking them, and then adjusting the gear so that it's at 12'oclock instead of 1'oclock.

any help would be great, timing isn't my strong point

 

Your tbelt is not on right if the two cam gears are not parallel.

 

^but they are parallel because i have pins in both of the cams no?

 

Is this your first tbelt? You said one is at 12 and the other is 1, how is that parallel? If there is that much slop when staking the cams, then your pins are not big enough to hold them securly. It sounds like you may be off a tooth on one cam gear or the tbelt is not tightened properly and the belt has slack in it.

 

sorry, i should have said that the t-belt was tight, the one cam gear wasen't that off, just a bit, but enought that it wasen't at 12. if i move the belt one tooth to either side, then it's way off. more like exhaust is at 12 and the intake will either be at like 11 or just past 12. did that make sence?

 

ok next question, are you sure its lined up the correct line on the crank? the TDC mark, not the 16* BTDC mark. Do a compression test, if you get lowsey results then its likely the tbelt timing is all wrong.

 

^ok, i'll give that a try and see how my compression results are. i took some pics:

this is what i was saying, i have to move the distributer all the way back for the motor not to spudder:



here's the camgears, now they are not exactley at TDC, kinda hard to see when you turn the crank yourself, but it's almost there, but the point of the pic is that you can see how the one gear is just slighty off, when i searched on milling the head, someone said for every 20thou you take off is one degree on your cam gear; i'm not sure if this is true or not that's why i'm trying to figure this out



thanks for the help

 

jay give me a call later on if you're home and i'll stop by with my timing light to have a look.....

 

arent those two dots suppose to be lined up with each other? I mean they will only go on the cam 1 way so maybe not, but you should have some kind of lines or dots on the teeth to line up to each other. Thats just wierd.

 

^i thought that too, but they only go on one way and i guess those dots are supposed to be the "up" marks.

 

Why are there no timing(+-) on the intake cam gear.

 

i would suggest getting real skunk2 cam gears, and that may help with a lot.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SuperTeg95 &raquo;</TD></TR><TR><TD CLASS="quote">Why are there no timing(+-) on the intake cam gear. </TD></TR></TABLE>

you mean the exhaust gear.. there is, you just have to look close

 

there are marks on the exhaust gear, just can't see them too good with the light.

 

With your head milled...did you set the timing on the cam gears properly?

you have to compensate the milling on the cam gears.

If you did, just disregard my post.


<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by don lackey &raquo;</TD></TR><TR><TD CLASS="quote">Yeah.
The cam gear is 100mm in dia. The circumfrence is ~314mm (100mm x PI). So 1mm is about 1.1 cam gear degree (2 crank degrees).

Meaning when the head is milled 1mm (creating 1mm of t-belt slack) the cam gears need to rotate 1.1 degrees to take up the 1mm slack. </TD></TR></TABLE>

 

my head is milled 20 thous also.. i Just lined everything up (20 thous wont make if off a tooth) and i set my base timing to 16deg with a gun and sync'd it with the ECU. Car runs fine.

The roughness could be because you need it tuned properly, if its rich it idles poorly, dont go messing around with your ignition timing without a timing light.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BoostedJeff &raquo;</TD></TR><TR><TD CLASS="quote">

you mean the exhaust gear.. there is, you just have to look close</TD></TR></TABLE>

yeah, thats what I meant to say.

 

You have the dots up and down with the flat ground. They need to be straight up and down with the motor. It looks like they are both off by a tooth.

You need to have the OEM gears on there to see what I'm talking about. That's what happens when you buy cheap stuff....

 

When I had my head milled/block decked, my timing was 3 degrees off. The distributor is right to the end of it's throw(towards the back of the car). Not sure if that helps any, but a personal experience nonetheless