Cam Chain Timing Mark Drawings

here's the cam timing drawings




this is what you get in the timing chain kit


this is why the old jet blocks


old oil jet and new larger oil jet

Ehh.... don't know if I musunderstanding things here but. Is It like 1mm hole on the the old oil jet and 4mm on the new one? :eek:

They just take the insert in the jet away?!
I have somehow totally lost the valve timing after fitting a new cam chain. Is it possible to reset from scratch ? When I line up cams with marks on chain the cams appear to be in the wrong position. I thought that engine was TDC no 1 cylinder when I removed old chain, moved nothing, put new sprockets on and nothing would match up. How can I now be sure that no 1 piston is at TDC and get valve timing right. Any assistance would be much appreciated
How far out are the marks 1-2 teeth or a lot more? prob get away with tuning them into position if only out 1-2 teeth
You could reset from scratch you will have to put the crank 90 degrees BTDC ( making sure the valves are not going to get hit when turning the crank)so the pistons are all half way up the bores then reset the cams the turn the crank to TDC then refit the chain.
Thanks for that. I have reset the chain and sprockets according to the coloured links and timing marks. For some unknown reason the inlet cam sprocket was nearly half a turn out. This wories me as I thought I took extreme care to locate TDC for No 1 cylinder. I have now got the chain sorted, by the method you suggested and the pistons 1 and 4 are at TDC. How can I check that the crank is in the correct position and not a complete turn out? Many thanks for your help so far.
am just on with the chains.
i put balance chain on as shown in your pic
i got told to turn a full rev & it says if crank pulley marks dont line up, remove chain & re-align
ive done about 3 times & still out of line so started putting timing chain on.
have i done something wrong ?
any help will be well pleased
you will never re-align the marks in 3 turns :LOL:

it's something like 700 turns for the cam chain and proably 400 for the balancer chain !

once aligned the marks will all move by the same amount of links, so just count the difference, all three should be the same

ie; 2 links, 2.5 links or whatever
thanks for that i was getting a bit worried as i have put both chains on now & done a full turn to see if piston/valves were ok etc.
yeh when marks didnt line up at 1st i was a bit worried but you sorted my head out lol

vocky said:
yes that is all GM did, remove the brass insert :roll:
Is this the only attribute you can differ the old chain kit from the new one? My mate here had an engine blow up. The previous owner said, he changed the chain, but he has no bill or journalisation in the service book. So he is interested to check if there was the new kit fitted.
old chain kit had the brass insert in the oil jet and also the chain timing mark links are silver and bronze

the new chain kit has no brass insert and blue and purple timing mark links on the cam chain
vocky said:
old chain kit had the brass insert in the oil jet and also the chain timing mark links are silver and bronze

the new chain kit has no brass insert and blue and purple timing mark links on the cam chain
Thank you very much. Your can is just invaluable. (y)
hi just wondered if anyone can help, i'm trying to line up the timing marks on the balance chain and the timing mark on crank sprocket (pin hole) seams to be out half a link and doesnt completly line up with the mark on the chain, the timing mark on the sprocket is between teeth, is there any other way i can line up the bottom pully without this mark? i originally had chain slap and noticed that the tensioner wasn't put in right, would this cause the chain to jump as the engine seams restricted. notsure.gif
vocky said:
the mark is between the teeth and the centre of the coloured link should align to it (y)
yeh found it, just my eyes playing tricks as i had never timed a chain before, and living next door to unconsiderate noisey b*****ds dont help as i didnt get sleep for 2 days. but all back together to find out now that rings need replacing, just wait for the flex hone to turn up and on with the project, thanks for ur help anyway appreciate it very much.