Apologies for the crude layout below Just need a Quick question answered so posted in here so I could get some faster responses as I am getting ready to yank the wrong cam the original owner installed and then install the correct one.

If you read my idle thread you know I was having idle issues real bad and couldn't figure it out. Later on we found out the original owner has put in a 292 cam in an otherwise stock 455. This was a super huge cam for a stock valve train 455 so we figured out the idle and timing issues.

My question is just because I am curious. Right now when everything tore apart the timing chain marks are at 12 and 12, piston at TDC and dist pointing to 1.

Now I know it doesn't matter if the cam gear was installed at 12 or 6 or at least that is what I was reading in other threads. If I move the gear marks to point each other 12 and 6 oclock I get 180 out on the dist, 1 is at TDC but I believe on the exhaust stroke.

So is there any other way to make sure you are on a compression stroke for number 1 and timing is correct. Is there a way to look at other cylinders strokes? I thought the other cylinders should be at certain strokes as well?

Right now, with both gear marks pointing at 12oclock, the dist pointing to 1, cylinder 1 at TDC I have as follows.

This is if you were to stand on each side of car facing the head left valve or right valve facing head.

Open means the valve is not being compressed compressed

Cylinder #---Left Valve---Right Valve
1 --------- Open ---------- Open
3 --------- Compressed --------- Open
5 --------- Compressed --------- Open
6 --------- Compressed --------- Open

2 --------- Open --------- Open
4 --------- Open --------- Compressed
6 --------- Partial Compressed --------- Partial Compressed
8 --------- Partial Compressed --------- Partial Compressed

I would hope this means that the PO installed the cam correctly. I do notice a TON of slack in the chain. I know there will be a little on one side or the other but I can move the chain almost a full inch back and forth depending on which direction I have current force applied to the other side will have 1" of movable chain slack.

 

#6 is the cylinder 180 degrees from cylinder #1 your chart shows those valves partially open so it can be assumed you are at top dead center of cylinder #1

 

Gotcha. Yea number 6 isn't FULLY open in relation to how far I know the lifters come up so I wrote partial since it is not fully compressed nor fully open.

Thanks for the quick response, just what I needed to know.

 

And replace that chain - a jumped tooth can cause ALL the valves to bend!
Cloyes True Roller is a good one.

 

the valves on 6 are partially open because it is at tdc heading to the intake stroke. they are both open due to the overlap of the cam. the inch of play in the chain is a bit much. for the cost of a new chain and gears you should replace them now while it is apart.

 

Way ahead of ya guys. If you check my cam install thread in big block forum I have all new parts including lunati cam, cloyes double true roller, water pump, rockers, pushrods, fulcrums, Edelbrock intake, Edelbrock carb, HEI upgrade, full engine gasket kit, etc etc.

I just wanted to make sure the cam that WAS in there did not jump and I didn't think it did. Everything points to it being in time currently and that was what I was aiming for and worried about.

Thanks for the replies.