Alright, I'm gonna do a thorough tune-up here pretty soon including timing chain. I know that the dots on the cam and crank sprocket have to be lined at cam- 6 o'clock and crank - 12 o'clock. My question is once the crank cover has been removed and you are staring at the old timing chain and the dots are at some random position (say cam at 10 o'clock and crank at 11 o'clock or whatever it would be) how do you get them to line up at 6 and 12? Do you get a socket in there and turn it somehow or what? Are they easier to turn once the chain is off and you could turn one at the time, or would it mess up the valves if you turned just the cam sprocket without turning the crank sprocket i.e. would the valves be forced to touch the pistons? I don't have any idea, so any help would be greatly appreciated.

 

put on the cam sproket and turn the cam to 6 o clock...without oil pressure you wont bend valves..and i dont think u can turn it hard enough to bend them...the crank is a little more tricky...big vice grips...or screwdriver or seomthin of that sort on the flywheel
daniel

 

Lets leave the BFH and vice grips out of this, lol.

Undo the rocker arms, that will relieve valve train pressure.

You can turn the crank with the crank bolt. Just dont bottom it out.

The cam will then spin freely allowing you to line it up.

Install the chain, relash the rockers.

 

If you undo the rocker arms it closes up the valves so you are fighting compression coming and going. just did this last night and can vouch for that. you can leave the rocker arms intact without any change. You can turn the motor either way, will just be about 15-20 degrees then have to wait for the cylinder to leak down before you can progress.

Lining everything up is a no brainer, once you get it together you'll laugh at how much you pysched yourself up for it, i was the same way the first time. Crank keyway needs to be @ the 3 o'clock position in order for the engine to be tdc.

you need a bolt or threaded rod and nut to go into the snout of the crank so you can turn the motor over w/o messing with anything else. I used a hardened 7/16-20 threaded rod and a nut and washer or the crank bolt as atljar said, use washers to build it up so you don't run the bolt to the bottom of the crank.

The bolts on the timing cover are 3/8", cam bolts are 3/8", crank and harmonic balancer are 5/8" you do have to remove the oil pan to remove the timing cover, 3/8" and 1/2" for the pan. You need a 3 jaw puller to remove the crank gear and use something to press the new gear back on, I used a piece of pipe, washers, and the threaded rod, oiling everything as I progressed. When you install the new timing set, be sure to put some assembly lube on the back side of the cam gear and oil the chain.

 

Agreed, but with the valve train pressure on the cam it makes it harder to line up. I just rather fight the compression a litle, or unscrew a few spark plugs.

 

Thanks for all of the help guys.

Two more questions and hopefully that'll be it...

1. I've never rebuilt an engine so is there a certain brand of assembly lube y'all would recommend? Also, if I just go into an autoparts store, say O'Reilly's, and say I need some assembly lube, they'll point me in the right direction, correct.

2. I was reading on page 21 in Mike Mavrigian's "How to Rebuild Small-Block Chevy LT-1/LT-4 Engines" and he says that the crankshaft hub adapter (the part that's pressed onto the crank and the damper bolts to it) has no keyway to locate it. So, do I need to mark the position of the crankshaft hub adaptor before I remove it, or can I just press it back on in any position?

Thanks

 

You can use some heavy weight oil and just dip your parts into it. On a front chain thats more than enough lube. If you really want to buy assembly lube, Ive always used Permatex brand, and its called 'Ultra Stick" or "Ultra Slick" (I forget). That stuff is super super sticky and messy, but its ultra smooth and sticks where you put it. It comes in a small bottle and is dark red in color.

Its a good idea to mark the hub and put it on close, nothing exact needed. The front hub and balancer are zero balanced, so it shouldnt mater where it goes, but it never hurts to put things back on the way they came off.

 

1. yes. some engine builders just use synthetic oil as their assembly lube and then prime the motor very well before cranking it up. I just use the assembly lube I purchased from summit racing a while back, think it's crane cams assembly lube. looks like a mix between red bearing grease and motor oil.

2. when you line the crank and cam up the motor will be at top dead center, the key way for the timing gear will be sitting @ the 3 o'clock position. when the crank is sitting at this angle, the hub should be pressed on w/ the arrow pointing @ 12 o'clock. (you can also see where the keyway was sitting previously inside the hub once you remove it.) I know you're stocking up on answers, and thankfully I just did it and don't have to rely on my sh!tty memory, but once you pull everything down it should be cake.

I can list all the torque specs if you need them, I remember the hub bolt should be 75 ftlbs, harmonic balancer should be 60 ft/lbs. lol, about all I can faithfully remember right now.

 

Umm just pull the spark plugs to get rid of the compression to make it MUCH easier to turn.

 

At #6 TDC, the crank keyway is at 1:30 and the cam dowel would be at 3 o'clock. (sprocket dots aligned together)
At #1 TDC, the crank keyway is at 1:30 and the cam dowel pin is at 9 o'clock. (both sprocket dots at 12 o'clock)

 

Yeah you can see it in the picture above. Dots are aligned and keyway is at 1:30, not 3:00. Nice catch though.

 

Here is a picture of my chain install if you needed another reference.

 

Thanks Rob, I appreciate you catching that. Too many hrs in the garage and not enough sleep. (got it running last night though!!!) I was even looking at my own picture when I put down 3. need to go back to kindergarten and learn how to use a clock.

 

Thanks y'all, I was going to remove the plugs when lining the timing chain cause they're being replaced anyway...