Cam Chain Length

[Dr. Frankenstein]

Hi again;

I have a question about the 1964 CA77E cam chain length this time...

It seem like the cam chain is too long for where it should be. I took it out when I started the restoration, and the pistons were frozen so I had to carefully break it, NOT where the removable link was - that link was of course buried in the engine, on the opposite side from where I needed it to be; so I separated the chain where I could get to it, took it out, and went about my restoration - if you recall, I had several questions about how to remove seized pistons, which I finally did - but anyway....

The chain appears to be about two inches too long to put back in; even with the amount the rear cam chain tensioner will take up (although I haven't installed the tensioner yet), it seems like it's going to be way too 'floppy'; is it supposed to be like this? It should only (or appears to only) go around the lower rubber wheel and the cam chain sprocket, right? Or am I missing something? The manual I have Sucks when it comes to showing where and how it should go... will the tensioner take up that slack?

I'm psyched to get this installed, because I believe it's the final bit of engine assembly I need to do before I zip it all up and do the finer things like points adjustment and try to start it, and I REALLY do not want it to grenade on me when I hit the starter. Any ideas?

Thanks!

John

[48lesco]

It goes around the crank sprocket, both sides of the lower rubber wheel, and the cam sprocket with very little slack. New chains are usually too tight to install without temporarily clamping down on the head. I would replace the chain especially if the engine was stuck.

[Dr. Frankenstein]

Ohhh...so there's another sprocket IN the engine it needs to go around? That would make sense..I didn't crack the cases when I took the head off; all I needed to do was install new pistons and rings, and the procedures for measuring and checking for fit and wear of the engine checked out okay...

So, essentially, there is ANOTHER sprocket UNDER the rubber wheel the chain needs to go around, the crank sprocket? I've been dropping the end of the chain into the case, and using a magnetic pick-up to drag it through - just not far enough, I guess?

John

[48lesco]

Yes, I guess that's not really obvious from the parts manual diagrams, but something has to drive the camshaft right? You can see that sprocket if you look down in there. You're "entering a world of pain" (The Big Lebowski) if you are trying to loop that sucker around the crankshaft from above. When you take the head off you have to wire the ends of the cam chain through the top to the outside world to avoid your situation. I know yours was stuck, etc and you probably had no choice in the heat of battle. Maybe you can fish it around with wires, etc. but it may be easier to just take the oil pump off the bottom case for access. Not much to that, just the 6mm bolts and a couple of gaskets that I think are pretty readily available - maybe try RetroBikes:

http://www.olypen.com/retro/

[Dr. Frankenstein]

Actually, it wasn't all that bad. The cam roller and the drive sprocket are pretty much in-line with each other...it was simply a matter of drooping the chain over the drive sprocket, tilting the engine forward a bit to let gravity work With me so the chain would fall forward below the drive sprocket where I could see it, lighting my way with a flashlight and sticking my magnetic grabber in there; it popped right up, albeit after, like, two tries...and Yes, that takes care of the slack...now I just have to find some way to get it together, although I'm thinking a new cam chain would be best...now, it's too Short! :)

The big PITA was worming the chain up through the head without dropping it back in to the block...
I found tying a long zip-tie to the ends gave me the extra leader I needed to pull it up through...just FYI...

It's like, I need ONE more link and I should be able to pop it back together! Although like I said, in a perfect world a new cam chain would be the best way to go, but my world is not exactly perfect...so I may be facing Another work-stoppage, until my money tree blooms again...

BTW, what IS the procedure for getting the cam chain on...?? Do you have to assemble it IN the engine, or outside it, or what...?? to get it to go around all the gears?

John

[48lesco]

Way to go! Try to get equal amounts of chain on each side, slide the cylinder over the pistons, then feed both ends of the chain through the cylinder block. I use wire or zip ties on each end to get it up through. Then same for the head. You will probably have to clamp down on the head at this point to join the chain ends on the cam sprocket. Use a bunch of washers or a socket wrench etc as spacers on the 4 inner head studs to draw it down temporarily. Make sure your cam timing is correct (rotor at T, hole in cam sprocket straight up) and join the ends with a master link. Be sure to put the clip on with the open end facing aft. Don't forget the base gasket, head gasket and o-rings in the head gasket!

[Dr. Frankenstein]

What do you mean by 'clamp down on the head'?? Where?