Cam Swap

[fatguyzinc]

i ALWAYS run a geardrive if theres one available for the motor im building,
theres a reason every bicycle/motorcycle/chainsaw/etc in the world has a
way to adjust tension....

thought about one of these? run one on a circle track motor years back,
worked very very well....

[malc]

When I get some free time I'll be installing my
two piece timing cover and now I know where the cam's at, my Crane double roller chain.

[anotheridiot]

Well.....here we are again.
It "ran" but I couldīnt do anything with it, nothing.

Had it all apart and finally went for the Edelbrock timing chain which they tell you is the only way to time that cam
correctly.
Itīs a big single roller and I have my doubts about it.....


Iīll be surprised if it doesnīt fly off at any high rpm.
So I put it all back together making sure all the dots lined up etc.



Got it started....pretty much the same as before, and managed to get my vacuum gauge on it.
The best it can do is 13", should be 16" according to Edelbrock.

So 13" Iīm told is late valve timing....

Valve cover off driverīs side plugs out and watch as I turn the motor over by hand......everything happens as it should.

Then I find out 13" can also be a leak at the intake manifold so yesterday I do that, new intake and carb gaskets.

I left it twenty four hours to let the silicon set up and added coolant.

Start it up this morning....runs like crap still.

It runs like there is a big misfire, advancing the timing 14 on up makes no difference.

I wound the mixture screws out two whole turns....no difference.

What next, new plugs and a carb rebuild.....just because I īve run out of ideas and thereīs nothing else to
change.

Next week Iīm getting a CVR two piece timing cover and that will be the end of dropping that bloody oil pan.

holy crap, I just noticed this picture going back a page, is the cam gear is on backwards when you fit it. The pin hole is showing. Did you put it on the right way? That was why there was slop.

[malc]

holy crap, I just noticed this picture going back a page, is the cam gear is on backwards when you fit it. The pin hole is showing. Did you put it on the right way? That was why there was slop.

It'll only go on with the pin in that hole.
I did do a review on Summit pointing out that slack.
The chain is very agriculture engineering and no other chain I've ever used was like that.

[dieselhead]

Holy smokes that chain seems loose.

The timing chain is way too loose. It's either the wrong chain/gears or the mains in the block have been line bored. They make shorter timing chains for line bored blocks. I think you may have some bad lifters too.

[malc]

The timing chain is way too loose. It's either the wrong chain/gears or the mains in the block have been line bored. They make shorter timing chains for line bored blocks. I think you may have some bad lifters too.

It's not line bored, the chain and gears came as a set.
I've got other gear sets that fit perfectly, no slack, and as I said before this set is "recommended" by Edelbrock reason being I won't get the timing right with any other.
The lifters are brand bloody new !!!

[anotheridiot]

It's not line bored, the chain and gears came as a set.
I've got other gear sets that fit perfectly, no slack, and as I said before this set is "recommended" by Edelbrock reason being I won't get the timing right with any other.
The lifters are brand bloody new !!!

The whole thing is seeing where edelbrocks marks are on the gears and anyone elses. I got a cloyes set with 6 marks on the crank gear like you are supposed to know what to do with them.

[dieselhead]

It's not line bored, the chain and gears came as a set.
I've got other gear sets that fit perfectly, no slack, and as I said before this set is "recommended" by Edelbrock reason being I won't get the timing right with any other.
The lifters are brand bloody new !!!

The chain should be tight no matter what. Even though the chain and gears came as set doesn't they are the correct set. I had a new hydraulic cam and lifter kit (from Crane I think) that had 2 defective lifters. The lifters collapsed when I fired it up. Is there any way you can send a picture of your chain and gears to Edelbrock? I'm on your side and not trying to give you a hard time but something is wrong. Also I never worked on a Chevy engine that didn't have locking tabs on the timing gear bolts.

[anotheridiot]

It'll only go on with the pin in that hole.
I did do a review on Summit pointing out that slack.
The chain is very agriculture engineering and no other chain I've ever used was like that.

I mean the back of the gear is on the front side. Was there a timing mark on the other side of the cam gear. You usually see that machined surface on the side that touches the camshaft, so instead of the chain being in deeper, its out farther.

[malc]

It's not on reversed, find the pic of cam gear with crank gear......make it big....you can see the dot
on the bottom most cam gear tooth.
Back to front doesn't change diameter which would affect the chain.

[anotheridiot]

I can t make it bigger on the computer. Just wondering if there is a dot on the opposite side. I mean, you look at just about every timing chain set and the taper part of the gear is in the back. That has the chain fitting loose until the cam bolts are all the way tight and it snugs it up at that point.

[malc]

Dammit.....the cam gear can only go on one way
or the chain won't line up.
The cam gear is concave....goes up close to the block which is machined for clearance.

[malc]

Apart from all of that cam gear chain sprocket slack the motor runs just fine.....

[malc]

......and Edelbrock does not do email tech support,
they consider the telephone the most efficient way to comunicate......how quaint ?

[malc]

Aligned....straight up.

Maybe the slack is designed into the chain for that lumpy idle.....