Cam mechanics, need advice!
Thread Starter
Racer
Joined: Oct 2004
Posts: 285
Likes: 0
From: Stockholm
Cam mechanics, need advice!
Was going to check for possible collisions between rods/camshaft when I ran into this problem.
How far should the smaller timing gear be pressed in on the crank?
I thought it should be pressed so i bottoms against the cheek on the crank, but if I do so it will be impossible to get the chain to line up with the big gear!!
There is also a Torrington flat bearing behind the big gear.
Timing set is a Cloyes Hex-A-Just.
How far should the smaller timing gear be pressed in on the crank?
I thought it should be pressed so i bottoms against the cheek on the crank, but if I do so it will be impossible to get the chain to line up with the big gear!!
There is also a Torrington flat bearing behind the big gear.
Timing set is a Cloyes Hex-A-Just.
Le Mans Master
Joined: Oct 2004
Posts: 5,269
Likes: 54
From: Orlando Florida
St. Jude Donor '05
The crankshaft sprocket (smaller gear) needs to go further towards the block, it looks like you only have half way installed. The halfmoon shaped key (Woodruff key) is for the harmonic balancer, there should be a second key for the crankshaft sprocket.
You installed the torrington bearing between the bigger gear and the block ?
Here's one of my old photos, you can see the two keys in the crank:
You installed the torrington bearing between the bigger gear and the block ?
Here's one of my old photos, you can see the two keys in the crank:
Last edited by MYBAD79; Mar 20, 2007 at 03:14 PM.
Le Mans Master
Joined: Jul 2005
Posts: 5,752
Likes: 4
From: Austin Texas
Was going to check for possible collisions between rods/camshaft when I ran into this problem.
How far should the smaller timing gear be pressed in on the crank?
I thought it should be pressed so i bottoms against the cheek on the crank, but if I do so it will be impossible to get the chain to line up with the big gear!!
There is also a Torrington flat bearing behind the big gear.
Timing set is a Cloyes Hex-A-Just.
How far should the smaller timing gear be pressed in on the crank?
I thought it should be pressed so i bottoms against the cheek on the crank, but if I do so it will be impossible to get the chain to line up with the big gear!!
There is also a Torrington flat bearing behind the big gear.
Timing set is a Cloyes Hex-A-Just.
Race Director
Joined: Jul 2004
Posts: 12,706
Likes: 329
From: Scottsdale Arizona
Just went through this on the weekend on my 400. My timing set is a Comp Cams, but looks almost identical to yours. I ended up having to remove and reinstall the crank shaft sprocket after greasing the shaft. I was then able to get the sprocket all the way on to the second key and up against the cheek of the crank. I won't know if this is appropriate until I get the cam, but I agree with MYBAD; I don't think that your sprocket is on far enough.
Race Director
Joined: Jul 2004
Posts: 12,706
Likes: 329
From: Scottsdale Arizona
I thought the same thing but then "dry fit" the timing chain cover and found interferance.
Le Mans Master
Joined: Mar 2004
Posts: 7,502
Likes: 1,509
From: Little Rock AR
2 things here - the gear needs to go on all the way AND the dots on both gears need to be facing out where they are visible.
There is a relief cut in the inner face (opposite the outer "dot" face) at the bore to allow for the radius on the crank snout. If you do not install it all the way on to the crank cheek the pulleys will be out of alignment. The balancer will be too far out.
-Mark.
There is a relief cut in the inner face (opposite the outer "dot" face) at the bore to allow for the radius on the crank snout. If you do not install it all the way on to the crank cheek the pulleys will be out of alignment. The balancer will be too far out.
-Mark.
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Thread Starter
Racer
Joined: Oct 2004
Posts: 285
Likes: 0
From: Stockholm
I got some questions about the Cloyes markings.
I'm missing all installation papers.
There are 3 marks on the small gear.
One ring, one square and one triangle.
I know that the ring is the straight up mark.
But how many degrees will the cam be advanced/retarded if selecting one of the other marks?
And which one is the retard/advance mark?
On the big gear there are thin lines milled, is it 1 degree between the lines?
If turning the small excentric hex bushing clockwise, will the cam then be advanced or retarded?
I'm missing all installation papers.
There are 3 marks on the small gear.
One ring, one square and one triangle.
I know that the ring is the straight up mark.
But how many degrees will the cam be advanced/retarded if selecting one of the other marks?
And which one is the retard/advance mark?
On the big gear there are thin lines milled, is it 1 degree between the lines?
If turning the small excentric hex bushing clockwise, will the cam then be advanced or retarded?
Last edited by gbak; Mar 20, 2007 at 07:19 PM.
Le Mans Master
Joined: Mar 2004
Posts: 7,502
Likes: 1,509
From: Little Rock AR
You can stack up the whole assembly solid with the gear in contact with the crank cheek and the balancer in touch with the outer surface of the crank gear. You may end up pulling the balancer out a touch if the bottom pulley is too far in and needs to be out farther for proper belt alignment (but you hope that is not the case) or if the balancer is too close to the timing cover. The belt alignment is the main concern.
-Mark.
Abby Normal
Joined: Dec 2001
Posts: 53,460
Likes: 92
From: Press "2" for English
I got some questions about the Cloyes markings.
I'm missing all installation papers.
There are 3 marks on the small gear.
One ring, one square and one triangle.
I know that the ring is the straight up mark.
But how many degrees will the cam be advanced/retarded if selecting one of the other marks?
And which one is the retard/advance mark?
On the big gear there are thin lines milled, is it 1 degree between the lines?
If turning the small excentric hex bushing clockwise, will the cam then be advanced or retarded?
I'm missing all installation papers.
There are 3 marks on the small gear.
One ring, one square and one triangle.
I know that the ring is the straight up mark.
But how many degrees will the cam be advanced/retarded if selecting one of the other marks?
And which one is the retard/advance mark?
On the big gear there are thin lines milled, is it 1 degree between the lines?
If turning the small excentric hex bushing clockwise, will the cam then be advanced or retarded?
if you're referring to the lines around the cam alignment pin, i think that is to further dial in the cam but again, i think you really need to get the correct information from cloyes
Le Mans Master
Joined: Sep 2001
Posts: 7,739
Likes: 630
From: Unreconstructed, South Carolina
Ring = straight up
Triangle = 4* ADVANCE
Square = 4* RETARD
My experience w/ hexadjust is that those little lines are not exact ... about 1* but not exact ... you MUST LOOSEN the 3 cam gear bolts before you shift the hexadjust.
IMHO, hexadjust overkill for street ... 9-keyway better & cheaper.
If chain is quite tight ... chain WILL quickly stretch a bit ... if quite tight ... set it up about 1*-2* advanced MORE than target ... because chain stretch will effectively retard cam timing.
-edit- ???? just curious ... when did you buy your set? ... and what's stamped into chain sideplates (ie IWIS)??? ... and is there ANY evidence of split in rollers?
Triangle = 4* ADVANCE
Square = 4* RETARD
My experience w/ hexadjust is that those little lines are not exact ... about 1* but not exact ... you MUST LOOSEN the 3 cam gear bolts before you shift the hexadjust.
IMHO, hexadjust overkill for street ... 9-keyway better & cheaper.
If chain is quite tight ... chain WILL quickly stretch a bit ... if quite tight ... set it up about 1*-2* advanced MORE than target ... because chain stretch will effectively retard cam timing.
-edit- ???? just curious ... when did you buy your set? ... and what's stamped into chain sideplates (ie IWIS)??? ... and is there ANY evidence of split in rollers?
Last edited by jackson; Mar 21, 2007 at 09:30 AM.
Thread Starter
Racer
Joined: Oct 2004
Posts: 285
Likes: 0
From: Stockholm
Timing set was in the car when I got it, according to the seller of the car it had been garaged for 10 years, and engine just had a few miles since rebuild. So chain is from mid ninetees and is very tight.
I removed it when I changed cam in my other engine but put it on the shelf for use later.
My new timing set from Comp cams was more sloppy than the used Cloyes set.
I can check the stamp later tonight!
What do you mean by "split in rollers" ?
I removed it when I changed cam in my other engine but put it on the shelf for use later.
My new timing set from Comp cams was more sloppy than the used Cloyes set.
I can check the stamp later tonight!
What do you mean by "split in rollers" ?
Safety Car
Joined: May 2001
Posts: 3,758
Likes: 3
From: Surrey
All info regarding what I've seen with timing chains (& duplex/triplex roller chains) in non-Chevy engines removed. All I'll say is, if you get the chance, watch a worn timing chain running at all engine speeds upto the red line, including lots of variations in engine speed. It's quite illuminating as to how it behaves, eg. lifting off of the teeth on the driving sprocket, and could explain some of the damage seen. All references to non-Chevy were made as it's a heck of a lot easier to watch what a chain is doing on other engines. Sorry.
For accurate valve timing, soak a new chain in solvent to remove all the protective grease, dry & then liberally soak in engine oil. You're more likely to get closer to the required timing once the chain has bedded in.
Last edited by UKPaul; Mar 24, 2007 at 07:42 AM. Reason: post too long, with irrelevant info on chains
Le Mans Master
Joined: Sep 2001
Posts: 7,739
Likes: 630
From: Unreconstructed, South Carolina
Split ... as in a seam ... like the metal was curled into a tube during manufacture ... rather than a seamless tube. Cloyes used chains from different manufacturers who did it both ways ... many of the newer sets have seamless (NO split) rollers such as those made by German IWIS. Many Renold rollers are split ... look close at rollers. The stamp on sideplate is THE brand identifier ... regardless what you may've been told by someone who hasn't seen YOUR set. My curiosity has ended now ... because it was in your motor when you got motor & you don't know when it was purchased.
Under very high stress, the split can become a point where the teeth chip out a chunk of roller ... got several such t-shirts.
Under very high stress, the split can become a point where the teeth chip out a chunk of roller ... got several such t-shirts.
Abby Normal
Joined: Dec 2001
Posts: 53,460
Likes: 92
From: Press "2" for English
still, interesting info. i did no such thing with the double roller i just installed in my roller motor. since the subject hadn't come up at the time, i never inspected the rollers but i sure don't recall them being split, as i think that would have caught my attention.
granted the split may last just as long, for the 1 out of 1000 odds, wouldn't you rather just spend the extra $10-20 on the solid rollers?
and regarding what you mentioned about the chain slop and landing high on the teeth, on disassembly of the early engine, half the teeth were missing from my cam sprocket. this was on an aftermarket "budget performance" set from summit that was less than 20k miles old. the mileage isn't what gets it, it's the rapping the engine up to 5-6000rpm for long periods of time that did it. so something for you to remember if you're building a high hp/ high rpm small block is make sure both gears are steel. many sets use a cast iron cam gear, they go away after a while.
Safety Car
Joined: May 2001
Posts: 3,758
Likes: 3
From: Surrey
The best (within my budget) duplex roller chains I know are Renold, which have split rollers. Currently working on something that puts over 80rwhp through a duplex roller chain & know of others used on race tracks. I've not heard of split rollers falling apart on good condition/quality chains, so what's different with Chevys? Is it because there's no method of tensioning the chain? Or did the chains have a high mileage on them? :scratchinghead
Last edited by UKPaul; Mar 24, 2007 at 07:35 AM. Reason: Removed non-Chevy info
Le Mans Master
Joined: Sep 2001
Posts: 7,739
Likes: 630
From: Unreconstructed, South Carolina
I was referring to chevy timing chains in race motor ... not MC. I recall this thread was about chevy.
I dunno how to quantify high stress other than to say I was referring to top quality duplex/double chevy timing chains in a circle track race motor.
I do not deal with MC chains on a daily basis ... but I've NEVER seen a MC final drive chain that wouldn't stretch ... and I've never seen one that was not a single. Yea, Yea I've had sportsters (triplex) and big twins (duplex) that had primary chains. I've been on a few drag bikes too. Quite frankly, I'm not up on MC chain technology anymore ... so, other than to say I think there's a great deal of differences of stress between cam drives & final drives ... I can't add anything meaningful to MC chain discussion.
I dunno how to quantify high stress other than to say I was referring to top quality duplex/double chevy timing chains in a circle track race motor.
I do not deal with MC chains on a daily basis ... but I've NEVER seen a MC final drive chain that wouldn't stretch ... and I've never seen one that was not a single. Yea, Yea I've had sportsters (triplex) and big twins (duplex) that had primary chains. I've been on a few drag bikes too. Quite frankly, I'm not up on MC chain technology anymore ... so, other than to say I think there's a great deal of differences of stress between cam drives & final drives ... I can't add anything meaningful to MC chain discussion.