Chain help
Thread Starter
Heel & Toe
Joined: Dec 2011
Posts: 23
Likes: 0
From: Eatontown NJ
Chain help
Good morning fellow gear heads, Doing a clean up and dress up on my 77 so I pull the timing cover off to replace with the chrome one and I see a nylon cam gear. Well its got to go so I buy another set from my local NAPA and in comes a Cloyes Heavy duty performance Napa part# 10-3023X. It’s a double chain and gears any problems doing the install? As far as fit and cover clearance? And I am going to assume that the standard clocking of the crank gear rather then the advance or retarded settings is the way to go its not a race car just a summer time weekend play toy. Thanks these are the kind of questions I promised to plague you with when I signed up to the forum
Le Mans Master
Joined: Oct 2010
Posts: 6,922
Likes: 839
From: melbourne florida
2023 C3 of the Year Finalist - Modified
the factory retarded the cam 4 degrees for emissions reasons. they were designed to run straight up. advancing it 4 degrees puts the cam where it should be. i personally would not put it back any other way. you wont be disappointed i did my 79 and back when my 78 was new i did it too.
Melting Slicks
Joined: Mar 2009
Posts: 3,126
Likes: 15
Hey, Dave. If it is not the stock cam I think you should time it at 0degrees. My new Lunati has transformed my stock L82. It will burn the tires from a dead stop on new concrete road surface. Stock L82 cam would not turn a tire on any dry surface. mike...
Melting Slicks
Joined: Aug 2010
Posts: 2,487
Likes: 10
From: Palm Beach Florida
St. Jude Donor '12
That was my thought also. They say the new cam has timing advance built into it. My L48 spins the tires now at a stand still start. Did you have your timing/distrib. set right before? You should have been able to do a spin.
Melting Slicks
Joined: Mar 2009
Posts: 3,126
Likes: 15
The L82 cam, in '77, is a total DOG. High RPM only. No torque whatsoever. Yes all was correct before. The improvement was due to the cam. mike...
Last edited by mds3013; Jan 14, 2012 at 01:26 PM.
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
Shouldn't be any issues with clearance under the cover or at the cam gear boss - but certainly check carefully during mock-up and/or final ***'y.
Generally, a cam should be installed "straight up" with no advance/retard at install via the crank gear. If you want different advance...buy a different cam.
So many off-the-shelf choices these days there's not a lot of reason to do this any more.
Generally, changing the advance moves the power peaks - about 500 RPM for each 4 degrees of advance. Advancing the cam moves it down, retarding the cam moves it up. There are other side effects as well - so if unless you're doing it for a specific reason and you understand what's happening...don't.
Generally, a cam should be installed "straight up" with no advance/retard at install via the crank gear. If you want different advance...buy a different cam.
So many off-the-shelf choices these days there's not a lot of reason to do this any more.Generally, changing the advance moves the power peaks - about 500 RPM for each 4 degrees of advance. Advancing the cam moves it down, retarding the cam moves it up. There are other side effects as well - so if unless you're doing it for a specific reason and you understand what's happening...don't.
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Racer
Joined: Feb 2005
Posts: 317
Likes: 2
From: coral gables miami
Shouldn't be any issues with clearance under the cover or at the cam gear boss - but certainly check carefully during mock-up and/or final ***'y.
Generally, a cam should be installed "straight up" with no advance/retard at install via the crank gear. If you want different advance...buy a different cam. So many off-the-shelf choices these days there's not a lot of reason to do this any more.
Generally, changing the advance moves the power peaks - about 500 RPM for each 4 degrees of advance. Advancing the cam moves it down, retarding the cam moves it up. There are other side effects as well - so if unless you're doing it for a specific reason and you understand what's happening...don't.
Generally, a cam should be installed "straight up" with no advance/retard at install via the crank gear. If you want different advance...buy a different cam.
So many off-the-shelf choices these days there's not a lot of reason to do this any more.Generally, changing the advance moves the power peaks - about 500 RPM for each 4 degrees of advance. Advancing the cam moves it down, retarding the cam moves it up. There are other side effects as well - so if unless you're doing it for a specific reason and you understand what's happening...don't.
Racer
Joined: Jul 2010
Posts: 261
Likes: 0
From: Manahawkin NJ
When you remove the cam sprocket you will see three oil galley plugs. Square up the radius above the middle plug with a grinder if it is close to the back of the new sprocket being careful not to let shavings get into the oil pan.
Le Mans Master
Joined: Dec 2003
Posts: 5,727
Likes: 38
From: Fremont CA
Edelbrock dosent make timing chains or grind camshafts. They only repackage off the shelf products and mark them up considerably for the re-boxing process they perform. You can find most Edelbrock grinds in a Melling engine parts catalog if you know where to look. They are about 1/2-2/3rds the price of the Eldelbrock items.
Burning Brakes
Joined: Feb 2011
Posts: 849
Likes: 0
From: Woodland California
Edelbrock dosent make timing chains or grind camshafts. They only repackage off the shelf products and mark them up considerably for the re-boxing process they perform. You can find most Edelbrock grinds in a Melling engine parts catalog if you know where to look. They are about 1/2-2/3rds the price of the Eldelbrock items.
I've been very happy with Edelbrock timing gears and chain.
Would be even happier at 1/2 price.
Ralph
Drifting
Joined: Jul 2002
Posts: 1,944
Likes: 20
From: The only Corvettes in Highett Victoria
1974?
the factory retarded the cam 4 degrees for emissions reasons. they were designed to run straight up. advancing it 4 degrees puts the cam where it should be. i personally would not put it back any other way. you wont be disappointed i did my 79 and back when my 78 was new i did it too.
One thing I love about this Forum is that I can always learn something new from people such as you. I flat out did not know that the factory installed the cams retarded and I thank you for educating me. I bought a '74 L48 from Solid LT1 two years ago and am very happy with it but if there's some "free" horsepower to unleash, I'm all for it.
Apart from the obvious disassembly of the balancer, water pump and timing cover, exactly how does one go about advancing the cam 4 degrees? Unless Eric chimes in and says otherwise, I'm presuming that the cam is the stock factory one.
Once this is done, the dissy will need to be altered, and Lars told me that the smart thing to do is fit lighter advance springs to bring full advance in at a lower than factory rpm. Your comments?
I feel sure that few here knew of the factory retard situation, so many can learn from your response. Thanks, and.........
Regards from Down Under.
aussiejohn
Instructor
Joined: Jan 2012
Posts: 201
Likes: 0
From: some hole in the ground town- camp verde:) arizona
i'm with the aussie. i had no idea it was retarded for emissions purposes only. come summer when i can afford to tinker with the car with no worries of needin it i'll try runnin it at 0 degrees. right now i need it 4 college 3 days a week at just over 100 mile round trips.
dependable as always!!!
dependable as always!!!
Instructor
Joined: Jan 2012
Posts: 201
Likes: 0
From: some hole in the ground town- camp verde:) arizona
7t9,
One thing I love about this Forum is that I can always learn something new from people such as you. I flat out did not know that the factory installed the cams retarded and I thank you for educating me. I bought a '74 L48 from Solid LT1 two years ago and am very happy with it but if there's some "free" horsepower to unleash, I'm all for it.
Apart from the obvious disassembly of the balancer, water pump and timing cover, exactly how does one go about advancing the cam 4 degrees? Unless Eric chimes in and says otherwise, I'm presuming that the cam is the stock factory one.
Once this is done, the dissy will need to be altered, and Lars told me that the smart thing to do is fit lighter advance springs to bring full advance in at a lower than factory rpm. Your comments?
I feel sure that few here knew of the factory retard situation, so many can learn from your response. Thanks, and.........
Regards from Down Under.
aussiejohn
One thing I love about this Forum is that I can always learn something new from people such as you. I flat out did not know that the factory installed the cams retarded and I thank you for educating me. I bought a '74 L48 from Solid LT1 two years ago and am very happy with it but if there's some "free" horsepower to unleash, I'm all for it.
Apart from the obvious disassembly of the balancer, water pump and timing cover, exactly how does one go about advancing the cam 4 degrees? Unless Eric chimes in and says otherwise, I'm presuming that the cam is the stock factory one.
Once this is done, the dissy will need to be altered, and Lars told me that the smart thing to do is fit lighter advance springs to bring full advance in at a lower than factory rpm. Your comments?
I feel sure that few here knew of the factory retard situation, so many can learn from your response. Thanks, and.........
Regards from Down Under.
aussiejohn
my ? is will this cause me to need to make changes to my idle speed?
Last edited by 75vetteman; Jan 15, 2012 at 08:58 PM.
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
Can someone post a shop manual reference or comparative photo showing where the L-82 cam is factory-installed 4 degrees retarded? Would just like to see this as it's new to me
Drifting
Joined: Jul 2002
Posts: 1,944
Likes: 20
From: The only Corvettes in Highett Victoria
That's what I thought.
I knew that turning the dissy would not advance the cam, so it looks like I will have to get a new timing chain set with adjustable keyways. It's a pity, as I just had the harmonic balancer replaced - the outer ring had slipped and I had to time it by ear.
I'll leave it alone for the time being, but will do this in the future, probably during winter (June-August). Thanks again for highlighting this.
Regards from Down Under.
aussiejohn