Cam Sprocket Bolt (single bolt instead of three)
Thread Starter
Staging Lane
Joined: Nov 2006
Posts: 76
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Cam Sprocket Bolt (single bolt instead of three) Messing with a friends LS2 out of his Trailblazer SS. Got the timing cover off and noticed that there is one large bolt holding the cam sprocket on instead of three bolts like I've seen in other LSx applications.
Well I put a socket on it and reefed on it pretty good, but it just won't break loose. I tried both directions in the event that it was a reverse thread for some queer reason. So I have two questions.
1) When did the LSx switch over to this type of cam sprocket bolt?
2) Has anyone had issues removing said bolt, I'm inclined to try the impact on it.
3) I assume its torque to yield, does anyone know the part number or torque value of the bolt??
Thanks very much for any help.
Well I put a socket on it and reefed on it pretty good, but it just won't break loose. I tried both directions in the event that it was a reverse thread for some queer reason. So I have two questions.
1) When did the LSx switch over to this type of cam sprocket bolt?
2) Has anyone had issues removing said bolt, I'm inclined to try the impact on it.
3) I assume its torque to yield, does anyone know the part number or torque value of the bolt??
Thanks very much for any help.
Thread Starter
Staging Lane
Joined: Nov 2006
Posts: 76
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Ok I've gotten to the bottom of this. Apparently in 2007 they went to a single bolt to hold on the cam sprocket. 2008's are said to be back to three bolts, but I haven't seen one to verify this info.
Thanks for the input here fellas.
Thanks for the input here fellas.
Thread Starter
Staging Lane
Joined: Nov 2006
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During the transition between Gen3 and Gen4 there were three types of timing sprockets...
Gen3: 3 bolt w/24x
Gen4 Early: 3 bolt w/58x (LS7, Early LS2, Early L92)
Gen4 regular production: 1 bolt w/ 58x
Regular thread direction (250-320Nm of torque)
Be careful removing the bolt because you can damage the timing chain...
Hope this helps.
Gen3: 3 bolt w/24x
Gen4 Early: 3 bolt w/58x (LS7, Early LS2, Early L92)
Gen4 regular production: 1 bolt w/ 58x
Regular thread direction (250-320Nm of torque)
Be careful removing the bolt because you can damage the timing chain...
Hope this helps.
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Thread Starter
Staging Lane
Joined: Nov 2006
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The only thing holding tension on the Cam sprocket in a single bolt cam is the timing chain.
On the old 3 bolt sprocket you had a radial bias. (Three point deflection)
And as far as the 2008 going back to 3 bolt...Incorrect
The single bolt IS the new type of fastener and will stay.
The only cam sprocket that will stay 3 bolts is the LS7
On the old 3 bolt sprocket you had a radial bias. (Three point deflection)
And as far as the 2008 going back to 3 bolt...Incorrect
The single bolt IS the new type of fastener and will stay.
The only cam sprocket that will stay 3 bolts is the LS7
I see your point. I have an adapter I made that fits on the back of the crank and stops the engine from turning on the stand. That offers a much more stable resistence to loosen things against.
Even still I see what you mean about tension, however don't you feel that the increased diameter of the bolt is stout enough to absorb the load of torquing it on and removing it? My guess is that is why GM made the bolt the way they did, make it as large as the three bolts combined and lengten it to disperse the load put on it during the installation and removal process. Not to mention during operation.
In the end, I opted out of the impact and just used an 18" breaker bar and socket. It came off on the first attempt without incident.
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Verdad Gallardo You are correct. 2007 is the only year with the single bolt. Check it out.
http://service.gm.com/servlets/BlobS...psdsubkey=6313
http://service.gm.com/servlets/BlobS...psdsubkey=6313
LS1Speed appears to have the cure for this single bolt delema with their custom sprocket. You just buy the old style cam(3 bolt) you want with the duration, lift, LSA, advance, etc., you want and install it with their custom sprocket on you one bolt VVT engine. If you look at the photo on their site you can see it has the single center bolt holes as well as the legacy 3 bolt holes with the dowel hole meaning their sprocket should work with either system.
Thread Starter
Staging Lane
Joined: Nov 2006
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If I'm not mistaken, the PCM/ECU can not account for cam timing changed at the timing set. Rather it can only change spark timing that the engine will see. Two different types of timing, and not to mention 90% of the adjustable sets out there are set at zero advance anyhow.
11 Second Club
Joined: May 2007
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From: Sydney
LS1Speed appears to have the cure for this single bolt delema with their custom sprocket. You just buy the old style cam(3 bolt) you want with the duration, lift, LSA, advance, etc., you want and install it with their custom sprocket on you one bolt VVT engine. If you look at the photo on their site you can see it has the single center bolt holes as well as the legacy 3 bolt holes with the dowel hole meaning their sprocket should work with either system.
cheers
LS1Speed appears to have the cure for this single bolt delema with their custom sprocket. You just buy the old style cam(3 bolt) you want with the duration, lift, LSA, advance, etc., you want and install it with their custom sprocket on you one bolt VVT engine. If you look at the photo on their site you can see it has the single center bolt holes as well as the legacy 3 bolt holes with the dowel hole meaning their sprocket should work with either system.
I just did this swap on a 07 Vortec Max 6.0L truck with a single bolt and DOD/VVT.
I swapped out the lifters to LS7 lifters and used a LS7 upper timing sprocket. Worked great.
I am wondering about my new Truck. I just bought an new Comp Cams(LS1 Design) 206/212 112 LSA. My truck is a 2007 Silverado 4.8 (LY2 engine Code). I know the 4.8 is a gen 4 design, but the 4.8 liter is the only engine in the lineup without VVT and/or AFM. My truck also came with the 243 heads. I am wondering if my truck will have the 3 bolt sprocket or the single bolt, and what valvesprings come stock in the 243 heads, With the lowlift cam I'm going to use, I wanna use LS6 springs.
If you don't have VVT(cam phaser) you're not going to have that type of cam. You should be able to bolt the new cam right up. As for you springs you didn't mention the lift numbers. You need to find out the lift numbers for the OEM springs and compare that to the lift of the new cam to see if you're over the limit or close to it. If you're close you should do the swap. Buy the Vinci/Crane tool if you do.
I ran into this problem about a month on a 07 silverado with the 6.0L. I didn't know what to think at first. Found out only the engines with vvt have it. I got a kit from lingenfelter that had the 3-bolt sprocket, 3 bolts, and a different chain tensioner. I had to get a new front cover without the vvt phaser hole in it too. Then I was set to run any aftermarket cam.
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