Reinstalling rockers?
12-17-2007, 04:47 PM
#1
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Reinstalling rockers? Is there a specific order I need to use while reinstalling my rockers after my cam and spring swap? Just trying to get it right.
12-17-2007, 05:23 PM
#2
No particular order. Apply Loctite to all the rocker bolts and reinstall all the rockers. Torque the rockers to 22lb/ft, rotate the crankshaft 180 degrees and double check the torque on all the rocker arm bolts.
And BTW tell me how u enjoy the new 224 cam i sold you.
And BTW tell me how u enjoy the new 224 cam i sold you.
12-17-2007, 06:24 PM
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man vette, your always buy the book.
i'm sure the timing cover is already on, so just snug each rocker arm bolt up, then go back thru them 1 at a time. If you start tighting a rocker arm down and the bolt just keeps turning, and turning, it's probably opening/closing the valve, so rotate the motor over untill that valve is closed, then tighten to 22ft lbs.
i'm sure the timing cover is already on, so just snug each rocker arm bolt up, then go back thru them 1 at a time. If you start tighting a rocker arm down and the bolt just keeps turning, and turning, it's probably opening/closing the valve, so rotate the motor over untill that valve is closed, then tighten to 22ft lbs.
12-17-2007, 08:15 PM
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No particular order. Apply Loctite to all the rocker bolts and reinstall all the rockers. Torque the rockers to 22lb/ft, rotate the crankshaft 180 degrees and double check the torque on all the rocker arm bolts.
And BTW tell me how u enjoy the new 224 cam i sold you.
And BTW tell me how u enjoy the new 224 cam i sold you.
12-18-2007, 05:42 AM
#6
The reason for the procedure is the torque measurement you are making with your wrench is approximately 85% friction. If you are compressing the valve spring at the same time, the forces on the bolt are higher and as a result your friction is higher and the torque reading is wrong with regards to bolt preload. Loose rockers or other issues can result, including bolt flex that will break a bolt. There are some guys here who scratch their heads with broken rocker bolts, these things happen for a reason and a lot of it results from not understanding bolt preload and bolted joint properties.
12-18-2007, 05:58 AM
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The reason for the procedure is the torque measurement you are making with your wrench is approximately 85% friction. If you are compressing the valve spring at the same time, the forces on the bolt are higher and as a result your friction is higher and the torque reading is wrong with regards to bolt preload. Loose rockers or other issues can result, including bolt flex that will break a bolt. There are some guys here who scratch their heads with broken rocker bolts, these things happen for a reason and a lot of it results from not understanding bolt preload and bolted joint properties.
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12-18-2007, 03:23 PM
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On each cylinder the exhaust valve is the one closest to inline with the exhaust port or header tube if they're installed.
12-18-2007, 03:30 PM
#9
[QUOTE=vidal77boxing;8322077] Torque the rockers to 22lb/ft, rotate the crankshaft 180 degrees and double check the torque on all the rocker arm bolts.
QUOTE]I wish someone would have told me that when I did my cam/valvetrain swap. A loose rocker makes a hellish noise!!!
QUOTE]I wish someone would have told me that when I did my cam/valvetrain swap. A loose rocker makes a hellish noise!!!
12-18-2007, 11:52 PM
#11
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Follow the TDC sequence with cam on base circle. 1-6 etc..
trq to 22 lbs as per sequence
2 or 3 full motor revolution (remove plugs)
recheck trq on all rockers.
trq to 22 lbs as per sequence
2 or 3 full motor revolution (remove plugs)
recheck trq on all rockers.
12-19-2007, 05:21 AM
#15
The Vette is very hard to get at, but I made a special wrench from 1/8" flat bar and the correct size socket. I cut the socket in half so it was short and welded it to the bar. The long length allows you to accurately control position as well.
12-26-2007, 05:22 PM
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Finished her up today and everything is working fine. It took some time but it sounds sweet and after a good dyno tune it will be rockin. My SES light is on but that is to be expected I guess. I will put a couple hundred miles on her to get the PCM to learn a little and get the springs broke in. It has been very satisfying doing this cam install. Saved some big bucks and have alot of pride in the car I am building. Thanks to all on LS1 Tech for the helpful guidance. I will post up the numbers when I get it tuned.
12-27-2007, 07:20 AM
#17
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200 miles untunes could be your last 200 miles. When are poeple gonna learn that you should tune your car IMMEDIATELY before or after cam install.
Too rich and you fry your O2s, wash up your cylinders and cake the pistons, too lean and you detonate and kill your pistons wich are cast BTW.
Your springs need only 3 heat cycles. Meaning warm and cool cycles, no miles needed.
Congrat on the swap. noe continue the good job and tune it.
Too rich and you fry your O2s, wash up your cylinders and cake the pistons, too lean and you detonate and kill your pistons wich are cast BTW.
Your springs need only 3 heat cycles. Meaning warm and cool cycles, no miles needed.
Congrat on the swap. noe continue the good job and tune it.
12-27-2007, 07:24 AM
#18
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200 miles untunes could be your last 200 miles. When are poeple gonna learn that you should tune your car IMMEDIATELY before or after cam install.
Too rich and you fry your O2s, wash up your cylinders and cake the pistons, too lean and you detonate and kill your pistons wich are cast BTW.
Your springs need only 3 heat cycles. Meaning warm and cool cycles, no miles needed.
Congrat on the swap. noe continue the good job and tune it.
Too rich and you fry your O2s, wash up your cylinders and cake the pistons, too lean and you detonate and kill your pistons wich are cast BTW.
Your springs need only 3 heat cycles. Meaning warm and cool cycles, no miles needed.
Congrat on the swap. noe continue the good job and tune it.
12-27-2007, 09:53 AM
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My tuner is 170 miles from me and I was going to drive it there.... now I'm getting afraid to do this.
12-27-2007, 10:40 AM
#20
I guess its time for you to learn LS1Edit...I do to. But Either way I drove my ms4 cam in my m6 SS to the tuner about 15 miles away, and I kept it under 3500rpm's. I also had put two heat cycles of just idling and then I drove it so all my springs where good.