Rocker Arm Install
10-09-2011, 12:37 PM
#1
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Rocker Arm Install Everything went fine, until the third to last one. When torquing the rocker arm bolts down, every bolt took about 1 1/2-1 3/4 turns from snug to 22ft/lbs. I wasn't counting the exact amount of turns or anything, just noticed it usually took that many turns to torque them down.
When tightening the exhaust rocker bolt on cylinder 4, it took about a 1/2 turn from snug to 22ft/lbs. I removed both rockers from that cylinder and redid them, but the exhaust rocker still only got 3/4 turns to 22ft/lbs. Am I being paranoid???
Short version on how I did it(LS How to book);
Apply downward pressure to pushrods, while rotating crank clockwise.
Once the exhaust pushrod moves upward, install the intake rocker and torque down.
Apply downward pressure to exhaust pushrod, while rotating crank clockwise till the intake valve opens, then almost completely closes.
Install exhaust rocker and torque down.
Setup:
AI 243 Heads
AI Cam
7.350" Pushrods
LS7 Lifters
Stock rockers w/trunion upgrade
When tightening the exhaust rocker bolt on cylinder 4, it took about a 1/2 turn from snug to 22ft/lbs. I removed both rockers from that cylinder and redid them, but the exhaust rocker still only got 3/4 turns to 22ft/lbs. Am I being paranoid???
Short version on how I did it(LS How to book);
Apply downward pressure to pushrods, while rotating crank clockwise.
Once the exhaust pushrod moves upward, install the intake rocker and torque down.
Apply downward pressure to exhaust pushrod, while rotating crank clockwise till the intake valve opens, then almost completely closes.
Install exhaust rocker and torque down.
Setup:
AI 243 Heads
AI Cam
7.350" Pushrods
LS7 Lifters
Stock rockers w/trunion upgrade
10-09-2011, 01:56 PM
#2
No, I don't think you're being paranoid.
I'd pull the #4 exhaust rocker arm and pushrod, and on the #4 intake also, compare them side-by-side to make sure #4 exhaust is all good. I'd also take a good look at the rocker mount bolt threads and make sure the rocker bolt threads in the block are good.
I'd pull the #4 exhaust rocker arm and pushrod, and on the #4 intake also, compare them side-by-side to make sure #4 exhaust is all good. I'd also take a good look at the rocker mount bolt threads and make sure the rocker bolt threads in the block are good.
10-09-2011, 02:03 PM
#3
Short version on how I did it(LS How to book);
Apply downward pressure to pushrods, while rotating crank clockwise.
Once the exhaust pushrod moves upward, install the intake rocker and torque down.
Apply downward pressure to exhaust pushrod, while rotating crank clockwise till the intake valve opens, then almost completely closes.
Install exhaust rocker and torque down.
Apply downward pressure to pushrods, while rotating crank clockwise.
Once the exhaust pushrod moves upward, install the intake rocker and torque down.
Apply downward pressure to exhaust pushrod, while rotating crank clockwise till the intake valve opens, then almost completely closes.
Install exhaust rocker and torque down.
EO/IC = Exhaust Opening / Intake Closing
----------------------------------------
· For a given cylinder as the Exhaust valve is Opening, the intake lifter will be on the base circle of the cam and lash/preload should be checked for that intake valve.
· For a given cylinder as the Intake valve is closing, the exhaust lifter will be on the base circle of the cam and lash/preload should be checked for that exhaust valve.
It helps to see how this works when you look at a cam lobe pair for a particular cylinder (attached figure).
10-10-2011, 04:26 PM
#4
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Well I removed both rockers for cyl #4. Cleaned/inspected the bolt threads, and holes. Everything checked out ok. I switched rocker assemblies around and torqued down the exhaust side first. 1 3/4 turns to 22 ft/lbs. Did the intake side and ditto, 1 3/4 to 22 ft/lbs. Redid them a second time just to make sure, but torqued down the intake first and got the same results. Must of been a sliver or something, but none the less Im satisfied.
Hopefully only a few more weeks till I fire her up.
Hopefully only a few more weeks till I fire her up.
