Rocker Arm movement
04-13-2008, 01:27 PM
#11
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Join Date: Dec 2006
Location: louisiana
Posts: 2,763
RE: Rocker Arm movement
well i do have a brand new balancer, it only has like 60 miles on it! lol
i pulled the timing cover, the cam was dot to dot (crank at 12, cam at 6)
using the degree wheel, with rocker arm and last untouched, i was getting an intake centerline, which is max lift, of 116-118 (i wound up moving the wheel slightly after max lift and 118 was where it was at) the cam card has 110, thats very retarded then
i pulled the timing cover, the cam was dot to dot (crank at 12, cam at 6)
using the degree wheel, with rocker arm and last untouched, i was getting an intake centerline, which is max lift, of 116-118 (i wound up moving the wheel slightly after max lift and 118 was where it was at) the cam card has 110, thats very retarded then
04-13-2008, 04:14 PM
#13
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04-13-2008, 04:43 PM
#14
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Location: Warner Robins,GA
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RE: Rocker Arm movement
The pics of the rockers show's that the geometry is not correct. You may already know this and if i am repeating the obvious, i apologize. Here are a couple of links that shows correct valve train geometry from comps website.
http://www.compcams.com/information/Products/Pushrods/
Here's something from holley's site. Since yours is riding on the side and not centered according to this your pushrods are too short.
How To Verify Proper Valve Train Geometry
from Holly.com
The following is a method of verifying proper valve train geometry. After you have estimated the required pushrod length using a Pushrod Length Checker, use this method to verify that the valve train geometry is correct (using the rockers you are using in your engine):
1
The first step is to install a solid lifter and an adjustable pushrod. Mark the tip of the valve with a marker
2
Install your rocker arm and set it up with zero lash.
3
Rotate the crankshaft clockwise several times. Remove the rocker arm. The contact pattern of the rocker tip will be where the marker has been wiped away from the valve tip. The pattern should be centered on the valve tip, and as narrow as possible. If it is not, experiment with varying the pushrod length to yield the best pattern.
4
Pushrod Too Long: Notice how the pattern is wide, and shifted to the exhaust side of the valve tip.
5
Pushrod Too Short: Notice how the pattern is wide, and shifted to the intake side of the valve tip.
6
Pushrod Length Correct: Notice how the pattern is narrow and is centered on the valve tip.
http://www.compcams.com/information/Products/Pushrods/
Here's something from holley's site. Since yours is riding on the side and not centered according to this your pushrods are too short.
How To Verify Proper Valve Train Geometry
from Holly.com
The following is a method of verifying proper valve train geometry. After you have estimated the required pushrod length using a Pushrod Length Checker, use this method to verify that the valve train geometry is correct (using the rockers you are using in your engine):
1
The first step is to install a solid lifter and an adjustable pushrod. Mark the tip of the valve with a marker
2
Install your rocker arm and set it up with zero lash.
3
Rotate the crankshaft clockwise several times. Remove the rocker arm. The contact pattern of the rocker tip will be where the marker has been wiped away from the valve tip. The pattern should be centered on the valve tip, and as narrow as possible. If it is not, experiment with varying the pushrod length to yield the best pattern.
4
Pushrod Too Long: Notice how the pattern is wide, and shifted to the exhaust side of the valve tip.
5
Pushrod Too Short: Notice how the pattern is wide, and shifted to the intake side of the valve tip.
6
Pushrod Length Correct: Notice how the pattern is narrow and is centered on the valve tip.
04-14-2008, 08:07 PM
#15
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Join Date: Dec 2006
Location: louisiana
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RE: Rocker Arm movement
done it lol
i checked a couple rockers that arent cocked, the pattern is perfect.
the cocked rocker has a good pattern, but seems slightly further back on the valve, not horrible though...shoot i had the stock 6.250 rods before decked the block and it was way off. i have 6.1in now.
i was told by a couple people that the guide plate has to be moved some to fix that.
i checked a couple rockers that arent cocked, the pattern is perfect.
the cocked rocker has a good pattern, but seems slightly further back on the valve, not horrible though...shoot i had the stock 6.250 rods before decked the block and it was way off. i have 6.1in now.
i was told by a couple people that the guide plate has to be moved some to fix that.
04-15-2008, 01:23 PM
#19
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Join Date: Dec 2006
Location: louisiana
Posts: 2,763
RE: Rocker Arm movement
u had cainfields or was it afr's?
didnt you go the custom cam and head combo?, suprised it didnt fit.
well what plates worked for you?
whats your pushrod length and rocker arms?
didnt you go the custom cam and head combo?, suprised it didnt fit.
well what plates worked for you?
whats your pushrod length and rocker arms?
