74 valve tick help
Thread Starter
Cruising
Joined: Sep 2003
Posts: 12
Likes: 0
From: Pittsburgh PA
74 valve tick help
Good evening everyone,
Looking for some assistance on a 74 l48 motor. I just helped a friend out by doing the top end of of the motor. Stock 74 piston, edelbrock 60909 64cc alum heads, edelbrock performer cam, intake, & 600cfm carb, comp cam roller tip rockers 1.5 ratio with edelbrock 7.800 pushrods. There is an audiable valve tick and I am concerned. I followed the lash procedure with the cam with no sucess. I am concened that the push rods are slightly longer than stock and this is the problem. Any sugestions and or assistance is greatly appreciated.
Thanks
Rick
Looking for some assistance on a 74 l48 motor. I just helped a friend out by doing the top end of of the motor. Stock 74 piston, edelbrock 60909 64cc alum heads, edelbrock performer cam, intake, & 600cfm carb, comp cam roller tip rockers 1.5 ratio with edelbrock 7.800 pushrods. There is an audiable valve tick and I am concerned. I followed the lash procedure with the cam with no sucess. I am concened that the push rods are slightly longer than stock and this is the problem. Any sugestions and or assistance is greatly appreciated.
Thanks
Rick
Pro
Joined: Jan 2002
Posts: 624
Likes: 0
From: Marietta ga
Did you break in the cam correctly?
Did you compare the old push rods to the new ones?
What was the motor temp and air temp when you lashed the valves?
What procedure did you use?
Did you check Rocker Arm to spring clearance at full lift?
*if you did all of this correctly there still might be a slight tick because the comp roller tips will always make a little noise. The noise should be fairly even across all of the valves.
Did you compare the old push rods to the new ones?
What was the motor temp and air temp when you lashed the valves?
What procedure did you use?
Did you check Rocker Arm to spring clearance at full lift?
*if you did all of this correctly there still might be a slight tick because the comp roller tips will always make a little noise. The noise should be fairly even across all of the valves.
Thread Starter
Cruising
Joined: Sep 2003
Posts: 12
Likes: 0
From: Pittsburgh PA
Cory,
Thanks for the input. As far as the cam goes it has been broken in properly since it has been running in the car for 2 years now. The push rods are .120 longer than stock, I believe, this was going off the recomendation from edelbrock's notes on the head when using roller rockers. As far as the lash goes it was set cold by hitting every closed valve and adjusting till tight then 1/2 turn more. The noise is even across all of the valves. One other note the rockers are not self aligning.
Thanks
Rick
Thanks for the input. As far as the cam goes it has been broken in properly since it has been running in the car for 2 years now. The push rods are .120 longer than stock, I believe, this was going off the recomendation from edelbrock's notes on the head when using roller rockers. As far as the lash goes it was set cold by hitting every closed valve and adjusting till tight then 1/2 turn more. The noise is even across all of the valves. One other note the rockers are not self aligning.
Thanks
Rick
Pro
Joined: Jan 2002
Posts: 624
Likes: 0
From: Marietta ga
Rick,
That sounds great, but I have a few questions. Are you using roller tip rocker arms or full rollers (comp magnum roller rockers or Pro magnum roller rockers)? How cold was it outside? What procedure did you use to make sure the valves were closed? When you say "tight" are you refering to Zero Lash or did you actualy tighten them down? I am not sure if you have to use self aligning arms on those heads, check the edlebrock site.
Cory
That sounds great, but I have a few questions. Are you using roller tip rocker arms or full rollers (comp magnum roller rockers or Pro magnum roller rockers)? How cold was it outside? What procedure did you use to make sure the valves were closed? When you say "tight" are you refering to Zero Lash or did you actualy tighten them down? I am not sure if you have to use self aligning arms on those heads, check the edlebrock site.
Cory
Team Owner
Joined: May 2005
Posts: 31,496
Likes: 1,313
From: Huntsville AL
Originally Posted by Ricks95
Good evening everyone,
Looking for some assistance on a 74 l48 motor. I just helped a friend out by doing the top end of of the motor. Stock 74 piston, edelbrock 60909 64cc alum heads, edelbrock performer cam, intake, & 600cfm carb, comp cam roller tip rockers 1.5 ratio with edelbrock 7.800 pushrods. There is an audiable valve tick and I am concerned. I followed the lash procedure with the cam with no sucess. I am concened that the push rods are slightly longer than stock and this is the problem. Any sugestions and or assistance is greatly appreciated.
Thanks
Rick
Looking for some assistance on a 74 l48 motor. I just helped a friend out by doing the top end of of the motor. Stock 74 piston, edelbrock 60909 64cc alum heads, edelbrock performer cam, intake, & 600cfm carb, comp cam roller tip rockers 1.5 ratio with edelbrock 7.800 pushrods. There is an audiable valve tick and I am concerned. I followed the lash procedure with the cam with no sucess. I am concened that the push rods are slightly longer than stock and this is the problem. Any sugestions and or assistance is greatly appreciated.
Thanks
Rick
Bottom line, it turned out to be the fuel pump rod (from the cam to the pump). Replaced this rod and all was fine. Sounded just like a lifter tapping.
Instructor
Joined: Jun 2005
Posts: 248
Likes: 1
From: Apopka Florida
Originally Posted by emccomas
Had a similar problem on a 73 L48 car many years ago. Finally got a mechanic's stethoscope and determined that the sound was coming from the front of the engine, low on the passenger side.
Bottom line, it turned out to be the fuel pump rod (from the cam to the pump). Replaced this rod and all was fine. Sounded just like a lifter tapping.
Bottom line, it turned out to be the fuel pump rod (from the cam to the pump). Replaced this rod and all was fine. Sounded just like a lifter tapping.
I had the same problem and thought it was the valves. Changed the fuel pump and it took care of the ticks.
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