Decking the Head Surface
Thread Starter
Racer
Joined: Jul 2007
Posts: 478
Likes: 1
From: Nesquehoning PA
Decking the Head Surface
This question might seem silly but;
How many thousandths does a block have to be decked in order for the engine stampings to just about disappear?
I ask this because my car is soooo full of surprises. I found out today that it has a goodwrench 350 in it(mileage unknown) but the stamping numbers are just about gone, so I figure that the block was decked at some point.
I know these engines had woefully low compression numbers but this has World products heads, I am hoping that whatever PO did this was headed in the right direction.
I haven't figured out if it has an aftermarket cam or not. Is it possible to get an accurate lift reading with a dial indicator measuring at the valve side of the rocker arm?
Thanks,
JC
How many thousandths does a block have to be decked in order for the engine stampings to just about disappear?
I ask this because my car is soooo full of surprises. I found out today that it has a goodwrench 350 in it(mileage unknown) but the stamping numbers are just about gone, so I figure that the block was decked at some point.
I know these engines had woefully low compression numbers but this has World products heads, I am hoping that whatever PO did this was headed in the right direction.
I haven't figured out if it has an aftermarket cam or not. Is it possible to get an accurate lift reading with a dial indicator measuring at the valve side of the rocker arm?
Thanks,
JC
Le Mans Master
Joined: Feb 2000
Posts: 9,715
Likes: 27
From: Kempner Texas
Not all that much actually. My guess is in the range of .020".
You can pretty close to the actual valve lift just as long as the dial indicator stem is installed parallel to the valve stem and the lifter plunger doesn't depress. If taken at the retainer you'll have the crunch the numbers to account for the rocker ratio.
I think you'd get more accurate results if you take the reading directly off the pushrod though. That would eliminate the lifter concern since no spring pressure would be involved.
Jake
You can pretty close to the actual valve lift just as long as the dial indicator stem is installed parallel to the valve stem and the lifter plunger doesn't depress. If taken at the retainer you'll have the crunch the numbers to account for the rocker ratio.
I think you'd get more accurate results if you take the reading directly off the pushrod though. That would eliminate the lifter concern since no spring pressure would be involved.
Jake
Thread Starter
Racer
Joined: Jul 2007
Posts: 478
Likes: 1
From: Nesquehoning PA
Not all that much actually. My guess is in the range of .020".
You can pretty close to the actual valve lift just as long as the dial indicator stem is installed parallel to the valve stem and the lifter plunger doesn't depress. If taken at the retainer you'll have the crunch the numbers to account for the rocker ratio.
I think you'd get more accurate results if you take the reading directly off the pushrod though. That would eliminate the lifter concern since no spring pressure would be involved.
Jake
You can pretty close to the actual valve lift just as long as the dial indicator stem is installed parallel to the valve stem and the lifter plunger doesn't depress. If taken at the retainer you'll have the crunch the numbers to account for the rocker ratio.
I think you'd get more accurate results if you take the reading directly off the pushrod though. That would eliminate the lifter concern since no spring pressure would be involved.
Jake
Thanks,
JC
