I just recently purchased a car with a 355 small block chevy in it. The only problem i have is that i do not know what size cam is in the car? Is there any way to find out the cam duration and lift without ripping it out of the engine? Thanks for any help. Josh

Originally posted by jcchevelle:
I just recently purchased a car with a 355 small block chevy in it. The only problem i have is that i do not know what size cam is in the car? Is there any way to find out the cam duration and lift without ripping it out of the engine? Thanks for any help. Josh =
Finding out who built the engine comes to mind :D :D

Finding out can be done, but involves a little work.
You need at least a dial indicator on a magnetic stand, and a degree wheel.
Pull off a valve cover and put the dial indicator on #1 intake or exhaust. The exhaust will open 1st, so you may want to use this.
Find TDC. Your degree wheel needs to be mounted on the crank, and you have to put some sort of indicator on the block. I find TDC using a philips screwdriver and a very soft touch. Turn the crank one direction until the piston just lightly touches the screwdriver. Mark that place on your degree wheel. Some sort of grease pencil comes in handy here. Now turn the crank the other direction until the piston again lightly touches the screwdriver. Mark this place also.
Add the 2 numbers and divide by 2. This is where TDC is located. Check it again, and again. That's 3 checks. If the numbers agree each time, you've found TDC.
Set TDC at 0.
Now with the dial indicator on the exhaust valve retainer, zero the dial indicator right as the INTAKE valve starts to sit on the seat.
Turn the engine over slowly, counting the valve lift on the dial indicator. When it starts down, you've just found max exhaust valve lift.
Do the same for the intake. You zero the dial indicator on the intake retainer right as the exhaust valve STARTS to open.
Finding the duration is a little harder.
Determine if there is lash in the system or not. Check several valves. If there is lash, you have a solid lifter cam. If there is no lash, you have a hydraulic lifter cam.
Either way, with your dial indicator still on a retainer, turn the engine over at least twice to get a feel for .050" on the indicator. Turn up to .050" retainer lift, and mark this on your degree wheel. Turn on over the nose/max lift point, and count down until .050" before valve closure. Mark this on the degree wheel.
Counting the number of degrees between the 2 marks tells you the .050 duration.
Do the same for the other valve.
I would not try finding seat duration until you were very comfortable with finding .050" durations.
Good hunting!

UDHarold