So, you guys know that I dont know much about this motor... it just came with the car. I do know that it's been massaged cuz I have some receipts from previous owner... but I have no cam info accept that the bill says it was replaced... stock, RV, street, race (doubt race).

Is there a way to tell lift and duration? I have a degree wheel, but have only used it to mark the balancer/pully with timing marks. Do I have to be really smart to use it otherwise.

Cheers... Brian

Cylinder Index = 84

Current Experiment = `57 Tbird, Grand Rapids, Michigan

With a magnetic base and 1" travel dial indicator set up on the valve stem and the degree wheel, you can come close to getting the valve lift and advertised duration of the cam.  (start of open to close of valve)  It's easier if the engine is out of the vehicle.  If you're going to take the engine apart, sometimes manufacturers will stamp a part number on the cam that can be back traced for specs. 

While you’re checking with the dial indicator, also measure the lobes at 0.050” opening and closing.  Be sure to also check the opening specs at 0.006” and at 0.015”-0.019”.  Either of these could be the advertised duration points of measurement depending upon the brand of camshaft.  Once you do both the intake and exhaust lobes, then there is enough information to calculate the lobe centerline of the camshaft.

 

I would also recommned checking the lobes on more than one cylinder.  The #6 cylinder is easy to check as it shares the same TDC as #1 on the degree wheel once the wheel has been properly set up.  The results will only be as accurate as your degree wheel so make sure you have exact TDC located on the degree wheel.

Lorena, Texas (South of Waco)

Thanks fellas... this sounds doable for me... I just want to get close at this point to knowing the category of the grind.

The car had a 312 from factory, but the casting numbers say 292 , and a mechanics receipt says it was bored .060 over... so I dont know if he kept all the swinging parts and the "G" heads from the 312 to put in this "replacement" block, or if it is simply a reworked transplant, or what.

I'll be dropping the pan for clues on the mains and crank this weekend.

Cheers... Brian

Cylinder Index = 84

Current Experiment = `57 Tbird, Grand Rapids, Michigan