the tag on my Y-block, was a cam tag, from Neilson cams, in farmington Utah.the following is what the original tag read if the downloads dont come out.

Engine..... Y-Block ford

Cam Grind.....280M

Valve Lift      .465" @ 1.54 ratio

Duration.....280 Degrees (232 Degrees @ .050")

Valve Clearance     .026" in & ex

110 degrees L.S.A.

Nielson Cams

644 west 100 North

P.O. Box 416

Farmington, UT 84025

       The folks at neilson cams were nice enough to decode the tag, send me a spec sheet,decal and explanation on valve lash, from a grinders perspective and a price sheet to boot.

 Now with a little more help maybe I can figure out what kind of build this really is...is there a way of getting more info without tearing it down? like maybe measuring the amount of air displaced? is there a tool for that? sorry to be a pain but this is all greek to me, and the motor appears to have been put together really well I would rather not tear it down.

THanks

John

With the engine on an engine stand and with an empty sparkplug hole facing straght up into the air, rotate the crankshaft so that the piston is at TDC on the hole on which you are going to perform your measurements.  Make sure the rocker arms are off the engine as you don’t want the valves working for this.  Using a graduated buret, fill that chamber up until fluid is even with the bottom of the spark plug threads.  ATF works well as the medium being used.  Record this number which should be in cc’s.  Without dumping the fluid that’s already in the cylinder, turn the crankshaft exactly 180° so the piston is at BDC and continue filling the cylinder once more until fluid is at the bottom of the spark plug threads once again.  Record this number.

The difference between the two recorded values is the displacement of the cylinder as measured in cc's.  Take this value and divide by 16.387 and then multiply by 8 and you’ll have the cubic inches of the engine.  Let's assume you measured ~90cc with the piston at TDC.  With the piston at BDC, let's assume you the total fluid amount is ~707cc.  The calculation looks something like this: (707-90) / 16.387 X 8 = 301.2 cubic inches.

For this next calculation, divide the first number you obtained by the second value.  That first number was the amount of fluid with the piston at TDC while the second number was the total fluid at BDC.  The result of this division will be the compression ratio of the engine.  Here's what the calculation looks like with the same values used above: 707 / 90 = 7.9:1CR

that is why I love this site, it amazes me the amount of practical knowledge a dumb newbie like me can pick up

thanks!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!