I don't think it is likely that the crank is mis-ground. More likely is the combination of the crank, timing set, and cam is not right on; you don't know if it is "straight up." You have determined some physical aspects of the cam and they won't change no matter how bad the crank is you are using but without devising a way to account for the error due to the tolerances in the crank, timing set, and cam, you may not be able to accurately determine what those specs should be in relation to the crankshaft. But I'm sure some safe assumptions can be made based on general camshaft knowledge.


Lawrenceville, GA

Heads are off block, only one ringless piston rod assembly installed in #1 at the front and passenger side.  1st front lifter exhaust, next is intake.  Magnetic base with dial indicator on the deck.  Cam installed with all of nose hardware to keep it from walking around.  TDC found using deck bridge and dial indicator.  Degree wheel is 11 in.

Is it possible that the crank has been missground, somehow throwing everything off, beginning with the TDC location?  Before removing pistons I visually noted a large discrepancy in piston to deck clearance between #1 and a piston on the other side (dont remember which) .  Checked number one and it was .045.  Didnt check the other that I had noticed on the opposite bank, but believe it was .010 or less.  Figured the issue was different rod lengths from rod resizing, and that I would try and sort it all out later.  However when I put this current piston rod assembly (different than when originally taken down) into #1, clearance was still .045.  Crank has been ground quite a few times, as it is now .050 under on rods and .040 on mains, so even with journals being in good shape this will be the blocks last go round.  Block is .080 OS.  Numbered markings on rods had no correlation to their location as found.  I think only one rod piston assembly was in the proper hole according to its number, and that must have been someone's dumb luck.

I chose this block to check the cam only for convenience.

Mike, located in the Siskiyou mountains, Southern, OR 292 powered 1946 Ford 1/2 ton, '62 Mercury Meteor, '55 Country Squire (parting out), '64 Falcon, '54 Ford 600 tractor.

O.K.-Make me understand your method of measurement.

Are you using the right hand side of the block (passenger side) for #1 cylinder?

And then using the most forward lifter bore on the right side as E-1 ?

Then the second lifter bore on the right side as I-1?

I am not clear on how you are counting back the lifter bores.

Oldmics

I've been working on number one cylinder, with the front lifter being ex. and second intake.   No problem here with questioning the method, as it is clear my cam understanding can be improved, and actually has been helped with this exercise and you and John's input.  The .050 closing was definitely at 1/2 BTDC.  I was carefully bumping over the crank and the wheel indicator wouldnt quite make it to 0. 

In the next few days will check at least #2-4 cylinder lobes to help rule out methodology error and premature lobe wear.  Visual inspection didnt show any wear, but then the eyesight used to be better.

Mike

Mike, located in the Siskiyou mountains, Southern, OR 292 powered 1946 Ford 1/2 ton, '62 Mercury Meteor, '55 Country Squire (parting out), '64 Falcon, '54 Ford 600 tractor.

My calculations at .050 on your second set of figures comes out to close to what you calculate for duration.

I get 228.5 for intake and 230 on exhaust for duration.

The intake centerline moves to 110.8, exhaust centerline 114.5

Lobe spread of 112.6, Advance of 1.9*, and an overlap of 4 *

My concern is about the exhaust closing BTDC (.5) That doesnt sound right and will obviously screw up all the figures.It should be an ATDC measurement.Perhaps an error in spec placement nomenclature?

Are you sure that you are measuring the correct lobes?

The cam is setup front to back as E5-E1-I5-I1. Are you sure you are on the correct lobes?

Forgive me for asking but the basics have to be correct before going deeper.

Respectfully,Oldmics

Ok, yes I understand.  Thanks!

Mike, located in the Siskiyou mountains, Southern, OR 292 powered 1946 Ford 1/2 ton, '62 Mercury Meteor, '55 Country Squire (parting out), '64 Falcon, '54 Ford 600 tractor.

The lash affects when the valve actually opens.  If, for instance, the intake lash was to be set at .015 instead of .020, the valve would open earlier and close later, giving a reading of more duration.  If the lash were set looser, the valve would open later and close earlier, therefore giving a shorter duration figure.  Does this make sense to you?

What I'm trying to say is that maybe he intake lash should be around .016 and the exhaust around .020, giving a duration of around 272, which wouldn't be all that unusual.  Crane used to grind cams with "odd" durations, I think the one I'm running now has an intake advertised duration of 292 and exhaust 302.

John - "The Hoosier Hurricane"

I set it up and redid the measurements.  The intake was basically the same.  Exhaust was some different, and as for the last figure, I must have misread the wheel first time around:

Intake lobe lift .291

          .020 ope at 19 BTDC

           .050 open 3.5 BTDC

           .050 closed 45 ABDC

           .020 closed 63 ABDC

Exhaust lobe lift .294

            .020 open 69.5 BBDC

            .050 open 49.5 BBDC

            .050 closed .5 BTDC

            .020 closed 27 ATDC 

262/276 cam.  Weird.

.050 Durations are almost the same.  228.5 and 229 .                                                                                    

           

Mike, located in the Siskiyou mountains, Southern, OR 292 powered 1946 Ford 1/2 ton, '62 Mercury Meteor, '55 Country Squire (parting out), '64 Falcon, '54 Ford 600 tractor.

John, this probably is a dumb question, but what is meant by "If .020 is close to operating clearance"?  It sounds like you dont think the figures add up, and I agree a 261/273 duration cam is a surprise.  Maybe this evening I can do the measurements again.

Mike, located in the Siskiyou mountains, Southern, OR 292 powered 1946 Ford 1/2 ton, '62 Mercury Meteor, '55 Country Squire (parting out), '64 Falcon, '54 Ford 600 tractor.

If .020 is close to operating clearance, advertised duration on the intake would be 261 and the exhaust 273.  Cams of that era were seldom dual pattern, so I would surmise that the intake clearance would be less than the exhaust and the advertised duration to be in the 270 area.  These figures come from the .020 opening degrees plus the closing degrees plus 180.

John - "The Hoosier Hurricane"