I'm confused!

New cam, new chain, installed straight up and checked at the lifter. TDC determined with positive stop method.

Timing card says; 6 - 42 intake, 42 - 6 exhaust,  228 deg duration @ .050",  112 lobe center.

         I get;        7 - 40 intake, 51 - (5) exhaust. (That's -5 or 5 BTDC.)  

I don't understand what's going on. Is this cam junk? What performance can I expect if I leave it alone? Does it need to be retarded? Has any one else had issues with Isky cams? Thanks.

FIGHT CONFORMITY! 

Well, with all the tolerances between the cam, crank, and timing set, it's very unlikely that a cam installed in the "straight up" position is actually straight up. That's why it's smart to degree the cam as you have done. So the fact that it doesn't match in that respect should not be a concern as long as it's reasonably close.

I don't know if the variance in the measured cam timing vs that stated is something to be worried about. Check one or two other lobes to see how they compare.


Lawrenceville, GA

I say close enough.

The real question is where are you going to put it at?

Oldmics

The cam card is wrong. The figures it quotes come out to a 108 degree lobe separation while the RPM-300 is supposed to be 112. What you've measured is 113 lobe separation advanced 5 degrees. I have no idea where the Isky intends for the cam to land if installed straight-up but advanced 5 is probably fine.

http://ford-y-block.com 

20 miles east of San Diego, 20 miles north of Mexico

That is a bummer.  I had similar problems degreeing in a new Isky E-4 close to this time last year.  Figured it was me.  Did it multiple times, and finally put it at my best guess of 3 degrees advanced.  Had one of the nice big degree wheels too.

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.

Checking a camshaft using the opening / closing specs on the supplied card will typically give some discrepancies when compared to the cam card for a variety of reasons.  For most camshafts, measuring cam timing using the lobe centerline method is more desirable than by checking against the opening and closing events.  If a camshaft is simply being installed by aligning the dots or counting the link pins, it’s not being installed straight up but simply being installed.  A camshaft being installed straightup references a camshaft being installed on its ground lobe centerline and this can only be done if the camshaft is being degreed in.  If a camshaft is ground on 110° lobe centerline then for this cam to be installed straight up, the intake and exhaust lobe centerlines will each be at 110° from TDC.  If the camshaft is installed 2° advanced, then the intake lobe centerline will be 108° from TDC while the exhaust lobe centerline will be 112° from TDC.

 

When degreeing in the camshaft be sure to also move the dial indicator over to the #6 cylinder and verify that it's reading the same as #1.  The #1 and #6 cylinders share the same TDC so this is relatively easy and doesn't require readjusting the degree wheel.  If you don't get similar results between these two cylinders, then you'll need to check every cylinder and then determine if you want to replace the camshaft with another.  Just degreeing in the camshaft in on the #1 cylinder and assuming all is good will not rule out a mis-ground shaft or sloppy grinding on the part of the camshaft manufacturer.  There are some brands that I will simply not use due to the lobe variances seen between the cylinders.  It's one thing for the camshaft to not agree with the specs and completely another for all the lobes to be inconsistent when compared against each other.

 

And here’s a past thread delving into some of the timing chain nuances and other things related to camshaft timing.

http://www.y-blocksforever.com/forums/Topic27991-3-2.aspx

Lorena, Texas (South of Waco)

I spoke to Ron Iskenderian, He said the same thing and was suppose to email the correct timing specs, he didn't. Went to their site and found it; 112, 2-46 46-2 @ .050". OK, so that makes more sense now. 5 deg seems like a lot to compensate for chain streach though. Lost some faith in Isky....Looked at Comp Cams 'thumpr' series for Y-Blocks, but even the mildest one seems too radical for the street; 14-37 55-10, 231 and 245 dur. @ .050". .319 and .313 lobe lift, 107 LCA, 102 IN centerline. Is this just a "noise-maker" cam? Has anyone tried one or offer any advice on it? Thanks.

FIGHT CONFORMITY! 

Like John, I get 5½° camshaft advance based on the numbers you posted.  This is a good place to leave it as chain stretch in extreme cases will take up 6° or more.  If your camshaft had been installed at 112° intake lobe centerline, then it would have only retarded further from that point on as you put the miles on it and performance as well as fuel economy would be slowly degrading.

Lorena, Texas (South of Waco)

Ted, I posted that last reply before I read yours. Thanks.

I did check #6 EX and it matched #1, I'll also check the IN and a few other, or maybe all cylinders. YES, "just installed". This is the first time I've tried to degree a cam and I'm very glad did. I learned from your link that the chain set is more likely to blame for the discrepancy! What do you think of that Crower anyway? 

FIGHT CONFORMITY! 

I meant to say "Comp Thumpr" not Crower! I'm a nervous wreck!

FIGHT CONFORMITY!