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Old 09-11-2014, 07:06 PM
blykins blykins is offline
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Cam is degreed...

Cam thrust clearance is checked...

Piston to valve clearance is checked...



Look at where the crank gear ended up....



I degreed this thing about 4 times, using both methods. The cam card says that it's a 112 LSA on a 108 LSA. I initially wanted the ICL on a 106, so in preparation for degreeing, I went ahead and put the crank gear on the 2°A keyway. To my surprise, when I degreed it the first time, it came up with a 112 ICL.

Thinking the lobes may have been asymmetric, I checked it with the valve event method and came up with the same results.

So, I checked TDC again, and then degreed one more time. Same thing.

Since I was on a 2°A key way anyway and was still at a 112° ICL, I went straight to the 8°A key way and gave her a shot. Came in at 105.25° with the ICL method, checked exhaust at 118° and that verified the LSA at 111.6°.

Checked it all again with valve event method, threw the numbers in some cam software, and came up with 112 LSA and a 106 ICL. Bingo.

Checked .050" duration on the intake side, then checked lobe lift. Should be a .440/.440 lobe lift, but got .438/.436.

And that, my friends, is why you always measure and double check everything yourself. You could also see why one engine could perform better than another. When I was in high school, a couple buddies had some Z28 Camaros. The cars were essentially identical, but one would walk the dog on the other. This is why....there are tolerances and variations on every part, and this is what separates a custom engine from a factory engine or a crate engine. You figure out where you want the specs, then you measure, and make them go where you want.

After that fiasco, I went ahead and checked piston/wall clearance and was glad I did...coming up with .005" and the Diamond card says we need .0065" with the coated skirts. So.....dropping the block back off tomorrow to let him double check me, then hone a little out of it.

Planning to drop the rotating assembly off the beginning of next week to have the rod journals massaged and everything balanced.
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Last edited by blykins; 09-11-2014 at 07:10 PM..
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