Ive got a quick camshaft question that is driving me crazy and holding up my motor progress. Last year i ran the Comp cams extreme energy 268/280 duration .477/.480 hydrolic camshaft....and i had to grind my connecting rods in places for the cam to clear. This year i got new vortec heads, and i want to put in a comp cams extreme energy 284/296 duration .507/.510 lift hydrolic camshaft. I have heard that once you grind your rods once you dont have to do it again... is this true? I realize the cam cant get that much bigger cause it wouldnt fit through the opening to get the camshaft in the motor..... any ideas guys?

 

Dummy it up and see... odds are it will be OK, but if it isn't, you don't want to find out after everything is already built.

 

well assuming both cams have the same base circle, the old cam had a lift of .32" and the new cam has a life of .34" so thats 2 thousands difference.

But as RB said, theres no sure way of telling without mocking it up. A alittle extra time spent now is better than a rebuild later

 

yeah.... true i was just trying to decide whether or not it would be worth spending the extra money on a small base circle cam or not. i think i will just get a reg one and if i have to grind a little more on the rods. Thanks guys

 

Scottland- Your math terminology is a little off...The difference would be 20 thousandths, or two hundredths. (about the thickness of a paper clip.)

 

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I knew that didn't look right. thx for catching the slip up

 

so if the old cam cleared with no problems and i already have all the pistons and rods out i should just go ahead and grind a little more off every rod where i ground them before and stick them in one at a time with the cam in and see what happens. A paperclip dosent seem like too much but it only takes a little bit

 

i wouldn't go to the trouble of grinding them first, but yep, test fit them each one at a time with the cam installed, and turn the crank to check for clearnence.