Originally Posted by GMC boogie
SBC hydraulic roller. Valve events at .050 listed on cam card:
IO 8º BTDC
IC 40º ABDC
EO 48º BBDC
EC 0º ATDC
IO 7º BTDC
IC 46º ABDC
EO 47º BBDC
EC 6º ATDC
Another thing, This is suppose to be a 228/228 duration at .050 cam. It measures 233 on both the intake and exhaust. What is the deal with that?
Specs on cam is 228/228 at .050 280/280 at .006 110LSA 4º advance. install intake lobe to 106º centerline.
Also done the Intake centerline method and got 109º which tells me I need to advance the cam 3º to put it at 106
I am very confident I have found true TDC. I am using a fixture that fits in the lifter bore with indicator that reads directly off the lobe for the degreeing process.
Sounds about right? Who makes the cam. It is not uncommon for cams to be way out of spec. I like to map out the cams to be sure i got what i purchased. One wrong stamping and your cam might not even be the one you purchased.
Some manufactures are really bad with cam grinds. A lot of ppl like isky but never mapped on myself so cant tell either way. If the cam is ground in house or a regrind it may not be done on equipment that can make those types of cuts. Sometimes cam mfr. Dont let stuff like that get in the way of the sales pitch.