How much cam for a 265 SBC Gen 1?
 

I'm attempting to build a Gen 1 SBC 265 for a 56 Sedan Delivery, 4 Bbl. How much cam fits the power pac heads and 4 Bbl cast iron intake to work for a stocker? I'm no veteran at this stuff.

Re: How much cam for a 265 SBC Gen 1?
 

Best bet is to contact a Cam company. For a Stocker your limited to stock lift but you can do what you want with all other spec's. Cam company will help you work within rules.

Re: How much cam for a 265 SBC Gen 1?
 

Jere Stahl

Re: How much cam for a 265 SBC Gen 1?
 

I'd call Marv Ripes. Haven't seen him in years but I think he is still running A1.

Re: How much cam for a 265 SBC Gen 1?
 

I would suggest calling Carl Downard in Idaho as he just built one and ran some different cams on the Dyno I believe. I know he said since the 55 265 ci does not have any piston valve reliefs you will be limited on duration.

Re: How much cam for a 265 SBC Gen 1?
 

assuming this is a class stocker...the original '55 and '56 265 pistons do not have valve reliefs. the pistons are flat. however, if you are going to an overbore, you will not find 'replacement' pistons which do not have four reliefs. real race pistons can be had with only two reliefs.
'55 and '56 heads had the plug way back in a notch, the chambers were small, but the valves were further away from the piston at TDC, than later model heads. power pac heads had a a smaller CC chamber than the 2V heads, which raised the compression. stock class cams had less than .400" intake lift. you will not have any problems with a true flat top piston.
if this is NOT a class legal car, and you have notched pistons, you can run a fair amount of lift .480 or more, as long as you stay with the 1.75" intake. with a 60 overbore and a deep notch you can run a .570 lift with a 1.94" intake. a 1.6" exhaust valve will also clear the bore. however a 2.02" intake will hit the bore with anything more that a .500" in a 462/492 style head.
put your cyl. head on the block with the piston at TDC, pull the spring off the intake and drop the valve down and use a caliper to get a close measurement.
rod in AZ

Re: How much cam for a 265 SBC Gen 1?
 

I would check with a soft spring and open valve to max lift then add feeler gauges to be sure I had at least .050 clearance between valve and cylinder.
Piston to valve clearance will be closest about 10 btdc and 10 atdc depending on lobe sep.,centerline,duration.
A easy way to remember is piston chases ex valve closed and in valve chases the piston down @ their closest points.
If this is a stocker the valve to cylinder should'nt be a issue,but piston to valve clearance will be.
Mike Taylor 3601