How much cam for a 265 SBC Gen 1?

wheezer · 10-30-2012, 10:21 PM

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.

Terry Cain · 10-31-2012, 08:52 AM

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.

Dan Lattimore · 10-31-2012, 10:46 AM

Jere Stahl

kansas stocker · 10-31-2012, 03:16 PM

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

Jim Parsons · 10-31-2012, 05:58 PM

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.

rod · 11-02-2012, 07:19 PM

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

Mike Taylor 3601 · 11-02-2012, 08:51 PM

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

10-30-2012, 10:21 PM	#1
wheezer Junior Member Join Date: Sep 2009 Location: Dallas/FtWorth Posts: 13 Likes: 0 Liked 0 Times in 0 Posts	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.

10-31-2012, 08:52 AM	#2
Terry Cain Senior Member Join Date: Feb 2008 Location: Georgetown, Indiana (close to Louisville, KY) Posts: 774 Likes: 530 Liked 230 Times in 106 Posts	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. __________________ Terry Cain ???? STK tcain19689585@gmail.com

10-31-2012, 10:46 AM	#3
Dan Lattimore Member Join Date: Jan 2003 Location: Beaverdam, Va./ Port St. Lucie,Fla. Posts: 362 Likes: 177 Liked 154 Times in 37 Posts	Re: How much cam for a 265 SBC Gen 1? Jere Stahl __________________ 66W30POST

10-31-2012, 03:16 PM	#4
kansas stocker Member Join Date: Oct 2002 Location: kansas Posts: 235 Likes: 491 Liked 249 Times in 48 Posts	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.

10-31-2012, 05:58 PM	#5
Jim Parsons Member Join Date: Feb 2002 Location: Kearney Mo Posts: 197 Likes: 412 Liked 195 Times in 30 Posts	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.

11-02-2012, 07:19 PM	#6
rod Member Join Date: Dec 2009 Location: Kingman, NW AZ. in the middle of the longest stretch of Route 66 Posts: 313 Likes: 0 Liked 20 Times in 15 Posts	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

11-02-2012, 08:51 PM	#7
Mike Taylor 3601 VIP Member Join Date: Oct 2008 Location: Somerset,Ky Posts: 1,362 Likes: 337 Liked 279 Times in 96 Posts	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