Hello all!!! Been a member here for a bit and this is my first post!!! I've "exhausted" my patience.. I am trying to identify a camshaft I pulled from my 350 SBC... Numbers read 7274WB... I've Googled and Googled for 3 days now and can't find a thing on it... So, I am now measuring the lobes to figure out the exhaust and intake lift. My problem is I don't know which lobe is which... I've also tried to find diagrams but to no avail... This is my first time pulling a cam so please be nice, i'm trying to learn as much as possible so any information would be grateful. Block casting info is 10243880, the stamped numbers are gone to the block being decked...
I was able to find that out, althoughhhh I pulled a hydraulic flat tapped cam out of this thing. I did read that these casting numbers come up frequently as crate motors. I bought it 10+ years ago and it sat for that long with about 500 miles on it. I was told that it was purchased as a crate motor but no way to verify that.
but seriously...you took the cam out, but you can't figure out which lobe is which? Hint: look at the head, you should be able to figure out which ports go to the intake, and which go to the exhaust. Then look at the offset of the heads on the block, you'll see that the driver side head (cylinders 1,3,5,7) is forward just a bit of the pass side head. But that it's about half as far forward, as the valves are spaced apart. So...two exhaust valves, four intake valves, four exhaust valves, four intake valves, two exhaust valves. edit: Like he said. also, they used roller capable blocks for lots of low perf TBI engines that had flat tappet cams
Perfect! Now I can determine which is which! I have a feeling that I wore down a lobe or two on my current cam.. Several valve adjustments and this tick/clack never went away. #1 cyl was also misfiring... Hopefully this does the trick! Thank you for the input.
From what I saw online, two other threads asking about "7274WB" cam number seemed to indicate 1974- 1980's smog GM truck engine. A tick or clack noise can also be a sticking or worn lifter that won't pump up, slightly bent pushrod, or sticking valve. Sometimes slight exhaust gasket leaks get mistaken for valve noise. Point is: Who cares, that cam is nothing special, probably a stocker, new Chevy cams are so cheap (as low as $48.99 from Summit) I wouldn't consider reusing it, get a new cam and lifter set and move on. Main thing pulling out tha camshaft is: if you hope to reuse the bearings be real careful not to nick or gouge the cam bearings you got in there as the cam is slid out. That turns a cam swap into an engine pull real fast. Nice avatar car! by the way...
After measuring the cam I decided to go with a basic replacement from Summit... new lifters and a gasket set. Hopefully it goes in as smoothly as it came out! Thank you on the photo.. That's my old gal... 54' 210 picture was taken at Fiesta Island in San Diego.
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