comp 262 vs 268

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dodgethis12

dodgethis12

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In layman's terms can someone explain to me the difference between the comp cams extreme energy 262 vs the 268? In terms of power band, idle, performance, etc.... (I have been recommended both by experts, but cant decide)

Subject in question is 70 318 that will have a performer intake, 600 eddelbrock carb, headers and 2.5" x pipe exhaust.

thanks guys
 
The 262 will have a smoother idle and more low end torque than the 268. The 268 will require a lower gear ratio out back and a higher stall converter if it is an automatic. If it is for street use go with the smaller cam.
 
They are pretty similar so it's more of a case of which will work better with what you're not changing. The 262 is slightly shorter duration and lift, which will tend to idle cleaner with more vacuum, and start making power earlier regardless of the pistons or static compression. If you have stock parts, you have a lower static than the books suggest and the 262 will be "more forgiving" than the 268. Teh 268 will make more power, obviously bigger means more power. But the drivability may be compromised where the 262 will be almost as strong, but more drivable in a stock longblock.
 
So the 268 will have less power than the 262 in my otherwise stock longblock and 904? I do plan on adding a shift kit, but dont plan on removing the trans or engine right now... so the stock converter will stay!
 
No. That's not what I said. I said the 268 will not be as well mannered as the 262 in your stock original 318. The 268 will make more power, but it will need a convertor and a little gear before it's as drivable as the 262 would be.
 
will the 262 be more fuel efficient since I am leaning towards ordering one soon?
 
I love my XE268 cam in my similar 318 build, with a 2500 stall TC and at the moment, 3.23 gears in my Duster. Decent torque, runs 14s.
 
With a 2500 stall (now considering) , shift kit, 391's, and a small amount of ..... spray... high 12's?? That is if I didnt scatter the bottom end of the little 318!
 
I think overall the 262 would be more efficient as the car currently sits. He said 14s... not 12s. You could get a 318 to run that fast. But you'll need to do a lot more than a cam swap.
 
pre...73? (guessing) 318's have a smaller rod than later years correct? Im just wondering how much abuse this bottom end can take and still live a relatively problem free life... 350 Hp? I dont know..... (assuming that its in good condition now as it sits)
 
You can beat the tar out of it if it's healthy. No difference in rods except for pre '71 IIRC have full floating pins like the 340s and 273s. I ran a '74 witha stick and NOS for a while. That was at least 400hp with the bottle open. All stock, never even looked at the lower end.
 
dodgethis12 said:
With a 2500 stall (now considering) , shift kit, 391's, and a small amount of ..... spray... high 12's?? That is if I didnt scatter the bottom end of the little 318!
Click to expand...

I suppose with a 100 shot of nitrous and 3.91 to 4.11 gears, bottom 13's or high 12's are remotely possible, considering the bottom end is healthy. If so, it should hold together.

I am running 14.4-14.5 currently, with my 3.21 gear setup.
 
On an otherwise stock 318, you will be happier with the 262. Given your stock compression ratio, low RPM cylinder pressure will suffer with the larger cam. So then will low RPM torque and throttle response.

I'd run the 262 with anything less than 9:1 actual compression ratio.

The bottom end of your engine, so long as it is in good condition will easily handle any amount of power you'll make with either cam, a Performer, 600 CFM carb and headers.
 
dodgethis12 said:
With a 2500 stall (now considering) , shift kit, 391's, and a small amount of ..... spray... high 12's?? That is if I didnt scatter the bottom end of the little 318!
Click to expand...

Now you are going to the opposite end of the spectrum - the above setup is WAY different than your original question implied - what do you want from this car, daily drive-ability and manners or high 12s? 3.91 gears and a 3-speed are not going to be freeway-friendly at all, regardless of stall speed

Besides, all this talk is academic until you run a compression/leakdown test, IMO, cause the heads are just as much an unknown as piston vol, cyl pressure & ring seal

Sorry if this comes off heavy
 
Yea... I know... I probably should just leave it alone for now. Too bad I cant run 13's and DD it on the cheap at the same time, but thats not gonna happen with a 80 mile per day commute!
 
Ill probably just go with a carb, intake, 262 cam, exhaust and some 3.23's for now.
 
dodgethis12 said:
Ill probably just go with a carb, intake, 262 cam, exhaust and some 3.23's for now.
Click to expand...

Do yourself a favor and run a compression test on all 8 cyls. Disconnect the coil, pull and label all plugs and check cranking compression. While you are at it take a good look at the plugs and note gap of each.

This way you get a picture of HOW your engine is running
 
Comp cams says the 268 is the biggest cam for use with a stock converter..my buddy runs it in his "smog" 318 with a pair of small valve j-heads,dual-plane intake,headers and 3.91's car goes pretty good for what it is..
 
dodgethis12 said:
So the 268 will have less power than the 262 in my otherwise stock longblock and 904? I do plan on adding a shift kit, but dont plan on removing the trans or engine right now... so the stock converter will stay!
Click to expand...

Just a thought...if you have power brakes...the bigger the cam ...the less vacuum idling in gear which affects brakes.
 
nope... I've got the highly prized sucky manual drums... (I'd be willing to let them go for the right price!)
 
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