[TedRamAirII]

I had a HE268 in a 67 400 GTO. Pulled hard, until 5K rpm, then its done.

[gto19]

Originally Posted by TedRamAirII

I had a HE268 in a 67 400 GTO. Pulled hard, until 5K rpm, then its done.

Did you mean XE 268 ?

[TedRamAirII]

Originally Posted by gto19

Did you mean XE 268 ?

High Energy 268. I think it was a .450 lift? this was 35 years ago.

[77 TRASHCAN]

Originally Posted by TedRamAirII

High Energy 268. I think it was a .450 lift? this was 35 years ago.

35 years ago cam selection for a street car were thin. Compression ratios had been low since 71 and got ridiculous low in the mid 70's and on. Comp came out with their High Energy cams some time in the 80's (I believe....).

Their High Energy cams became a hit with street driven vehicles, making a huge difference in performance. I sold a few Chevy versions and some Pontiac's as well. Everyone enjoyed how they performed.

My buddy had a 66 Chevy C 10 pickup. Our mutual friend engine builder built a 400 small block for him. Had a 268H cam, early performer intake, 3310 Holley 750 carb. Slightly modified stock 441 iron Chevy heads (I say slightly, the builder was serious about where to grind and where NOT to grind. Grind in one wrong spot, and you've just screwed everything up...), 1-1/2 O.D. headers (sounds small LOL). A 3.42 posi rear end from a later Chevy 4X4 pickup, and a Muncie M20. Compression ratio was approximately 9:1, builder was a little afraid it was a fuzz too high, for a heavy pickup (it was not).
The 406 belted out 300HP and 400 ft/lb torque. THe number sound lame, but were SAE Net numbers, nothing added to fluff anything up. The builder always used these numbers on any build.

My buddy is about 75 years old now, and in poor health. That old Chevy pickup was bad ass. he never, so called, raced anyone, but stop light challenged many of the wanna be Hot Rodders in town, NEVER lost to one...

Point being, High Energy Comp Cams are still made but ARE NOT the same the their currently touted "modern" XE cams

[pastry_chef]

Originally Posted by 77 TRASHCAN

Point being, High Energy Comp Cams are still made but ARE NOT the same the their currently touted "modern" XE cams

The Comp catalogue says they are different.
Different applications have different requirements.
You probably would say an 'HE' would always perform better than the 'XE', that is false.
A SBC with a modern 195 AFR head (275 CFM through a 2.05 valve) would enjoy the XE or even more aggressive, a Pontiac d-port flowing 260 CFM or less through a 2.11 valve lesser so in general. Piston speed is also a major consideration.

[77 TRASHCAN]

Originally Posted by pastry_chef

The Comp catalogue says they are different.
Different applications have different requirements.
You probably would say an 'HE' would always perform better than the 'XE', that is false.
A SBC with a modern 195 AFR head (275 CFM through a 2.05 valve) would enjoy the XE or even more aggressive, a Pontiac d-port flowing 260 CFM or less through a 2.11 valve lesser so in general. Piston speed is also a major consideration.

My point was for folks new to the hobby, to not assume that the XE was the newest version of the HE cams, possibly replacing the HE cams.