[Cliff R]

"The 244/252 cam against the Old Faithful cam looks to be just a mismatch of appropriate parts. It wasn't the LSA's fault, but possibly could be running out of valve spring, too aggressive of a lobe, or the duration did not match the cylinder heads/intake."

Not so. Actually that cam was supplied by one of the biggest Pontiac engine building shops in this industry to replace the OF cam at much less cost. It did OK, but came up WAY short of the OF cam at every rpm.

The last one of those engines we dyno'd made 552hp/604tq and over 500 ft lbs torque across the entire load/speed range. The ONLY real difference was the camshaft.

The flat solid had PLENTY of spring pressure, same springs we use for the OF and RP roller cams, and it never showed any signs of "lifter crash" like the Comp XE cams do around 5000-5200 rpms.

On paper it's a bigger cam in terms of .050" seat timing. The engine didn't see it that way, and the 110LSA pulled power down in the rpm range.

As far as experimenting with camshafts, I've done a LOT of it, even tested a custom ground HR recently ground on a 111LSA with "better" lobes than Dave uses for the OF cam. It actually did very well, and made the power we were looking for, but showed NOTHING better anyplace than the "lazier" lobes the OF cam uses and wider LSA.

All of my full drag race and circle track stuff in other brands than Pontiac are super tight LSA with few exceptions. I also pull the LSA down in the 3.75" and 4" stroke engines in most cases. With the 4.21, 4.25, and 4.5" stroke Pontiac builds and big CID in street applications we go the other direction. The biggest reason is that it allows for higher compression on pump gas, as it spread out the torque curve instead of narrowing it up. It also pushes peak torque and HP higher in the rpms range, where the events happen quicker and less tendency to ping on lower octane.

Brent, I wished you could have been here the day a customer brought his very well prepared 455 Super Duty engine to our shop for "custom" tuning. He had a TON of money in the build, 9.5 to 1 compression, and XR276HR cam. That engine acted like 12 to 1 compression and POUNDED like sledgehammers with normal timing/fuel curves in it. I've never seen anything like it, had to limit total timing to 26 degrees to get it to quit pounding and really throw some fuel at it. It wouldn't even take 8 degrees from the vacuum unit at cruise or it pinged pretty hard. Without high octane race gas it was a complete TURD everyplace, and we couldn't "crutch" it with any sort of tuning.

About all I could do is install a set of Harland Sharp 1.65 rockers which helped some (acts like a small cam change), but it still wasn't going to effective manage pump gas.

I'd also add that that cam idled like shi#, and noticeable "reversion" around 1800-2000rpms, where the engine kicked and bucked in protest to the early closing intake and tight LSA. I've ran into that a LOT with the longer stroke stuff, and don't know why it happens, but when we run into this it is ALWAYS with 108/110LSA. Our 112/114 cams idle really nice, and smooth off idle and for all "normal" driving.

Anyhow, we're pretty much done here with engine building, at most 1-2 a year these days. They just don't ship in a 12 x 12 x 12 box like a carburetor does!........Cliff