Packard Forum Index » V-8 (1955-56)

Hi, Craig,

Again, interesting stuff. Am still trying to understand how, with more camshaft duration, the 348" has higher volumetric efficiency than the Packard at the lower RPMs. I would have expected the Packard's shorter cam to have more V/E below the torque peak and the Chev to have more V/E above the horsepower peak. Your thoughts?
Quote: BTW, I had Iskenderian check an OEM '56 Packard V8 cam on their CamDoctor computerized machine. It came out dead nuts on the advertised numbers you used.

thnx, jack vines

Jack,

I think the unexpected difference is due to the way Dyno2K emulates camshaft ramp profiles when given 0.050 duration numbers. For instance, if I put the Packard 6480561 cam profile in the 348, it produces almost the same VE numbers (69.4@2000 and 77.1@4000) for the 348 as the 352.

As for the Isky CamDoctor, the duration was measured at what lift?

I've found that Dyno2K does OK with stock ramp profiles and hydraulic tappet, but requires solid flat tappet to get close on the aftermarket agressive ramp profiles.

Craig

IIRC, seat-to-seat is at .002" and of course, .050" is what it is, 185 intake, 180 exhaust. Is this what you are using?

thnx, jack vines

Leave it to those Ford guys to say nice things about the Packard V8, and incidently how GM's bb was related to it:

Find the original post at

ford-trucks.com/forums/74161-500-cid-lincoln-y-block-for-53-56-f100.html


Quote:

That is beyond clueless with his "facts"; even has the Daytona dates wrong and certainly had never even seen a photo of a Packard V8 valve train. However, like the old broad in the dark bar, it's still a compliment, even if liquor is involved.

thnx, jack vines

Thanks for your reply, Jack. (I just quoted you on the 'Build Codes' thread from an old AACA post on Packard racing. Hope you don't mind.)

It's always "buyer beware" on info found in posts, and this poster didn't back it up with any proof, but he was not a newbe on the board, having over 2000 posts. I'm not saying that makes him right, be it does lend a little credibility.

It would seem to be verifiable if GM bought a patent or licensed a design for heads from Packard. Whether that resulted in the 'porcupine head" engine--which did exist for a short time (too many cubes and the 400 ci limit probably killed it)--is another matter. Anyone know the similarities/differences between heads on the Packard and BB Chevy?

Craig seemed to have lots of info on early Chev BB.

That we love Packards shouldn't blind us to history and fact.

1. There is no reason GM would have wanted any head technology from Packard. The Packard head was completely conventional, exactly like what GM had been building since '49 with Cadillac and Oldsmobile as was Studebaker since '51. I've never seen any reliable information to the contrary.
2. The GM canted valve/semi-hemi head design was developed in-house in the late '50s and first used on the W-engine platform in the '63 Daytona race. In '65 it was put into production on the new big-block 396", which ultimately was built in 366", 402", 427", 454", 502" and 572" engines.

Bottom line, the Packard V8 broke absolutely no new ground technologically. It had its' good and bad points, but basically was just an up-sized first-generation Kettering V8 and obsolescent when it was introduced.

thnx, jack vines

I think Jack sums it up quite eloquently. As to the statement about licensing technology from Packard, I've spent a bit of time reviewing Packards patents but haven't seen any that deal with the V8 engines, if in fact there were any. I rather doubt there was anything significant in the V8 that was patentable - to be so it would have to have been something new, novel and useful and not obvious to one skilled in the art, and there is certainly nothing like that in the Packard V8 that is apparent to me.

Even if their early (starting in 1954) toying around with fuel injection for the V8 had come to fruition (which apparently was pretty much a disaster, as were Chrysler's early attempts as well), they were using the technology of others, primarily American Bosch but also Lucas, Simmonds and Bendix. But it wasn't "their" technology. Who knows, maybe this was the reason for the high performance build sheet code, assigned prematurely and aborted. Along the line of that other thread, that Packard built special "pursuit" cars? Come on now, you'd think something would have surfaced in the past 50+ years. They could barely build what the already had on their plate.

As an aside, I'm only aware of the one photo many of us have probably seen of the FI installation on a v8 (the one published in Hemmings "Packard" book of past drive-reports). Does anyone have others? Or other bona fide Packard references to the system they tried to develop? it would make interesting reading.

A while back I read a magazine interview with a Mr. McKellar who was in charge of designing the Pontiac V8. One of the questions they asked was whether the rumor was true, that the Pontiac head was copied off the Packard or vice versa?

He replied that at the time they were working on the new design a machine tool supplier offered them a new type of head machining facility that gave a distinctive look to the head, how it differed from the conventional head he did not state.

He assumed since Packard was working on their engine at the same time they probably bought their tooling from the same supplier and that would account for the resemblance.

One difference was that Pontiac had 4 head bolts surrounding each cylinder where Packard had 5. This argues for a different design approach from the very beginning and means it is practically impossible that one influenced the other.

When you look at the big block Chev 396 or 454 head has anyone noticed that it is the same as a Chrysler Polysphere? Both are an effort to get the advantages of a hemi head in a simpler lighter package. The biggest difference is the typical cheap stamped tin Chev rocker arms used on the Chev. Plus the fact that Chrysler was dropping this design (1966) just as Chev was picking it up (1965).

Geez, how many disclaimers do I have to put on a post without it resulting in all this scolding? I mean, I cited the source as a post ("buyer beware") and only continued on the what-if idea to stimulate some "interesting reading" like Owen points out could be the result. If there isn't someone saying "what if" there are a whole lot of discoveries that won't be made, like "what if" the earth was not the center of the universe?

I was hoping, also, that Craig, who has a lot of info and even a cutaway diagram of the old "W" Chevy, and may have more on the later BB would chime in here. Not that input is not welcome from everyone.

It's just that speculation that is not presented as fact should rightly be accepted as such--speculation, and even contrary speculation is still just speculation without some backing information.

Quote:
I agree you'd think, but can we all be positive that nothing has, or nothing remains to be surfaced?