Re: The Second Packard "Twin Six"
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Forum Ambassador
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John, I read that excellent article and I was quite impressed. I realize that it was written primarily from an American perspective emphasizing the use of the Packard built engines in the P51 Mustang. Perhaps many of the readers are unaware that the Merlin engine was used in a wide variety of allied aircraft including the British and Canadian Lancaster, Halifax, Battles and Mosquito bombers as well as the Spitfire and Hurricane fighters . Another bit of Merlin history often omitted was that Ford of England also made several modifications to the Rolls-Royce engine enabling it to be mass produced in England. The Ford plant at Manchester was able to manufacture 400 engines per week as a result of the modifications they made.
At the Rolls-Royce plant at Derby is a statue of a young pilot and the following inscription; 'To the pilots of the RAF who, in the Battle of Britain, turned the work of our hands into the salvation of our country.'
Posted on: 2008/9/22 12:47
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Re: The Second Packard "Twin Six"
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Home away from home
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Owen,
Thanks for the extra shot of the blueprint, with piston at TDC. I guessed right on what the cross-section of the compression chamber would look like: a triangle instead of a true wedge, with one side of the triangle being the face of the intake valve. Is there any other engine out there that used this design? It looks like it would not only be "free breathing" but would also set up a heck of a swirl for the intake mixture. It would be highly unlikely we'd have anything like this ever mass produced except for those crazy multi-cylinder "wars" of the '30s. Was that ever the wrong timing for the economic conditions. Maybe Cadillac put out the V16 just to try to run some of the independents out of business playing "catch-up." I wouldn't put it past them. Somewhere around here I have a blueprint of the '55 V8, and will post a link if and when I find it. FOUND IT! packardinfo.com/xoops/html/modules/myalbum/photo.php?lid=2351&cid=57 Don't know why it'll only print the link, though. Little help here? Anyway I posted it in Packard Pictures and it probably should go in one of the more techical sections of the forum.
Posted on: 2008/9/22 21:29
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Guy
[b]Not an Expert[/ |
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Re: The Second Packard "Twin Six"
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Quite a regular
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As you point out, getting a good "swirl" in the combustion chamber is vital. Obviously, Packard understood this, but knew this WAY before Packard engineers laid out its automotive V-12 introduced in the fall of 1931.
Packard correctly believed that given the fuel/compression ratios of the day, and given the primary uses of its products, there was no advantage to its customers, to the additional cost & complexity of over-head valves or cams for its automotive products. As noted earlier, Packard was a pioneer in the mass-production of high-performance concepts such as over-head valves, cams, superchargers, and cross-flow heads (see the "Liberty" engine Packard designed during World War one). Its commercial and aviation division products saw these concepts; again, it saw no advantage to its customers to put them to use in its automotive line. As I suggested earlier, my belief is had Packard felt there was a market for a car in the Duesenburg price range, I suspect you would have seen the above "exotic" engine design features, in a reliable engine that would reflect traditional Packard philosophy - translation - would have blown the doors off the Dusie ! In answer to your question about combustion chambers - as for making the angle between the bores and the top of the block different from 90 degrees, GM tried that in some of its high performance engines many many years later. Sure it works to improve power/effiency, but adds to cost from both a manufacture, production, and maintaince standpoint. I am not aware of any mass-produced automotive engine utilzing that these days. I note some confusion over "who designed the Packard V-12". Some of the confusion stems from the obvious fact that the so called 'Van Ranst' Packard had front wheel drive, and a much smaller displacement version of the Packard V-12. But that was a drive-line issue; not a power-plant issue. With this qualifcation. Somewhere I read that Packard did NOT design the valve lifter set-up; read somewhere they had to pay royalties to use the system in the Packard V-12. Simply put, the Packard V-12 does NOT have hydraulic valve lifters, at least not in the conventional sense. They are SOLID lifters with an "off-center cam lash take-up". Big difference.
Posted on: 2008/9/22 22:00
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Re: The Second Packard "Twin Six"
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Home away from home
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Quote:
As I suggested earlier, my belief is had Packard felt there was a market for a car in the Duesenburg price range, I suspect you would have seen the above "exotic" engine design features, in a reliable engine that would reflect traditional Packard philosophy - translation - would have blown the doors off the Dusie ! I don't get the reference to a 'reliable engine.' Was the 2nd generation Packard V12 less reliable than its counterparts? Was Packard's philosophy to "blow the doors off" other big makes? It seems more like they wanted to produce an efficient engine that had a lot of useable power in everyday use. Who had hydraulic lifters back then anyway? I think the GM engines you're referring to are the "Nailheads" of the '50s and '60s Buicks, with with overhead valves working in an upright motion while the cylinders ran at an angle. Kind of an upside-down version of the Packard design, but it's hard to make a comparison because Packard did not use overhead valves. No matter who designed the 2nd generation Packard V12 valve geometry, it's quite different from anything I have seen. Owen, you've got the blueprints, did the engineers sign them? No matter, whether it was completely Packard engineered or not, I'd say it was a darn good application, and probably unique in automotive engine design.
Posted on: 2008/9/22 22:39
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Guy
[b]Not an Expert[/ |
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Re: The Second Packard "Twin Six"
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Quite a regular
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You are confusing VALVE lay-outs with BORE lay-outs.
The "nail-head" Buick blocks YOU think that I think I was referring to, were of conventional design, in that the cyl. bores were at right angles to the top of the block, like most internal combustion engines. This makes for MUCH easier machinging and and service than having an ANGLE between the BORE and the BLOCK. Re-boring most production automotive-engines involves a relatively simple "set up" for the boring bore. Bolt it down, start it up, and down goes the cutting tool. Re-boring a Packard Twelve is impossible with most production boring machines. Can't be done. You have to have either a very special Packard-unique boring plate adapter, or (I am told - never actually seen one, much less operated one) a boring bar rig that CAN bore at angles.
Posted on: 2008/9/23 9:09
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Re: The Second Packard "Twin Six"
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Home away from home
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Clipper47, You are correct, the Merlin was used in many single and multi engine aircraft. Just one more comment on the Merlin then I'll shutup. A four-engined British Lancaster bomber could have been powered by Rolls Royce-, or Packard-, or Ford-built Merlin engines; or any combination of them.
Posted on: 2008/9/23 10:41
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We move toward
And make happen What occupies our mind... (W. Scherer) |
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Re: The Second Packard "Twin Six"
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Home away from home
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So basically, a Packard V12 used the same bore to deck layout as a 348/409 Chevy. That's rather interesting to say the least.
Posted on: 2008/9/23 13:19
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Re: The Second Packard "Twin Six"
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Home away from home
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Peter: The difference in price between the Caddy and Packard was $1145.00.
How ever I wasn't talking about about performance. The Packard V12 of Ed's just seemed to be of a better quality and feel than that of the Caddy. John F. Shireman
Posted on: 2008/9/23 19:52
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REMEMBERING BRAD BERRY MY PACKARD TEACHER
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Re: The Second Packard "Twin Six"
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Quite a regular
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John - again, you arent listening. Of course a car that cost a THOUSAND DOLLARS more in the early thirties (multiply that by a factor of about 15 to get its equiv. value in today's money) is going to be a superior car (especially if it is a Packard !).
THINK - when you compare cars, be FAIR, REALISTIC, AND RELEVANT - for the ten millionth time - dont go comparing a car from one price range with a competitor's car from a different price range. Do you think you'd get an accurate impression if you compared a '36 Packard 120-B with a '36 Cadillac V-12 or 16? If you compare a '32 Packard V-12 with a '32 Cadillac of ITS price range, you would find a LOT to like in the Cadillac.
Posted on: 2008/9/23 20:47
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