Just a few RPMs from total destruction
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Home away from home
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As most of you know, the first generation Packard V8 valve spring retainers were too soft. When the engine was revved to valve float/lifter pump-up, sometimes the keepers would pull through the valve spring retainer and drop the valve into the cylinder. When this happened at 5,000 RPMs usually the piston broke up and the rod holed the cylinder wall.
Literally every standard shift 1956 Studebaker Golden Hawk I've ever torn down showed evidence of at least one, sometimes two disasters. I recently stripped an engine which was just a few revs from catastrophe. The keepers had almost pulled through the retainer. Notice the marks on the outer rim where the rocker arm body had been hitting and the marks in the center where the rocker tip had been hitting. How it held together was a mystery. Packard valve spring retainer photos FWIW, Packard Engineering began specifying hardened retainers somewhere late in the process, but few engines have them. A file test will determine which you have. The early soft retainers cut easily with a file, whereas a file will skate on the later hardened retainers. jack vines
Posted on: 2013/8/1 17:48
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Re: Just a few RPMs from total destruction
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Home away from home
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At 110 mph the 55 Patrician was turning around 4100 rpm.
I'm sure there are other retainers that can be subbed in the Packard V-8, or the soft ones can be hardened at a machine shop. So there is no need to panic. I had a 61 Ford that I used to rev into forced upshifts and it never broke. I also had a Chrysler four that I could bury the tach into 6000 rpm with no results. Ditto a slant six Dodge that I would floorboard in low.
Posted on: 2013/8/1 19:24
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Re: Just a few RPMs from total destruction
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I wasn't aware of any supply problem getting the original factory-improved (hardened) retainers, I routinely got a set from one of the national Packard vendors a year or so ago. Has the supply run dry?
Posted on: 2013/8/1 19:27
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Re: Just a few RPMs from total destruction
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Quote:
So begs the question: how did the 25000 mile car manage that feat at that speed yet when it was over have the engine torn down to find only "minimal" wear. Isn't that one of the things they would have looked for -- or did they find it and was the reason for the hardened seat recommendation "late in the process". Quote: At 110 mph the 55 Patrician was turning around 4100 rpm. I'm at a loss as to what the above add to the discussion. It's not debatable if the original Packard retainers will cause destructive failure. It's an established fact. What Fords, Chrysler fours or Chrysler six won't do is not really germaine; or am I missing something here? BTW, Tim, If you're so sure, I'd appreciate a part number for the retainers which can be subbed in or a machine shop which guarantees to harden a fifty year old retainer of unknown metallurgy. jack vines
Posted on: 2013/8/1 20:35
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Re: Just a few RPMs from total destruction
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I don't think anyone is doubting the weak collars. There is your experience and the STB's or SC's addressing the problem.
HH56 does raise a good point about the 25K mile test car tho. It AVERAGED 105 miles /hr. Perihaps that mite mean that the test car was NOT a production engine. In any case, HIGHLY unlikely the tezt car had a production engine anyway and therefore probably had better spring collars among other minor mods.
Posted on: 2013/8/1 20:56
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VAPOR LOCK demystified: See paragraph SEVEN of PMCC documentaion as listed in post #11 of the following thread:f
packardinfo.com/xoops/html/modules/newbb/viewtopic.php?topic_id=7245 |
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Re: Just a few RPMs from total destruction
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Home away from home
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Yes, if there is some commonly available substitute collar i'd like to know what it is too.
Posted on: 2013/8/1 20:59
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VAPOR LOCK demystified: See paragraph SEVEN of PMCC documentaion as listed in post #11 of the following thread:f
packardinfo.com/xoops/html/modules/newbb/viewtopic.php?topic_id=7245 |
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Re: Just a few RPMs from total destruction
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Home away from home
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I'll second that!
Posted on: 2013/8/1 21:26
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1951 200 Deluxe Touring Sedan
1951 200 Deluxe Touring Sedan (parts ?) 1951 Patrician Touring Sedan 1955 Patrician Touring Sedan |
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Re: Just a few RPMs from total destruction
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Home away from home
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Quote:
At 110 mph the 55 Patrician was turning around 4100 rpm. If memory serves, the last time we ran this (my car, the usual 3.54 rear end, P235 R 75 radials) the calculation was that at 71 mph (actual) the engine was doing 3000 rpm. That last 1,000 rpm gives a wonderful speed advantage.....
Posted on: 2013/8/2 0:38
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When two men ride the same horse, one has to be in the back...
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Re: Just a few RPMs from total destruction
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The "abuse" was probably un-intentional and could have occurred during "spirited" driving in D during the shift from L to H and this would have been made much worse by the somewhat common problem of "flaring" ( engine revving going from L to H). This flaring problem is the subject of a number of Tech Bulletins.
Thanks to Jack for pointing out a near miss, rather than a big hole in the block. Moral of the story is "don't "race" it unless you are prepared to "blow" it!" Best regards Peter Toet
Posted on: 2013/8/2 2:58
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I like people, Packards and old motorbikes
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