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Cylinder Compression Questions
#1
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50 2382
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I'm a newbie and have just acquired a 1950 2382-5 Super 8 with the 327cu in engine. It won't run...otherwise it is in very good condition body wise and poor condition interior wise.

Question 1. What should normal compression be in the cylinders. All mine hover around 40-50 psi even after dumping oil in the cylinders. I suspect stuck valves...opinions please.

Question 2.I need a good source for a shop manual as it looks like the 327 is going to come out if I can't get the compression up.

Thanks!

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Posted on: 2014/11/14 17:24
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Re: Cylinder Compression Questions
#2
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HH56
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Congratulations and welcome. Believe around 100psi +/- has been given as a workable number for a decent condition engine. Varies a little depending on the compression ratio. Stuck valves are a good possibility if the engine has been sitting a long time.

There are copies of the service and parts manuals on site which you can download. If you want paper then the Packard clubhttp://www.packardclub.org/ has reprints as do the major Packard vendors. The original 46-50 service manual was a small format roughly 6 x 9 inches with 7 individual booklets as chapters. That small size in one volume is the format available from PAC and vendors. For those like me with feeble eyes, I personally prefer a larger format 8 1/2x11 version made available by Faxon Auto lit.http://www.faxonautoliterature.com/1946-1950-Packard-Service-Manual-Reprint-P9235.aspx

Posted on: 2014/11/14 17:47
Howard
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Re: Cylinder Compression Questions
#3
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50 2382
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Thanks Howard. The PO says that the car ran well before he let it sit for what I think is a couple of years. I am giving it the penetrating oil/ Marvel Mystery Oil in the cylinders soak today and we will see if it will do more than sputter. It tries but there just isn't enough pop to make it run.

Posted on: 2014/11/14 17:53
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Re: Cylinder Compression Questions
#4
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HH56
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The sputter is encouraging. One thing on 6v systems with the larger engines is the electrical has to be top condition so the large current draw when starting doesn't drop the spark down to a hit or miss range. Well charged and ample capacity battery, proper size 0 or 00 ga battery cables, and good clean connections. Points and plugs also need to be in good shape -- particularly if it hasn't been started for awhile.

Posted on: 2014/11/14 17:58
Howard
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Re: Cylinder Compression Questions
#5
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David Grubbs
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I ran a compression test on my 39 120 last month, using a screw in type compression gauge. My car runs decently, but hasn't be overhauled since Jimmy Carter was the President. With the engine cold, all spark plugs removed and the throttle held open, I turned the engine over at least six times on each cylinder. Got readings of 40 to 50. One of the problems in getting a good reading is the small 10 mm plugs - if you are using a rubber cone type compression gauge it is even more difficult to get an accurate reading. I found out that the readings tend to be lower when the engine is cold. If the readings are fairly uniform, I wouldn't worry too much just yet. The earlier comments about the electrical system is right on - if you can replace the points and condenser, rotor and cap, and clean and gap the plugs, then get the timing and dwell set, the engine should start. Once you get it running and warm, try the compression test again. I suspect that it will be up in the more acceptable range of 75-80 (which isn't bad on an older engine).

The Marvel Mystery Oil in the cylinders is a good treatment before attempting to start the engine. The old flatheads were prone to rusting around the valves when they weren't run regularly or sat for a while. Removing the side panels and squirting some PB blaster on the valves isn't a bad idea. While the panels are off, have someone crank over the engine while you watch the valves.

Last hint - find the nearest Packard Club and join. You will find people with the same experience and plenty of advice.

Posted on: 2014/11/14 20:10
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Re: Cylinder Compression Questions
#6
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Ernie Vitucci
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Good Evening...

I recommend that you make sure your battery terminals are clean and that the connections on the other ends of the cables are clean and bare metal to bare metal.

On 'Miss Prudence', we also use Marine Terminals on our battery which allow an easy second positive ground cable to run between the positive battery terminal and the frame, by drilling a 5/16" screw hole in the frame, down in front of the battery.

The battery cables should be 00 cables with soldered ends. The parts are usually available at NAPA. The second ground cable really makes a difference with a nice hot ZAP spark. 'Miss Prudence is a 1949 2362 with a 288 engine and she has started much easier since the second ground cable was installed.

Ernie

Posted on: 2014/11/14 21:39
Caretaker of the 1949-288 Deluxe Touring Sedan
'Miss Prudence' and the 1931 Model A Ford Tudor 'Miss Princess'
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Re: Cylinder Compression Questions
#7
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Fish'n Jim
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Alot depends on how many miles are on it what good pressure would be. If cylinders are all pretty much the same, I doubt valves are stuck. Common mythology. You'll get really low values, like zero, if one's stuck open.
Valves may not be adjusted and not closing or opening fully giving lower pressure but it's difficult to get any meaningful pressure readings on cold rings even with the wet test. They contract and by-pass. Plus you need oil circulating to get the cylinder and head to pressure seal.
May want to start on a fuel cell if the tanks been sitting.
Old gas is trouble for the carb and pump.
If it's got the silly carb starter, by-pass it for now. Check all the wiring, etc. I don't like to even try to fire or put juice to one until all that's done first, so don't get to in a hurry.
Clean the oil pan or check for clean oil too. No sense circulating sludge if it fires. Replace all the fluids.
Concentrate on getting the spark good and the fuel mixture/carb doing it's job before you worry about the compression. Carb may need rebuilt, if it's dried out and new gas is in it. They'll fire if all that's right even if there's a few cylinders out, zero compression.

Posted on: 2014/11/14 21:49
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Re: Cylinder Compression Questions
#8
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PackardV8
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1. If an INTAKE valve (JUST ONE) is hanging open ever so slightly it will keep ALL EIGHT cylinders from drawing enuf fuel/airr mixture to run the engine at all. NOT necessarily true if only one or 2 EXhaust valves are open.
2. When running a compression test SQUIRT OIL into cylinders otherwise compression reading will be low by at least 20 psi.
3. One can test for stuck valves by blowing smoke thru the spark plug holes when each cylinder is on power stroke. Can also use compressed air at about 20 to 30 psi and listen close to exhaust pipe and carb.
4. To make a compression tester adapter for 10mm use a 10mm spark plug. Knocke the guts out of it and tap it for 14mm. I'll have to look at my adaapter i made from from a spark 10mm sparkk plug to verify the tap size and plumbing but it is rather simple.

Posted on: 2014/11/14 22:41
VAPOR LOCK demystified: See paragraph SEVEN of PMCC documentaion as listed in post #11 of the following thread:f
http://packardinfo.com/xoops/html/modules/newbb/viewtopic.php?topic_id=7245
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Re: Cylinder Compression Questions
#9
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Rusty O\'Toole
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My Service Data Book says 110 PSI. Your readings are pretty low, almost too low to start on. If the MMM helps, and you can get it to start and run long enough to warm up (at least 15 minutes) there is a good chance the engine will come back to life, the rings and valves tighten up and run much better. When a car has been out of commission for many years it can take several hundred, or even 1000 miles of driving to break it in again.

Get the starter working good. If you oil the cylinders spin the engine on the starter to blow out excess oil. Throw some old rags over the plug holes, to stop the oil that blows out.

You may need to clean the points and plugs to get it to fire and maybe even give it a shot of gas down the carburetor.

I have revived many old motors, if I was there I could have that car eating out of my hand in a few hours. There are lots of smart guys on this board, you should be able to get it running without tearing anything apart.

Posted on: 2014/11/14 23:38
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Re: Cylinder Compression Questions
#10
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Rusty O\'Toole
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The best shop manual is the one the factory issued to dealers when your car was new.

They are not as hard to find as you might think. They printed enough for every dealer and hundreds are still around. You should be able to find one at an auto flea market or from an on line literature dealer or that auction web site. Usual price under $100, I have paid from $20 to $75 for factory manuals of other makes.

Posted on: 2014/11/14 23:42
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