Packard Forum Index » Post-War (1946-54)

Can anyone tell me what the compression distance is on the 288/327 engines? I used to have this information, and I can't seem to find it anymore.

68 views and no one has any idea? Come on now, I can't be the only one here who knows this kind of stuff!!

G'day Eric, I, as probably most people who viewed the thread are not sure of what you mean by compression distance. Could you please define what you mean by compression distance? Best Regards and please excuse my ignorance. Peter Toet

Compression distance, or pin height, is the distance from the center of the piston pin to the top of the piston.

G'day Eric, According to the Serviceman's Training book for the 24th Series Packard: The Height from the centerline of the pin to the top of the piston of the 288/327 engine is 2.125 inches ( two and one-eighth inches) Best regards for Xmas, Peter Toet

Thank you very much! That's what I needed to know to start, now I need the rod length of the 288 and 327 engines. I'll explain all this eventually.

Eric, my manual shows the 288 rod length centre to centre as 7 15/16"
The 327 is 7 11/16"

The 356" is 9 1/4" !
I didn't find an overall length if that is what you need.

That's what I thought, between the 288 and the 327 using the same pistons. Which would mean that they made up the difference in stroke by shortening/lengthening the rods, or changing the deck height. The 288 has a 3.75 stroke, and the 327 has a 4.25 stroke. A 7.6875" rod in the 327 + 2.125" for the piston + 2.125" (1/2 the stroke)= 11.9375", which is the approximate deck height of a 327.

A 288, at 7.9375" rod, + 2.125" pin height, + 1.875" (1/2 the stroke)= 11.9375". Which means they have the same deck height. Now, change this up a little, put the 288 rod in the 327 engine, now you have: a 7.9375" rod, + a 2.125" (1/2 the stroke)= 10.0625", the total length of the 1/2 stroke and the rod. Now, take the 11.9375" deck height - the 10.0625", and you come up with: 1.875", which is now the new pin height.

OR

You could have just done this: asked me! All this holds true if the deck heights are the same. I won't even go into the 356 as it's a different breed of engine, and from what I can tell from repair manuals, the rods from the later engines won't fit into the 356.

Now, the point of this exercise is twofold: #1-To obtain a shorter pin height piston that is more easily available in custom forged pistons than the stock piston pin height. 2.125" is a tall piston in a 3.5" bore configuration.

And #2-To increase the rod/stroke ratio. Everyone knows that a longer rod makes more torque, since the piston stays longer at the top and bottom of the stroke. Now, in my particular application, this will be most beneficial. As long as, the longer rods don't meet the sides of the block or the camshaft. Hence the need for a 327 9 main engine over the 356 or even the 359. Shorter stroke on the 327, plus the longer rods of the 288, and I should be able to make more torque at lower revs than with the stock rods. Plus, I get the added benefit of less friction on the cylinder walls with the shorter piston.

Have I lost it? Probably!!

G'day Eric, I appreciate your efforts to progress the potential of the Packard engine , but I am somewhat puzzled that you have settled on the 288 or the 327 engine. If you value the fact that longer rod gives greater torque then the 359 is the winner , however it is not that simple. Let me demonstrate:

1948: 288 engine, 7.00, 130 hp at 3600 rpm
226 lbs at 2000 rpm ( yes I know ft/lbs)
1948: 327 engine, 7.1, 150 hp at 3600
226 at 2000
1953 288 " , 7.7, 150 at 4,000
260 at 2200
327 " , 8.0, 160 at 3600
295 at 2000
1954 288 " , 7.7, 150 at 4,000
260 at 2,100
327 " , 8.0, 185 at 4,000
295 at 2,200
359 " , 8.7, 212 at 4,000
330 at 2,200
In fact Packard was pushing it's engines further than the rest of the industry. Packard also supercharged the 359 to 275 hp in 1954. But if you look at the 1955 V8 figures, the side valves were a performance thing of the past. I wish you luck with your endeavours as I have always been very keen to keep the Packard Standard flying. I would suggest that you start with a 185 hp, 5 main Mayfair 4 bbl Packard, blue-print it, add a big hairdryer( turbo), get it to run 5,500 rpm and you will get your 500hp. ( if you can get some sodium filled valves for it) Best regards Peter Toet P.s. I have dug up the pics of the 49 Packard Sedan "flintstone Flyer" that held the NHRA Association Nationals in 1962 and 63. I shall post them when I can scan them. best regards Peter Toet

I want the shorter stroke of the 327 over the 359 so I get a higher RPM and piston speed out of it. I want to use the longer rods of the 288 to keep the pistons at the top of the stroke longer to help build power. I need the strength of 9 mains to keep the crankshaft flex down, since with 4 more main bearings holding the crankshaft down sure can't hurt anything. I feel that I can get more power out of the 327 9 main engine than Packard did in 1954 with the supercharged 359. I'll be using a few things that they didn't have, however. Two turbos and a special fuel for starters. One large turbo won't suit my needs as it takes too long to spool up, as compared to two smaller turbos. The things I want to do I can't do with a Packard V8, I can't do as easily as I can with straight eight.