Packard Forum Index » Modification Discussion

There are certain things that can be done to any motor, that were more or less standard procedure in hot rod circles back in the forties and fifties. They don't necessarily require buying impossible to find parts either.

Here are some basic ideas. One is to start with the largest displacement engine, a 327 or 359. A 288 can have a 327 crankshaft and rods installed for more displacement. And a block of that era has very thick cylinder walls and can be bored 1/8" oversize.

Heads can be planed for higher compression, or a 288 head used. A bored and stroked engine will automatically have higher compression.

You already have the manifold but if necessary a stock intake manifold can be modified by welding on short stacks and flanges to take 2 or 3 carbs. Packard owners are lucky that it was one of only 2 straight eights to come with a 4 barrel from the factory, therefore a 4 barrel manifold is available.

This would be the best choice for a hop up although, multiple carbs always look cool.

Then you need a free exhaust. The simplest solution is to have a new exhaust system bent up with pipes 1/2" larger than stock. Next step is to split the manifold. This involves welding a pipe and flange onto the stock manifold for dual exhausts. The ultimate would be to build a header of steel tubing.

Then there is the key to the whole engine, the camshaft. Once again you are in luck as the Packard came with solid lifters and a light weight valve train. Many cam companies have masters suitable for a flathead engine and can regrind your cam. Install new valve springs and shim .060 for a little extra tension.

The valves and seats should be seen to and the ports relieved with a stone. Commonly called a 3 angle valve job.

Finally, the flywheel can be shaved down for quicker acceleration and throttle response.

Those are the basics. It would be great if you could find an Edmunds aluminum head but even without that there is a lot that can be done using stock parts, suitably modified.

All this is great advice for a stick shift car. With my Ultramatic the only good hop up is to try to increase peak torque without sacrificing any low end. Perhaps a modern cam grind can do that, along with more compression and displacement. The main reason for the dual carb manifold for me is:
1. It looks cool to have old speed equipment
2. Better mixture distribution on this long engine
3. It would look even better with the Edmunds head and air filters

Of course there is always the modification to swap out the Ultramatic for a multispeed modern transmission, but I like to stick with old-time equipment that matches the vintage of the car.

Or you could side step all this and install a McCulloch supercharger.

They were introduced in 1953 specially to enhance street performance on engines of the day, and should work well on a Packard. They would even qualify as a contemporary accessory. Packard tried them out in 1953 and 54 on some straight eight models but did not put them into production, no doubt the new V8 made the supercharger unnecessary. Although 57 and 58 Stude V8 powered Packards used the McCulloch.

They claimed to increase rear wheel horsepower by 40%. This was with a 5 pound boost. It is possible to make a few adjustments and increase this to 10 or 12 pounds if you want to go crazy.

Hi, Rusty,

Quote:Here we'll have to agree to disagree:

1. It requires much more than a few adjustments. A complete rebuild with different races, impellers and pulleys.
2. Above 5 PSI, the McCulloch/Paxton becomes a centrifugal hand grenade. The life expectancy is so short, Paxton would not warranty the racing blowers with high-output impellers and pulleys.
3. Those who are willing to take the chances and the expense find even for twelve seconds on the drag strip, higher boost and higher RPMs eats belts like popcorn. With new dual belts and sandblasted pulleys for more grip, belts are gone at the end of the day.

jack vines

I'd be happy with 5PSI boost, i just wouldn't know where to begin jetting the carb to have the right mixture. It would wake up an ultramatic car a bit though!

Edit: Also they seem to be scarce and a chunk of cash.

some other basic hot rod tips would be to to to an 11/32 or even a 5/16 valve with the light spring pressure and low rpm's these engines turn you shouldn't have to worry about breaking a valve and put in titanium retainers you can get some from comp cams for there bee hive springs that should fit with a little modifications. Usually a counter weighted crank can be cut down about 1/4 of an inch on the counter weights to help the engine turn up quicker. If you wanted to spent the money you could step up to a custom light weight piston with thinner rings to reduce friction and again help the engine rev quicker. Remember the more power you make naturally aspirated the more you will make supercharged.