Packard Forum Index » V-8 (1955-56)

Eric,

How is your Super Charger doing on your Patrician? Did you finally get it all dialed in?

I know you mentioned before that you still had some tuning to do with it.

The supercharger I'm afraid, isn't putting out the power that I think it can. When I drive it down the interstate at speeds above 70, I have 0 psi, with NO vacuum. Now, this tells me that it is moving air, but not enough. I believe that the pulley ratio isn't correct, but I don't know what the original crank pulley diameter was on the Avanti that it came off of. So, since I can't easily change the diameter of the crank pulley, I bought a new pulley for the supercharger that's 1/2 the diameter of the original pulley. When warmer weather hits, I'm going to put it on and see how much difference it makes. I have a feeling that my crankshaft pulley is at least 1" smaller in diameter than the Avanti pulley, but without one to compare to, I'm flying blind here.

It has made a difference in some ways, I have more power than before, but my top speed is still only 90-95 mph. Hopefully, when the 374 is done, 125mph will be attained.

Eric

Have you had to make any changes to the Carb in terms of jetting or anything like that?

Also did you make any changes to the exhaust for better flow or anything in that regards?

I haven't changed any jetting on the carb because it was running rich in the first place. I have a 600 CFM Edelbrock on it right now, which was kinda big for my little 320 that I'm running. I'm pretty sure it's not in the carb, as jetting won't affect the airflow through the engine. It's also possible that the carb's too big, even with the supercharger, but I don't think so. In fact, I'm thinking that I'm going to have to move to a 700 CFM for the 374.

As to the exhaust, I'm using the stock pipes with glasspacks and no resonators. In a month or so, I'm taking it to the exhaust shop to have as large a pipe that I can fit under there put on. Most likely 2.5" will be the biggest that I can put under there, and still be in the stock location. There will be two Flowmaster's at the back, and that's all. Eventually, I plan on getting headers put on for the 374, which I'll probably have to make myself. I want this car to sound like it's got some guts, even if it doesn't yet.

When it's all said and done, it will have a nice muscle car sound to it, but yet you'll still be able to have a decent conversation inside the car, while traveling at 120+MPH.

On a side note, for those of you that have the '51-'56 body, as long as the lower front control arms are similar enough, I may have found a beefier front sway bar for our cars, in the form of a 4X4 2005+ F150 pickup. The front bar on those are 1.3255", whereas a stock Packard front sway bar is 0.63". I think I can use one off a F250, F350 for the rear. I don't know about everyone else, but the body lean in a sharp corner at speed has got to go. I'll keep you all posted as to my progress. Like I said, there's going to be some exciting stuff in the V8 Packard world this year!

Eric

Eric,

I looked at my '63 R2 Avanti and the crank pulley looks to be 7.5" (hard to get an accurate measurement as it is really tight against the shroud). Check with some of the Stude Paxton guys like Ted Harbit or John Erb...there are high output pulley options for the Paxton, but be careful how fast you spin the blower, they do have a limit!

If u get that blower set up the way u want it it ought to make that 320 sing just as strong or STRONGER than the best of any 374's. I can hit over 100 mph with my stock 352 and a 3:16 rear end.

Well, with the 7.5 diameter pulley on the crank will give me the correct ratio to go with. I'm thinking that the stock Packard crank pulley is 6", so with my 2.5" pulley that I bought for the supercharger, might be too much. I'd really like to know what the maximum speed is for the SN60.

Keith, I'm sure that the 320 can keep up with the best of the 374's, but just think of the 374 built up with the supercharger! Oooohh yeah!

Eric

Eric,
Here is a link to Ted Harbit:

stude.com/Ted/

He is very savvy re the Paxtons and a nice guy to deal with.
And some other Paxton guys, I've dealt with John Erb and he is also a straight shooter:

vs57.com/vendors.htm

Either of these guys can tell you how high you can spin the Paxton (I believe there are upgraded brgs available). My Avanti does not show boost at highway speeds either, but blows around 6 or 7 above 3000 RPM & up when you punch it?..at light throttle cruise they only register slight pos pressure.

Packard8, thanks for the link. My supercharger doens't show any positive boost at all, just goes to "0" on the gauge under throttle pressure, then drops back down to 15-20 in. when the throttle's off. I still feel this is because of two things: #1, the engine's bigger than the original 289, and therefore, using more air, and #2, it's not spinning fast enough for the supercharger to kick in any real useable boost.

Eric

Sounds like it may need to spin faster, you should see at least 5# boost while accelerating above 3000 RPM. The largest cid Paxton/Mac app I can think of was Stude 305 and Ford 312, so not too different than the 320 Packard. This vendor lists some pulley options:

studebakervendors.com/lstone.htm

Also ask about the high output brg kit.