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Thanks for the replies everyone, your advice has been very helpful. I'm not a troll, I've just admired Packards since I was a little boy and always wanted to build a faster one. (BTW, another young boy once saw a Packard Twin six and was inspired to build a hot rod version. His name was Enzo Ferrari.) Is it possible to get a stronger crankshaft made for htese engines?

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Yes, just bring your (big, fat) wallet.

From a performance standpoint, you'd be way better off with an OHV rather than a flattie, but you probably know that. Boost (SC or Turbo) only makes up for so much.

Craig

Quote:G'day hiboy24,
to PackardInfo.

Anything is possible, all you need is money and for that sort of exercise plenty of it!

The Packard straight 8's have been supercharged but always with a thought to the limitations of the engine, namely the long stroke.

What Peter Packard says makes sense with more horsepower being freed up through higher compression and better breathing. I read somewhere once that a 20hp increase was easily obtained just with some port matching and smoothing of the passages, this was used by 30's gangsters in their Packards!

And of course I have to ask - Is this Packard engine on steroids destined to power a Packard or something else? If it is powering a Packard could you please include your Packard in the Packard Owner's Registry here, together with a pic, any known history and how you acquired it? And the more detail the better!

There has been considerable discussion of this very point on this board and on others.

For certain technical reasons related to breathing and compression, a flathead engine should respond well to supercharging.

This was proven in the 30s when Cord, Auburn, and Graham built successful supercharged flatheads as production cars. They proved to be efficient, powerful and trouble free.

Turbos are not recommended. Flatheads suffer from exhaust valve overheating and valve failure when turbocharged.

The big limiting factor is cooling not crankshaft strength. You should be able to get near double the stock horsepower out of a Packard without too many problems, but will not be able to sustain such outputs for more than a few minutes before a critical degree of heat is exceeded.

The most powerful Packard straight eight was the 1954 359 cu in 212 HP model. It had 9 mains and an aluminum head.

You should be able to get close to 400HP out of one of those. For how long, and how many times before it blows, is another question.

Forged pistons, careful blueprinting of the bottom end and keeping the revs down to 5000RPM or less should keep the bottom end together.

Then, there is the heat issue.That can be controlled up to a point by using a new aftermarket aluminum head, keeping the cooling system clean and pressurizing to 16 pounds or more.

What you are talking about is quite doable and would make an impressive project.

The fact that you could build a Chev 350 to make the same power, for 1/5 the money and effort, is beside the point.

Besides where's the fun in building yet another (yawn) small block Chev?

Now if you really want horsepower how about a 374 Packard OHV V8? You should be able to get 400 HP out of one of them without a supercharger and without overstraining anything.

In case my previous post was not clear. Do not worry about the crankshaft. The stock one will be fine.

Use a 1954 359 cu in straight eight. Blueprint the bottom end and install forged pistons. Keep the revs down to 5000 RPM or less.

15 pounds boost should give you 400HP. The problem will be dissipating the heat through a cooling system designed for 1/2 that power level.

Pay attention to the cooling system, install a new aluminum head, and do not use full power too long at one time and it should work great.

A Paxton or Vortec type of centrifugal blower will work the best for what you want. They make up for the flathead's restricted breathing at high RPMS without overdoing it at low RPMS. They have the least parasitic drag. And are the easiest to fit.

Would also recommend heavy duty valves, exhaust valve seats, and a cam made for the application.

You will need to make up a header. A stock intake may be OK but convert to port injection.

If you use a Megasquirt system you can have crank triggered ignition too. Otherwise, electronic ignition and an MSD box.

Should be quite a ride.

This is a build I've been considering, but haven't found the right home for it.

JMHO, based upon a lot of practical experience, turbocharging is the best friend a long-stroke flathead can have. With proper control of boost, ignition and fuel, it is possible to make big power at livable RPMs.

Yes, the '54 359" would be the first choice, but they aren't easy to find. A late 327" would be almost as good. Have custom stainless or inconel exhaust valves made and install hard seats. (I've always wanted to try the beryllium-bronze NASCAR seats I've got on the shelf. They transfer heat better than anything.)

Go for it and post your progress here.

thnx, jack vines

Jack I value your experience in this field. How do you compare a turbo to a centrifugal engine driven blower? I like the engine driven blower because it reduces the heat problem not only on the exhaust valves but on the cooling system generally.

Would also value your critique of my suggestions. They are theoretical in nature not based on experience. Experience is the best guide if you don't mind sharing yours.

I've found a website concerning a custom made (machined) head for the straight 8 packard powerplants, I'm not knowing as to whether or not they are available at this juncture due to the fact that the site was at least 10 years old. Would you know of any other contingents that offer such and/ or could fabricate that special cylinder head???. I have posted a letter to the party responsible for that site but as I indicated I don't know as to whether it will be available or feazable( letter was recently posted waiting for a reply).

FWIW, turbochargers are far more thermodynamically efficient than centrifugal superchargers. In every form of racing where they are/were allowed, turbochargers are always the choice. Look at F1, Indy; seen any centrifugal superchargers since the 1965 Novi?

Turbos don't add damaging heat to the cooling system and exhaust valves. There are turbocharged stationary engines which run boost for weeks at a time without damage. The generally shorter valve timing of turbo cams actually leave the exhaust valve on the seat longer to transfer more heat than would the cam timing of an equivalent output NA engine. Turbochargers can develop more horsepower at lower RPM and thus less stress on rotating/reciprocating parts.

I've driven turbocharged street cars for thirty years and built a few performance and race versions. Over that time, I've had fewer problems with turbos than centrifugal. The McCulloch/Paxton supercharger was one of the most unreliable mechanical devices ever sold for an automobile.

thnx, jack vines