Packard Forum Index » Modification Discussion

I got a call from a very well known cam grinder who wanted some technical info on the Packard V8 cam. The one example he had came in to him after a failed regrind by another shop.

When I went over the OEM specs, we discussed them and agreed much has been learned about cam design in fifty-seven years.

He says he can do a modern profile which will make more power everywhere and still idle smoothly.

However, and there always is one, the Packard lifters, pushrods, springs and retainers are marginal for any performance upgrades.

A cam kit with all the above would be at least a $1500 bill.

Is there any interest?

jack vines

Grinding a cam ain't that big a job, I gotta believe the springs and keepers can be sourced from other applications.
A modern, light & strong push rod would be money well spent.

Lifters could get expensive as well as new rocker shafts and/or arms.

Let's see some Dyno tests!
(Or can that be plunked down on a computer these days?)

Yes there is interest. Further thoughts of yours are appreciated.

Quote:No, but selecting the maximum area under the curve which will fit on the Packard cam core is. You can't grind air. There are a lot of modern high intensity profiles which are too large to fit. There just isn't the material there to fit inside the shape.

Quote:

Just tell me where to find them. Packard used one of the largest OD/ID springs ever put on a modern V8. Yes, I use higher performance springs and retainers all the time. I've used Cadillac V8, big block Chevy V8 springs; however, they all require machining of the Packard V8 valve guide boss because they're smaller ID.

It's not difficult to change the springs and retainers, just costly. When we're already spending $1500 on the cam kit, the extra machining just ups the price.

jack vines

When I had the spring seats done for the valve springs I used from lunati on my v8 it was only like 65 bucks... When you are spending 1500 who cares about 65 bucks. Plus when it was all done the lunati springs I picked were absolute and perfect! I think those springs would do just fine in your modern cam profile and really not add much cost in machine work.

If he is willing, Craig can plug your new modern cam numbers in is software and give you a good estimate of performance change. He was able to do this with the cam I already bought from you.

Henry, you did good work to source out best springs for your application. For those who don't know the details, you might share the part numbers for the Lunati springs and retainers and the total cost for the conversion.

jack vines

I would think that a profile for a Pontiac or Buick would wok well with a Packard the breathing limitations and RPM limits of the design match well.

I have a friend who is a retired cam engineer, he worked at Chevrolet from 1960-1988, and designed many of their high performance cams. After "being retired" he set up his own consulting firm, worked for all the GM divisions, Ford, Chrysler, Import companies, a steam engine company, McClaren high performance,and other go-fast clients.
He taught classes at the 3 American car companies for young engineers "how to design a camshaft WITHOUT a computer".
He is still really sharp. If you would like I can run any specs you have past him, he'd probably enjoy looking it over.

MrPushbutton Quote:

Ok, I'll bite. From Dyno2000 Computer Engine Simulation v3.10:

My Panther engine with custom Lazer high performance regrind:


Details on the cam profile (regrind on original cam):


Dyno output graph:


Above graph in chart form with additional data:


The engine has stock 1956 cast iron 2x4 intake with 2 500CFM carbs, gasket matched heads with 3-angle valve job and my custom 3-tube headers. This is a 4-speed stick shift setup, so idle was not too big a concern, hence the 108deg CL of the cam. I have all these parts, so this is not some "bench racing" deal.

402HP at 5500RPM, 436Ft-lbs at 4000RPM.

Craig

By comparison, the same D2K simulation program with the specs of the 1956 Caribbean engine:



309HP at 4500RPM, 406 Ft-lbs at 3000RPM

The above is very close to advertised HP/TQ. As to whether that is real or not is certainly debatable, but I was interested in the difference made by the various upgrades:

+93HP, +30TQ Total

Craig