Packard Forum Index » V-8 (1955-56)

I've been collecting the 374" blocks and head gaskets, but these days there seems to be a shortage of brave guys who want big bore builds.

Back in the bad old days, the bench racing claim was any Packard V8 could be bored out 1/4" (.250") My sonic testing indicates this would leave the cylinder walls too thin for such a tall column, but that's another story.

Head gaskets were always a problem for the larger bores. Back in '56 when Hot Rod ran a story on how C-T Automotive bored and stroked the 352" to 414", they couldn't find any 374" gaskets in time.

Boring a 374" .250" over would be 4.375" and there's never been a commercially available gasket that size.

However, the 374" Packard V8 can definitely be bored 1/8" to 4.250". Problem is, the OEM steel shim 374" gaskets are only 4.240" diameter.

In all the years of building these engines, I've only seen one set of Fitzgerald 4.250" bore head gaskets. They are quite different in appearance and execution than the OEM steel shim gaskets.

Anyone else have or have seen the Fitzgerald big bore gaskets. Any other true 4.250" bore gaskets?

jack vines

A few years back, I read in an English antique car magazine, a story about a small firm in England that will hand make gaskets for anything. Including metal clad asbestos (or asbestos substitute) head gaskets.

Don't remember the name but a web search might turn something up.

Later

A search for hand made head gaskets got 1,300,000 hits. The first page included gasket manufacturers in England, Australia and the US that will make any gasket in small quantities.

There are no shortages of companies which will make custom head gaskets of composite or copper. Most these days aren't done by hand, but by CNC machines. I saw one demonstrated at a big trade show.

Bring them any gasket, even a paper tracing. It is scanned into the computer, the desired material is fed into a machine, which wisks around stamping and machining holes and seconds later, out comes your gasket.

All it takes is money.

jack vines

"All it takes is money."

If that doesn't describe everything big or small about our hobby, i don't know what does.

quote:
" the OEM steel shim 374" gaskets ...."

I'm a little confused. U are using the term "shim". Are u talking about the shims for lower compression ratio or just the embossed steel head gasket???? I've never heard of a head gasket refered to as a "shim gasket" unless it is to reduce compression. So i'm not sure which part (head gasket OR the shim) that u are talking about.

I don't understand this. These motors are old and boring them out will only shorten the service life and render them unusable. I think the 352 is the best Packard V-8 because it is not as stressed as the 374. If you like Ultramatic, and Torsion level ride, but don't like the Packard V-8 then why not change the motor to something out of a modern truck?

It will have computer controls for maximum horsepower and will burn a lot of gas too. If one of those things weigh less that is even better for the ride.

Quote:

In the fifty years I've been in and around engine shops, the term "steel shim head gasket" is used interchangeably with "embossed steel head gasket". Your experiences and cognitive vocabulary may vary.

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Packards are collector cars and these days few receiving a rebuilt engine are driven enough to ever require another rebore. In all the years I've built Packard V8s, only one owner has put enough miles on his engine to need it freshened. All the others are still going strong and will outlast their owners.

There are way more engines surviving than Packards to need them. I've had to quit buying core engines because I've run out of space. How many do you want built to your specs?

That the 1956 Studebaker Golden Hawk was the fastest car built that year and showed the Packard V8 has some performance potential is the only thing which first got me interested in these boat anchors.

Packard and Studebaker Golden Hawk owners have been hot-rodding and boring out the Packard V8 since Day One and I'm just carryin' on the family tradition.

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That's one way to look at it. On the other hand, some of us find other uses for the surplus of Packard V8s. My '55 Studebaker 3/4t truck has a Packard V8 I built to heavy duty truck specs. My '56 Studebaker Hawk has a Latham supercharged engine and I'm looking for a Bonneville Stude to run the full-race Hilborn injected Packard V8 engine sitting on an engine stand in my garage. Several I've built have gone into Studebakers, Nashes, Hudsons and a couple of street rods.

Quote: By that logic, maybe we should all be running the '55 320" 2-bbl single exhaust engines. As far as "stressed", the Packard V8 is so understressed and so hamstrung by the TU transmission, I've never seen any evidence from wear that the 374" is more stressed than the 352". Yes, the higher compression of the '56 engines in general and the 374" in particular does require a more precise tuneup, premium fuel and octane boosters. Preignition and detonation are the only problems the 374" has to a slightly greater degree than the '56 352". Your experiences and results may vary.

jack vines

I think the 352 is the best Packard V-8 because it is not as stressed as the 374.
I don't understand the term "stressed". Do you think the cylinder walls are thicker in the 352 than the 374? You do know they changed the cores when they made a 374 so that the cylinder walls are the same nominal thickness as they were in the 352?? The 374 does have a higher compression and the timing was advanced, but 10:1 compression and 10 degrees advance is not drastic at all.

here is what i bought from MAX. you notice it says 56 senior. the block is a 55, but i bored it out to stock 374 and i am running a hotter cam and valve springs. i have no worries that it will be just fine. there is only 1/8th of an inch difference in the bore between a 352 and 374. not alot.

i did tell max what i was doing as to get the right parts.

as you can see, Jack, the head gaskets are metalic type and made by Best. Max was the cheapest at 149.

Hank

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[flash=,]http://bestgasket.com/pop_up_picture.asp?PartNumber=RS719G[/flash]

Many dealers have old stock on the shelves. Follow the above link to confirm Best is now supplying composite gaskets.

jack vines