322 Buick/Chevy Truck nailhead--info anyone?

[brad54]

The 322 Nailhead last appeared in a Buick in '56, but after that GM utilized the tooling for big Chevy Truck engines from '57-'59.

Anyone have any info on the truck engines? I have a fuel pump from one, and it's a single-action, rebuildable pump (not the dual-action wiper/fuel pump like on passenger cars). Anyone know anything about these engines, or know where I could find the HP an Torque Ratings for these engines? By now they're hard to come by, too, but every now and then something pops up for them (like the fuel pump I bought).

Thanks,

-Brad

[GMPARTSMAN]

I have a parts book at work for 46-72 Medium Duty Chevy trucks. I will check

for specs listings on Monday

[NTX5467]

Brad, from what I've seen, the V-8s like that went into the GMC trucks and not Chevrolets. They had HydraMatics in them too. They might have been in the Chevys, but I haven't researched them that much. Don't recall seeing them listed in the light duty or medium duty parts listings, but then it's been quite a while since I've been in those books.

Back then, if you wanted a "fancy" upscale pickup, you generally bought the fancier GMCs instead of the more plain Chevys. Many more 6 cylinders that I saw than V-8s, until the older 6 cylinders were discontinued in the earlier 1960s.

Pontiac V-8s were used in the light trucks too. Pontiacs were in the 1/2 tons and the Buicks were in the heavier duty models, or vice versa?

I found a neat book on GMC truck history a while back. It mentioned how the Buick inline 6s and others Buick engines were used in the early HD GMC trucks. The GMC that Cannonball Baker drove from the east coast to the west coast, setting speed records at the time, had a Buick engine in it. When Buick stopped building the inline 6s, that's when the GMC inline 6 cylinder engines were born. Just how much of the GMC 6 cylinders might have been similar to the prior Buick 6s was not mentioned, though, but I suspect that would be highly interesting.

It was easy to see the great enthusiasm at the GMC division back then, although the production figures might have seemed "tame" by some modern standards. They were "cutting edge" trucks for the times and they were doing some neat things. A really neat book that chronicles all of those times.

We've got a set of the older light duty and medium/heavy duty truck books at work, gathering dust in the computer age. I've also got an old Sealed Power/Perfect Circle engine parts book here. Lots of interesting historical information in the aftermarket parts book!

As most of the light truck engines were rated for low octane fuels, they probably were in the 7.5 to 1 or 8.00 to 1 compression ratio range, kind of like an "export" car engine, with appropriately lower "net" power ratings. Back then, the engine the pickup came with had a plate with those ratings on the left hand kick panel, should anybody care to look (for licensing or titling or toll fee use, I suspect). Seems like the power ratings were in the front of the old Chevy light or medium duty truck parts books.

Enjoy!

NTX5467

[old-tank]

I hope no one chokes on this hotrod link here .

[brad54]

That hotrodders.com link is awesome!

For the 322 in a Chevy schoolbus chassis, there is a spec that says 310lb/ft torque. That's pretty stout for a little nailhead!

Thanks guys!

If anyone has anything else, please keep addin'!

-Brad

[Guest imported_MrEarl]

Now how much cooler could you get than a 55-56 school bus with a 322 Nailhead converted into a car hauler/sleeper loaded up with a 54 Roadmaster

[brad54]

How could that be any cooler? Easy--instead of the Roadmaster, a Special that's been built to run the La Carrera Panamericana Road Race down Mexico way!

-Brad

[Gene Brink]

Brad,

Acquired a '58 Apache pick-up four years ago and the first thing I bought was a '58 Shevrolet Truck Shop Manual (now if I could only get going on fixing the thing up!). It has a fairly short section on the 322 (which was used in the '58 10802 series Chevy bus models only in '58 [have no idea about other years]).

For '58 figures are:

195 horsepower (gross) - 170 (net)

7.7 compression ratio

310 pound feet of torque @ 2200 rpm (gross) - 282 (net)

2 barrel carb only

5 speed or automatic transmission only

Painted red with "LOADMASTER V-8" decal on each rockerarm cover

Exhaust valves have a rotator on them which I don't remember any Buick nailhead having.

Regards,

[brad54]

Cool info. I didn't think to check in Chevy truck manuals--and it's so obvious!

Good info on the power specs. Really low on the CR!

Unfortunatly, I fell asleep on the NOS truck cam that was on ebay for $10. AAaargh!

But I should probably be able to get one from NAPA or something--I'll keep researching these specs and such to find out more differences on the engines.

Bumping that compression ratio up on the truck engine to the '56 Super/Century/Roadmaster spec of 9.5:1 would put out a bunch more power, as would a 4bbl carb, everything else being equal. The cars put out 255hp @ 4,400rpm, and 341 lb/ft at 3,200rpm.

Most telling is the Special engine, with 8.9:1CR made 220hp at 4,400 and 319lb/ft at 2,200rpm--again, with a 2bbl carb.

Thanks again!

-Brad