54-55 vs 56

[wolfpupsdad]

what makes the 56 322 more desirable over the 54 and 55 ? or is there anything at all?

[brian barling]

This is an interesting read on the Nailhead.
Not as involved as some I have read, but good non the less.
The 3 years the 322 was produced it was upgraded each year, with 1956 being the most desirable of the three. Better Cylinder heads,higher compression and I believe even Piston design.
http://en.wikipedia.org/wiki/Buick_Century

[raycow]

The 3 years the 322 was produced it was upgraded each year, with 1956 being the most desirable of the three. Better Cylinder heads,higher compression and I believe even Piston design.
http://en.wikipedia.org/wiki/Buick_Century

The 322 engine was installed in Buick passenger cars for four model years (1953-56) and was installed in Chevrolet trucks until 1959.
http://chevy.oldcarmanualproject.com...to/59ted12.htm

Ray

[brian barling]

The 322 engine was installed in Buick passenger cars for four model years (1953-56) and was installed in Chevrolet trucks until 1959.
http://chevy.oldcarmanualproject.com...to/59ted12.htm

Ray

Yes Ray, you are absolutely correct, how I did the math to get 3 years, is well embarrassing.
I apologize for my error. 1953-1956 is 4 model years for sure, thanks for getting this right!

And the Truck usage is indeed correct as well, but that seems to surprise alot of people that were not aware that this great engine was used in the Truck Line thru 59

[raycow]

And the Truck usage is indeed correct as well, but that seems to surprise alot of people that were not aware that this great engine was used in the Truck Line thru 59

It's a mystery to me too. One of the reasons Chevy developed the 348 was so that they could have an engine for their heavy trucks. I would love to find out why the Buick engine wasn't discontinued (in trucks) after 1957.

Ray

[brian barling]

Ray, do you think that GM was nervous to put an unproven new Big cubic inch engine in a Truck application, they are considered severe duty and suffer stress cycles and failures that automotive applications do not see.
GM had just gone through so many updates in their model line. IE: First V-8 passenger Car Engine (1955) First Passenger Car Open Driveline (1955) Also were 1/2 model year behind with the 1955 Pick-up Truck after spending so much of their resources in the 1955 Model year Car Model. I love the Buick Nailhead Engine and think that GM used it as a security blanket in the truck models until they were confident in there new W style V-8 engines.
your thoughts on this are appreciated!
Brian

[raycow]

Ray, do you think that GM was nervous to put an unproven new Big cubic inch engine in a Truck application, they are considered severe duty and suffer stress cycles and failures that automotive applications do not see.

Brian, that's part of the mystery. Chevrolet DID offer the 348 in their heavy trucks in 1958 and 1959, right alongside the 322.

http://chevy.oldcarmanualproject.com...i/58npi43.html

Ray

[bhambulldog]

The 322 was improved each year. Also the Dynaflow transmission had improvements each year. '55 having an improved Turbine. And, '56 having the variable pitch available for the Low and Reverse as well as Drive.

I don't agree however that, the under-seat heater deletion from the '56 is an improvement

[MrEarl]

More horsepower would be my first reply. up from 54's 200 HP and '55's 236 HP to 255 HP in '56. They achieved this via increased compression ratios (9.0 - 1 in 55 to 9.5 -1 in '56), using a new Y-type and dual exhaust, new camshafts and exhaust valves and new combustion chamber designs. The engines also stayed together better by continuing to use the pressed in wrist pins which started in 55.
As someone already mentioned the piston dome height increased in 55 and again in 56. The cylinder head combustion chamber changed on the valve side for better breathing. They also went to a hotter cast iron cam. And finally, a new increased flow capacity water pump.