Flint or Tonawanda

[Frank Bernier]

hi guys

First question
My 69 vette is 427 L-68 400hp tri-power 4 speed
the production plant is St-Louis
Is the engine pad should start with a "V" for flint or "T" for tonawanda ???
(manufactured source code letter)

second question
does it sounds right ... ENGINE BLOCK 3955270 ...the casting date of my engine is SEPTEMBER 24 1968 the engine assembly date is DECEMBER 2 1968 and car assembly date is DECEMBER 17 1968
is the time span between casting date and engine assembly date could be right ?

thanks
frank

[Stephen L.]

Re: Flint or Tonawanda

All sounds good to me. BB were made at Tonawanda.....

[John H.]

Re: Flint or Tonawanda

The crew at Tonawanda just loved "big-blocks", and they were nothing new to them in the 60's; they built Pratt & Whitney R-2800's (2,000hp) during WWII (from the GM Heritage Center engine display)

[mike cobine]

Re: Flint or Tonawanda

An original porcupine, John?

[John H.]

Re: Flint or Tonawanda

Outgunned only by the 36-cylinder Wright R-3350 turbo-compound "corncob" engines used on the B-36 (only needed 432 spark plugs for a plug change on a B-36)

[Joe L.]

Re: Flint or Tonawanda

John-----

I believe that the B-36 used Pratt and Whitney R-4360 engines (for its 6 reciprocating engines). In terms of cylinders, this was the largest ever built in the US. They had 28 cylinders (4 rows of 7) and a rated horsepower of 3,800. I think that there was another version called the R-4600 that was actually larger in displacement, but it wasn't used in the B-36. It may have been used for Howard Hughes' H-2 ("Spruce Goose").

The R-4360 was also used in the Boeing B-50, which was the follow-on to the B-29. The main difference was the engines. The B-29 used the R-3350s and the B-50 used the R-4360. Some versions of the B-50 were also assisted by 2 jet engines.

I think that the R-3350 "turbo compound" engine had 18 cylinders with 2 rows of 9 cylinders. It was rated at about 2,200 hp in the B-29, but I think that it may have been up to about 3,000 hp for other applications. It was also used in the Douglas DC-7, Lockheed Super Constellation, and Boeing Stratocruiser.

[John H.]

Re: Flint or Tonawanda

Joe -

You're absolutely correct - the R-4360 was the "corncob" . The turbo-compound R-3350's primary application was for the DC-7B, but it had so many reliability problems in that passenger application (complexity), many 7B's were retrofitted back to the non-compound configuration for passenger service or were re-configured for freight service. Gotta admire the mechanics in those days that kept those extremely complex supercharged twin-row radials running in scheduled service

[Joe L.]

Re: Flint or Tonawanda

John-----

I used to have a good friend that once flew commercial aircraft with the R-3350 engines. He said that on take off the co-pilot kept one hand on the throttles and one hand on the fire extinguishers!

The turbo compound engine was an exercise in how to get absolute maximum power out of a given number of cubic inches for a radial aircraft engine. But, as with most things, there are "compromises". And, the compromise here was reliability-----not something that one really wants to have in question with an aircraft engine.

About 10, or so, years ago Sara and I were up on Vancouver Island. We stooped at a place called Port Alberni. Nearby was the base for Forest Industries Flying Tankers, the fire-fighting arm of the timber company MacMillan-Bloedel. They had what has to be just about the most ingenious aerial firefighting operation in the world. Their seaplane aircraft are fitted with bottom scoops and they are based on a long, narrow lake. To refill their water tanks, they simply fly down close to the lake and scoop it up. Then, they're off for another pass. The operation, though, is contingent upon the "core" equipment. That equipment consisted of 2 Martin Mars flying boats, the largest flying boats ever built, converted for their unique and efficient forest fire fighting operation.

These aircraft use the P&W R-4360. I spoke for quite awhile with the pilots and mechanics. The mechanics told me that an important item to the company was keeping spare engines and props in inventory. They said whenever these engines or props come up for sale anywhere in the world, one of their people will be dispatched immediately to buy them. And, he said that no one had ever or would ever outbid them for what they're after.