Mystery engine

[Michael G.]

I've come across what I initially thought was a short block from a '66 Corvette. The pad is stamped with T0112HT (no VIN) with a casting #3858180. The HT would indicate 327/350hp manual transmission however I don't see where that casting # was used. Any clarity appreciated.

[Joe L.]

Re: Mystery engine

I've come across what I initially thought was a short block from a '66 Corvette. The pad is stamped with T0112HT (no VIN) with a casting #3858180. The HT would indicate 327/350hp manual transmission however I don't see where that casting # was used. Any clarity appreciated.

Michael------


Yes, the 3858150 block was used for some 1966 Chevelle applications. However, as I recall, these engines were rated at 325 HP and not 350 HP. They were designated L-79 and had the same internal parts as other L-79's but were rated a little lower. In fact, in 1966 a salesman at McCullough Chevrolet in Hayward, CA tried to talk me into going with one of these rather than the SS 396 I really wanted. I didn't bite, though, and held out for the 396.

As can be seen from the engine code you mentioned, this was a Tonawanda-bult engine. I believe the 3858180 block was only cast at the Tonawanda foundry, with most machined and assembled at the Tonawanda engine plant. However, a few of these blocks might have been machined at Flint and installed in Corvettes. The fact that there is no VIN derivative on the stamp pad would indicate this was a SERVICE complete engine assembly.

[Michael J.]

Re: Mystery engine

My '66 L79 was stamped Flint, not Tonawanda. I don't think I have seen a '66 Corvette small block from Tonawanda.

[David L.]

Re: Mystery engine

I have a 1966 Chev. 327 engine with a "3858180" casting number and a "E 18 6" (or maybe "E 16 6") casting date stamped "T0521HAR" (Tonowanda, May 21, 327 w/M.T. and Roch. 4 bbl.). I bought the engine back in the 1980's complete with all the original matching date components (starter, fuel pump, carb, etc.) for $25. I have never seen a 3858180 block in a Corvette but have heard that they were used for a short time during the 1964 Corvette production because of a shortage 3782870 Flint blocks.

Dave

[Terry M.]

[Dan A.]

Re: Mystery engine

[Michael W.]

Re: Mystery engine

The engine in question has a Tonawanda assembly code. No Corvette ever came with a small block engine assembled there AFAIK.

[Joe L.]

Re: Mystery engine

My '66 L79 was stamped Flint, not Tonawanda. I don't think I have seen a '66 Corvette small block from Tonawanda.

Michael------


All Corvette small blocks were machined and assembled at Flint. For the most part, Flint's source for castings was the Saginaw gray iron foundry. However, a small number of Tonawanda castings were shipped to Flint.

The thing that sometimes confuses folks is that Tonawanda at one time had BOTH a foundry and an engine plant. They were separate operations but they were co-located. So, it is possible to have casting manufactured at the Tonawanda foundry but machined and assembled at Flint. It's also possible to have a Saginaw casting that was machined and assembled at the Tonawanda engine plant.

When discussing Tonawanda one has to be specific as to whether one is talking about the FOUNDRY or the ENGINE PLANT or BOTH. The Tonawanda foundry was shut down permanently in 1984 but the engine plants there continue to this day. They don't manufacture Gen I small blocks or any big blocks anymore but they still make engines. Among them, they will be manufacturing the new Gen 6 LT1 engines.

So, what was the source of castings for the Tonawanda engine plant after the Tonawanda foundry shut down? Mostly, it was the GM foundries located in Defiance, OH.

[Terry M.]

Re: Mystery engine

Michael what is the casting date?

There were a small number of 180 Tonawanda cast Flint machined and assembled blocks used in 1965 Corvettes and this is recognized in the judging manual. I was given to understand that this came about due to a labour problem. But in a recent conversation with Mark Gorney he spoke of a the two foundries, Saginaw and Flint exchanging so to speak raw castings for quality control reasons. Mark worked for Central Foundry for years I think. I believe this is what Terry M is also referring to as well. The recognition of this practice in the 68-72 manuals is refreshing

That information has been in the 1970-72 TIM&JG since 1993, and in the 1968-69 manual nearly as long. It ought to be no secret, but just like I don't read the other manuals folks with interests other than 1968-1972 probably don't read those manuals. The class isolation within NCRS is a loss to all of us.

[Richard M.]

Re: Mystery engine

Michael------


All Corvette small blocks were machined and assembled at Flint. For the most part, Flint's source for castings was the Saginaw gray iron foundry. However, a small number of Tonawanda castings were shipped to Flint.

The thing that sometimes confuses folks is that Tonawanda at one time had BOTH a foundry and an engine plant. They were separate operations but they were co-located. So, it is possible to have casting manufactured at the Tonawanda foundry but machined and assembled at Flint. It's also possible to have a Saginaw casting that was machined and assembled at the Tonawanda engine plant.

When discussing Tonawanda one has to be specific as to whether one is talking about the FOUNDRY or the ENGINE PLANT or BOTH. The Tonawanda foundry was shut down permanently in 1984 but the engine plants there continue to this day. They don't manufacture Gen I small blocks or any big blocks anymore but they still make engines. Among them, they will be manufacturing the new Gen 6 LT1 engines.

So, what was the source of castings for the Tonawanda engine plant after the Tonawanda foundry shut down? Mostly, it was the GM foundries located in Defiance, OH.

Joe I'd just like to say it's great that you share this information with all of us here. I love to read your posts and always save your info away in my personal Corvette data archives. I didn't know some of the details you just explained.

I felt compelled to state this..... Thanks for being here.

Rich

[Leif A.]

Re: Mystery engine

Joe I'd just like to say it's great that you share this information with all of us here. I love to read your posts and always save your info away in my personal Corvette data archives. I didn't know some of the details you just explained.

I felt compelled to state this..... Thanks for being here.

Rich

Well said, Richard...I couldn't agree more.

[Joe L.]

Re: Mystery engine

One more thing I should have mentioned about Tonawanda. In addition to the FOUNDRY and ENGINE PLANTS, there was also once-upon-a-time a FORGE located in the Tonawanda manufacturing complex. At the time, GM had 3 forging operations. One in Detroit, one in Tonawanda, and another in Buffalo, NY.

About 20-odd years ago, GM "spun off" the forging operations to American Axle and Mnaufacturing (AAM), headed by Richard Dauch, a former GM "big wig". AAM refurbished the run down forging operations and operated them for about 15 years. However, I believe that all three have now been shut down, although I'm not certain. As far as I know, AAM now does all its forging operations in Mexico.

Since the "spin off", I don't think that GM has any in-house forging capability, at all.