Demise of the Big Block Engine?

[Joe L.]

While I've not been able to confirm it yet, it appears that the manufacture of the big block engine by GM has ceased. The last big block produced by GM was the 8.1L, aka "Gen VII". However, installation of this engine in any Chevrolet or GMC pick-up truck ended about 2 years ago. The 8.1L continued to be available in MD trucks such as the Kodiak, but GM sold off the MD truck line some time ago. So, there is now no PRODUCTION use of the 8.1L engine for any GM vehicle.

I also find that GM no longer offers the 8.1L engine for marine or industrial applications. Their "big" engine now for marine applications is a 6.2L supercharged engine similar to the engine used in the Cadillac CTS-V. But, NO big block.

Of course, as far as I know, SERVICE big block engines are still available. However, I believe these engines are actually assembled by a GM contract engine assembler from GM components. I don't think that Tonawanda has produced any big block except the 8.1L for several years.

I very much doubt that the big block engine assembly line at Tonawanda is still in operation. With no PRODUCTION applications and no major marine or industrial offerings, I just can't see GM keeping this going. So, what began in 1965 (and, actually, in late 1957 for the Mark I big blocks) may finally have come to an end. In the event it has not actually come to an end, I would expect that its days are VERY numbered.

[Bill M.]

Re: Demise of the Big Block Engine?

I very much doubt that the big block engine assembly line at Tonawanda is still in operation.

Joe:

My most vivid memory of the Mark IV line (summer '69) is the guys who installed the cylinder heads; one guy on each side of the line. They looked like professional fighters...very tall and very strong.

Bill

[Clem Z.]

Re: Demise of the Big Block Engine?

While I've not been able to confirm it yet, it appears that the manufacture of the big block engine by GM has ceased. The last big block produced by GM was the 8.1L, aka "Gen VII". However, installation of this engine in any Chevrolet or GMC pick-up truck ended about 2 years ago. The 8.1L continued to be available in MD trucks such as the Kodiak, but GM sold off the MD truck line some time ago. So, there is now no PRODUCTION use of the 8.1L engine for any GM vehicle.

I also find that GM no longer offers the 8.1L engine for marine or industrial applications. Their "big" engine now for marine applications is a 6.2L supercharged engine similar to the engine used in the Cadillac CTS-V. But, NO big block. there are plenty of aftermarket vendors for both engines out there now.

Of course, as far as I know, SERVICE big block engines are still available. However, I believe these engines are actually assembled by a GM contract engine assembler from GM components. I don't think that Tonawanda has produced any big block except the 8.1L for several years.

I very much doubt that the big block engine assembly line at Tonawanda is still in operation. With no PRODUCTION applications and no major marine or industrial offerings, I just can't see GM keeping this going. So, what began in 1965 (and, actually, in late 1957 for the Mark I big blocks) may finally have come to an end. In the event it has not actually come to an end, I would expect that its days are VERY numbered.

i wonder how long BBC crate engine will be around as i bet they are not casting them anymore. same for the old SBC how long do you think they will be casting them as the LS has been out for over 10 years. there are plenty of after market people casting both SBC and BBC blocks and heads

[Clem Z.]

Re: Demise of the Big Block Engine?

i wonder how long BBC crate engine will be around as i bet they are not casting them anymore. same for the old SBC how long do you think they will be casting them as the LS has been out for over 10 years.

i will be going to the PRI show in orlando in a couple of weeks and if any one of the old timers i used to deal with are at the GMPP booth i will see what i can find out.

[Joe L.]

Re: Demise of the Big Block Engine?

i will be going to the PRI show in orlando in a couple of weeks and if any one of the old timers i used to deal with are at the GMPP booth i will see what i can find out.

clem------


That would be great.

[Joe L.]

Re: Demise of the Big Block Engine?

i wonder how long BBC crate engine will be around as i bet they are not casting them anymore. same for the old SBC how long do you think they will be casting them as the LS has been out for over 10 years. there are plenty of after market people casting both SBC and BBC blocks and heads

clem-----


The small block engine might be around for somewhat longer. They have a line set-up at the Toluca, Mexico engine plant for it and they can probably sell enough SERVICE engines and parts to justify it for awhile. Plus, these engines still represent the core of their marine engine market. I would imagine there are a lot of "marine guys" that don't want an engine made of aluminum, in whole or part, and all the marine LS engines at least have aluminum heads. That might be ok for the "fast boat" guys but not for the "bread-and-butter" applications like commercial fishing, etc.

The big blocks are different, though. I just cannot see GM setting up a line at Toluca for them---there just wouldn't be enough demand to justify the cost.

[Clem Z.]

Re: Demise of the Big Block Engine?

there are no more "mark 4" blocks but GM has improved the "mark 5 and Mark 6 " blocks to use the mark 4 heads and head gaskets

[Joe L.]

Re: Demise of the Big Block Engine?

there are no more "mark 4" blocks but GM has improved the "mark 5 and Mark 6 " blocks to use the mark 4 heads and head gaskets

clem-----


I don't think that Tonawanda has produced any Mark IV big blocks since 1991. When the Gen V came into PRODUCTION in 1991, production of the Mark IV ceased. Then, when the Gen VI came into production a few years later, I think the manufacture of Gen V ceased.

GM did put some Mark IV pieces back into production for awhile in order to satisfy truck fleet operators who howled about the lack of availability of service parts, but I think that manufacture has ceased now.

When the 8.1L went into production several years ago, it was my understanding that Tonawanda ceased production of all earlier big blocks. The 8.1L is considerably different than earlier big blocks and I don't think it can be produced on the same equipment or assembly line as the earlier engines.

Of course, GM does still offer Gen VI big blocks for SERVICE. I don't know where the major components for these are manufactured. However, I think that assembly is done by a contract outfit that assembles a lot of the GMPP non-PRODUCTION engines.

[Clem Z.]

Re: Demise of the Big Block Engine?

they are still selling 11 BBC crate engines from 427 CI to 572 CI and lots of parts to build your own. i guess the BBC will be around till the demand goes away. GM is pushing the LS series with crate engines up to 454 CI and they are available with carbs. these crate engine 454 LSX series make up to 620 HP and 590 # ft of torque on 92 octane gasoline where the BBC crate engine 454 CI makes only 440HP and 500 # ft of torque on 92 octane. the LS series is the way to go if you are looking for HP per CI. the 92 octane BBC 572 CI makes 620 HP and 650 # ft of torque. the 8.1 block was the same as the other BBC with 4.250 bore and a 4.375 stroke. the heads were different as they had equal spaced intake ports not 2 by 2 like the other BBC. the head bolt pattern was also a little bit different because of the porting. there is a company making aluminum heads to fit the 8.1 block for lighter weight. 8.1 or 496 CI is a common size being built for racing by the after market. i could not find out if GM is still casting BBC blocks and heads and if not they must have a very large supply stored somewhere.

[Clem Z.]

Re: Demise of the Big Block Engine?

looks like GM is still selling the 8.1 marine engine for 2010. http://www.gm.com/experience/technol..._HP_Marine.pdf

[Dick W.]

Re: Demise of the Big Block Engine?

What one tends to forget that the Tonawanda engine machine line has been there since 1957. Same basic line that did the Mark I or "W" series engine. Tooling is not very flexible compared to todays modern machine tools.

[Joe L.]

Re: Demise of the Big Block Engine?

looks like GM is still selling the 8.1 marine engine for 2010. http://www.gm.com/experience/technol..._HP_Marine.pdf

clem------


I missed that. I checked the GM Powertrain site prior to posting my original message. I could not find the 8.1L at that time, even in the 2010 Marine or Industrial engine section. Perhaps, they realized their mistake in not including it and added it to the site. In fact, at the time I checked it, they had a picture displaying all of their marine engines and the 8.1L was not among them. I'm very glad to see that it's not discontinued.

Quite a few years ago, about during the early 90's, I toured the Tonawanda engine plant with Ken Kaiser who was the big block manager at the time. At that time they were manufacturing the Gen V engine. Ken told me that when they stopped manufacturing the Mark IV engines, they had no plans to manufacture any more of these engines or parts thereof. However, due to protests from the fleet truck operators, they put some of the Mark IV engines and/or parts thereof back into production.

One big problem he explained to me was the fact that the Gen V block had no provisions for a mechanical fuel pump and this was a big part of the basis for the fleet operator complaints. At the time I was there, Tonawanda had no capability of machining the fuel pump pad area since the Gen V block had no provisions for it and their capability apparently "went away" with the Mark IV. However, Ken told me that as part of the plan to add the boss back to some of the castings (manufactured elsewhere) and machine it at Tonawanda for SERVICE applications, they were in the process of obtaining certain machining equipment which GM owned from the Mercury Marine plant in Stillwater, OK which manufactured the LT5 engine. Since that engine was out-of-production by that time, the equipment was available and could be used for the fuel pump pad machining process.

The Gen V engine was rather short-lived and was soon replaced by the Gen VI. I don't think that any Gen V engines were ever made with the fuel pump provisions but it's possible some were. The Gen VI engine definitely had a SERVICE-only block which had mechanical fuel pump provisions. However, it was/is available only in 4.250 bore size.

A few years ago when the 8.1L ("Gen VII") engine was introduced, I saw an article and pictorial presentation in Automotive News which said that when the 8.1L engine went into production at Tonawanda, the manufacture of all previous big blocks ended. However, it was not clear on whether the manufacture of COMPONENTS for earlier engines also ended.

It is very possible that components (e.g. blocks, heads, cranks, rods, etc.) for earlier engines are still manufactured at Tonawanda. However, if the Automotive News article was correct, I don't think that any SERVICE big block engine assemblies (except 8.1L) are manufactured there. So, I expect that the crate big blocks are assembled at the same contract vendor as some other SERVICE-only engines (i.e. the"ZZ4", "ZZ383", etc.) from, possibly, Tonawanda-manufactured components..

[Joe L.]

Re: Demise of the Big Block Engine?

looks like GM is still selling the 8.1 marine engine for 2010. http://www.gm.com/experience/technol..._HP_Marine.pdf

clem------


I just went back and checked the GM Powertrain web-site page for marine engines. I found the same thing I found the last time---no listing of the 8.1L engine. In the text of the main marine engine page it says that they have available marine engines in 1.4 to 6.2L displacements. They also picture all of the engines and no 8.1L is shown.

I realize the link that you posted appears to be a 2010 listing for the 8.1L engine, but I just don't see how it fits in with the information on the page I viewed. Here's a link to that page:

http://www.gm.com/experience/technology/gmpowertrain/engines/specialized/marine/marine_engines.jsp

[Clem Z.]

Re: Demise of the Big Block Engine?

clem------


I just went back and checked the GM Powertrain web-site page for marine engines. I found the same thing I found the last time---no listing of the 8.1L engine. In the text of the main marine engine page it says that they have available marine engines in 1.4 to 6.2L displacements. They also picture all of the engines and no 8.1L is shown.

I realize the link that you posted appears to be a 2010 listing for the 8.1L engine, but I just don't see how it fits in with the information on the page I viewed. Here's a link to that page:

http://www.gm.com/experience/technol...ne_engines.jsp

i would think the 8.1 would have to be available for a few years as the ones in the trucks and suburbans were warrantied for 5 years and they just stopped putting them in these vehicles and same for the boat engines.

[Joe L.]

Re: Demise of the Big Block Engine?

i would think the 8.1 would have to be available for a few years as the ones in the trucks and suburbans were warrantied for 5 years and they just stopped putting them in these vehicles and same for the boat engines.

clem-----


I agree. There would definitely have to be 8.1L engines available for SERVICE requirements as well as component parts. However, it could be that they built up an inventory for this purpose (like they did for the LT5 engine way back when).

For example, consider that the 3.8L V-6 engine went out-of-production about a year ago. In fact, I think the only plant where it was manufactured has been demolished. GM has a lot of these engines out there and will have a long-term warranty commitment, especially given the 100,000 mile warranty and the extended warranties that they have sold. So, they must have built up an inventory of engines and spare parts before the line was shut down.