New GM gas engines

[kevm14]

So there is the 6.6L RPO L8T that runs on 87. 401 hp and 464 lb-ft. That is going in the 2020 3/4 ton and 1 ton vehicles (maybe even heavier, too?).

I can dig up some info on that when I have more time but I knew about this for a couple weeks now. But the more interesting stuff was the reintroduction of the 4500, 5500 and 6500 medium duty trucks. And their engines. Rumors are GM is working on a large displacement engine of 8.0L or greater. OK, they had the 8100. That is gone. I did some quick research and found this:
https://www.gminsidenews.com/forums/f22 ... ec-177554/

There was an 8.0L released around 2014 that this thread thinks is actually based on an older big block design. It seems to be specifically designed for CNG or propane, the latter of which apparently runs very hot and is hard on many components (including design of the water jackets around the cylinders) if not properly designed.

https://gmserviceinsights.com/2014/04/n ... -extremes/

And this company called Origin sells it as an industrial engine.
https://www.originengines.com/Engines/80Liter.aspx
https://www.originengines.com/Portals/0 ... 5-1-18.pdf

An industrial engine basically translates to sustained, lower RPM operation. Lower power ratings are common as are lower RPMs. And the term industrial is not marketing. Look at this:

EPA Certification allows packages to operate on propane and pipeline natural gas— as well as wellhead natural gas.

Imagine one of these humming along at a natural gas well site, tapped directly off the gas coming straight out of the well. Powering pumps, lighting, equipment, etc. Now that's industrial.

But yeah evidently these are already in use in stuff from Freightliner and vehicles like school buses. Not sure if it is just due for an update and that's what the talk is all about. But the other rumor is they are partnering with International on the trucks. HOPEFULLY not on the engines. Keywords are: GM 8.0L LFI

While Ford is doing their new 7.3L gas, I might wager that this 8.0L update engine may only go in the new medium duty trucks. Could be wrong though.

I think the somewhat new-found development of these engines is due to two main factors:
- Increasing complexity of turbo diesel engines
- Favorable cost of 87 octane gas vs price of diesel fuel

Somewhere between those two factors I think there is actually a LOT of demand for these larger gas engines.

[kevm14]

Go look at that PDF. The engine is offered as an 8.0L which we already knew about, but also a 9.1L and 10.3L. Which is hilarious.

Industrial engine ratings
8.0L
233 hp @ 2800 and 469 lb-ft @ 1800 on propane
212 hp @ 2800 and 426 lb-ft @ 1800 on CNG

9.1L
290 hp @ 2800 and 540 lb-ft @ 1800 on propane
265 hp @ 2800 and 493 lb-ft @ 1800 on CNG

10.3L
310 hp @ 2800 and 615 lb-ft @ 1800 on propane
280 hp @ 2800 and 560 lb-ft @ 1800 on CNG

Those torque figures are hilarious. But again this is industrial tune. The 8.0L on gas is rated at 375 hp @ 4200 rpm and 475 lb ft of torque at 3200 rpm. 315 hp @ 4500 rpm and 390 lb ft of torque at 3500 rpm in CNG/LPG applications. So you can see how that is a higher state of tune even for the propane stuff. But you can sort of extrapolate to the larger ones.

Now this is also interesting:

Contrary to popular belief the big blocks have never gone away, they just aren’t manufactured by GM anymore.

The 8.0L here is based on the Gen VI L29 7.4L architecture and is actually manufactured by a company called Powertrain Integration ( http://powertrainintegration.com/) where they sell their engines to large truck manufacturers like Freightliner, Navistar, etc. for specialty vehicles. They are also used as well pump power engines as well as starter engines to start huge oceanliner diesel engines not to mention they are widely used in the marine industry. GM also buys them to sell through their service parts group and performance parts.

Similarly, the 8.1L architecture now belongs to a company called Power Solutions International ( http://www.psiengines.com/) where purchased the rights to manufacture the L18 8.1L which they sell as an 8.8L version as well. These engines are also purchased by large truck manufacturers like Freightliner and Navistar as well as stationary power plants, well pump power engines and marine just like PI on the 8.0L.

Basically you have two different companies that now own the rights to two similar versions of the GM big block. Both companies are competing for the same business. Think if PSI and PI as a gas equivalent of Cummins where they sell loose engines to manufacturers and end users. This will be interesting to see how this turns out in years to come.

With the high cost, complexity and dwindling durability/reliability of today’s modern diesel engines it is a perfect time to see a major return of big block gas engines coming back to certain vocational trucks where they can run on gasoline, propane and natural gas. These big blocks are perfect for that! Navistar totally missed the boat when they had the opportunity to purchase the 8.1L architecture from GM back in 2009. It would also be interesting to see if GM ever reinters the medium duty market and if so, if they would buy one of their own engines they sold to someone else to use back in production of a future truck. A GM engine built by someone else other than GM in a GM vehicle. Hmmm, lots to ponder but I wouldn’t rule anything out.

Big blocks are my thing, hence the avatar......Not sure if I mentioned it here before, but I shoved a L18 8.1L into a ’78 K10 back in 2008. It now has 30K on it and runs like a dream and pulls like a freight train. I am currently doing the same L18 swap into an ’89 Suburban right now. The 8.1L is a piece of cake to swap and makes the little LS engines look like kids toys in big trucks. Sure the Gen III LS is a great HP engine, it just doesn’t have any real word torque to propel large trucks where the 8.1L does. In stock form it is already making over 300 lb. ft. of torque at idle. Can’t say that for an Gen III small block that doesn’t make any torque until you spin the hell out of it at 4,000+ RPMs. Once you start playing with the cam profile, add direct injection and engine calibrations on these big blocks it is not difficult to reach well above diesel torque numbers with these beasts. That is why PI and PSI are really pushing these two engines to the alternative fuel market. Say you never heard of a BBC with over 700 lb ft of torque running on Natural Gas? Keep watching this market in a few years.

Fascinating. That post is from 2014. Especially this part:

Navistar totally missed the boat when they had the opportunity to purchase the 8.1L architecture from GM back in 2009. It would also be interesting to see if GM ever reinters the medium duty market and if so, if they would buy one of their own engines they sold to someone else to use back in production of a future truck. A GM engine built by someone else other than GM in a GM vehicle. Hmmm, lots to ponder but I wouldn’t rule anything out.

I think that may be precisely what we are dealing with here. 5 years later.

[kevm14]

http://gmauthority.com/blog/2018/10/201 ... dium-duty/
https://www.internationaltrucks.com/trucks/cv-series

Chevrolet has already announced its 2019 Silverado Medium Duty trucks – the Class 4 Silverado 4500HD, Class 5 Silverado 5500HD and Class 6 Silverado 6500HD – that was developed in conjunction with Navistar due to a new partnership with GM. Navistar is to have a version of the truck for its International brand, but we have yet to see International’s version of the truck – until now.

Though Navistar has yet to officially announce its own model, we just got our hands on a brochure for the new truck – giving us a significant amount of information on the vehicle, some of which is rather noteworthy.

Set to be called International CV Series, Navistar is positioning its model as a truck “designed, distributed and supported by a manufacturer that specializes in commercial trucks”.

Like the 2019 Silverado Medium Duty, the new International CV truck is offered in Regular Cab or Crew Cab configurations, with wheelbases ranging from 141″ to 243 inches. The trucks look almost identical to the Silverado Medium Duty, while featuring a different grille with vertical slats. It also features the same high-strength steel frame rail, available air ride rear suspension, and forward-tilting hood with easy-to-reach maintenance points.

The CV Series is powered exclusively by the same 6.6L Duramax turbo-diesel V8 engine (L5D) as in the Silverado Medium Duty. The engine is the sole powerplant for both trucks, at least for the time being. Sending power to the wheels will be a 6-speed Allison transmission in either 1700, 1750, or 2700 series configurations.

Interestingly, Navistar’s brochure for the International CV truck only lists Class 4 and 5 versions, not making any mention of a Class 6 model. Meanwhile, the 2019 Silverado Medium Duty will be offered in Class 4, 5 and 6 versions ranging from a GVWR of 15,000 to 23,500 pounds.

To top it all off, Navistar says that “the CV Series is supported by the largest commercial dealer network in the industry with more dedicated truck bays and diesel technicians than anyone else.”

No pricing for the International CV is available just yet, but the 2019 Silverado Medium Duty starts at $48,685 – which should provide a fairly good idea of the price of Navistar’s variant. Both trucks are manufactured at the Navistar plant in Springfield, Ohio, with an on-sale date in late fall 2018.

[kevm14]

On what the 8.0 LFI is (which GM had ready around 2010 for medium duty trucks but got out of that market in the downturn/bankruptcy):

Yes, the Mark VI Big Block, not the LS. The production Big Block Marks are as follows:
Mark I, 1958-1964 348 and 409.
Mark II, 1963 427.
Mark III, design study only.
Mark IV, 1965-1990 366, 396, 402, 427, 454.
Mark V, 1991-1995 366, 427, 454.
Mark VI, 1996-2001 Vortec 7.4L.
Mark VII, 2001-2010 Vortec 8.1L.

This 8.0L is based on the Mark VI Big Block, not any LS and not the Mark VII 8.1L. Nonetheless, I really doubt the 8.0L is the rumored new engine. It does not have VVT or DI in current form.

And this guy has some good info but I take it with a grain of salt, mainly because I think he may be mistranslating certain things.

The 8.0LFI engine was never classed as a Mark engine because GM didn’t get that far in 2010. It was never a complete fully running engine for GM. Even today, it is sold without any intake manifold, because GM never built it with one. When Brian Thomson developed and tested it, he put an aftermarket intake manifold on it. That is why Brian sent the first three engines he built and tested over to the other company in Michigan, so they could design and make an industrial suitable low RPM torque intake manifold with the fittings for propane. I only talked to that other shop about three times and they got caught short because GM stopped selling Medium Duty trucks. GM was going through a bailout and both the Canadian and Ontario and U.S. governments took billions worth of shares to help GM. Once again, there is no MARK label ever put on an incomplete engine. But, GM could now be adding a cam phaser to it, to boost the low end by about 35 to 55 extra lbs feet of torque. Brian told me that only one part was the same as the 8.1 liter engine. It was a clean sheet design, so GM could sell this truck engine to those who wanted to run it on propane or natural gas. By the way, when Brian got the engines running, they did not use a forged crank. That really shocked me and i told the GM engineer in his shop, that they were making a big mistake by using a cast crank. The other aftermarket companies got Callies to make a longer stroke 4.5 inch forged crank. That is how PSI sells it today.

Clean sheet redesign that seems a lot like a Mark VI BBC?

[kevm14]

Whew.

Homer says:
February 19, 2019 at 6:00 am
Power Solutions International, (PSI), produces a 8.8l engine which is the market leader in gaseus fuel MD and HD truck powertrain. PSI is a large producer of engines for various transportation and stationary applications. They inherited conversion of GM LS based trucks for cng and lpg from another company that got out of the automotive business.

Reply
Homer says:
February 19, 2019 at 6:29 am
Because Navistar is currently using the PSI 8.8l engine, MD industry rumor is that this is the engine that Navistar will install in the 4500/5500/6500 MD they produce and brand as GM.

Reply
MARK SMYTH member of the SAE since 1988 says:
February 20, 2019 at 2:38 pm
Yes, this is the PSI Illinois based company that uses the new design 8.0 liter GM developed big block in 2010. After Brian Thomson of Thomson Automotive developed and tested the 6 first engines that GM contracted to him, Brian sent the first 3 engines over to the other Michigan company for the propane intake manifold and testing. Brian only tested the engines on gasoline, ( he used a 10 to one compression ratio ) as he was not a propane expert. That other Michigan company DID NOT go out of business, it was bought by PSI. Yes, PSI offers both smaller LS type GM propane and CNG fueled powerplants, but they also offer huge 16 liter industrial versions and others of 35 Liter ( 2,136 cubic inch ) and 40 liter ( 2,440 cubic inch ) size. Here is the link to the GM industrial new design 8.0 liter as FIRST built in 2010, for those who keep ignoring the various TRUE facts that i keep posting. link https://gmpowertrain.com/engines/8l-lfi.html

Reply
Bob B. says:
February 20, 2019 at 8:09 pm
Powertrain Integration was the company marketing the 8.0L to OEM’s, PSI was doing the 8.1L based 8.8L, which PSI assembles themselves. PSI did buy Powertrain Integration a few years ago. I think the company that was doing the CNG conversions of LS powered trucks was Impco, who did get out of the OEM CNG upfit business. PSI has taken over as GM’s preferred CNG conversion upfitter.

Reply
Homer says:
February 21, 2019 at 8:10 am
Bob, you are correct. IMPCO is still in business, but not performing final assembly of bi fuel vehicles for GM. IMPCO’s GM business and some of their personnel shifted to PSI. The 8.8l engine is a PSI designed and assembled engine, architecturally based on 8.1l. Back on story subject for GM engine larger than 6.6l. unconfirmed information to me from a manufacturer’s employee is that Navistar will assemble GM branded 4500/5500/6500 MD with PSI 8.8l engine with engineering integration performed jointly between Navistar, GM, and PSI pending successful completion. So the question posed in the first post is an unconfirmed yes.

Reply
Bob B. says:
February 21, 2019 at 9:56 am
Might be a little more to it than that! We will have to wait and see, but I do think the PSI 8.8L has a future.

Arguing whether that 8.8L is based on the 8.0L LFI or the Vortec 8100. Kind of an interesting story here. Someday maybe someone will write an article (maybe Hot Rod?) about all of this when the trucks come out. If that is of any interest to Hot Rod readers. Or maybe some other publication.

One thing that came out of this is a plausable answer on why the 8.0L LFI was based on an older big block design. And that is mainly cooling to support hardening for propane use. I don't know if the older 454 had a "better" water jacket design or if somehow starting with that design got them closer to where they needed to be, rather than modify the 8100.

[rpaoness]

I wonder if these will have the "standard" big block bellhousing pattern and mate with a typical 4L/5L80E or Allison 1000.

[kevm14]

From above:

The CV Series is powered exclusively by the same 6.6L Duramax turbo-diesel V8 engine (L5D) as in the Silverado Medium Duty. The engine is the sole powerplant for both trucks, at least for the time being. Sending power to the wheels will be a 6-speed Allison transmission in either 1700, 1750, or 2700 series configurations.

So, those. All heavier than even the Allison 1000. The lightest non-Allison transmission I could possibly see is the 6L90. That transmission is still going to be common even on the 2020 redesign for 2500s and 3500s but I would be surprised to see it in a medium duty application.

Of course your question stands. Not sure about the bolt pattern. Even if we saw an Allison 1000, I am pretty sure Allison could supply any bellhousing pattern, per customer requirements. So even that wouldn't prove anything.