(first posted 10/21/2013) This is not how you’re probably used to having a Chevy 250 six look. North American Chevy sixes had one barrel carbs, and were never offered in any state of tune except mild. But In Brazil, the long-lived six as used in the Opala and Comodoro and Diplomata and ultimately the Omega continued to be developed further. For the first three years of the Omega, it used an Opel 3 Liter six, But for 1995, the 250 (now called 4.1) was sent to Lotus for a working-over. The result was fuel injection and other modernization, and 168 net hp; roughly about the same as the four-barrel OHC Pontiac Sprint six (215-230 gross hp).
Here’s the car it was used in. This is the generation of Omega before the one that was sent stateside as the Catera. As the story is told, Lotus built a DOHC head for the 4.1, which was good for 250-300 hp. But GM Brazil decided to stick to the lower-cost version with a reworked OHV head. It only lasted until 1998, when the next gen Brazilian Omega was imported from Holden, a re-badged Calais, with the 3.8 L V6.
Seen in the UK as a Vauxhall Omega.They were also used as Police cars here though I’ve not seen an Omega for a long time
I almost would be tempted to swap that in place my 305 V8 in my 77 Chevelle… that would actually be kind of awesome!
Too bad the Catera did not get the inline 6. I had no idea that this old jewel stayed around so long.
A straight-6 was supposed to not fit into the 2nd-gen Opel Omega which originated the Catera, but hey, some Diesel versions of the 2nd-gen Omega were powered by BMW straight-6 engines…
!
I continue to be impressed by what I learn on this site about what foreign subsidiaries have done with obsolete US designs, engines, and other elements: Kaiser Torino, Opala, and now this.
168 horsepower does not make this engine a powerhouse, but I suspect that with a few tuning tweaks it would be competitive with the hot Slant Sixes and Ford sixes that the aftermarket is making possible. Does a Slant Six vs. Ford six vs. Pontiac OHC six vs. Brazilian Chevy six racing challenge sound interesting to anyone else?
Can’t forget the Australian Chrysler Hemi six! Not a US designed six, but nevertheless connected to one of the Big Three.
Actually, that engine was designed in Highland Park: https://www.curbsideclassic.com/blog/cohort-classic-1971-australian-valiant-charger-rt-hemi-six-pack-that-thing-got-a-hemi-um-not-quite/
It began as a truck motor in the US and was installed in trucks in Aussie but in tuned form was the fastest 6 on the planet for some years even the stockers put out some 200+ ponies
I don’t know if this is still the fastest naturally aspirated chevy six in Brazil… but it held the title for some time.
The Australians are crazy about this engine as much as we are and the owner of this car imported an Australian built aluminum head for the 250. It costed a fortune but works wonders.
https://youtu.be/CBK3XJmxP7s
Rubens, is that car running a Chev 250 six? There aren’t a lot of those downunder, and I haven’t seen much of an aftermarket or racing scene. The only one I can think of off the top of my head was a 292 in a 1971-72 Holden Torana (which originally had the Holden Red six) that was pretty fast in the quarter, about 25 years ago.
Sure, it can… here in Brazil get 400, 500hp easily from the 250…. That´s the engine that a brazilian chevy fan have around… And it´s fun to see owners of brazilian 302 Mavericks and 318 Darts furious with the straight 6 Opala or Omega…
I owned about 10 different vehicles equipped with a “stove Bolt”. The first thing that comes to mind is the side pan covers. They all leaked,and the gasket was a nightmare to change.
On a positive note. A properly maintained chevy six with a good battery,would start without a block heater, when nothing else would. When the temperature drops below – 25 ? Good luck trying to start a 66 Ford V8. Just try and pull the plugs and dry them out of slant six,at minus 25. Then try and reinstall them.
The good new is that the girls wanted to sit in my ugly rusty chevy, with the old 250 purring like a kitten, and heat coming out.
My dad ran his “bob tail” GMC logging truck with the big six (292 I think) in the northern Minnesota area in the 50’s and I do remember them being warmer in the cab then the flathead Fords he had before that and also a lot faster on the highway, with better gas mileage to boot. Said the Fords would freeze you in the winter then overheat in the summer. They would start fine (better then the fords) till the temperature got south of -40 then he would start a fuel oil and rag fire under the oil pan. That worked out ok till he set the oil a-fire that had accumulated on the side of the engine, must of been the side pan for the valves as you stated. After that he found out the ether starting fluid they used in the Cats (Caterpillar tractors) in the woods would start them up with a shot down the carb if the battery would turn the engine over at all. Makes me wonder what he would of thought of them making a hot rod engine out of that great old work horse.
Hot rodders LOVED the big GMC 292 six. A common 50s setup was a 12-port Wayne head and overboring for 302ci. A Wayne Jimmy in a dragster was nothing unusual. Keep the RPMs down (they’ve got a LONG stroke) and they’d even burn nitro.
John ;
It’s not clear here that you’re talking about two very different engines .
The thinwall 292CID i6 is a _Chevrolet_ engine used in GMC trucks, BTW .
-Nate
What they mean is the GMC 270/302 six, a totally different engine.
Same car was tuned by Lotus for Vauxhall and resulted in the fastest four door car ever with a 3.5L twin turbo 6 only a Ferrari could out pace one so using a tuned stovebolt isnt such a big deal really,
Same car was built by Holdens in Australia with Corvette trans and back axle and holden V8 power, slower than the Vauxhall but much faster than anything sedan like from the US.
Any car that get’s angry letters in the Daily Mail is a good one.I read people were buying Lotus Carltons and storing them having never even run them
The Lotus Omega/Carlton is one of my all-time favorite cars. When it came out it was so way beyond any other fast sedan that it was just ridiculous. 376hp – contemporary M5s had 315 while the big, bad Benz, the 500E had 326. And the Lotus looked like it would win a fist fight over the other two as well.
IIRC the Lotus Omega was a different affair, with its engine being based on the Opel CIH block instead of the Stovebolt Six.
The Holden versions from 1988 was an amalgamation of omega and senator bits cobbled together, widened and stretched on a tougher platform with Borg Warner rear axle with hydramatic 700 auto, tremec manual, Buick 3.8 v6 and Holden 304 v8 so quite a different animal, later models could be optioned with a opel derived IRS
Interesting, I only know the Lotus Omega, must be the powersedan Bryce mentions.
Lotus enlarged Opel’s 3.0 liter 6 cylinder inline to 3.6 liter, added 2 turbochargers and an intercooler. That resulted in a 382 hp monster.
(Photo: http://www.youngtimerclassic.com/img-pg/cars-for-sale/lotus-cars/lotus-omega-carlton/lotus-omega-carlton.htm)
Yep they did a German version the UK version was speed limited by govt edict I was quite impressed that it used the trans and back axle imported from Holdens as nothing else from GM could handle the power and Holdens got that straight from the Corvette but of course it was configured for that bodyshell by GMH. The Holden used the locally developed 308 cube V8 and was signifigantly slower than the Lotus 6 but then most Aussie states at the time had speed limits not all though.
Yes, it was a pleasure to (re)read all the details about this King of the Mountain of its era.
Of course Audi, Mercedes and BMW built sports sedans too, but as far as I know these had
factory 250 km/h (156 mph) speed limiters and less brute power and looks.
Possibly Alpina (BMW based) and Brabus (Mercedes based) made the non-speed limiter editions in the early nineties.
The UK police were upset not to get Lotus Carltons they hasd to make do with 138mph Omegas while BMWs best effort did 155 absolutely nothing could beat a Carlton the same problem exists for German car makers now trying to build something faster than a Vauxhall badged Holden they cant do it except at far more money.
155 mph because of the factory speed limiter, a “gentlemen’s agreement” in Germany. These days a 6 cylinder diesel is enough to get there. (and exceed it without limiter, like the Alpina D5 BiTurbo)
Holden is strictly Down Under. We never had them, and probably never will.
Not sure why you say Holden is strictly Down Under. Several last-model Pontiacs (the G6 and G8 RWD models come to mind) were rebadged Holdens, brought in after GM committed to FWD just to satisy their RWD fans. Word I heard at the time was that Pontiac was going to return to all RWD vehicles as a division, to give it an identity. Holdens also were imported – sometimes re-badged under local nameplates – to the Union of South Africa and Brazil. Not sure if any made it to Europe or the UK. While not sold as Holdens, those cars nevertheless got around.
They went to the UK in HSV trim badged as Vauxhalls, also the Middle East as Chevys
I’m wondering if this could be a bolt in swap for an old stovebolt.
Yees… it´s plug and play…
Isn’t Toyota still making the F series for forklifts and other equipment? That engine is pretty much a metricized stovebolt six.
The 250 is significantly different from the Toyota F and the pre 1962 Stovebolt. At a glance, the distributors are in different positions.
the stovebolt distributor position is in the dead center between cyl 3 and 4 – same configuration as the rival AMC six (which includes the Jeep 4.0L)
I’d like to stick one of these, with the twin turboes in a Chevy ll. Corvette tranaxle and some tweaks to make it handle. It could be a monster.
God GM would it have been a crime to give us an I-6 in a full size Chevy truck built within the last 10 years!!!!!!!!
Wasn’t there a 4.2L vortec I6 available about 2002-3? I heard something about it, then it seemed to have died with the downturn in the economy.
The Vortec 4200 was never available in the full-size trucks, only in the early Trailblazer and its stablemates from GMC, Isuzu and Saab.
And it was a pile.
Very interesting to read of this, it echoes what Ford Australia did with their 250ci inline 6, although the dohc did eventuate in that case.
Interesting to read of the Holden-sourced replacement too, making sure the engine would run on ethanol seems to have been the biggest change. I found an article that said they forecast selling about 600 cars per year when reintroduced in 2010 until the import duty increase killed it in 2011.
My mind is buzzing. First of the missed opportunity of putting this in a Nova sized car in the US. What tripped me out on overload was the thought of this in an S10 like the one I had with long bed and overload springs. Must have had the torque to pull tree stumps.
My understanding is that the 4.2 was designed to go into trucks but it’s hard to kill a winner and the 4.3 was a winner. 2014 sees the intro of a new 4.3 that shares nothing with the old. That’s enough to tell you what GM thinks.
I think I would commit a crime to have that sort of torque in a small body but I don’t have to. Repairs have put my truck down and I am borrowing an S10 with 302 Ford power to do some short term farm work. Probably won’t want to give it back.
Nice read! Very happy to read about Brazilian/South American cars at CC.
I had to check that, and apparently the 250 remained in the South American market for two more years. GM used it in a less powerful version (138 hp) in two other vehicles: the Silverado pickup truck until 1999 and the SUV GrandBlazer until 2001. They were both built in Argentina. Anyway the Omega was the last proper car that used it.
The GrandBlazer, which was essentially a rebadged Tahoe, was introduced in late-’98 and phased out in early-2000 when the production of the Silverado switched to Brazil where it lasted until late-2001, by then only with Diesel engine.
Pretty cool ! .
The fuel injection is the icing on the cake .
Thanx Paul .
-Nate
Sweet! I This engine—Yes, I’ll take the Lotus head, please and thanks—would do just nicely in that ’78-’79 Caprice I build in my head from time to time.
Chev inline-6s in South America…Ford inline-6s in Australia…none of the above here: there is no god.