Cummins new gas engine

[terex herder]

Yes. A tremendous amount of work has gone into airflow development in cylinder heads. 40 years ago air flow benches were few and far between even in the auto manufacturers. Once they started working with airflow, first they started working on bulk air flow. Then they started looking at swirl (GM Vortec). Then they started looking at tumble. I left the business decades ago, don't know what state of the art is today.

 

[Truck Shop]

Yes. A tremendous amount of work has gone into airflow development in cylinder heads. 40 years ago air flow benches were few and far between even in the auto manufacturers. Once they started working with airflow, first they started working on bulk air flow. Then they started looking at swirl (GM Vortec). Then they started looking at tumble. I left the business decades ago, don't know what state of the art is today.

Well the art has produced aluminum cylinder heads with nothing else changed just heads,
a horse power gain of an average 40 plus in some cases 60. With changing intake it approaches
70 to 75 without the detonation worries. Combustion chamber hot spots are virtually eliminated.

 

[Truck Shop]

The geometry of an inline engine lends itself to longer rods and longer strokes, giving more low end torque. The slant 6 had the longest stroke of any contemporary Detroit gas engine. The long stroke gave the engine a low end driveability as good as engines with 50 more cubes, even though the largest of the slant 6 engines was only 225 cid.

This was bugging me because I knew I turned some short stroke slant six cranks.
*
All had a 3.406 bore.
170 had a 3.125 stroke
198 had a 3.64 stroke
225 had a 4.125 stroke.

 

[Vetech63]

Detroit

Thats a cuss word to TS lol

 

[terex herder]

Thats a cuss word to TS lol

Yea, but I was using it as a place, not as a religion.

 

[Truck Shop]

Thats a cuss word to TS lol

Yea, but I was using it as a place, not as a religion.

You both got it wrong when it comes that---Motown Muscle then Detroit Iron when it comes
to gas ice.---

 

[Welder Dave]

Not a vehicle engine but a Perkins 3-152 was made in gas and diesel versions and the HP and torque were almost identical. The gas version was super heavy duty as it was basically a converted diesel. They both had exceptional fuel efficiency. Why can't they use industrial/tractor type lower RPM gas engines in vehicles like they have with diesels? They'd last a long time.

 

[Truck Shop]

There was the Toro Flow gas/diesel GM converted back in the 60's.

 

[Welder Dave]

Maybe this new Cummins will be a decent engine. Curious what the RPM range is?

 

[Steve Frazier]

The school district where I live has phased out diesels for their school busses and are now powered by propane. The diesels were just getting too costly to run with all the emissions repairs. The Bluebird chassis use Ford engines, either the V10 or the 7.3 Godzilla depending on the age. They have a number of International chassis busses as well and IH has offered a gas V8 option in the medium duty chassis now.

One beer distributor in the area has a Volvo tractor pulling a side loader trailer that is CNG powered. I was able to hear it start up one afternoon and it sounded like a big 6 cylinder.

Personally I've stopped buying diesel pickups because the cost and headaches that go with them aren't worth the little bit of extra fuel mileage to me. I'm OK getting somewhere a few minutes later because I don't have as much power for towing, today's gas engines are pulling better than diesels from 20 years ago.

 

[Birken Vogt]

Not a vehicle engine but a Perkins 3-152 was made in gas and diesel versions and the HP and torque were almost identical. The gas version was super heavy duty as it was basically a converted diesel. They both had exceptional fuel efficiency. Why can't they use industrial/tractor type lower RPM gas engines in vehicles like they have with diesels? They'd last a long time.

I can think of a number of industrial engines that go both ways. The Lister LP/Alpha series and Kubota is pushing hard several gas/propane/NG versions of their 4 cylinder diesels, very good engines, simple. I have seen a brand new industrial Cummins 5.9 vapor fueled engine, has 6 valve covers it's basically an old 12 valve. Also I understand they make an 8.3 or 8.9 liter version, probably mainly different pistons and heads. Blocks are cast in India.

 

[Welder Dave]

Propane buses were really popular as were propane conversions. Then the price of propane made it no longer a cost effective option. Diesel jumping in price and trucks having worse mileage and all the emissions makes gas engines more desirable. What ever fuel seems to be the most in demand, the more it jumps in price. Diesel used to be quite a bit less than gas but now it's a fair amount more.

 

[Welder Dave]

I can think of a number of industrial engines that go both ways. The Lister LP/Alpha series and Kubota is pushing hard several gas/propane/NG versions of their 4 cylinder diesels, very good engines, simple. I have seen a brand new industrial Cummins 5.9 vapor fueled engine, has 6 valve covers it's basically an old 12 valve. Also I understand they make an 8.3 or 8.9 liter version, probably mainly different pistons and heads. Blocks are cast in India.

These new Cummins engines have several fuel options.

 

[Truck Shop]

The thing about propane was it likes compression, 11.1 works well, and too many engines
had propane installed with lower compression ratios. But because it's dry seats and valves
designed for propane are a must.

 

[Truck Shop]

Funny thing about all this is the huge displacement gas engines of 45 years ago in
some ways are making a come back. The price of a core 454 complete has jumped
in the last 3 years, and not because those are rare. But because there is enough
performance aftermarket parts now to build stout horse power/torque and still land
in a area of 12 mpg, sometimes more. A brand new set of aluminum sbc heads
complete can be had for $900.00, to rebuild a set of iron $350 to $400. But the
trouble with using a diesel block design is the unnecessary weight in a highway
vehicle.
*
The big advancement in gas engines from factory--CNC machined heads, roller cams
and fuel injection with coil pack ignition.

 

[92U 3406]

I'd rather have a blown gasser than any diesel from the EGR era and newer.

 

[MG84]

Funny thing about all this is the huge displacement gas engines of 45 years ago in
some ways are making a come back. The price of a core 454 complete has jumped
in the last 3 years, and not because those are rare. But because there is enough
performance aftermarket parts now to build stout horse power/torque and still land
in a area of 12 mpg, sometimes more. A brand new set of aluminum sbc heads
complete can be had for $900.00, to rebuild a set of iron $350 to $400. But the
trouble with using a diesel block design is the unnecessary weight in a highway
vehicle.
*
The big advancement in gas engines from factory--CNC machined heads, roller cams
and fuel injection with coil pack ignition.

I still think Ford would have been better off to modernize the 302/351w/460 instead of that whole Mod motor debacle, an now they've basically come full circle with the 6.8/7.3 gas motors. Put some really good heads and modern EFI on the 351w and 460 and the Chevy LS would have had some serious contenders. I'm still of the belief the Chevy LS motors are basically a 351w with High port Yates heads and modern EFI/ignition. They certainly have a lot more in common with a SBF than a SBC.

I do like the way the old big blocks pulled. Have a '88 F-250 with a 460, not a ton of power by todays standards but peak torque was at 1800rpms and the torque curve was flat as a skillet. Hit a hill with a good load behind and just keep your foot in it, seemed like it would just pull forever before you had to drop a gear, similar to my 7.3IDI actually. I can see why these new diesel pickups are all automatics, drove one of the last manual Dodges with the 6.7 Cummins and it was a miserable thing to tow with. All the power in the world if you kept it in that narrow power band, way at the top. Fall off the boost and nobody's home and not enough gears to keep it where it was happy.

 

[Truck Shop]

I still think Ford would have been better off to modernize the 302/351w

And not just my op but the 351C was/ still is twice the engine the W ever was or is. The only
reason Ford quit producing the 351C was the company memorandum sent out in early 1973
that all high performance R&D will cease and desist as of now on. Then came the Granada's.
Same with Chevrolet & Chrysler--in 1974 a 454 came with two horse power options, 215 &
235. A two barrel 327 in 1967 put out more hp and torque.
*
Everyone forgets what the gas crisis in 73 did--well not many on here are even old enough
to remember.

 

[MG84]

And not just my op but the 351C was/ still is twice the engine the W ever was or is. The only
reason Ford quit producing the 351C was the company memorandum sent out in early 1973
that all high performance R&D will cease and desist as of now on. Then came the Granada's.
Same with Chevrolet & Chrysler--in 1974 a 454 came with two horse power options, 215 &
235. A two barrel 327 in 1967 put out more hp and torque.
*
Everyone forgets what the gas crisis in 73 did--well not many on here are even old enough
to remember.

I won't argue with that, in stock trim there was no comparison. But sheer numbers produced are what changed the tides for the 351C vs 351W, that and the 5.0 Foxbody mustang. Once the aftermarket sbf heads started becoming available in the early 90's that changed everything. Even those early World, Yates, and Ford Motorsports heads made the 351w a real runner. And along with the heads came the roller cams.

One can argue the benefits of the 351C short block vs the W, but the real difference was the heads. The aftermarket closed that gap, and unfortunately there are very few 351C's left. Closest thing to a 351C I've ever had in my possession is a 351M (not even close I know), but I've got several Windsor small blocks on the shelf. That said, I would absolutely love to build a 351C if one were to show up at my doorstep wrapped in a '70-71 Mustang, Cougar or Torino...

 

[Welder Dave]

What was difference on the 351M compared to the 351W?