General Motors first introduced the idea of a lighter, more compact Duramax diesel at last year’s SEMA Show in Las Vegas, with the project moving full speed ahead in the subsequent months. GM revealed the top half of the engine late last year – including a turbocharger residing in the space usually reserved for the intake manifold – but kept mum on other engine details. But the wraps have officially come off the new 4.5L diesel, with plenty of details now available.
As with most automotive applications these days, weight was a key concern for GM engineers with the new Duramax powerplant. With that in mind, engineers came up with a new way of holding the engine’s crankshaft. The 4.5L’s crank journals – the part of the engine block responsible for holding up the crankshaft – was created through a unique process called fracture splitting. This technique actually results in greater precision, greater strength and a reduction in cost – both in materials and machining.
This unique design also allows for better air circulations between the cylinder banks. According to GM engineer Charlie Freese, this design reduces pumping losses, resulting in greater performance. “One of the big issues for these modern diesels is the ability to handle the exchange of pressures through the crankcase itself,” Freese told Automotive News.
In fact, the new design is so success that GM is looking to use the technique in some of its future gasoline engines.
Further tweaks to the engine’s lower half also resulted in a block that in 30 percent stiffer than any other benchmark design.
The net result is an engine that cranks out 310 horsepower and 520 lb-ft of torques, yet is 25 percent more fuel efficient than a comparable gas engine. The new Duramax is also 50-sate legal.
The new 4.5L Duramax is slated for full-size truck and SUV duty – likely in late 2009 or 2010 – but there have also been rumors that the diesel mill fits nicely beneath the hood of the Cadillac CTS.
10/21, 11:47 AM
posted by:
Chris C.
You guys at LLN really need to look into more carefully proofing your articles and maybe the occasional employment of the spell checker. Just a thought…
10/21, 11:59 AM
posted by:
mulletmaster
Or perhaps grammar checker
“In fact, the new design is so success that GM is looking to use the technique in some of its future gasoline engines.”
Successful perhaps?
10/21, 12:14 PM
posted by:
A4
this is going to be the most amazing engine theyve put out in years
10/21, 12:16 PM
posted by:
A4
and yeah LLN get a damn grammar/spell checker, you sound like idiots
10/21, 12:28 PM
posted by:
beatusmongous
LLN should hire me. I’ll do it for $10.00 per post.
10/21, 12:30 PM
posted by:
Ketzer
The text is probably just copied from some other lazy-as who didn’t bother to sPeLz cHek their work. It’s comforting to know that grammar and spelling are not part of a journalism degree.
10/21, 12:31 PM
posted by:
DrFill
500 lb ft will be the standard in the light-truck diesel class.
Ford better get to work, cus 430 lbs ain’t gonna git it
DrFill
10/21, 12:33 PM
posted by:
DrFill
My mistake
The 4.4 from Ford doesn’t even make 400 lb. ft
DrFill
10/21, 12:36 PM
posted by:
pavlindrom
sounds great this far. put it in the car, and I’ll read a review about it later….
10/21, 12:53 PM
posted by:
yarddog82abn
Guess who’s buying a diesel… and yes I do have need for it…
Maybe not a lift kit, big wheels & tire’s, Banks power pack, but come-on now you really don’t expect me to be rolling stock trim… Do you???
Come-on kid, homes don’t let homes roll stock….
10/21, 12:59 PM
posted by:
johnnycanuck
beatus, I have no doubt there are plenty of things you’d do for $10, so please try to be more specific.
10/21, 3:32 PM
posted by:
Z06ified
It’s a great engine – too bad it is DOA in the U.S. market thanks to the ridiculously high price disparity of diesel fuel versus gas. Even if there is a net cost savings, very few people are going to sit down and do the fuel cost calculations to see it. Instead, they see $4.00/gallon for diesel versus $3.00/gallon for gasoline, and they buy a gas powered vehicle.
Until government steps in and does something about these diesel prices, new clean diesels like the 4.5L Duramax will be introduced to a dead market.
10/21, 4:06 PM
posted by:
A4
depending on how much the new engine costs i may go out and buy one
10/21, 5:31 PM
posted by:
beatusmongous
Whatever you were thinking, Johnny, THAT’s probably not one of them…
However, I know someone who will…
So, to be more specific, I’ll proofread and correct LLN’s posts for $10.00 per post.
10/21, 6:25 PM
posted by:
Blakkarr
STEAM! Build a freakin’ steam engine. It’ll be more efficient.
10/21, 7:21 PM
posted by:
jayjc08
Very good news. It sounds very promising, if the costs are low enough then this surely will leapfrog anything else out there. Good work GM!
10/21, 7:36 PM
posted by:
Bmacc
They ought to take the initiative and put this (with a little more HP) in a sports car.
10/21, 7:39 PM
posted by:
1c3d0g
Yes, GM…finally! Yesss (evil Megatron voice)…
10/21, 9:27 PM
posted by:
autonut
I wonder if company will live long enough to place under the actual hood of an actual car. I wish they did.
10/22, 7:29 PM
posted by:
urmomspanties
DrFILL
I agree… Its been years since Ford could come up with powertrains like GM. Now when it comes to truck chassis’, towing capacity, & payload they do have to bow to Ford.
I wish I could just put a GM diesel in a new 2009 F150. From what I hear, Ford’s draggin their feet about their diesel because its comsumes 20% less fuel BUT fuel costs 21% more…
WTF!!!!
10/23, 9:18 PM
posted by:
The Stig
Fracture splitting the journals is possible because CGI is used as the block material. Audi uses this for their diesel engines – it’s extremely stiff and very well suited for a diesel block – far better than aluminum with only a reasonable penalty in weight because it can be cast thin.
I must tip my hat to GM for this design – it’s really innovative and not what I’d expect from them.
Betcha this engine wins the awards next year.