I know very little about this new little diesel that gm is comnig out with. I was wondering if GM did somethnig similiar to what they did with the old 4.3 gassers that theu used in the ols s10 blazers. They took the proven 350ci block and basicaly chopped 2 cylinders off then end to produce the 4.3. this makes sense not only from a reliability stand point but also from a production standpoint. Same rods/pistons/rings etc. could this new 4.5 diesel be a prpven 6.6 dmax with 2 cylinders wacker off??

According to the long info thread:

"The 4.5L will be a DOHC V8 with more than 310 hp and 520 lb.-ft. of torque"

Of course, it sounds really strage for GM to produce an engine with 3 extra cams on the top of the engine... If they do make it that way though I bet it will be an interesting sounding engine.

Not really. The heads are totally different from the 6.6 to start with. The block is smaller-different also. That would probably everything inside of it is different. So pretty much the only thing similar between them is that they go in to trucks with the same names, are diesel have the Duramax name and are V-8's.

4.5 dmax is also a 60* motor...basically nothing in common with the 6.6 dmax, except the fact they are both V8's, as said above :)

i would assume whatever new duramax for the 3/4 ton and up trucks for 2010 will be similar to the 4.5.

4.5 dmax is also a 60* motor...basically nothing in common with the 6.6 dmax, except the fact they are both V8's, as said above :)

Elsewhere I read it is a 72 degree block. As in add 2 cylinders for a perfectly
balanced V10. :idea:

GM ALREADY tried a 60 degree V8. Does anybody else recall the 638 CID
V8 from about 1966?

doh!!! My bad... :o:

yes you're right...72* block. I just remember reading it wasnt a 90* so I ASSumed it was a 60*. :duh:

To me the most significant(interesting) feature is the exhaust going in the V part of the block and the intake is on the outside of the block. interesting:cool:

I wonder how long it will take the aftermarket to come up with a stand alone wiring harness/ECU so we can put this engine in ??????:D

exhaust coming out through the "V"? Sounds like alot of heat to be concentrated in one spot.

To the OP..you better hope the 4.5 duramax is not like the 4.3 v6, cause those engines weren't known for their great power or economy! I had an s10 before my duramax and that thing got the same mileage as my silverado and had no power.

Elsewhere I read it is a 72 degree block. As in add 2 cylinders for a perfectly
balanced V10. :idea:

GM ALREADY tried a 60 degree V8. Does anybody else recall the 638 CID
V8 from about 1966?


Unless it uses over head cams, 60 degree v motors suck. If the cam is in the block the down force from the lifter is concentrated at +/- 30 degreese of the cam bearings' 12 o'clock position. The load of the valve train was too focused in one area of the bearing. in the 3.8L and 3.3L motors, that spelled toasted cam bearings.

the new baby dmax is DOHC ;)

Filed under: Diesel, GM



At the General Motors Powertrain Technology show, ABG learned more about the upcoming 2009 Duramax 4500 diesel V-8. GM made some unusual design choices in order to improve the efficiency and get the engine to fit in the same package size as the traditional small block V-8.

GM started off by choosing a 72 degree bank angle rather than the typical ninety degrees making the engine narrower. Most V-8 engines traditionally have had the intake manifold in the V between the cylinder banks with the exhaust manifolds on the outside of the heads. The new Duramax places the exhaust manifold in the valley along with the turbocharger.

Continue reading about the new Duramax 4500 after the jump.
Placing the exhaust and turbo in the V allows for very short exhaust runs and minimal heat lost from the exhaust gases. That means more of the energy in the hot exhaust can be used to spin the turbo and the response is quick. The intakes are on top of the cylinder heads directly over the intake valves. The outer sides of the cylinder heads are devoid any appendages which allows for easy assembly line installation.

Downstream of the turbocharger comes all the hardware to make the new engine fifty-state legal and Tier 2 Bin 5-compliant. A diesel particulate filter cleans up the soot while excess nitrogen oxides are addressed by a urea injection system. The urea will need to be replenished periodically, but it should last longer than the oil change interval.

Overall, the Duramax 4500 should provide a great, fuel-efficient option for the light duty trucks while improving towing capability. The possibility of installing the new engine in passenger car applications certainly exists thanks to the packaging, but whether it happens will depend in part on how well other new diesels are accepted in the market in the next couple of years.

....in the 3.8L and 3.3L motors, that spelled toasted cam bearings.

I believe those engines were 90degree Buick V6's.

Its the 2.8, 3.1,3.4,3.5 engine family that is 60degrees.

I'll take a wait-and-see approach.

I love the idea of a small diesel in a 1/2 ton; had it been available a year ago, I might have passed on my 6.6L. I don't really need a 1-ton with 650 ftlb of torque. I could easily be happy in a 1/2 ton pulling my 5k pound travel trailer. Hope the little engine will get better mileage.

The only thing that concerns me is that there's a lot of new technology in this little engine, and they did it without Isuzu. Why dump your proven partner, which specializes in small diesel engines? Sounds like a little vanity crept into GM.

Time will tell.

.........Why dump your proven partner, which specializes in small diesel engines? Sounds like a little vanity crept into GM.

Time will tell.

That could well be, but my guess is it has much more to do with $$$$$$. I'm sure over the long run its cheaper to design the engine in-house than pay Isuzu $'s for each Dmax produced. And in the half ton market, I don't see peeps paying near as much for a diesel engine as they do in the HD market. Just my 2cents.

I had an s10 before my duramax and that thing got the same mileage as my silverado and had no power.

x2, i got one of those now(see sig), No Power when towing, decent when unloaded. I need my Dmax now, reason why? I tow at my current job and a v6 doesn't cut it.


Does anyone think the 6.6L duramax's will be in supply when that 4.5L diesel comes out?

I guess the thing that has my interest is the weight of the motor and how the truck will balance. I have 2 diesels (02 Dmax and 04 Powerstroke) and although I love much about them, the thing that bugs me is their weight and the weight distribution. They don't do very well in the mud and if you don't have 4wd you are screwed if you get in the soft stuff. I had an 00 F-150 that I rarely had to put into 4wd when it encountered sand or mud, but put a 3/4 ton diesel in the same environment and you will use the 4wd all the time. It is like the rear tires are trying to push a lead sled.

Does anyone think the 6.6L duramax's will be in supply when that 4.5L diesel comes out?

What do you mean by Supply. If you mean the physical supply of engines, they are assembled at different plants so that should not be an issue. Or do you mean emissions not making the engine available or GM making an engine of its own? dunno about that.

This engine sounds like a great idea. I'd be interested in seeing it's specs for towing. I can see getting rid of my 2500HD CC and going to a smaller travel trailer when my kids are gone in about 5 years. A lighter trailer and pickup with plenty of hauling power would be great.

engine is VM Motori engine, 72degree is same as VW engine also. GM just bought out penske's side of VM Motori and think is same or decented of engine in corvette and cadillac's running around europe. large diesels run exhaust inside V, there is new insulating compound that is done when casting component to outside, so expect to see something like this.

I'd like to see a smaller diesel in the Tahoe. Although I love my 5.3, I would have liked a diesel better. I don't need a 3/4 ton Tahoe, I would prefer a lower hood line and better turning radius than the 4 lanes this Silverado needs.

engine is VM Motori engine, 72degree is same as VW engine also. GM just bought out penske's side of VM Motori and think is same or decented of engine in corvette and cadillac's running around europe. large diesels run exhaust inside V, there is new insulating compound that is done when casting component to outside, so expect to see something like this.


I had heard it was an Italian design.

Can't wait to see it either. I would love to have more diesel choices. My next vehicle, I may not need/want a long bed, Crew Cab, 1 ton truck..

As was previously stated, I wonder what the premium price for this motor will be? A 5k premium will keep me out of the market.

x2, i got one of those now(see sig), No Power when towing, decent when unloaded. I need my Dmax now, reason why? I tow at my current job and a v6 doesn't cut it.


Does anyone think the 6.6L duramax's will be in supply when that 4.5L diesel comes out?

Probably. I don't see the 4.5 moving 15,000lb loads day in and day out like some people do with the 6.6.

I believe those engines were 90degree Buick V6's.

Its the 2.8, 3.1,3.4,3.5 engine family that is 60degrees.


your right 3.8 is 90 degree not sure what the 3.3 was

as for cam bearings the 3.8 is probably the best v6 gm ever built

I would have to agree on the 3.8 being an excellent V6 engine. last family car we had was a 92 Bonneville with the 3.8. Put just under 300,000km on it and it still ran good...too bad the body/interior was kinda crappin out. Good car, good motor. Funny, I've never had a major issue with Pontiac.

stk