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LS1LT1 12-13-2012 01:20 PM

A little more info on GM's new engine line up for the trucks, EcoTec3
 
Some of the new Corvette's engine technology will spill over into the trucks (and likely Camaro and the new SS 4 door as well of course) as we'd all already assumed.
A little info on the new 5.3L V8 and 4.3L V6:

http://www.lsxtv.com/news/gen-v-fami...ncluding-a-v6/

BlueOx 12-13-2012 01:28 PM

Wow, am I really counting THREE belts?
http://speednik.com/files/2012/12/20...coTec3-050.jpg
http://cdn.lsxtv.com/image/2012/12/2...coTec3-001.jpg

LS1LT1 12-13-2012 01:33 PM


Originally Posted by BlueOx (Post 1582558968)
Wow, am I really counting THREE belts?

Yes it does appear that way. But that's not necessarily a bad thing either, going back to a 'multi belt' set up can both free up some horsepower (parasitic losses) and possibly improve reliability (with the current serpentine belt set up, if it breaks we're basically stranded).

LS1LT1 12-13-2012 01:35 PM

And this isn't directly 'Corvette related' of course but here are the brand new trucks that these awesome engines will be going into. :yesnod:
The new line up looks VERY nice in my opinion. :cool:

https://www.facebook.com/media/set/?.../photos_stream
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BlueOx 12-13-2012 01:36 PM


Originally Posted by LS1LT1 (Post 1582558991)
Yes it does appear that way. But that's not necessarily a bad thing either, going back to a 'multi belt' set up can both free up some horsepower (parasitic losses) and possibly improve reliability (with the current serpentine belt set up, if it breaks we're basically stranded).

I'm not saying it is a bad thing necessarily but it does look like the two lower ones would be a real be-atch to change. I do see your point about losses. Just surprised to see the LT1 with one belt and these all having 3.

LS1LT1 12-13-2012 01:41 PM


Originally Posted by BlueOx (Post 1582559014)
I'm not saying it is a bad thing necessarily but it does look like the two lower ones would be a real be-atch to change. I do see your point about losses. Just surprised to see the LT1 with one belt and these all having 3.

True, might be a little easier to change them being in a larger truck frame/platform and all (more room in the engine bay and accessibility from underneath?) but I agree it is also a little odd that it is different from the LT1.

oldvtr 12-13-2012 01:42 PM


Originally Posted by BlueOx (Post 1582558968)

Hmmm? Looks like one for the AC compressor and one for the oil pump and then one for everything else. With the switch to electric steering assist, no need for a power steering pump. Looks like the oil pump belt runs behind the balancer on the crank shaft on a smaller diameter pulley. Suppose that allowed a smaller pulley on the oil pump while still providing the optimum pump speed?

BlueOx 12-13-2012 01:47 PM


Originally Posted by LS1LT1 (Post 1582559047)
True, might be a little easier to change them being in a larger truck frame/platform and all (more room in the engine bay and accessibility from underneath?) but I agree it is also a little odd that it is different from the LT1.

It's really easy to change a single belt vs trying to change that small one way in the back. You'd have to take the other two off to get to it wouldn't you?

Larry/car 12-13-2012 01:52 PM

I wouldn't worry to much, my truck belt is to be replaced at 160,000 miles. Years and Years before most Corvettes reach that mark.

LS1LT1 12-13-2012 02:30 PM


Originally Posted by BlueOx (Post 1582559089)
It's really easy to change a single belt vs trying to change that small one way in the back. You'd have to take the other two off to get to it wouldn't you?

Yes true...but even now one would have to take the main serpentine belt off just to change the small A/C belt as well (C5/C6).

BuckyThreadkiller 12-13-2012 03:06 PM

I put this in another thread, but it fits here better - the dash images from the new trucks show a Tach that only goes to 6K. Doesn't say if that the V6 or the V8s but that still seems low.

Kappa 12-13-2012 03:24 PM


Originally Posted by BuckyThreadkiller (Post 1582559599)
I put this in another thread, but it fits here better - the dash images from the new trucks show a Tach that only goes to 6K. Doesn't say if that the V6 or the V8s but that still seems low.

Sounds about right to me. Ford's 6.2 and the Hemi engines are limited to about the same. These trucks aren't make to make much power above 5000-5500rpm. Need low end torque more than anything.

BlueOx 12-13-2012 10:35 PM


Originally Posted by Kappa (Post 1582559706)
Sounds about right to me. Ford's 6.2 and the Hemi engines are limited to about the same. These trucks aren't make to make much power above 5000-5500rpm. Need low end torque more than anything.

Funny we don't hear about that very often but my 5.3 'rado has plenty of power without revving very high.

McGirk94LT1 12-14-2012 01:06 AM

I'm a little confused, although obviously final numbers are needed first. Dodge and Ford both put their new hi po v6 in their trucks, yet Chevy won't?(3.6 in camaro and others) I feel like as long as they mpg was decent, either adding the 3.6 or dropping a v6 altogether and trimming the price on the 5.3 would have been a much better idea. The number of v8 to v6 buyers is probably significant, and most would take the v8 if it was the same or just 1 mpg less then dodge/Ford's v6's. The 4.3 is well past it's expiration date honestly. Now in 2013 it's in the same boat as Ford's 5.4 was. Guess we'll see if this total revamp was actually worth it. I'd wager not a whole lot.

NSC5 12-14-2012 08:45 AM


Originally Posted by McGirk94LT1 (Post 1582564336)
I'm a little confused, although obviously final numbers are needed first. Dodge and Ford both put their new hi po v6 in their trucks, yet Chevy won't?(3.6 in camaro and others) I feel like as long as they mpg was decent, either adding the 3.6 or dropping a v6 altogether and trimming the price on the 5.3 would have been a much better idea. The number of v8 to v6 buyers is probably significant, and most would take the v8 if it was the same or just 1 mpg less then dodge/Ford's v6's. The 4.3 is well past it's expiration date honestly. Now in 2013 it's in the same boat as Ford's 5.4 was. Guess we'll see if this total revamp was actually worth it. I'd wager not a whole lot.

The 4.3 is getting the same technology treatment as the two new V-8 engines so its only real relationship to the old iron block 4.3 is its displacement. From that point of view I think that is a mistake because many are going to jump to the same conclusion you did-that it is the same old 4.3 derived from the vintage 5.7 SBC.

I have a 3.6 in my CTS and it is a fun engine but probably not as well suited for truck type tasks. A 3.6 may not function well moving a moderately heavy load up a sustained grade and the basic cooling design for the block was probably biased more to reduced weight and fast warm up time instead of for sufficient cooling under sustained heavy load. I expect the 4.3 would have sufficient capacity to tow a smaller trailer and certainly the power to handle rated bed payload under typical conditions.

I don't need the complete payload and towing capacity of my current GMC 2500HD with Duramax diesel. I will be looking closely at the 1500 specs now that the crew cab will be available with a 6.5' bed. I will miss the torque characteristics of the diesel but with the price spread between gas and diesel coupled and the greatly increased emissions complexity for the newer models compared to my 2006 I think my next pickup will be gas powered.

Jinx 12-14-2012 11:58 AM

Chrysler probably doesn't sell enough V6 pickups to make engineering a competitive V6 out of their pushrod V8 worthwhile. It makes sense that they'd put everything into one V6 they can use in cars and trucks.

Ford is leveraging commonality with their EcoBoost, and a Coyote V6 probably doesn't save them anything.

GM's approach makes sense for them. They do enough volume that they can justify lopping two cylinders off the new pushrod V8. The resulting engine is probably lighter and cheaper to build, with a more truck-appropriate torque curve, and more service commonality with the V8 which will make commercial customers happy.

It pretty much cements that GM is not in any hurry to follow Ford's EcoBoost lead on trucks. As if there was any doubt :)

I didn't pore through the details, does the new V6 get cylinder deactivation?

.Jinx

BlueOx 12-14-2012 12:05 PM


Originally Posted by Jinx (Post 1582566939)
Chrysler probably doesn't sell enough V6 pickups to make engineering a competitive V6 out of their pushrod V8 worthwhile. It makes sense that they'd put everything into one V6 they can use in cars and trucks.

Ford is leveraging commonality with their EcoBoost, and a Coyote V6 probably doesn't save them anything.

GM's approach makes sense for them. They do enough volume that they can justify lopping two cylinders off the new pushrod V8. The resulting engine is probably lighter and cheaper to build, with a more truck-appropriate torque curve, and more service commonality with the V8 which will make commercial customers happy.

It pretty much cements that GM is not in any hurry to follow Ford's EcoBoost lead on trucks. As if there was any doubt :)

I didn't pore through the details, does the new V6 get cylinder deactivation?

.Jinx

Yes, all of them get the same stuff...

All three engines feature similar technologies found on the 6.2-liter Corvette engine that was introduced in October: direct injection, cylinder deactivation and continuously variable valve timing. While the Corvette engine is designed for performance to enhance the driving experience of a sports car, the truck engines will be tuned for towing and durability.

5.3L V8 and 4.3L V6 EcoTec3
All three have aluminum blocks and boast an 11:1 compression ratio, except the 6.2 that has 11.5:1. All three have a 92mm stroke (3.62 inches) crankshaft with cylinder bores of 3.92 inches for the V6 and 3.78 and 4.06 inches for the 5.3L and 6.2L, respectively. The cylinder head design appears identical to the Corvette engine, based on excerpts from the press release: switched intake and exhaust valve positions, revised spark-plug location, pistons with unique topography, large rectangular intake ports with a twist to enhance mixture motion and the “advanced combustion system.”

JoesC5 12-14-2012 12:06 PM


Originally Posted by Jinx (Post 1582566939)
Chrysler probably doesn't sell enough V6 pickups to make engineering a competitive V6 out of their pushrod V8 worthwhile. It makes sense that they'd put everything into one V6 they can use in cars and trucks.

Ford is leveraging commonality with their EcoBoost, and a Coyote V6 probably doesn't save them anything.

GM's approach makes sense for them. They do enough volume that they can justify lopping two cylinders off the new pushrod V8. The resulting engine is probably lighter and cheaper to build, with a more truck-appropriate torque curve, and more service commonality with the V8 which will make commercial customers happy.

It pretty much cements that GM is not in any hurry to follow Ford's EcoBoost lead on trucks. As if there was any doubt :)

I didn't pore through the details, does the new V6 get cylinder deactivation?

.Jinx

It appears that the V6 is the LT1 design, just missing two cylinders. DI, AFM (6 to 4) and VVT.

chaase 12-14-2012 12:10 PM

A belt driven oil pump just seems wrong.

JoesC5 12-14-2012 12:22 PM


Originally Posted by chaase (Post 1582567016)
A belt driven oil pump just seems wrong.

I agree. That engine does not have a dry sump and we know from the details released on the LT1, including the dry sump option, the oil pump(s) is(are) driven by the crankshaft, just like on the C6 engines.

The info I have read on the 2014 Silverado, it , like the C7, will have electric assisted steering vs the current hydraulic assisted(that does require a pump like shown in the above photos).

Now, that begs the question...what is that pump for? Maybe transmission cooling pump for the manual?


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