DOHC comes back?

[scholtmj]

Posted this a while back:
http://www.zr1.net/forum/showthread.php?t=10824

GM will put DOHC/cam phasing/DI on a V8. If anyone read the latest Automobile magazine (i think) they quoted a GM engineer not ruling out turbo V6 power in the C7 Vette. That move was compared to ditching flip-up headlights for the C6; part of evolution for performance.

[rkreigh]

good article in the latest car mags, the pony car wars between the mustang and camaro are alive and well

they are almost a dead heat, with the LS3 taking just a bit of a top end charge dispite the better power to weight of the mustang (torq of the larger LS3 displacement)

keep in mind the "little" rustang motor makes almost a much HP from a smaller displacement

the thought of a twin turbo version of this motor sounds pretty good,

I actually do like the looks of the new car, except the back end

but I'm not a huge fan of the camaro styling either

love to see a DOHC chevy motor, as many remember the new "5.4" version of the northstar was going to come out before GM ran out of dough and the new CAFE hit the streets.

all about the MPG across the fleet and the dev costs of a new engine are staggering

GM could build a "V8 ecotec" with twin turbos and direct injection with just a few new parts in the bucket, but certification and tooling ain't cheap

love to see it. a fully ported ecotec head flows pretty good

as many of you remember, 1100+ hp in a certain ecotec

4 cyl variety

[LGAFF]

As much as I like the concept of a 412hp 5.0 American engine, I hate to see a mustang out perform a stock Z....kinda starts to date our cars. But they really pulled out all the stops on this one, even has headers from the factory, and clearly there will be no more to gain on this motor from exhaust mods.

[Kevin]

Originally Posted by LGAFF

As much as I like the concept of a 412hp 5.0 American engine, I hate to see a mustang out perform a stock Z....kinda starts to date our cars. But they really pulled out all the stops on this one, even has headers from the factory, and clearly there will be no more to gain on this motor from exhaust mods.

never forget that one is made to drag race and sorta turn and the other is made to turn and sorta drag race

[tomtom72]

JMHO, I'll go along with the "dating" of our motors....but our motor's official company sponsored development stopped some time nearly twenty years ago, and that's a very long time to have to engineer improvements into a DOHC/4V format. No?

No sour grapes, kudos to the blue oval boys for taking a different path and coming up with something that looks to be sweet for the street.

I would like to know how they got past what GM said were the prohibitive production costs? Are the Ford modular family of motors that much less expensive to build? Why? Poor quality control? Cheap machining? Cheap internal parts? Their list of parts looks pretty good...I guess I don't understand.


Tom

[Kevin]

Originally Posted by tomtom72

JMHO, I'll go along with the "dating" of our motors....but our motor's official company sponsored development stopped some time nearly twenty years ago, and that's a very long time to have to engineer improvements into a DOHC/4V format. No?

No sour grapes, kudos to the blue oval boys for taking a different path and coming up with something that looks to be sweet for the street.

I would like to know how they got past what GM said were the prohibitive production costs? Are the Ford modular family of motors that much less expensive to build? Why? Poor quality control? Cheap machining? Cheap internal parts? Their list of parts looks pretty good...I guess I don't understand.


Tom

well if they've stepped up from the powdered metal connecting rods that are in my daily driver 2v that would be nice. perhaps the price of parts came down, perhaps gm was full of it,

[LGAFF]

Here is the responsed to direct injection quesiton, the article is pretty good.......

As a Coyote team engineer put it, "On a naturally-aspirated engine, the biggest benefit of DI is charge cooling-and it's a volumetric efficiency benefit and not a tolerance benefit. We squirt the injectors while the [intake] valve is open, and it's open a long time, which we haven't done before. It seems simple and gets you half the benefit of DI-for no costs at all."

The only apparent downside is cylinder-wall washing at low engine speeds, so the injector is limited to closed-valve periods at low rpm. Also, the camshafts change valve timing, so that's something else to synchronize with the injector in the engine management calibration.

[LT-5 Music]

Evolution Performance http://www.facebook.com/pages/Evolut...c/262882950647 has been working on one. Very complicated to tune 'em they said. Best time so far I think is 12.04 @117mph - 1.70 60ft with an off-road exhaust, tune, ET Streets, K&N Drop in Air Filter, upper and lower control arms.

Nice vid from Ford on the 2011 Mustang GT 5.0 here.

http://www.youtube.com/watch?v=-3WODZvJVu8

[Aurora40]

Originally Posted by tomtom72

I would like to know how they got past what GM said were the prohibitive production costs? Are the Ford modular family of motors that much less expensive to build? Why? Poor quality control? Cheap machining? Cheap internal parts? Their list of parts looks pretty good...I guess I don't understand.

The Ford motors are not hand assembled, they are mass produced like most others. GM mass-produced the Northstar just fine.

The LT5 specifically was probably expensive to produce, not all DOHC V8's.

Also, certainly the game is changing lately. Even Hyundai produces a DOHC V8 now, making 385hp from 4.6L.

[DaveK]

As far as I can see it - GM wanted to kill the ZR-1/LT5 and came up with a bunch of rationalisations to justify doing that. Few of them really seem to hold up under scrutiny.