how doess ford and the other car makers decide how to make an engine like what made them move to modular over pushrod and **** like that.

 

$$$$ and emissions.

 

well **** emissions.....global warming is bull**** and........the modular is 2x's as expensive as push rod i mean look at the LSx series of motor the best bang for buck motor on the road is the LS2 (pushrod).

 

Your question was general in nature and I gave a general response. Money and government mandates seem to dictate everything with automobiles. Either they can make it cheaper, make it more desirable or the government mandates necessary changes. You may say "f*&k" emissions, but that is not exactly what I'd consider enlightened thinking. Regardless of one's position on the existence and/or cause of global warming, it is tough to argue with the impact of automobile emissions on air quality, and in turn, health and quality of life. As crappy as the air in L.A. is now, it is far better than it was 30 years ago even with many more cars on the road now than then. Now, if we could only get the Ports of L.A./Long Beach to clean up their act ...

 

They put incredible amounts of engineering to keep their pushrod LS series in the game with economy, emissions, and performance. As much money as ford put into their overhead cam design I'm pretty sure chevy put far more into their LS series. Also the modular design is actually older than most of us think and the LS is still a completely new design even though it shares the displacement with the old 350.

 

I agree with gothand with emissions helping out alot. But still global warming is not affected by us, its a cyclic event and it actually help us, Global Warming:A Chilling Perspective. That site is a nice compilation of research instead of going to 50 different sites. We only contribute about 0.2 - 0.3% of the green house gases. But emissions affect our day to day life, I prefer not to live in my own filth.

 

very good article, weather is a cycle in 100yr 40yr and 5 yr least thats what i've seen here in the south. but just for ****s and giggles im gonna go out on a limb and say GM does not exist. but what caused ford to move from flat head to V and so on, then why change the litres from 5.0-> 4.6 the 5.0 was doing so well.

 

flat head to OHV was simple, its all about a more powerful engine and updated designs usually equal better durability. the modular motors were a rip from the japanese motors that outlive our "american designed" engines like the 302.

 

a 302 is goin to outlive a 281, i've seen a 250k 302 i've never seen a 250k 281

 

I'm going to risk starting a verylarge fire, but the mod motors probably do have better durability than the small blocks, and offer much better perfomance potential (though emissions and money were probably Ford's motivations). I have pulled 2 4.6 DOHC aluminummotors apart, one with 80K and the other with 108K and you can still clearly see the honing and they both had virtually no wear on the pistons. The cylinderwear in each was about .001". The machine shop said to hone and go with new rings (though I bored and went with new pistons). That can probably be attributed to fuel injection rather than overall design (though cylinder head design probably helps). And I have seen posts on Corral.net from guys with 250K+on Cobras that they run hard.

But the big plus is thatthe mod motorsmake more power per ci than most small blocks. It is no problem at all to get 350-360 flywheel HP from a 4.6stockDOHC motor (that is NET hp) - basically a tune andcold air kit. It takes quite a bit ofhardware (some internal - cam)to get that kind of power from a 302/5.0, much less a 289 (the 4.6 is 281). The old'hi-po' 289 made 271 gross HP(which is probably about 245-250 net). Shelby managed to get it up to 306(which is probably about 270 net).A bone stock 01 Cobramakes 320 net(or about 360 gross HP), about 50HPmore than the Shelby modified 289. And it can do that and still get 25+ mpg in a car that weighs 600-700 lbs more than a 65 Mustang.

And with a blower, the 4.6 motors make much more power than a comparable small block.It doesn't take much at all to get 600 HP (at the wheels) from a 4.6 DOHC. I haven't read of many streetable small blocks with Vortechs that make that kind of power (450-500 iscommon, even for 351s). The big difference is cylinder heads - these things breathe like crazy. And with the short stroke and overhead cams, they can rev to 7500 without much problem or risk. Push a small block to 7500 on a regular basis and you might have lots of little pieces. (Though most stock 4.6 motors havepowdered metal rods and hypereutectic pistons while theold small blocks had forged rods and pistons, which are better forblowers. The 4.6 Cobra motors do have forged cranks.)

The same is true of LS motors vs. small block Chevys. The LS heads make all the difference. In the old days torque ruled and 60' times were make or break. These LS motors may not have the torque or the 60' times of an old big block in a similarly set up car, but they pull away from the old big blocks not too far down the track. Technology sometimes IS our friend!