Captain_Toyota said:
Id prefer they partner with Ford over GM. At least Ford is using somewhat modern engine technology whereas GM is still holding onto the OHV engines. While the OHV engines are certainly good, reliable engines, they arent known for great power per cubic inch.
OHV engines are great.
Holding on to them is probably one of the smartest things GM has ever done. The V6's are extremely space efficient (much much smaller than Japanese DOHC V6's) and cost anywhere from $600-1000 less to produce than a DOHC V6. This is what allows GM to sell you a pushrod V6 at the same price point as a Japanese 4-cylinder. And the compact design allows them to dedicate more room to passenger space and less to the engine bay which works out well too. Pushrod OHV engines also use just a small timing chain which lasts the life of the engine so no changing needed. The camshaft in a pushrod V engine is just above the crank in the V-valley so it's a really small chain. Also, due to only turning 1 cam, and 12 valves on an OHV V6 vs 2 or 4 cams and 24 valves on a SOHC/DOHC V6 engine, you have an extremely similified design with fewer moving parts and very low overall friction. The Chevy Malibu 3.5L V6 makes 200hp/220tq, and gets 23 mpg city, 32 mpg hwy. That is DAMN GOOD mileage, and also very good power. It's better than Toyota's 1MZ-FE on regular even with DOHC, VVT-i, and a variable intake manifold, and it's practically the same as the 3MZ-FE all while being a much simpler and much cheaper engine. It gets better fuel mileage than all of those engines too.
When it comes to V8 engines, OHVs have an even bigger advantage. DOHC 90* V8 engines are friggin huge. They require enormous engine bays, massive heads, and get extremely heavy. In comparison an OHV V8 is tiny, and since the engines are so space efficient more of the engine area can be dedicated to displacement which is what makes torque rather than wasting it all away on DOHC heads and lots of valves.
GM's OHV V8 truck engines blow away Ford's 4.6/5.4L SOHCs. Ford can't even compete and as a result I've read that they're coming out with a 6.2L pushrod OHV engine to finally do battle with the bigger GM OHV V8s and the DCX Hemi engine. I would take a GM OHV V6 any day over the crappy Ford 3.0L Duratec DOHC V6. That thing is unrefined, underpowered, and doesn't even get very good gas mileage. A GM OHV 3800 makes about the same peak horsepower, makes way more torque, and also gets better mileage (30 mpg easy, vs 26-27 for the Duratec). Now that Ford's 3.5L DOHC V6 is coming out finally though, the GM vs Ford V6 wars will finally get a lot more interesting.
BTW, GM realized a long time ago that to sell in premium segments they just
have to have a "modern" DOHC 24-valve V6 engine. So they have a global "high feature" V6 lineup with all the high end stuff. DOHC, 24 valves, dual VVT, and displacements of 2.8, 3.2, and 3.6L. These are used mainly in the Cadillac cars, and a few others. There's also a turbocharged 2.8L V6 used in a Saab that won a Ward's 10 Best engine award this year too. And then there's the Northstar V8 which is fully modern and has been around for ages too.
So GM has all the bases covered whether their application demands a space and cost efficient OHV V6, or a "premium" high feature one with all the importesque stuff. If anybody has really been hurting lately in domestic powertrains it is DEFINITELY Ford, not GM or Chrysler. Ford has by far had the weakest and most pathetic powertrain lineup in the past few years that it's not even funny. The 3.5L V6 will help that a lot, and then if this 6.2L OHV V8 comes out that will help Ford a ton too. They've had some really stellar products (Five Hundred, Fusion, Freestyle, etc) but no decent engines to put in them.

GM's OHV V engines are extremely modern, very efficient, and perfectly viable in today's marketplace. There is a perception problem with them to some extent, but the C6 Z06 LS7 engine, the DCX Hemi, the LS1/LS2, and the 303hp/28mpg LS4 engine have all helped to change that perception.