DaewooOfDeath wrote:
In reply to Knurled:
That's what I'm saying. If a truck will swallow your quad cam 135 degree v12 no problem, why did GM go to all that trouble making the LS package well?
Pushrod engines inherently package well for V engines, and GM decided that, to meet various goals, pushrod valve actuation was more than sufficient.
A lot of the advances over the small-block are down to not having to work with cylinder head geometry tailored to making a carburetor fit under a hood. The port shapes and geometry are light-years ahead of anything designed when carbs were king. That, combined with a bottom end that doesn't suck, is why they are such good engines.
Mod motors have all of these qualities too, they are just a lot bulkier and more expensive to build, and arguably maintain.
mad_machine wrote:
codrus wrote:
BrokenYugo wrote:
codrus wrote:
Also, OHC engines have an advantage in specific power (power/displacement) and in a lot of other countries cars are taxed based upon displacement, so an engine that makes the same power at 30% less displacement has to pay less tax to those governments.
Is this really relevant when you get up to V8 sized engines? When I think of displacement based car taxes I think of 660CC Kei cars.
Probably not, but it drives the adoption of OHC engines at the low end, which drives the R&D and tooling design, so it feeds into the "cheaper to make them all the same" thing.
exactly.. technically a V8 can be built of two I4s. In reality, it never works that way.. but if the cams, retainers, pulleys, cam bearings, valves, valve springs and retainers, and a whole slew of parts up to and including the valve covers can be shared between the I4 and the V8.. that is winning efficiently.
It may not make the most power.. but as far as building cars, the more parts you can share, the cheaper they become
fun fact, International Harvester had 2 4 cylinder engines that were exactly that, half of there v8 counterparts. they have the 152ci and 196ci, both exactly half of the v8 304ci and 392ci. Change up block and intake manifold castings to block one side, different cam, and you have your self a half'd v8.
with how easy custom cams are to get these days it would be fun to make one out of an LS and see what kind of power you can make, just make a plate to block one bank and cut and block half of a metal intake manifold. 
edit:
also looks like pontiac did the same thing:
this one looks to be cut down to 2 cylinders, and check out that BOV!
im sure theres a few others as well.
