Quote:

Re: Ford mod V8s
My knock on the mod motor is this:
When Ford designed the mod motor they were too pessimistic about their ability to sell or possibly certify a large smallblock so they made the bore spacing too small (3.937"). While this made a nice short engine front-to-back, it didn't leave a lot of room for expansion. So when the cry came for more power, they couldn't add a lot to the bore size, instead they had to stroke the engine. So now they have a 330 cubic inch engine with a 4.165" stroke. Even a 273 block with a 4" crank, also about 330 cubic inches, has a shorter stroke.
Part of the thrill of a DOHC engine is that it breathes well and the lightweight valvetrain allows it to rev much higher than typical pushrods. But having a DOHC head on a 4.165" stroke is kind of like putting racing flats on a shot putter.

End of lecture.
R.



Yes, i'd agree. Part ov the reason why i like them so much is because i AM into smaller, lighter cars now than i was. Anything i'll be driving will do more than fine with 5.0L or less. The 5.4DOHC still seems to work very very well however. In fact, it seems to be one ov those 'freak' engines everyone is talking about in that other thread... it just works, better than we'd think it should. Ov course, the guys that do need more torque are forced to stroke it even further... up to 5.8L i think. Al Pappito, the foremost 5.4DOHC guru has made some monsters... He'd say "My piston speeds would make you puke." I can imagine. But again... Mustangs/Cobras are on the smaller lighter side... and my Challenger would be considerably lighter still. I've since got off that wagon though...

As for the MDS. I still dont like it. Its hokey. Just design a more efficient engine!!! If it changes (effectively) to a 4-cylinder... then it must sound like one as well... and in that case i am most definitely out. I dont care if it runs 9's and gets 40mpg. I'll buy a Honda if i want a 4-popper. And on the efficiency track... my point was more that a modern DOHC V8 should always be more efficient than a (admittedly compromised) 'sort-ov' hemi design, or even the almighty LS-engine design forged by God himself (according to Hotrod magazine and Chevy guys)... though i'll admit i've yet to see the actual math on that one yet.

They are good... and kept within their comfort zone (smaller, lighter cars) they are pretty damn successful.

Now, if i was jamming a modern plant into a 71 Charger, or a C-body, or even something mid-size with an automatic transmission... ... the hemi (or the LS) makes a more obvious choice.