2valve Vs. 4valve

[jzack]

Could one of the great Mack experts on this site please explain which Mack motors came with 4v or had the 4v option. What's the difference? Is it like gas engines where the 4v is generally more efficient.

I'm specifically interested in the E7's. I currently own a 94 E7 350 and am looking at a 93 E7 350 where the owner lists it as a "350 4valve". The 94 is electronic while the 93 I believe is mechanical (if that makes a difference).

Any help is greatly appreciated!

[theakerstwo]

the 4valve will flow air better than a 2valve and it will also eat camshafts faster. They have the injector installed straight down in the center of the piston vers the 2 valve were it is in the side at a angle. the injector i quess will direct the heat more even on top of the piston making a better exspanion of the piston. the 4 valve will get more power out of them and ever one wants to replace a 2 valve when they have to with a 4 valve. i run a 2 valve some in a DM and it is a 237 and i dont know what it would take to tear it up but wish it was a 4 valve. glenn

[jzack]

Thanks Glenn. So 4valves have more power but 2valves are indestructible. I'm assuming most recent diesels (i.e. E7) are all 4valve. Right?

[theakerstwo]

Thanks Glenn. So 4valves have more power but 2valves are indestructible. I'm assuming most recent diesels (i.e. E7) are all 4valve. Right?

right.