4v 2v wha?

[65fastback2+2]

I know on older stangs theres an A 4v motor and a C 2v motor, is the Xv referring to the carb or the heads??? If its heads, that means an A code is a 32 valve motor??

 

[John Z]

the v is for venturi or the technical name for "barrels". A 2v is a two barrel carb. All classic mustang heads have 2 valves per cylinder.

 

[88 Fox GT]

I believe the 351 Clevelands had 4v and 2v heads. Referring to either a 4 bbl or 2bbl carb. The heads were different for flow rates, the 4v head would flow better. But they were still 2 valves per cylinder.

 

[D.Hearne]

There were also the 68 4 bbl 302 heads, but they were just re-cast earlier 289 heads, still had same ports and valves as the 2 bbl 302 heads, difference was smaller chambers for higher compression.

 

[geegee]

Yes, it means all those things. You have to know the context of what's being discussed.

2v could mean 2 venturi (carb) or 2 valve (overhead cam engines).
4v could mean 4 venturi (carb) or 4 valve (overhead cam engines).

If you're speaking of the older generation of carbureted engines then it refers to the carb layout. If you're speaking of modular motors, 4.6L for example then it refers to the valve layout.

Exceptions to the above are Cleveland early engines. 2 v and 4 v also referred to the heads used with specific engines. 2 v were heads were used in widespread production and mounted a 2 v carb. 4 v heads were used in superstock engines for enhanced performance.

There are probably other exceptions too, so the best deal is to pay attention and soon it all makes sense (well mostly! ).

 

[hungrymonkey]

and when you get in the habit of saying valve instead of venturi, people start to look at you like your and idiot...

even though you know what you meant, and you know that there is only an exhaust valve and intake valve per cylinder...