In-Tech wrote: ↑Tue Nov 07, 2017 2:28 pm
Since this thread is about ford and chev and other heads, I have a question. I am misunderstanding the nomenclature
http://www.chiheads.com.au/product-cate ... -heads/3v/
What's the gig with 2v 3v 4v 5v heads? I always thought that meant how many valves per cylinder yet the above link calls that two valve head a 3v... Whattha????
Back in the day 2v and 4v meant carburetor. Someone please help me understand. Thanks.
In original Ford speak,,,
2V = 2 Venturi Carb , (used on the small port cleveland heads)
4V = 4 Venturi Carb , (used on the large port cleveland heads)
But it only really applied to port size on USA Clevelands as Ford used 2V & 4V on the FE & 385 series big blocks and SBF with no change in port size and then Ford Australia did the Cleveland using 2V & 4V carb and naming on small port heads.
Basically if you're talking Clevelands and say 2V you're refering to small port heads and 4V is refering to large port heads.
Chi use 3V as a designation for a port size part way between traditional 2v and 4v, in loose term its a floor filled (and much improved) 4v port. Basically industry slang to reference different size/location/volume aftermarket ports.
Craig.