whats is the issue with BBF exhaust ports

i was done some reading , what seems to the the issue with the BBf exhaust port flow, even with big valves and fully ported most have a hard time getting any good flow numbers with out going to a high dollar alum head..im seeing 200-220 cfm..my sbf heads are half the size and way smaller valve and go 246..but they are a aftermarket iron head but still retain the standard valve angle and location

Shock towers and hard headed engineers and bean counters.

Cam will solve the problem................... Not as big of an issue as the chevy guys will tell you it is.

johndickjr wrote:i was done some reading , what seems to the the issue with the BBf exhaust port flow, even with big valves and fully ported most have a hard time getting any good flow numbers with out going to a high dollar alum head..im seeing 200-220 cfm..my sbf heads are half the size and way smaller valve and go 246..but they are a aftermarket iron head but still retain the standard valve angle and location

Pretty much the 120 degree turn of the port which the exhaust is required to navigate.

Those "little" ports have supported well over 800hp, and Blake has one with p51's making over a 1000hp..... So how bad are they?

Those sorry ports always cause me to break U joints and spider gears. Junk......

Not really sure what you are talking about - Scotty J from RHP got me 248cfm ex from Eddy RPM's...

tribal wrote:Not really sure what you are talking about - Scotty J from RHP got me 248cfm ex from Eddy RPM's...

I thought the OP was talking about regular OEM iron heads and anything over 220 cfm or more with those would be a dream.

johndickjr wrote:whats is the issue with BBF exhaust ports?

With the knowledge that has been gained over the decades about how to port them, with the knowledge that has been gained in camshaft lobe profiles, cam timing events, etc, etc, etc, there are no major issues with the OEM iron BBF exhaust ports anymore. Those days are gone.