Holley Carb and PCV valve help

[KLFrank]

Hello and thanks for looking at my post. I have a 1989 Carrera with 460 OMC King Cobra. The Holley 4160 marine carb (600cfm)was old and shot out. Rather then rebuild it I opted to replace with the same marine 4160 from summitt.

The old 4160 has the 3/8 port under the front bowl (primary side) this is where the pcv hose connected. The motor ran well.

The new 4160 has the 3/8 port under the back bowl(secondary side) this is now where I plugged in the pcv hose.

Now, when I'm at WOT, and I'm going to back off the throttle, there is a loud whistle sound when the secondaries are closing. Kinda sounds like a turbo...

Is this whistle because of the change in pcv placement(from front to back)

Don't want to blow any seals with too much/not emough crankcase pressure.

Any ideas or thoughts are greatly appreciated.

 

[kenny nunez]

That sound is just the air flowing over the port for the PCV. There should be another place on the manifold where you can get vacuum for the PVC.

 

[KLFrank]

Thanks for the response Kenny.

 

[Scott Danforth]

the whistling is probably from the air rushing past the closing secondaries, vary common. my 4150 does that coming off throttle

are you sure your new 4160 is a marine carb?

 

[KLFrank]

Scott, thanks for the reply. The top tubes do a u-turn so I'm assuming it's marine. Also the summit order # listed as marine. It's just weird to hear this new whistle after the carb swap and pcv location change.