High-pitch whistle

[Lbracing]

Hello--- I had thought I had finished cleaning up my intake ports and was vacuuming them out and noticed a high pitched whistle..so i stuck my finger along the floor about 2" in and it went away..had this same whistle on each port of this one head, the other was fine..I also noticed that if i put my finger 3/4" in on the long wall roof it went away to.

I tried the finger in all the floors and two were about 2" in and one was 1/2" in and the other was just before the crest of the short turn---to stop the whistling noise.

But they all stop as soon as i put my finger about 3/4" in at the top corner radius on the long wall.

what usually cause's this type of noise?? and where should i start to try to eliminate it? I did not have any entry plate or it was not on a bench--compared to the other port there is no real visible difference. I did have the same type of seal on both heads..

I have not finished the bench yet..long process..lol but any thoughts or opinions are appreciated.

It is a big block chevy oval port..head..

Thanks

[Lbracing]

Update----helps if you have the valve in place and also wouldn't hurt to have the rocker stud in either... again put the ole finger over the guide...bang no whistle...

[storm]

Good job figuring it out.

[Brucepts]

I was thinking spark plug . . .

[Lbracing]

Wouldn't hurt to plug that either...