Noise from Chrysler 360 head u shaped hole?

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Bud719
Member
Posts: 15
Joined: Wed Apr 05, 2017 5:49 pm
Location: Riva, MD

Noise from Chrysler 360 head u shaped hole?

Post by Bud719 »

You know those upside down “U” shaped hole in your Chrysler small block heads? (For some emissions control or cross over, I don’t know, but not used on our marine version engine).
I am getting engine noise from this as well as exhaust or hot air) just on one of the heads of my 360. This is a replacement long block with maybe 100 hours on it.
If I pack it wit a shop rag or aluminum foil, that’s enough to make it go away and sound like my other 360.
Engine otherwise runs great, oil pressure, water, temperature.
I’m thinking maybe a crack near the exhaust valve or something.
The noise however is very loud if not muffled.
Anyone know what this is?
Bud
Bud
1990 Marinette 32 Sedan “Mostly Harmless”
Twin Chrysler 360s
Westerbeke 6.5 KW
Beard’s Creek, South River,
Chesapeake Bay, Maryland
jralbert
Site Admin
Posts: 821
Joined: Fri Jul 11, 2014 9:15 pm

Re: Noise from Chrysler 360 head u shaped hole?

Post by jralbert »

Not an expert and so don't want to make a worthless post. While this board's crowd has some well-informed residents, don't fail to contact the reman outfit from whom you bought the long block. Good luck -- I think you are onto something when you mention a crack or seal. Hope you rsupplier stands behind their wares.

((Sort of jealous. South River is among the world's best pleasure boat locales. I used to be in Deale))
-joel-
former owner 1988 '32 FB Sedan
Chesapeake Bay
twin 318 / 240 hp
Potomac MD
Bud719
Member
Posts: 15
Joined: Wed Apr 05, 2017 5:49 pm
Location: Riva, MD

Re: Noise from Chrysler 360 head u shaped hole?

Post by Bud719 »

Thanks Joel, it is really nice here. Just barnacles are bad, but you can’t have everything!
Bud
Bud
1990 Marinette 32 Sedan “Mostly Harmless”
Twin Chrysler 360s
Westerbeke 6.5 KW
Beard’s Creek, South River,
Chesapeake Bay, Maryland
Fastjeff
Site Admin
Posts: 1451
Joined: Sat Jul 12, 2014 5:06 am
Location: Rock Halll, MD

Re: Noise from Chrysler 360 head u shaped hole?

Post by Fastjeff »

Been a while, but I recall the marine intake manifold gaskets have a metal plate that blocks off that hole.

Drag racers used t fill the cross over passage in the manifold with plaster or cement.

The passage is not needed or wanted in a marine application.

Hope that helps.

Jeff
"We live at the bottom of an ocean of air, not at the top." General Marvage Slatington
Bud719
Member
Posts: 15
Joined: Wed Apr 05, 2017 5:49 pm
Location: Riva, MD

Re: Noise from Chrysler 360 head u shaped hole?

Post by Bud719 »

Yes, it does Jeff, Thanks!
Bud
Bud
1990 Marinette 32 Sedan “Mostly Harmless”
Twin Chrysler 360s
Westerbeke 6.5 KW
Beard’s Creek, South River,
Chesapeake Bay, Maryland
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