noblejr

I've got my intake manifold off my 77 to clean and paint it. There is a pan on the underside of the manifold. What does this pan do?

Guru_4_hire

prevents hot oil from splashing onto the intake manifold heating up the incomming air.

Paul L

The oil splash shield also prevents the oil from hitting the manifold exhaust cross-over passage. If that happens, it will cause coking of oil and contaminants on the passage surface leading to hard carbon and other bits of abrasive burnt materials breaking off over time and circulating in the oil. Not a pleasant situation.

Guru_4_hire

Thats probably the real reason.

noblejr

thanks. I couldn't get a good view under the pan and wanted to make sure there was nothing in there I would damage with the solvents.

BEBOP138

As long as you have it off that cover does come off, It`s held on with four small rivets. If you tap it lightly with chisel in a upwards motion they will come off. There usually is a big glob of hardened junk inside good to get rid of now while it`s off. Use loctite or get neww rivets and re-install. If your not confident of doing it yourself bring it to your favorite machine shop have them do it and have them hot tank it. Think about powder coating it makes it look so niccccce!!!! :chevy

noblejr

Thanks for the tip. There was quite a bit of junk stored up in there. I won't be powdercoating, but I am putting a fresh coat of it's GM blue coloring. I'll probably have things powdercoated when I do a full rebuild, but that won't be for quite a while.

Paul L

Just another tip and a bit of an aside. If anyone is contemplating bead-blasting an intake remove the shield first. If you do not, colonies of the blasting medium (e.g. glass) will grow behind the shield. Once sucked into the engine.....