Thin metal under intake manifold

[rsmarr1982]

Has anyone left this piece of thin metal out from under the intake manifold. I am installing a 4 Barrel Factory intake manifold on my 72 K20. I noticed there was a bunch of carbon stuck in between the thin metal in intake manifold upon removing the thin piece of metal I broke it up a little bit. I was thinking of leaving it off I've never seen aftermarket intake with it on there just wondering if it would hurt anything

[cdowns]

it is a form of a heat shield to prevent fuel from boiling

[jlsanborn]

Yup, keeps hot oil off the intake, under the carby. Not at all necessary but sure wouldn't hurt anything either.

[mike16]

The exauste cross over under the intake runners help to keep the fuel in an evaporative state. the underside of that exaste cross over runner gets very hot. So hot that it will burn off the oil that splashes on its underside and while the liquid oil component evaporates the solids in the oil solidify and build up on the underside of the intake manifold. the heat shield prevents to some degree the splashing evaporation and build up of solids on the underside of the manifold. The fact that there is some solids that continue to build up indicates that it works to a certain degree. those solids are retained inside the sheatmetal heatshield to prevent the solids from loosening and braking off and contaminating the oil and allowing solids to flow through the oiling system like other forms of abrasives... with similer results. Its primary purpose is as a heatshield. Best quality oil(mobile 1) and regular oil changes prevent this build up.

you can carefully remove the rivets that hold the heat shield in place and remove the solids build up..befor hot tanking the intake. most chemical and heat related cleaning systems will not remove it so a physical process is nessessarry to remove it. Bead blasting or some other form of abrasive removal system.

if the heat shield is not removed and the intake is dipped in some chemical cleaning solution. it may loosen and brake up the solids build up under the intake but will not nessessarrily remove them. The solids will eventually break up further over time and contaminate your oiling system with solid abrasive dibris and damage your engine as well

If you intend to use the intake, remove the heat shield. Often times the rivets can be disloged with out breaking the heads off. If the heads break off, they can be drilled out. its a soft metal those rivets

New rivets are available from several corvette parts vendors. sheet metal screws can also be used to reinstall the heat shield, providing that judges at a local car show dont gig you for incorrect rivets or screws.....?

It may be just as easy to discard the heat shield. If its not there its less likely to come loose and rattle around in your engine lifter valley.

think long and hard about reusing an intake with the heat shield that has not been cleaned out. Allowing those solids to circulate in your oiling system is often catostrophic.

If you choose to use an abrasive removal system be absolutely sure to remove the abrasive media as well as it too can enter the oiling system and cause considerable damage

Aftermarket intakes dont usually have the heat shields for several reasons. Primarily as a cost saving measure but also to prevent debris build up as well. And also because often they are either designed with out the exhuats cross over, or often times it is blocked.

what ever you choose to do, be absolutely sure that it is spotlessly clean befor reusing that intake. It only takes a very small nugget of solid debris to really tear up some bearings.