Intake Manifold Restrictors at Gasket

[larry bud]

What is the purpose of these aluminum restrictors? Do I really need them? Should they be completely blocked off, or are the ones with about 1/2" hole in them be OK?

I take it these cause the motor to warm up faster. I'm in Michigan, and do drive the car in the winter. Is this a serious issue if I leave these off?

 

[larry bud]

Nobody knows?

 

[WhalePirot]

Are you referring to the squarish aluminum 'plugs' for the center gasket holes, which are part of the EGR system?

 

[Ken]

The restriction was built into the design after much research I imagine, and if the engine's stock, I'd replace "in kind." I doubt if it would hep you warm up any faster and may even cause problems with the stock cooling system, such as "burbling/gurgling" in the heater routing.

 

[larry bud]

Yes, the aluminum plugs, but they go in the rear coolant holes, not the middle.

 

[larry bud]

Ken, the restrictors that were in there COMPLETELY blocked the rear port. The ones that I got with my fel-pro gaskets are made to only partially block the CENTER port. Hence I have the confusion as to what I should do.

 

[Mart]

I used these gaskets on my 86, those gaskets are meant for various years and designs, I do know that on an 86 with cast iron heads you need to remove the restrictors (aluminum plates). Not sure about the 86 with aluminum heads, check the gaskets that you remove from the intake and compare.

They will basically block the flow of coolant through the intake, which is the design on several later models.

As far as the center holes go this has been blocked off on the manifold itself (On one side only I think)

I removed all plugs on mine and have had no problems, that is the way they were to begin with.

Mart

 

[Ken]

I believe the bypass line, a small line from right rear of the intake to the heater hose, plays a part in this somehow.

 

[larry bud]

I used these gaskets on my 86, those gaskets are meant for various years and designs, I do know that on an 86 with cast iron heads you need to remove the restrictors (aluminum plates). Not sure about the 86 with aluminum heads, check the gaskets that you remove from the intake and compare.
Mart

I have iron heads, and put it all together without the restrictors. Everything seems to be fine in the heating/cooling area. It was 40 degrees this morning, so I guess I'll see what happens when it's 10F!!!

 

[G Winter]

larry bud,, you drive your vette when it is 10 deg? don't you put it away for the winter ?

 

[larry bud]

larry bud,, you drive your vette when it is 10 deg? don't you put it away for the winter ?

No, as long as there isn't snow and ice on the pavement, I drive it.

Why not?? I've got 170k+ miles on this thing. It's made to drive!

 

[G Winter]

larry , you got a point but I don't like the salt factor.