Keith5

Why do these gaskets have the rear coolant port blocked up? Can these be cut out to help with cooling? What's the deal?

jeffs82z28

Look at an sbc intake manifold and you will see that there is no water passage.

Keith5

My stock one does, and my Edelbrock one does. On the stock manifold that is where the heater hose goes too, but there is a port on each side, and it looks like the ports are connected through through the manifold.

jeffs82z28

Look at the other end

Keith5

What are you talking about? I've got water passages on the front and the back of my manifolds.

jeffs82z28

I am referring to the back of the intake manifold.
On both of my stock manifolds, my Edelbrock performer and torker II manifolds and the stock 2 barrel manifold tha t was on my 283, there is no passage in the back of the manifold for coolant to flow through.
There is a passage in the front and the thermostat sits in the middle.
I am at a loss as to what your manifold looks like. Maybe the 1989 motors are different from the sbc's that I have.
I would suggest re-posting the question and maybe some body else can answer your question.
Sorry

gpierce

If somehow you have an intake manifold that has passages through it in the rear, then yes you can cut out the center of the blocked holes. I thought the main reason there were no passages was because the distribututor is in the way.

If you check again, and you're manifold does not have a passage, you can still cut out the holes in the gaskets and use it. You will have to drill and tap the intake manifold in those locations and connect the two together with NPT fittings and braided hose.

I doubt it would really increase cooling that much to go to all that trouble on a street car though.

GP

Desert86Roc

The Edelbrock manifold, as with any other TPI manifold, do not have rear water passages.

Keith5

Who the hell said anything about TPI?

Here are pictures of my intakes. It looks like there are water passages at the back of the intake.

bullfrawg

here is the trick. Look at your old gaskets. If they are cut out then cut yours out.

DM91RS

On the TBI engines the intakes are designed to be heated with the water passing through the entire length of the manifold. The gaskets that you have in the pic's are the correct ones for the TBI intake as it came from the factory. The stock and the Edelbrock TBI intakes both should use this gasket. The small holes are to help bleed any pockets of air that get trapped there as far as I can tell.

DM91RS

I forgot that you asked this....no do not enlarge the small holes in the gaskets. The water should pass through the intake and not bypass it.

Keith5

They weren't cut out, I just wanted to know if it would help in cooling if I had cut out the new ones.

I see that big cavity that holds the coolant in the intake now. It would be nice if I could keep that thing with ice water all the time

gwman

I am running into the same question on my 91 350 TBI motor. I am have heating problems so bad that I was started to tear down the old 305 and put it back in. It still had a portion of the intake gasket on the 305 and it looked as if it was fully open in the rear jacket so I took the intake of the 350 (with restricted ports in the back) and put fully open gaskets on. Now get this, IT GETS HOTTER QUICKER NOW! I give up I gon't get it!

Keith5

Maybe if those rear ports are open it causes the flow to be disturbed or something. I put mine on today, I left them blocked.

gwman

keith 5 did u say that on the factory gasket you took off that the rear ports were restricted or were they fully open? What year and what motor do you have? Let me know how it goes after you put the restricted gaskets on.
I have noticed that since I put the fully open gaskets on it does get hotter quicker so the fan kicks on and off more frequently, but with the A/C on (fan always on) it seems to stay right at 180* (I run a 180* stat).

gwman

one more thing I think the reason why they restirct the rear ports is so that little water flows through the rear of the intake so that not so much water goes through the heater outlet (so more water flows through the radiator) and that it is forced up through the upper hose. I could be wrong though.

Keith5

My factory gaskets were restricted at the rear ports just like the ones in the picture. I've got the original motor, an '89 throttle body injected car. Mine has always run at 160* as long as I'm moving, I put a 180* stat in as soon as I got the car.