Can anyone tell me what the slots are in the center of each head manifold side. One by the EGR valve and other opposite side same location. They are not covered by the intake manifold or valve cover.
This is the first Olds I have worked on. Never seen these on any Chevy motor Ive built. Is there something missing, part of the AIR possibly.
Any info would be great.

 

Exhaust crossover, routes exhaust through separate passage in intake manifold. Provides heat for choke, EGR and warms carb/fuel (for better or worse), my belief is for nice fuel atomization & discouraging carb icing.

It is common practice to block this heat by various techniques in performance application so intake charge & carb stay cooler.

 

Are you talking about the exhaust crossovers? If so, 1) they ARE covered by the intake manifold and 2) they ARE on every Chevy head ever made.

 

Well they werent covered by my intake. These slots were clearly visible with the intake installed. They are hard to see in the picture but they are directly above the center exhaust port on the head.

 

Guess I should have said they werent visible with the intake manifold installed on the Chevys I have worked on, and if I knew they were crossovers I wouldnt have asked the question in the first place Joe.

 

bccan, thanks for the reply. Not sure if thats what they are. With my stock manifold in place they are visible. I will get better pictures this evening when I get home. Thanks again.

 

I'm sorry if I'm being dense here, but I'm still not sure if you are talking about the exhaust crossovers, or some divot in the casting above the crossover port. If you are talking about a divot above the crossover, ignore it. It doesn't do anything and it does not need to be sealed. Just be sure you have the correct intake manifold gasket for your heads. There are two versions from FelPro, one with small crossover ports for the 1972-earlier heads and one with larger crossovers for the 1973-later heads.

 

ok. Here is a better picture. As you can see the slot is next to the EGR mount and is clearly visible with the intake in place. There is a identical slot on the opposite side. Nothing was attached to either opening and the engine started and seemed to run fine prior to removal. This is a 77-80 350 block casting #554716.

 

My 79 Delta 88 had that. The engine was a 350 Olds.

 

Just lightening features used on the 1977-up motors. Nothing to worry about.

 

What are there function? Seems like it would be a good way for moisture, trash etc to enter. Would it hurt to block them off? I'm a fanatic for keeping the engine bay clean and it just seems wrong to wash a motor with those openings!
Thanks for the reply Joe.
Its the first Olds motor I've had and just want to make sure I'm doing things right. It will be going in a 83 Cutlass that currently has a Buick V6 so I'm sure I'll be asking more questions as this winter project unfolds!

 

Why it looks to me there is more trash elsewhere on that pic not in that opening?Waste of time.

 

True. This motor is very dirty, but realize I just bought this car and it had been setting for a couple years. I assure you when it goes into my cutlass it will be spotless and will stay that way!

 

I think Joe answered that question in the post before, no?

- Eric

 

To weigh less...

In response to then-new gov't fuel economy standards, Olds redesigned it's engine castings for the 1977 model year to reduce weight by eliminating unnecessary metal. The best know of these weight reductions is the windowed main webs in the blocks, but there were other places where unneeded cast iron was eliminated, as evidenced by these pockets. Based on personal measurements using the most accurate Chinesium bathroom scale sold by WalMart, I can tell you that there was about a 30 lb reduction in the weight of the bare block with these redesigns. I don't have total assembled engine weight differences, however.

 

And if your wanting to keep that part of the engine clean, an air hose and a low pressure sprayer will clean out those places.