EGR port.

 

Awesome, thx.

Is there any benefit to having it vent into the carb barrels? That's how it was before the swap.

What happens if I just block it off and it doesnt vent to anywhere?

 

Don't allow it to vent anywhere.
Block it off completely.

 

That's how its set up now, prolly gonna keep it that way.

I'm just curious how it works- why do you recommend that?

 

That port goes directly into the exhaust crossover passage that runs under the intake and connects to the exhaust on each side of the engine.
The EGR system valve allows a small bit of exhaust gasses to enter the intake along with the air and fuel.
You removed that EGR valve... so....

If you vented that passage anywhere you would have a massive exhaust leak.

BTW are you sure that is a Cleveland?
Not a 351M?

How did you ID the engine?

 

I don't recall actually how I first ID'd the motor ...but apparently the C has vertical fuel pump bolts and the M has horizontal ones. Mine is vertical (I just checked)

I didn't actually remove the EGR valve so far as I know. I just removed the aluminum spacer that channeled from the EGR port into the carburator barrels above the intake (see image of removed spacer). The port on the back of the spacer was already plugged with a bolt when I bought the thing like 15 years ago. So I guess it has been venting exhaust back into the fuel/air mix all that time... Now that it isn't, is that perhaps what has caused my unstable idle at starting temp and increased idle at operating temp? I'm just trying to figure out whether I should adjust the carb to the new configuration, or if I have the new configuration wrong...

 

I don't recall actually how I first ID'd the motor ...but apparently the C has vertical fuel pump bolts and the M has horizontal ones. Mine is vertical (I just checked)

I didn't actually remove the EGR valve so far as I know. I just removed the aluminum spacer that channeled from the EGR port into the carburator barrels above the intake (see image of removed spacer). The port on the back of the spacer was already plugged with a bolt when I bought the thing like 15 years ago. So I guess it has been venting exhaust back into the fuel/air mix all that time... Now that it isn't, is that perhaps what has caused my unstable idle at starting temp and increased idle at operating temp? I'm just trying to figure out whether I should adjust the carb to the new configuration, or if I have the new configuration wrong...

View attachment 186370

That is not an EGR SPACER, it is a 2V carb spacer with a PCV SYSTEM vacuum source. An EGR SPACER will have a provision on the backside to mount an EGR valve.

Surprised it didn't burn through the spacer (ALUM).

The 351C and 351M both had vertical fuel pump mtg bolts. The 351W had the horizontal.

To defeat the EGR source on a OEM intake, you need to drill and tap the hole for a block-off plug -

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You can also buy a block-off plate to cover the hot air choke stove -

Do you see any raised CASTING ID on the intake?

 

Actually, I think the EGR wasn't venting anything into the mixture, or almost not anything, the gasket between the spacer and the manifold doesnt have any holes in it. So maybe tiny bits of exhaust leaked under the gasket where the channels left a void of material and failed to squish it tight in that little spot, but not much if any. So that probably isn't my problem...

 

That spacer is not for that , it is only a vacuum for brakes etc. For that hole in the intake, tap a thread and screw in a grub screw

 

What purpose do those notches in the carb barrels serve? They are channeled into the same air pathway as the vacuum for brakes etc...

 

The notches I'D say are just to equalize the vacuum feed from both sides of the dual planes

 

only if it's going racing . otherwise you need it for pcv