Technical Blocking EGR ports question

I want to run an Edelbrock 2701 EPS intake. I'll be bolting it to a set of factory GM iron heads that have the EGR ports as the factory intake obviously came with the EGR. The Edelbrock intake has the ports, but they are only connected by a "passage" that runs under the carb bank to bank with no EGR valve......

Can I, or should I completely block off the ports with a piece of sheet metal under the intake gasket?
The carb will be an Edlebrock 1405 with a manual choke

 

That intake has no EGR provision. The "passage" as you put it is how all SBC are done from the factory since 1955. You can block it if you wish but the winters where you live say do not.

 

I think you are talking about the exhaust crossover. It supplies heat under the carb for drivability. In Edmonton you might need the heat for cool weather driving. I've run both ways , blocked and open. Takes a little longer to warm up when blocked. Supposed to be better for performance when blocked but frankly I didn't notice either the drivability or performance change.

 

I guess you are correct Jethro, my terminology might be wrong. So the "crossover" in the intake would be ok to leave open? I mean, its an aluminum intake. I wouldn't want to see it melt somehow. The intake gaskets come with little thin metal tabs with a hole in them to allow some flow. I'm guessing I should use those at the minimum.
The car is a summer driver up to Halloween then it gets winter stored.
Thoughts?

 

It is not just a Winter thing. Carburetors can ice, even on just a cool day.

 

I grew up in Edmonton and I know how cold it can get. I think the only month that I haven't seen some sort of frozen precipitation is July. The carb heat helps to vaporize the liquid gas in the manifold , might help with drivability and carb icing. If it's not a hi performance car you probably won't notice.

 

Nope....bone stock 305.

 

Unless it's a race car where you're adjusting the tune after every run, leave it open. It can make a big difference in drivability.

 

You don't say what exhaust manifolds you are planning on. Remember stock cast iron ones had a flapper valve on the right side. It caused a lot of exhaust to pass under the carb for heat and a Thermo spring helped open when hotter. On mine I have it open and put gaskets with smaller holes so less heat will pass under. It's not cold where I live. I also have phenolic plates under carbs which was not advisable if using a stock style intake that has the 2 holes in the manifold that exit at the carb base.

 

Hmm, ok...I will be using Rams Horns manifolds and the heat riser valve will be gutted of the flapper with the shaft hole welded up, so its basicly a straight through passage.

 

That will keep less exhaust going under the carb/manifold but allow some heat to make for better combustion. Good luck with your project.

 

Thanks man...its going into the car in my avatar.

 

I had a 305 with a factory aluminum 2bbl intake manifold on it. Ran with an open crossover passage with no problems. That one had the hear tube in the cross over passage for the automatic choke, so blocking it would have serious problems with the choke opening properly. I had another one with a cast iron intake that was partially blocked. It had severe stumbling issues when cold. Mid summer was alight, but the rest of the year it sucked.

 

As best as I can remember the intake gasket will be supplied with partial block off plates . Thin stainless plates with holes about the size of a dime . Use those plates and all will be well . Same thinking as a thermostat in the coolant system , slow down the flow and intake will take on the heat for you .