Cold Air Intake for Pesto

[70spider]

I am currently building the air box so by the end of next week I'll give it a test run. The reason for this is to try to eliminate fuel fumes from interring the car, and maybe a pony or two.

[DRUMMOND]

It looks great!!

but wouldn't it be better to get the air from outside of the engine bay? Wouldn't take much more work. remember you have an hot exhaust and warm air from the rad to deal with.

[70spider]

but wouldn't it be better to get the air from outside of the engine bay?

Yes it would that is why I am enclosing the air filter within an aluminum air box with a duct hose exiting through the radiator support. That way I don't have to cut any metal to fit the filter, which I might regret later.

[chrisg]

interesting! what is the source of the housing? did you make it?

[AndyVAS]

Be sure your air box has some vent to prevent it building pressure at highway speeds. The pressure will cause your carb to run lean and trash the motor unless you rejet for that and then it will run rich all other times.

Also, most of the fuel smell tends to be from things other than the carb unless it is leaking. If you haven't replace the rubber fuel hose since the change to ethanol then it is destroying the old hose and you are smelling it through the hoses.

[70spider]

interesting! what is the source of the housing? did you make it?

It is a Spectre low profile. I had to design and make the adapter so it would fit the Weber 32/36 carb.

Also, most of the fuel smell tends to be from things other than the carb unless it is leaking. If you haven't replace the rubber fuel hose since the change to ethanol then it is destroying the old hose and you are smelling it through the hoses.

It seemed most of the odor was from the carb, mainly during warm up, I also had a Ramflo air cleaner. All my hoses are new. The box itself will not be 100% air tight, I don't know how to weld so I am using angle aluminum as a frame and bolting the box panels together, but thanks for the heads up on the pressure thing I would have not known that.

[JohnMc]

That looks really great! I wish there was a kit for same.

[70spider]

I wish there was a kit for same

The hardest part was creating the adapter to fit the air plenum (I will take pic of it and post later). The rest was easy parts are: Spectre Performance 98499 plenum, 4' to 3" reducer coupler, (2) 45 degree elbows, (2) 4" sections, (2) Clamps, and the K&N filter.
I did run into an issue with the first straight that runs over the exhaust cam's valve cover, so I had to flatten one side. I created a half circle holder out of 2x4 wood, 3" in diameter, that held the tube. I then used two 3"PVC pipe pressure test plugs on each end and set them in my table top press. I placed a solid bar approximately 3/4 the width of the vale cover and flatted the underside of the tube about 1/2". It is a tight fit but works.
One last issue is I will have to modify my hood a little, I need to relieve a 1.5" section of the center rib of the hood to fit over the reducer (the blue thing). Normally I would not cut any metal on my car however the PO had already put hood pins in.

[manoa matt]

There are kits: https://www.piercemanifolds.com/product_p/99217.090.htm

https://www.ebay.com/itm/WEBER-Carb-Rem ... 0667411851

Search long and hard enough and you might find it cheaper somewhere.

Also, rotate the plenum 90 deg. so the inlet points straight ahead, route the pipe and position the air cleaner just above the air horns. There is a hole in the header panel there where fresh cold air will come in to the air cleaner. Routing it as shown over the exhaust side heats the air. The 1979's were oriented that way.