Air cleaner assy.

[philo_beddoe]

I have a factory air inlet cover, but a 1977 shows no fresh air duct or snorkel, why is this?


And here is a pic of a 1977 factory set up.


Why do i have the air inlet cover if no factory snorkel? Like the above pic shows.

[VileZambonie]

Not sure what you are asking? EFE was standard equipment on GVW 6000 and under.

[philo_beddoe]

I think i got it, but i'll point it out next time i stop by. Minor issue.

[VileZambonie]

Trucks with higher GVW ratings did not require certain emissions items if you are asking why some do and some don't have those items?

[philo_beddoe]

What is the purpose of the fresh air duct snorkel anyway, in relation to emissions?

[philo_beddoe]

This would work, but i think i would need to cut a hole in the bottom of the neck and weld a sleeve there for the pre heater hose.
http://www.classicindustries.com/product/1977/truck/parts/m3361.html

[VileZambonie]

What is the purpose of the fresh air duct snorkel anyway, in relation to emissions?

The thermostatic air cleaner allows it to draw heat from the exhaust manifold for faster warm up, lower emissions and better cold engine performance. When the engine warms up it benefits from the cooler denser air charge.

[philo_beddoe]

"Better cold engine performance", so why ditch the factory set up and go to this? For looks?

[VileZambonie]

Most guys prefer the unrestricted volume for maximum power and cowl induction helps bring the cooler air into the engine compartment which is why they are popular mods. Once you start modifying the engine that little snorkel is like a noose

[Irish_Alley]

with the open air filters like that you will have issues when the engine is cold rich did a little post a while back about them

[Irish_Alley]

http://forum.73-87chevytrucks.com/smforum/index.php?topic=27239.msg226597#msg226597

[philo_beddoe]

Thanks, its good to cover the basics now and then.