air flow

[pwood]

hello i am looking to fit a new air cleaner set up on my 1984 6.2 jimmy. I live in australia so there is nothing that bolts straight up. I operate in very dusty conditions at times, i have fitted a rammed air snorkel home made and am now looking to modify something out of a toyota or nissan or go Donaldson. What i would like to know is what CFM does a air system need to flow for a N/A 6.2 single plane J code manifold 2.5 dual exshaust. Thanks for any replies great site could not have my jimmy without it

[More Power]

At 3000-RPM, your 6.2L diesel engine will require ~275 cubic feet per minute air flow at atmospheric pressure (non turbocharged).

Use as large an air filter element as will reasonably fit within the confines of your placement.

Jim

[pwood]

thanks for the reply i will start hunting down something with a 300 CFM. The swager air system i have seen on the diesel page looks alright but my mate does not like it as it blows directly on one portion of filter. Is there a diffuser in the system, thanks again.

[More Power]

thanks for the reply i will start hunting down something with a 300 CFM. The swager air system i have seen on the diesel page looks alright but my mate does not like it as it blows directly on one portion of filter. Is there a diffuser in the system, thanks again.

The original factory 6.2L air filter housing did allow the incoming air to blow directly onto the element. Interestingly, the Amsoil air filter element I tested in the late 1990s included a small aluminum deflector that prevented high velocity incoming particles from impacting the element. Good idea... Not hard to make either.

Dr. Lee Swanger's system was designed to allow for the minimum amount of restriction using disposable elements, yet still fit under the hood. A diesel engine inhales a lot more air that an equivalent sized gas engine because a diesel doesn't have a throttle-valve like a carburetor or injector body. A bigger element that is serviced often is important when maintaining the intake side of the a diesel...

Jim

[tomtaylor]

I bought an open single plane manifold for my 86 6.2 but a friend of mine insisted that large open plenums were intended for higher RPM and power. Since I am interested in fuel economy he wanted me to stick with the original manifold, can't remember the details of his explanation and information he downloaded about this but with a diesel is this a relevant issue?

everything I have read about 6.2's talks about improving breathing in and out, since I am not increasing fuel flow rate does it matter which manifold I use for economy?

Thanks for any info you can pass on.

[JohnC]

Reducing restrictions in either the intake or the exhaust will increase the volumetric efficiency of the engine. If you don't add fuel, the worst case is you break even.

[AJMBLAZER]

Little late to the party but there is an aftermarket Land Cruiser snorkel setup that fits your body style K5. I forget which one though. Been done several times over at www.ColoradoK5.com . Several of the guys put some time into it and made the install look like it was meant to be there.

[pwood]

i replaced my dual plane c code manifold with a single plane j code and the difference is great more responsive and starts much better with less glow as have manual glow control

[pwood]

your friend is right but that stands for petrol motors diesels want as much air flow un restricted as possible. petrol overlap on valves due to cam creating scavenging effect at high revs but when i replaced c code dual plane with j code single plane best money ever spent