Air filters?!

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Mar 8, 2018 | 10:08 AM

dragond80

Thread Starter

New User

Joined: Sep 2016

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Air filters?!

Has anyone ever tried to use a k&n cold air set up on a 70's truck??

Mar 9, 2018 | 12:43 PM

78 f150 400

Cross-Country

Joined: Jan 2017

Posts: 71

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K&N AIR FILTER

I installed a 14" round filter with the K&N top on mine about this same time last year. So there was lots of air flow to the carb. About 15 minutes into the first drive, I lost power and stalled. I still don't know if was the filter or if I encountered a fuel boiling issue, which I had run into before, but only in hot weather during the summer and after lots of idling..not in March temps in Atlanta. I couldn't get it restarted for about 8 minutes. I went home and put my paper filter back on and haven't had the problem since, although now I always buy the non-ethanol fuel. Since that time, I've installed a 1/2 wooden carb spacer to try and keep the heat off the carb.

I know that during that 15 minute drive, the fuel odor was strong with the K&N filter installed. I've been hesitant to try it again. This was not an actual cold set-up, just an open filter.

Mar 9, 2018 | 06:00 PM

niko20

More Turbo

Joined: Feb 2018

Posts: 710

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From: Oregon

What kind of carb do you have? I know Edelbrock carbs specifically say not to let air pass directly over the carb. Probably pulls all the fuel up out of the carb, which may be why you smelled fuel.

Mar 9, 2018 | 08:53 PM

PapaBearYuma

Cargo Master

Joined: Nov 2011

Posts: 3,354

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From: Great American SouthWest

I haven't seen a kit for our trucks, but I have K&N filters in chrome housings on all the trucks. They look cool and give at least 75-100 horsepower (lol)

While it may be true that paper filters are better, they look lame in a chrome housing.

I've never had a problem I could trace to the filters, but I've not used the filters with the element on top-all mine have a nice shiny plate I can see myself in. And that's got to be worth something!

Mar 10, 2018 | 10:39 AM

ranger140892

Grumpy goat

Joined: May 2017

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Papa, you posted a thread about AFR meters. Filters are what got me to wanting a AFR meter. I was playing with different breather / filter combos and found that any set up that had more air coming straight down, instead of from the side and turning down, gave more flow. Engine Masters later confirmed this and it's worth watching that episode. I was running a 14"x5" Allstar. Then I put a filter lid on top, and the engine went dead lean under a load. Lean enough to cause backfire out of the carb. That's detonation! Scary. I ended up with a Spectre dual carb hat with a 2" spacer, and two K&N cone filters. I have an Edelbrock AVS 650. I rejetted to .101" in primaries, .104" in secondaries, richest setting on accelerator pump, and I can't remember the metering rod I changed to. The truck runs great now with slightly better throttle response and transition. But I'm still thinking it's on the lean side. Hence the need for AFR meter.