I am not trying to turn this into a debate, infact if you see my other thread I want to see actual oil analysis filtration numbers. I have read all of the posts here and disagree that you have to have restriction to have better filtration.

On the AH-1 Cobra During Desert Storm we added an improved particle seperator. Prior to installation I lost 7 engines, ruined by sand in 6 days (the first week there). The mod gave us more horsepower 2.7% and I did not loose an engine for the next 7 months with over 1500 flight hours. So technology can give you better flow and better filtration.

I merely want to see the numbers. My understanding is that silicone in the oil is indicative of Air Filter performance. Once I see the numbers I will compare and decide. You can decrease restriction and provide better filtration, maybe or maybe not with the oil media. I want to see the numbers.

 

Look Here:

https://www.ford-trucks.com/forums/s...hreadid=221578

 

My .02 worth. Also posted on the Tymar / Oil thread.

I ran the stock air box and the K & N filter (oil type) for 27000 miles in my PSD and changed oil every 3000 before I sent in my first oil sample to Blackstone.

I inspected and serviced the K & N (cleaned, dried, light oil) at the same 3000 mile intervals as my oil changes.

My Blackstone report showed below universal average in every itemized element they tested and considering the mileage, age, etc.

The Silicon level with the K & N was 7 and Blackstone has a 10 for the universal average.

I installed an AIS and an oil bypass in the past few months and will be doing another Blackstone test in about 4000 miles. I'll post the results.

 

The physics not withstanding, your gas enigine is barely moving any air at idle and low rpm at all, where as the diesel not having a throttle plate is drawing a full slug of air for every revoloution.

I'll leave the advanced mathmatics to you, but I'd wager the 7x statement is pretty close to being accurate.

 

I'll buy that with non-turbocharged engines, at anything other than WOT.

Once you introduce boost in the intake manifold, the throttle plate restriction goes away and the cylinders will fill with the same CFM each time the piston goes down regardless of whether it is a diesel engine or a gas engine. Neither engine draws much air at idle compared to WOT, the problem is at high RPM.

For instance: the 444CI diesel at 0 lbs boost will draw in 55.5 ci of air each time the piston goes down since there is no restriction, whereas a 444CI gas would pull in substantially less. At an idle of 700RPM, the diesel draws about 90CFM, the gas engine much less.

At WOT on a non-boosted gas engine (with a big enough carburetor or FI system to produce a very low vacuum), at 6000RPM, the engine will suck in a theoretical maximum of 770CFM. At 3000 RPM, the non-turbocharged diesel will draw in a theoritical maximum of 385CFM.

With equal boost in the intake manifolds of each engine, the numbers will scale.

It really doesn't matter that the diesel draws in 7 times more air at idle, that isn't where the problem is with the air intake. It's at higher RPM when you are drawing in so much more air.

So, I still maintain that the higher revving gas engine, with the same boost as the diesel, will draw more air through the air cleaner.

QED

 

So, I still maintain that the higher revving gas engine, with the same boost as the diesel, will draw more air through the air cleaner. (yellow73bb)

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You are kinda making an illogical claim. Of course a higher revving engine will draw in more boost, it's turning faster and so will need more air. If you run both the gas engine and the diesel engine at the same rpm, given same ci, I would believe the diesel would draw in more air. Majority of gas engines on trucks don't have turbo or super chargers to produce the air intake that diesels with turbochargers do.

 

How do you convert cubic inches of air to cfm?

I still don't think it's an apples to apples comparison. The gasser will spend about as much time at six grand as the diesel does at three....practically none, and cuising the highway at any comparable rpm the diesel will be using more air, so aside from max rpm blasts the diesel will always be using more air.

Plus the rpm figures should be closer than your example. Your average big block isn't going to be turning much over 5K (assuming it's near stock), and the newer diesels (rev limiters on the 7.3 aside) will roll 4000 rpm easily.

Anyway, please continue the physics lesson, I am enjoying it, but my initial point was that Mark Craig is a good guy, and while there is probably no such thing as a truely honest businessman he isn't trying to get over on anybody.

Have you seen AFE's magnum force II? It's one bad looking mamba jamba. 5.5" inlet velocity stack filter. Pricey at $400.
picture

 

Seems to me all this talk of the Tymar or any open element being next to the battery is a moot point. The AFE Magnum Force II also has the filter right behind the battery.

 

There seems to be some words missing from your post. it never lets me put the word (b attery) up either.

I don't think the location of the filter is relevant, nor do I believe the drawing "hot under hood air" is detrimental, at least not while the vehicle is moving.

 

I don't think it's an issue either, just thought I would mention it since the point has been brought up before.

FYI, I don't see any missing words in my post unless you want to edit. Battery came up in blue, but I think that's because it's some sort of key word for searches.

 

That's odd. It dosen't show up on my screen at all, it's looks from here like "battery" got edited out of the post. I wonder what's wrong with my settings.

 

cfm (or more properly cf/m - cubic feet per minute) = ci/(1728*m) 1 foot = 12 inches, 1 cubic foot = 12*12*12 cubic inches.

My point wasn't so much that a gas engine running at 6000 RPM (or 5000 or whatever -- my basically stock 454 vette turns upwards of 5600 by the way, 5400 is redline) pulls in more air than a 444 diesel at 3000 (or 6.0L at 4000 or whatever), just the claim that the diesel pulls 7 times the air of a gas engine. The air filter is designed for worst case air flow, not idle. So it really doesn't matter if the diesel is open to the atmosphere and pulls more air at idle, both engines pull piddly amounts of air at idle and seven times a piddly amount of air is just a slightly less piddly amount of air. I don't know Craig, or anything about his business practices. It just sounds like he is using the claim of seven times more air (probably so at idle) in a totally irrelevant way to try to convince people to listen to him. That or he really doesn't know better and thinks that diesels pull 7 times more air at any given RPM.

Wasn't trying to rattle or insult anyone, sorry I came off so blunt (rude).

 

Thanks. That's handy. How does the boost fit into the equation? The boosted gasser at 6000 rpm makes what 7-9 psi, but the 3000 rpm diesel is pumping 20.

I would be interested to know what AFE's calculations are based on, if that is where they cam from. It seems unlikely that any one guy was sitting in the garage one night and just decided that 7x was the number to be used as a sales point.

 

Here goes:

n=(logP1 - logP2)/(logV2-logV1)

P1V1**n=P2V2**n

Solving this for V2 and using P1 as 1 ATM (59 degrees at Sea Level), with the Power Stroke 7.3L=447ci.

Result it is linear. So 7 PSI boost is 7*Volume

There for on the Diesel with 20 PSI that means I am flowing 20*447ci

So the guys equation was wrong unless he was just using 7PSI boost number if you use the 20 PSI boost number, then the Diesel flows 20 Times more air....

 

Remember, at 1 atmosphere you are already at about 14.7PSI. Therefore, at 30PSI you are really only doubling the mass of air introduced.

Another equation is n=PV/RT where n = the number of moles (the mass), P=pressure (zero referenced), R is the universal gas constant (8.3144 J/mol*K) and T is the temperature. So, as you stated, the mass induced varies linearly with the pressure and inversely with the temperature.

A pure vacuum is 29.92 inches of mercury, let's say your gas engine idles at about 15 inches of mercury. In that case your gas engine would pull in 1/2 of the mass of air. If it also runs at 15 while you are cruising and you are running 7 psi of boost on your diesel at cruise, then you'd be pulling in three times as much air as the gas engine with the same displacement. However, at WOT, if you run 28 psi of boost, you'd only be pulling in double the mass of air of the gas engine of same displacement.

Hope that helps.