BHAF restriction caused by "reinforcing" ABS pipe

[jlccc]

I myself haven't had any trouble with the intake hose coming off of the filter neck. But, since several members have, I thought I would at least look at the 3" ABS coupling that several members have reported using. Apparently the idea is to stiffen the filter outlet neck so it can't deform and allow the intake hose to come off.



Have any of you gentlemen considered the reduction in x-sectional area caused by use of this coupling/reinforcing? I haven't taken accurate measurements yet but I estimate the diameter of the intake is reduced by nearly 1/2". The reinforcing piece of ABS essentially becomes an orifice plate, negating to some degree, the reason why you installed the BHAF in the first place, namely to flow more air.



I believe that with careful installation of the intake hose on the filter neck, reinforcement is neither necessary or desirable. At least that's the case on the Fleetguard BHAF which is the one I'm using.

 

[JWhitcomb]

Hmmm, I wonder if you turned the ID to a cone shape if it would become a venturi and increase the speed of the flowing air. Would that speed increase over come the effect of the restriction of air? Just wondering.

 

[moparguy]

Hummmmm.

Well, I supose that's possible. I did consider that possibility when I used a PVC stiffiner in my filter neck. But my logic was that even with the ID reduction, the pressure drop over the short distance involved would be a reasonable trade-off considering how undersized the stock setup is on even a mildly bomded truck.



It would be a fairly simple to measure the pressure drop with remote mounted gauges inside the vehicle under maxium fueling conditions. At the same time, if temp. , inlet pressure, pressure drop and the diameter of the oriface were considered, flow could be calculated. Both with and without the insert.



That would give the true answer.



Ronnie

 

[JWhitcomb]

Hummmmmmm!

I'll make the part if someone wants to do the testing. I won't be using PVC, it will be alum. , if that matters.

 

[Big White Beast]

Or you could try this........

Use a 4" piece of ABS pipe and a clay pipe coupler. The rubber lined ones. Exact same size opening and the rubber on the coupler makes a tight seal. Oh and it makes for a nifty place to mount the minder.



Garrett



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[JStordahl]

jlccc: The filter neck on the Fleetguard 19037 BHAF is really smooth and slippery, and I too didn't want a plastic pipe restricting air flow. I just drilled a hole through the clamp and hose into the filter neck and screwed a stainless #8 screw in to allay my fears of the hose slipping off unnoticed.

 

[Mark_Kendrick]

Fellas,

The hose is under a vacume 99. 99% of the time and the surface and clamp are more than sufficient. Just make sure it's on straight and use a nut driver or ratchet to tighten the clamp.



as for the filter minder. . My bhaf is due for replacement. the new one will get a hole drilled in the end of the filter for the filter minder.



FWIW,

Mark

 

[JTBMC]

Rather than using PVC, I used a 3 inch long piece of 4 inch stainless exhaust pipe and there is no restriction to worry about and it stiffens up the area of concern to keep the clamp tight.

TJ

 

[JR2]

I did not use a stiffener at all. I slid the hose over the BHAF and tightned up the hose clamp. . done. It has never come off and I have not dust in the hose and my silicone levels in my oil analysis are the same as when running the stock set up or the KNRE0880.



I did order me one of those covers like in the pic above. . it will protect the filter and look real good with my red valve covers and soon to be red hose set up.

 

[JJW_ND]

They do need changing

Just a heads up, but these BHAF do need changing. Mine looked pretty good fromt he outside but notice more black smoke lately. Need to add the Filter minder.



Put on a new filter and was really surprise by the light diffusion through the new and used filter. Used filter was dark ... black dark.



I have always just clamped the hose direct to the filter. I use the fleetguard filters if that matters.



jjw

 

[JWRowe]

BHAF

Garrett, Nice looking set-up. What filter are you using. Could you post the size and part number?



Thanks in advance, John

 

[JR2]

The fleetguard # is AH19037. I just ordered two of em yesterday. The wrap over the outside is from Overtoms or something like that. If you call them at 1-800-967-3450 and ask for Scott. Tell him you need a cover for the AH19037. I believe they are about $25 for the cover, the filter at Cummins NW runs $45.



I have one one now and due to an exhaust leak (long story) the thing got covered in soot from start ups. I am going to change it out and put my a cover on it.

 

[jlccc]

Re: Fellas,

Originally posted by Mark_Kendrick

The hose is under a vacume 99. 99% of the time and the surface and clamp are more than sufficient.

I 99. 99% agree with you. But there is always the possibility that the same phenomenon that causes the turbo to "bark" (which has caused stock airboxes to crack under the pressure) could cause the filter outlet neck and intake hose to separate. The stiffener may provide some protection against this because the inlet hose can be fastened more tightly without worrying about deforming the filter outlet neck.

 

[illflem]

I used a short piece of 3" aluminum irrigation pipe for my stiffener because I had it and also didn't trust the rubber to rubber connection. Shouldn't cause much restriction since it's less than a 32nd thick. I always cringe at the thought of opening my hood after driving a thousand miles to find the air filter disconnected...

 

[Bigsaint]

Just my $0. 02, but I wouldn't worry about the slight restriction. I'm using the schedule 40 coupler inside the neck of my BHAF, performs as well as my K+N RE0880 did in the SAS.



Scott W.

 

[nickleinonen]

has anyone here added an in cab filter restriction gauge? it would need to be inches of h20 [0-30 would do] i have searched around but haven't found a gauge like that. once you were hitting 20 inh2o, it would be time for a filter change/cleaning...

 

[illflem]

Vacuum gauges are readily available, they are used quite often on gassers, Granger also has them. Problem is you would need one that records the high vacuum otherwise you need to watch it all the time.

 

[nickleinonen]

a normal vacuum gauge isn't going to do to much. they measure 0" - 30" of vacuum in "in-hg" [inches of mercury]. an air filter restriction gauge needs to read 0" - 30" in "in-h20" [inches of water] i have seen those gauges on a few kenworths and macks but i haven't been able to find out what company makes them. i have a 0 - 30 normal in-hg vacuum gauge on my air filter assembly and i have seen it once come off the stopper and almost go to 1" of vacuum. 1" of mercury is pretty much 3" of h20. the h20 is a finer scale and that is what the filterminders are measured in. 20" in-h2o is the max you want to have ever on a turbo diesel engine. that is just over 6" in-hg vacuum



searching the net, i could find some industrial low pressure gauges that measure the 0-30" h2o but they are 2. 5" diam and they are ugly. . does anyone know of gauge company that makes the automotive style gauges that measure vacuum in inches of water? i have had zero luck looking for one...

 

[Mark_Kendrick]

Re: Re: Fellas,

Originally posted by jlccc





I 99. 99% agree with you. But there is always the possibility that the same phenomenon that causes the turbo to "bark" (which has caused stock airboxes to crack under the pressure) could cause the filter outlet neck and intake hose to separate. The stiffener may provide some protection against this because the inlet hose can be fastened more tightly without worrying about deforming the filter outlet neck.

I have yet to hear of one coming off, and I bark a turbo rather regularly You have to remember that the flow reversal is headed for a porus filter. the pressure spike will be rather small in amplitude and very short duration.

 

[dezeldog]

BHAF

I haven't used any pipe in mine. Instead I put 2 #8 ss 1/2" screws in the end of the filter and slip the hose over them and tighten. The clamp does loosen a bit but I check it often enough as not to worry. Jim