K & N Filters

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EricMcKinley
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K & N Filters

#1 Post by EricMcKinley » Thu Feb 16, 2017 1:51 pm

I have a question I would like to ask about K & N Filters.

I was planning on using original filters on my engine however decided to purchase a set of K & N filters the same as the ones in the picture.

However unlike the original filters there is no place to vent the oil filter too.

I can remember some time back seeing an image of another 356 engine with the same K & N filters with a flexible hose going from the oil filter to the K & N filter.

I have also seen a few images of 356 engines sporting a very small cone shaped filter attached directly to the oil filter.
I found this image after a few minutes searching, I dont like this particular one however others I have seen in the past did look better.

I cant profess to know much about this subject but maybe someone can explain why it is vented to the filter.

So my question is, can anyone offer advise on either of these set ups using the K & N filter, if you do have this set up how did you achieve it.

Many Thanks.
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Mike Wilson
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Re: K & N Filters

#2 Post by Mike Wilson » Thu Feb 16, 2017 3:21 pm

You could direct the breather hose from the oil filler canister downward where the dip stick is. It'll require the engine tin with the hole for the hose. I think another option would be to attach a Solex hose fitting to the air filer top.
Mike Wilson
Lomita, CA
'63 B coupe

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EricMcKinley
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Re: K & N Filters

#3 Post by EricMcKinley » Thu Feb 16, 2017 3:38 pm

Thanks Mike.

On the oil filter I have a lower tube that is directed downwards as you mention.

There is a connection at the top of the oil filter also, this one could be vented onto the K &N filter on the carbs, however i like the look of these small filters.
Has anyone any experience of using one of these and any idea where to get them.
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M Penta
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Re: K & N Filters

#4 Post by M Penta » Thu Feb 16, 2017 5:36 pm

Here is what I did; 912 breather hose + PEX (high temp) elbow + Grommet. Works fine and looks OK. I chose not to vent to engine compartment.

Mark
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Dave Wildrick
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Re: K & N Filters

#5 Post by Dave Wildrick » Thu Feb 16, 2017 6:23 pm

According to Alan Klingen of "the Stable" in San Francisco, venting the crankcase to the right carb, as in C, SC, and 912 engines, may actually make more horsepower as follows:
[Subject: Re: Case Vent
From: "The Stable" <thestable@356car.com>
Date: Tue, 25 Mar 2003 18:46:48 -0800
The case is vented to the intake system where the vacuum produced by the motor "inhales" crankcase fumes and runs cleaner. This has been the law since 1966. A vacuum in the crankcase will actually help the motor make more HP because it decreases the windage of the pistons going up and down. All of the race motors we do have the main bearing webs streamlined to help in this regard. Porsche claimed that in the 906 motor it accounted for 5hp. Full on race motors actually have a vacuum pump to scavenge the case.
Sincerely,
Alan,
The Stable, San Francisco]

According to the late Harry Pellow, by adding velocity stacks inside the air cleaner and centering the right carb vent in the air cleaner lid in between them (toward the outboard side of the lid), you distribute the vented gases more efficiently between the 2 carb venturis.
Pellow also advocated venting to the rt. carb to reduce risk of oil leaks:
Subject: RE: breather hose
From: Harry Pellow <maestro@well.com>
Date: Wed, 18 Apr 2001 13:41:28 -0700
Harry Pellow wrote:
[If you just vent the blowby overboard from the C/912 Breather with UN-vented Valve Covers, the crankcase will be pressurized and oil leaks may occur.]

I used a piece of auto store heater hose to vent the crankcase. Mated that up to a right angle plastic PCV (positive crankcase ventilation) fitting (from your FLAPS), drilled a hole (keyhole-saw drill bit for steel [7/8in, I think] from Home Depot) in the middle of the outboard (right) side of the right carb filter lid, inserted a rubber PCV grommet (matching the size of the PCV angle fitting; from the FLAPS) in the hole, and that’s it.
Regards,
Dave Wildrick
#10230
C coupe x 2
Dave Wildrick
Houston, TX
#10230
64C coupe
65C coupe

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Vic Skirmants
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Re: K & N Filters

#6 Post by Vic Skirmants » Thu Feb 16, 2017 7:26 pm

Eric M; PLEASE use the correct terminology. You keep referring to the oil "filter", when you obviously mean the oil "filler".
Could confuse some old people like me.

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Doug McDonnell
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Re: K & N Filters

#7 Post by Doug McDonnell » Thu Feb 16, 2017 8:14 pm

Eric I have never liked the idea of venting the oil filler to the carb. My solution which many others have used before me is to use radiator hose and vent to earth. I simple used this cover plate http://www.stoddard.com/53906645.html and took my oil filler to the auto parts store and picked a radiator hose with 90 degree bend that fit.
1965 356C There is never enough time to do it right, but always enough time to do it over.

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Re: K & N Filters

#8 Post by Dick Weiss » Fri Feb 17, 2017 12:01 am

Eric,

Your oil filler/breather is from a 912, but if a hole exists in the head(s) for the small line, so be it.
However, if you like to breath oil fumes via the large breather exit to the cooling fan entry as shown, so be it #2!
If not, add a hose to the air filter like original Solex air filter had, OR--vent a hose downward next to the dipstick.

Dick

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John Brooks
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Re: K & N Filters

#9 Post by John Brooks » Fri Feb 17, 2017 1:03 am

I bought some of this silicon aerospace hose in 7/8" to replace the defroster duct hose on my 912. I used the left over section to vent the oil breather through the engine seal under the car.

This is high temp, impervious to oil and works well

http://www.aircraftspruce.com/catalog/appages/scat.php
John Brooks

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getting pushed around in porsches since 1965

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EricMcKinley
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Re: K & N Filters

#10 Post by EricMcKinley » Fri Feb 17, 2017 2:02 am

Gentlemen thank you very much for the replies, it all helps to make an informed decision.

I believe I am going to go ahead and do similar to what Mark has done to his engine.

I have posted a picture of my 912 engine which is going in my 356C, it has velocity stacks on it at present which will be removed and the K & N's fitted.

Mark I notice that you have no lower hose exiting from your oil filler, I have placed an arrow on the picture of my engine indicating which hose I mean. On my engine at present there is one.
If the oil filler is vented to the right carb is this no longer required?

Mark can you point me to the vendor you got your breather hose and the elbow from please.
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M Penta
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Re: K & N Filters

#11 Post by M Penta » Fri Feb 17, 2017 9:31 am

Hi Eric,

Since I have S90 heads I do not have the vent hole in head, so had to cap the extra port on the filler tank.
If I had 912 head with vent hole I would have run the hose down to it instead.

I got the PEX elbow from a plumbing supply store since they were the only place that had the high temp black fittings (local places only had grey). It is a tube x tube elbow, forget exact size. PEX measures by OD so sizing is different then pipe.



Mark
Last edited by M Penta on Fri Feb 17, 2017 9:52 am, edited 1 time in total.

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Doug McDonnell
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Re: K & N Filters

#12 Post by Doug McDonnell » Fri Feb 17, 2017 9:35 am

EASY sells the hose as does Stoddard I think. It looks like the correct elbow for SC air cleaners can be obtained here: http://www.sierramadrecollection.com/91 ... 23260.html Of course you would have to make a hole in the top of the K&N filter housing to use this. Your oil filler is for a 912 with the 2nd small breather used on 912s for pollution control. C/SC oil fillers only had the larger opening for the breather hose EASY and others sell. I am unsure but the 912 filler may have a different sized hose than the 356 filler. If so then the hose from EASY won't fit. Big discussion in this Dave Erickson link that discusses this. viewtopic.php?f=13&t=25396
1965 356C There is never enough time to do it right, but always enough time to do it over.

M Penta
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Re: K & N Filters

#13 Post by M Penta » Fri Feb 17, 2017 10:24 am

I bought the hose from Stoddard, I'll verify PN and report back. Also, I will see if I have another grommet and elbow fitting. If so I can drop them in mail to you.

BTW, I first looked for a brass or SS PEX elbow but could not find it in this size. I ended up liking the plastic better anyway considering the light plastic hose it connects to.

Mark

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EricMcKinley
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Re: K & N Filters

#14 Post by EricMcKinley » Fri Feb 17, 2017 1:42 pm

Doug,

I think you are correct, from doing a bit of research I see that the 912 oil filler is slightly larger than the 356 and Jim's hose may not fit.

I have looked at the Stoddard one as Mark has suggested and it appears to be correct.

Mark if you do have those parts it would be very helpful.

Just let me know what I owe you for the parts and the postage to Belfast.

Many Thanks.
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Brian R Adams
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Re: K & N Filters

#15 Post by Brian R Adams » Fri Feb 17, 2017 6:28 pm

Do me a favor: If your engine ever backfires, or so much as just "coughs" (for example, when running out of fuel, and switching to the reserve at speed) please pull over ASAP and check for a carburetor / K&N fire:
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Brian
"In God we trust. All others bring data." W. Edwards Deming

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