The Norman Nock use of a PCV valve to depressurise the crankcase is a work of
genius. I first found the mod and implemented it on my BJ8 in 2006.
The system uses a PCV valve but is NOT a Positive Crankcase Ventilation system.
It is a crankcase depressurisation system that ensures there is a constant
partial vacuum in the crankcase area to prevent positive pressure defeating oil
seals - especially the rather half-arsed cork seals around the the rear crank
journal.
The filler cap hole has to be sealed and a felt washer put around the dipstick
collar to prevent air getting in via the dip tube.
If air is allowed to circulate, by venting the crankcase, that air is
immediately drawn into the inlet manifold weakening the mixture of the rear
carb and raising the idle speed.
Install a PCV valve, seal the cap and dip tube and enjoy the result. It does
work.
Alan - from my iPad
> On 27 Apr 2021, at 14:07, Bob Begani via Healeys <healeys@autox.team.net>
> wrote:
>
> Bob:
>
> Let me know how your installation works with the hole in the oil fill cap
> soldered. No doubt, the rest of the engine is has no breather inlets such as
> the valve cover? The reason I ask is I did not solder or seal the oil fill
> cap and my aluminum valve cover has a vent on the side into which I stuffed
> a piece of oiled 3m sanding pad. The reason was that in the early days of
> PCV valves on engines the car makers were creating a breather so fresh air
> could circulate in the engine and some articles indicated it was desirable to
> keep air flowing to the crankcase.
>
> Maybe some of the other listeners who have been using a PVC system sealed
> could comment on the operation. Currently on regular 25-mile drives at no
> more than 60 mph the drips under the bell housing weep hole after the ride
> are limited to a spot the size of a quarter in the can underneath. Next time
> travel on I-75 for 50 miles at higher speeds I will see if the amount of oil
> increases. If it does I may seal vent to see what happens.
>
> Bob Begani
>
> -----Original Message-----
> From: Bob Haskell <rchaskell@earthlink.net>
> Sent: Monday, April 26, 2021 8:23 PM
> To: rfbegani@gmail.com; 'Healey List' <healeys@autox.team.net>
> Subject: Re: [Healeys] PCV valve installation
>
> Bob,
>
> Thanks for the info. I've got mine installed, but haven't driven the car yet
> - rebuilding a LCS pump for it. I machined a 5/8"-20 - 3/8"
> barb fitting to screw into the front manifold. Added six flats for a wrench -
> Whitworth so I can be annoyed with myself at some future date.
> To go from the 5/8" diameter on the valve cover tee to the 1/2" diameter
> inlet on the PCV valve, I shaved the ID of a 5/8" hose and the OD of a 1/2"
> hose on the lathe and glued them together with rubber cement. 3/8"
> hose connects the PVC valve to the manifold fitting. Added hose clamps at
> each connection and soldered the hole in the oil fill cap.
>
> Cheers,
>
> Bob Haskell
> Austin Healey 3000 BN7/BT7 registrar
>
>> On 4/26/21 6:00 PM, rfbegani@gmail.com wrote:
>>
>> Bob:
>>
>> I have completed the PCV valve installation by using a 3 inch piece of
>> the 5/8â?? hose on the manifold side and inserting a 5/16 â?? heater hose
>> into it with a hose clamp. Then the 5/16â?? hose attaches a 1/8â?? x ¼â??
>> brass fitting with a hose clamp from the parts store I installed into
>> the small opening on the intake manifold to the right of the large
>> opening for the brake booster. No leakage and strong negative
>> pressure have reduced my oil leaks into the bell housing and the
>> clutch dramatically.
>>
>> Bob Begani
>>
>> *From:* Healeys <healeys-bounces@autox.team.net> *On Behalf Of *Bob
>> Haskell
>> *Sent:* Friday, April 9, 2021 3:10 PM
>> *To:* Healey List <healeys@autox.team.net>
>> *Subject:* [Healeys] PCV valve installation
>>
>> Listers,
>>
>> Attempting to install a PCV valve on our tri-carb engine per Norm
>> Nock's Tech Tip (page 98). Made an adapter (5/8"-18 to 3/8" barb)
>> that replaces the plug in the front inlet manifold. 3/8" hose to the
>> PCV valve. Two questions:
>>
>> 1) Does the PCV valve need to be orientated in a particular way?
>> Norm's diagram shows it horizontal and I have seen them on non-Healeys
>> vertical (engine side down).
>>
>> 2) The valve cover tee is 5/8" diameter, the engine side of the PCV
>> valve is 1/2". Anyone know of a short hose with different diameters
>> on each end?
>>
>> Thanks.
>>
>> Cheers,
>> Bob Haskell
>> Austin Healey 3000 BN7/BT7 registrar
>
>
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