Oh, yeah!?!? I gotcher puck, right here..................

gmctd · **Posted:** Sat Nov 01, 2014 7:53 pm

Or........CDR, anyone?

A dissertation on our much beloved yet oft confusing "the puck" for your various and sundry entertainment - open-puck pics to follow

Note: BARO is substituted herein for atmospheric pressure

The camshaft cover, or head cover, has two 1"dia ports on top right side near the rear, to which an oil-separator puck is mounted - rearmost port
is unrestricted crankcase effluent, front port is also crankcase effluent, but is restricted by a ported baffle inside the oil separator housing -
also erroneously called the CCV, but which is a simple crankcase depression regulator, or CDR , the Diesel version of the gasser's PCV Positive
Crankcase Ventilation valve - both parts conform to the EPA-required Closed Crankcase Ventilation system

The oil slinger puck consists of a black thermo-plastic housing with a 1" port at the entrance of a snail-shaped scroll ending in a chamber
which is open to the vacuum chamber above, and is also ported thru a small-area opening in the baffle above the second crankcase port - the
centrifugal scroll is sealed by a thermo-plastic cover with a round puck-shaped vacuum chamber on top - a removeable round cover seals in-place a
large-diameter rubber diaphragm with a small spring beneath held captive in the vacuum\exhaust port -

The 1"dia crankcase effluent port at the rear feeds the scroll, but the restriction in the second port at the center of the scroll reduces
crankcase effluent thru that 1" port, which then serves as the oil drain-back port from the center of the scroll chamber - returned oil is
denser than crankcase effluent

In the center of the round vacuum chamber is a raised 1/2"dia exhaust port, separate from the scroll port, leading to a 3/4"dia hose barb for
the hose from the compressor intake duct

The diaphragm serves as a vacuum-operated valve on the exhaust port, with the spring keeping the valve in the static open state-
vacuum from the compressor intake duct is applied to the entire chamber area below the diaphragm when the exhaust port is open -
when vacuum on that large area exceeds spring tension, atmospheric pressure on the upper side of the diaphragm forces it down toward the
small-diameter exhaust port, closing the port - vacuum then acts only upon the smaller area of the diaphragm covering the port - the vacuum chamber then equalizes to BARO via a small bleed-port, barely visible at the 2 o'clock position in the down-side up puck cover - with the port closed, the small
port-cover area is way less than the overall diaphragm area in the puck, such that any crankcase pressure acting on the larger area adds to BARO pressure and spring
tension to overcome the vacuum applied thru the small exhaust port area, releasing any built-up crankcase pressure - repeat as necessary................

The center of the diaphragm valves-off the 1/2" diameter of the exhaust port, but the larger 2-11/32" dia area of the diaphragm is exposed
to BARO and crankcase effluent pressure in the chamber, "blowing it open", as necessary -
p.s.i. wins, again..................

The inner 2-1/8" diameter of the 2-11/32" diaphragm is thicker rubber with 8 thick radial ribs, allowing it to respond like a piston - the thinner
outer area of the circumference is recurved, allowing more compliance - considerable effort is required to compress it when seated in the vacuum
chamber - installing the spring requires even more effort -

I'm thinking possibly the normally-aspirated VM CRD gets only the diaphragm, and the spring was added for the turbocharged version -

I may get inspired to instrumentize and hookup my vacuum cleaner again to verify this conjecture, as was done to verify operation of the
CDR "tuna can" on the GM 6.5L-TD - be somewhat more difficult now, since all the instruments were fried when the li'l KJ was tasered by the
flying fickle finger of Jehovah - and the finger, having writ, moved on.....................

edited for clarity and syntax

gmctd · **Posted:** Wed Nov 05, 2014 3:13 am

DELETED - words with pics to follow - enjoy >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

gmctd · **Posted:** Wed Nov 05, 2014 3:47 am

Engine cover showing front and rear CDR ports - rear of engine is to left - MAP sensor top left - Cam Timing Sensor lower left:

CDR with 'puck' cover off showing BARO-side of diaphragm in-place:

Rotated view:

Engine side showing metered front port at center\exit of centrifugal scroll:

Rotated showing unmetered rear port to entrance of centrifugal scroll:

Top showing vacuum chamber with valved exhaust\vacuum port to compressor inlet duct:

Rotated showing scroll center-chamber port into vacuum chamber with metered passage to front port below:

Showing diaphragm helper spring as located in exhaust\vacuum port:

Puck cover down-side up on left, diaphragm BARO-side up on right:

Diaphragm vacuum side, ECO A with compliance of 60 Shore:

DOC4444 · **Posted:** Wed Nov 05, 2014 9:28 am

I vaguely recall a proposed mod to this unit at some point, but cannot find it. Anyone know about this?

DOC

gmctd · **Posted:** Wed Nov 05, 2014 5:32 pm

Other than the EHM, a rubber-hose simulation of the old steel breather downtube, a guy from the VW Diesel crowd offered a PVC kludge catch-can as used by that crowd - several here jumped on the PROVENT bandwagon with some success, altho somewhat more pricey than the EHM

WWDiesel · **Posted:** Wed Nov 05, 2014 6:14 pm

Thanks much gmctd, now we all know whats in the mystery puck on top of the little smoker!!!!

Great Information, and the design makes sense after studying the pictures.

One question, would there be any benefits to gain by removing the puck and carefully taking it apart and giving it a good cleaning??? :?:

gmctd · **Posted:** Wed Nov 05, 2014 6:33 pm

Be prepared for a horrible sooty mess, as the soot is exceeding difficult to remove from the pores and fingertip whorls - but, it could allow you to ascerain if the diaphragm is still compliant, or has been heat-hardened such that it is rendered no longer functional - heat and time are the enemy

Proclamation :

Hear ye, hear ye, hear ye:

By these presents let be it knownst to one and all:

Hereby, and henceforth from this day forward, shall the erstwhilst referred-to 'puck' be known as, accepted as, and further referred to as the Crankcase Depression Regulator, or CDR, in the vernacular.

As it is written, thus and so shall it be done, eh....................

Attention, DCJ: you'll need to do a service recall to address this much-needed change to the KJ CRD FSM, retroactive to 2005 and applicable years

WWDiesel · **Posted:** Wed Nov 05, 2014 8:42 pm

Anyone got part number for the Crankcase Depression Regulator (CDR) assembly. Might just be best to replace the whole assembly if age and thermal degradation has taken its toll on the internals... :roll:

gmctd · **Posted:** Wed Nov 05, 2014 8:56 pm

Item 6 - 05114348AB - Valve, pressure control

I've never even seen one on eBay - EGR's, heads, head covers, turbos, FCV's, t-stat housings, exhaust manifolds, motor supports, flex-plates, starters, alternators, water-pumps, viscous heaters - you name it, I've seen it - but no oil-slingin' CDR assy -

I removed this one from an engine with over 200kmi, and it and the head ports were filled with a sooty jelly - never saw anything like it in my 60yrs experience, and I'm still washing the soot from my pores - could be that's why none was listed on eBay - you can see some jelly in the rear port in the head-cover

Even at that, this assy cleaned up well, and the diaphragm seems compliant enuff with no heat-cracks

Well, you might know - there's one listed now from LUKE PARTS for $32.89 Item: 281377764703, as item 20 in the parts manual

And a 'nuther at $32.88 eBay item number:321559304942

DOC4444 · **Posted:** Thu Nov 06, 2014 8:02 am

I thought someone came up with a mod to this unit to reduce crankcase pressure at higher rpm. I assume it would allow more pressure to be released into the elephant hose.

DOC

Auberon · **Posted:** Thu Nov 06, 2014 8:36 am

If you get really coked up in the whorls - grab a lump of cheese from the fridge after you've given them a good scrub with all the usual wonder cleaners and rub it in.
Unless you're REAL hungry wouldn't suggest it passing the lips.

I came up with a design to replace the puck that kind of looks like a nautilus shell on the inside but it indeed did not happen as I either need to finish building my forge/furnace or build or buy a 3-d printer. The forge his significantly closer with raw materials and volumes of reference material and design gathered but time in short supply.

As routine maintenance I clean the puck every 5 oil changes or so and wipe out my CCA tubes. It stays pretty clean doing it that often and doesn't need complete disassembly. Doesn't take long either. It's only 3 screws 8 mm A/F hex head to remove it as I recall.
I don't disassemble it but to check it I feed a gun cleaning patch (or a synthetic lint-free cloth like a tack-cloth for the woodworkers) through with a piece of plastic coated fishing wire trace with an eye looped in the end to pull the cloth through - at least the snail shell arrangement gets a wipe out. A gentle blow of any lint etc with compressed air does the rest after another washout with solvent. The snail shell part doesn't open up.
All they did was create a really ineffective labyrinth that does a poor job of separating the oil mist from the air-stream. It's the kind of design work a really ordinary High School student would do in our country their HSC.

There may be a market for someone to develop a more enduring model if we all keep the KJ's to 1 000 000 miles or more :ROTFL:

gmctd · **Posted:** Thu Nov 06, 2014 2:34 pm

The usually open-ended configuration of the EHM does not allow any crankcase pressure buildup - it does allow the crankcase to freely "breathe" with the piston-displacement pulsations - any blow-by zips right out in the ensuing fracas - thus the clouds of smoke emitting from beneath the vehicle at incidence of stop-sign, red-lite, traffic jam, police stops for emitted pollution, and drive-thru fast-food pickup................

Currently unknown as to how the VM CDR performs in it's as-designed function on the normally-aspirated 2.8l CRD, I s'pect there has been a severe loss of interest in factory upgrades due to the lack of turbocharged engine units in current production - present and future owners will just have to punt in any endeavor to obtain that million mile goal

PROVENT is currently the American EPA-sanctioned punt-played solution

Further:

Judging from the disgusting jelly-like mess I found while analyzing this unit, it might not be a bad idea to R&R the module for a good cleanout, including the ports in the head-cover - this should serve to restore some as-designed-for function

Posted owner-input of results at task-completion should serve to encourage inspection and compliance

My input on this ~200k miles unit: I found about a cup-full of oily sooty jelly in the CDR and both ports in the head-cover, which I removed and dumped on the trash-pile for later burning, a weekly event out here in the woods

I'll do my much-lower mileage KJ sometime this week, after the rain stops

p.s. -

Almost fergot: gasoline, Diesel fuel, petroleum naphtha will each remove soot from pores and whorls, listed in decreasing order of danger to the sooted - then a good hand cleaner with aloe vera and lanolin to restore that manly soft-skin comfort..................

Oh, yeah!?!? I gotcher puck, right here..................

Who is online