No Oil Filter???

On Wed, 10 Nov 2004 21:59:07 +0200, Jan Andersson
> wrote:

>John Connolly wrote:
>>
>> it flows both ways in that tube Jan. It flows from crankcase to air filter
>> when the crankcase is pressurized (when the engine is making power), but it
>> flows the OTHER WAY during high vacuum decelleration (downshifting).
>
>
>Sounds like your rings are shot John Either that or you converted to
>2-stroke
>
>Please explain to me where the vacuum inside the engine case comes from?

I've been wondering where the vacuum during deceleration in the
crankcase comes from. I didn't know that happened. I can understand
the vacuum in the intake manifold during deceleration, but not in the
crankcase. I mean the throttle closes so air/fuel isn't dumping into
the intake, but the pistons are still going and sucking in what they
can through the intake valve on the intake stroke so that would cause
vacuum in the intake area. I don't get it for the case, though.

>Reversed blow-by during engine braking or deceleration? That's the only
>possible channel. Is that enough to overcome the suction of the
>carburator, inside the air filter, to create airFLOW back into the case?
>(Granted, there shouldn't be much of VACUUM in the aircleaner, just
>FLOW.. as the aircleaner itself is wide open to the athmosphere.)
>
>Even with the flaps "closed" (as far as they will close, leaving a gap
>and idle circuit open for air to get through), there's still quite a bit
>of suction through the carb.
>
>
>> That's why it's important that hose is connected on the filtered side of the air
>> filter. Our engines don't have that PCV valve which prevents flow one-way.
>
> (you could use the brake booster one-way valve from a baywindow
>bus....LOL)
>
>I just don't see how you get enough air to enter the otherwise sealed
>case to make noticeable FLOW possible.
>In either direction. Pressure pulses are easily relieved through that
>one hose. It's still not flow.
>
>
>> this isn't arguing, it's discussion. :-D
>
>Good
>
>
>I would already have performed tests with a vac/pressure gauge hooked up
>to one of my engines, but the damg gauge fell on the floor months ago
>and broke. ARGH. It would have told me the pressure/vacuum conditions
>inside the case during normal operation of a non-sand seal engine that
>was just broken in. (assuming fairly minimal blow-by)
>
>
>Jan

--

Always carry a flagon of whiskey in case of snakebite,
and furthermore always carry a small snake.
- W.C. Fields

On Wed, 10 Nov 2004 21:19:56 GMT, Michael Cecil >
wrote:

>On Wed, 10 Nov 2004 20:21:43 GMT, Narley Dude® >
>wrote:
>
>>You really need to check out V-Dubfolks in Irving. It has become like
>>a "Knight's" for me. I gladly drive all the way there from Ennis,
>>well worth the trip. Top quality parts... knowledgeable people... very
>>nice and friendly... POR15... Royal Purple... They do installations
>>and modifications... mechanics on staff that don't mind one asking
>>questions. They have tons of business!
>>There is another place in town for parts in Arlington called Black
>>Gold... They are very nice too.... a bit limited, but good quality
>>parts. Those are the only two places I purchase parts from in the
>>metroplex. On occasion you can find great deals at Auto-Zone or
>>O'Reilly's. For example: recently bought a Bosch 12V A/T Starter
>>GERMAN for $55!! Yes, it was rebuilt... BUT it has a Lifetime Warranty
>>(in which to me is just as good as a brand new) V-Dubfolks had the
>>very same one NEW for $95. Since I purchase parts tax exempt, it beats
>>most online places hands down.
>
>Don't worry, I planned to investigate V-Dubfolks after seeing you mention
>it previously.

You'll like it! Ben is the owner, Kerry is his right hand, Isaiah is
the left. Jared is a young 'whipper-snapper' mechanic... but, HE IS
VERY GOOD AT IT!!!
All I need is to find someone to install my new Top and Headliner (I
really don't want to mess with it unless I have to) in the Metroplex
that won't RAPE me $$$ wise.
DO NOT GO TO 'PISTON & PLUG' in Mesquite. TRUST ME ON THIS ONE!
Unless you want your car to get back to you worse than it did in other
areas... and IF you have any vintage German parts like: German Hella
Tail lights or internal items. You can bet they will be replaced by
repro's and sold to someone else for big $$$. Yeah... been there...
The place has only value if you are looking for an original fender,
deck lid, hoods and such.



Narley Dude®

Jan Andersson wrote:
> "Mike Rocket J. Squirrel Elliott" wrote:
>
>>I reckon we can speculate about this all we want. Empirical evidence --
>>John? -- seems to suggest that things are just hunky-dory when the sand
>>seal is installed and no other inlet provided.
>
> I say it probably is not an issue that would require a dozen or more
> newsgroup messages and extended debate over it

Aw, c'mon -- with very little effort we could keep this discussion alive
for a few more days!

Here, lemme show you -- watch a master:

Adding a sand seal to the pulley end of the crankshaft closes off the
"inlet" into the case (I am assuming that air generally goes /in/
through the opening and gases vent out through the oil filler vent hose
-- especially during the still-being-discussed vacuum-in-the-case
condition). I don't have my engine apart right now, but maybe someone
does: how big is the inlet? The cross-sectional area?

--
Mike "Rocket J Squirrel" Elliott
71 Type 2: the Wonderbus
84 Westphalia: "Mellow Yellow (The Electrical Banana)"
KG6RCR
-=-=-
If you can't dazzle them with brilliance, riddle them with bullets.
------------------------------------

Wrong guess.The bus is a '71,the engine is mexi.I would guess it uses the
later style cam,hence the later style pump.By the way.what is the advantage
why did VW change the design?Curious.
"Chris Perdue" > wrote in message
...
> >From: "Mike Rocket J. Squirrel
>
>>If I had to hazard a guess, I want the first type, the #1798 because
>>their dating scheme is probably for bugs and the bus had the upright
>>engine into 1971. Good guess?
>>
>
> your late model replacement engine will contain the 71+ "dished"
> cam....all
> aftermarket performance cams are the "flat" (pre 71) cam...the dished cam
> has
> four rivets holding the cam gear on and is "dished" in the center...so the
> pump
> has a longer shaft(from the gear) to meet up with the slot in the cam,w
> hich in
> turn, um, turns the gear to pump the oil....the later ones can have the
> gear
> pressed further onto the shaft and the shaft ground down flush if for some
> reason you would have the early cam(VERY doubtful, as far as i know all
> factory
> cams(like in your factory longblock) had the dished cam from 71...i have
> torn
> down two in the past couple years that were replacement engines and they
> were
> dished....)
> -------------------
> Chris Perdue
> "I'm ever so thankful for the Internet; it has allowed me to keep a finger
> in
> the pie and to make some small contribution to those younger who will
> carry the
> air-cooled legend forward"
> Jim Mais
> Feb. 2004

ilambert wrote:
> Wrong guess.The bus is a '71,the engine is mexi.I would guess it uses the
> later style cam,hence the later style pump.

Give the man a cigar -- CB Performance finally got back to me and
confirmed what you, and others, have said: use the later style. Thanks
for the help!

> By the way.what is the advantage
> why did VW change the design?Curious.

This, I reckon, is a Bob Hoover or Jan kinda question.

--
Mike "Rocket J Squirrel" Elliott
71 Type 2: the Wonderbus
84 Westphalia: "Mellow Yellow (The Electrical Banana)"
KG6RCR
-=-=-
All I want is a warm bed and a kind word and unlimited power.
-- Ashleigh Brilliant
------------------------------------

On Wed, 10 Nov 2004 15:16:22 -0800, "Mike Rocket J. Squirrel Elliott"
et> wrote:

>ilambert wrote:
>> Wrong guess.The bus is a '71,the engine is mexi.I would guess it uses the
>> later style cam,hence the later style pump.
>
>Give the man a cigar -- CB Performance finally got back to me and
>confirmed what you, and others, have said: use the later style. Thanks
>for the help!
>
>> By the way.what is the advantage
>> why did VW change the design?Curious.
>
>This, I reckon, is a Bob Hoover or Jan kinda question.

OK, then I won't answer it... :-)

--

Always carry a flagon of whiskey in case of snakebite,
and furthermore always carry a small snake.
- W.C. Fields

Shaggie wrote:
> On Wed, 10 Nov 2004 15:16:22 -0800, "Mike Rocket J. Squirrel Elliott"
> et> wrote:
>
>
>>ilambert wrote:
>>
>>>Wrong guess.The bus is a '71,the engine is mexi.I would guess it uses the
>>>later style cam,hence the later style pump.
>>
>>Give the man a cigar -- CB Performance finally got back to me and
>>confirmed what you, and others, have said: use the later style. Thanks
>>for the help!
>>
>>
>>>By the way.what is the advantage
>>>why did VW change the design?Curious.
>>
>>This, I reckon, is a Bob Hoover or Jan kinda question.
>
>
> OK, then I won't answer it... :-)
>

Okay then. Make that a Bob Hoover, Jan, or Shaggie kinda question.

Your move.

--
--
Mike "Rocket J Squirrel" Elliott
71 Type 2: the Wonderbus
84 Westphalia: "Mellow Yellow (The Electrical Banana)"
KG6RCR

Shaggie wrote:
> On Wed, 10 Nov 2004 21:59:07 +0200, Jan Andersson
> > wrote:
>
>> John Connolly wrote:
>>>
>>> it flows both ways in that tube Jan. It flows from crankcase to air
>>> filter
>>> when the crankcase is pressurized (when the engine is making
>>> power), but it flows the OTHER WAY during high vacuum decelleration
>>> (downshifting).
>>
>>
>> Sounds like your rings are shot John Either that or you
>> converted to 2-stroke
>>
>> Please explain to me where the vacuum inside the engine case comes
>> from?
>
> I've been wondering where the vacuum during deceleration in the
> crankcase comes from. I didn't know that happened. I can understand
> the vacuum in the intake manifold during deceleration, but not in the
> crankcase. I mean the throttle closes so air/fuel isn't dumping into
> the intake, but the pistons are still going and sucking in what they
> can through the intake valve on the intake stroke so that would cause
> vacuum in the intake area. I don't get it for the case, though.

On the power stroke, the hot gasses are forced behind the rings and the
pressure expands them outward to the cylinder surface. This is how the
rings seal. On the intake stroke, the rings have only internal tension
holding them outward which means they seal far less.

When the vacuum spikes on deceleration, this is felt in the combustion
chamber during the intake stroke. Especially since you no longer have
the charge velocity to compensate. And, with very little happening on
the power stroke to offset this, the net result is vacuum (or suction)
drawing crankcase air around the rings and through the ring gaps.
The resulting vacuum in the case draws air in from your vent.


RT
--
E-mail=fullname-at-telus.net

Mike Rocket J. Squirrel Elliott wrote:
> I reckon we can speculate about this all we want. Empirical evidence
> -- John? -- seems to suggest that things are just hunky-dory when the
> sand seal is installed and no other inlet provided. Jan reckons that
> things could be improved upon.
>
> Leaving the measurement of air flow and pressure aside, which don't
> really prove anything except air flows and pressure exists, the real
> test would be to monitor the chemical composition of the oil to see if
> stuff we hope would escape does or does not and is building up in the
> case. Is there anything else that matters?

I run a sand-seal. I've also given it some thought as to the need for
extra ventilation. I finally came to the conclusion that diesel engines
work with a simple vent tube to handle the blow-by. They usually have
a small mesh pad or some other baffle to trap some of the oil droplets
but are otherwise just a vent - no other inlet into the crankcase. Yes,
some could argue that a diesel has many differences, but the environ-
ment inside the crankcase is very similiar.

And I also use Chevron Delo 400 - in a straight 30 weight which is
recommended for gas and diesel engines and is designed for
"closed-crankcase" engines.


RT
--
E-mail=fullname-at-telus.net

On Wed, 10 Nov 2004 15:30:16 -0800, "Mike Rocket J. Squirrel Elliott"
et> wrote:

>Shaggie wrote:
>> On Wed, 10 Nov 2004 15:16:22 -0800, "Mike Rocket J. Squirrel Elliott"
>> et> wrote:
>>
>>
>>>ilambert wrote:
>>>
>>>>Wrong guess.The bus is a '71,the engine is mexi.I would guess it uses the
>>>>later style cam,hence the later style pump.
>>>
>>>Give the man a cigar -- CB Performance finally got back to me and
>>>confirmed what you, and others, have said: use the later style. Thanks
>>>for the help!
>>>
>>>
>>>>By the way.what is the advantage
>>>>why did VW change the design?Curious.
>>>
>>>This, I reckon, is a Bob Hoover or Jan kinda question.
>>
>>
>> OK, then I won't answer it... :-)
>>
>
>Okay then. Make that a Bob Hoover, Jan, or Shaggie kinda question.
>
>Your move.
>
>--

*knocks chess pieces all over the board with frustrated look*
OK, where's Bob or Jan when you need them!?!? ;-)
I dunno, dude. I was just feeling left out and trying to be a part of
things. *sniffle* Wow, Dan Rather almost cried during the closing of
the news just now. I'm kinda shook-up over that. :-/

--

Always carry a flagon of whiskey in case of snakebite,
and furthermore always carry a small snake.
- W.C. Fields