VW Mechanic of "23 years" claims his tests show flaps hurt vs. help
KWW
reputable VW shop owner told me yet again yesterday that he pleads with
customers to allow him to remove the flaps on rebuilds because they restrict
the airflow...
I noted reading that they direct the airflow even when opened all the
way.... He countered that he's measured head temperature and it is lower
with the flaps out. Is it cylinder temp that differs without the flaps? I
decided to keep them in, though I have had no luck finding a working
thermostat, but that's another story... For now they are locked upon by the
spring.
Clock starts today! I've got to get her running and passing inspection
before the end of the month!!! Thank God for Memorial day! If I fail you
will be able to spot me at any show - I'll be the one who looks like he's
been sleeping in a dog house (hopefully not doghouse cooler) in the back
yard for a few months...... ;)
dub driver
"KWW" <kwalke...@nospam.aircooled.net> wrote in message
news:Nk5P6.15442$CD5.7...@news2.rdc2.tx.home.com...
Tim Rogers
I've been doing what I do for a living for over twenty years (operating
the heart and lung machine among other things). If you randomly chose
another perfusionist like myself with a similar level of experience and
placed us in a room together, we'd probably be at each other's throats,
eventually. When that 85 year old, morbidly obese, cigarette smoking
diabetic doesn't survive his open heart surgery, it's not usually apparent
whether anyone was at fault (me, the surgeon, the anesthesiologist, the
nursing staff, the patient). Being an 'expert' doesn't mean that everything
that you think that you know is really true.
There is a large group of experienced people, many who also live in hot
climates like yours, who have learned from their experiences that there IS
better cooling of the heads when the flaps are left in place on a type1
engine. The opinions of people like Bob Hoover, John Connolly, etc. are a
tremendous resource for the rest of us here at RAMVA. If your mechanic is
smarter than them (along with the engineers who designed type1 cooling
system), then he must be a real genius!
Just my opinion.
Tim Rogers - - - 66 bug, 70 bug, 86 vanagon
t...@stny.rr.com
"KWW" <kwalke...@nospam.aircooled.net> wrote in message
news:Nk5P6.15442$CD5.7...@news2.rdc2.tx.home.com...
Jan Andersson
I still need a couple of pictures taken from a mock-up setup, to show
how the flaps, when in the open position, form a barrier between the
head and the cylinders, and force air to flow through th ecylinder head
fins. Without this barried and flow control, air would simply fly
downwards, never reaching the furthest corners of the head.
http://www.geocities.com/janbugger/flaps.html
Jan
John Henry
Where was the temp taken? Under load, or at idle. High rev's low revs.
(Hint: You wanna convert me? Let's see the temp at the plug base of #3 at
sustained load.)
KWW wrote:
--
John Henry
---------------
Visit the "BugShop" at http://www.geocities.com/thebugshop/
"NT has crashed. I am the Blue Screen of Death. No-one hears your screams."
Tom Mink
that flaps lower head temp. I don't recall seeing it. I'm not saying it aint
true, but everyone is so quick to jump on the flap bandwagon, I'd like to see
your with/without data, please.
Tony 72
Volkswagens since 1979. The Old School I was brought up on said to pull the
damn flaps (and the dealer installed A/C) in the desert, and I always have.
I hate to dispute the experts in this NG, but my current 1641 has gone
78,000 miles, runs strong, and has done it in AZ, Texas, New Mexico, and
even in Lakenheath, England. So flying in the face of oposition, I have not
only a 1641, which so many folks hate, but no flaps, which is supposedly a
kiss of death. But the damn thing still runs strong, and never required more
than a occasional tune-up, and the obligitory 3000 mile valve adjustment.
--
Tony 72 Standard
"Kids in the backseats cause accidents,
accidents in the backseat causes kids"
"KWW" <kwalke...@nospam.aircooled.net> wrote in message
news:Nk5P6.15442$CD5.7...@news2.rdc2.tx.home.com...
Kenny the GRAND CYCLOPS OF LIFE
the most elegantly designed car in history which has sold forty
million copies, all of which run, rather than your backwoods
"mechanic".
The flaps are there to regulate airflow to allow the engine to come to
operating temp quickly and massively reduce engine wear. Flapless
engines never run for 100,000 miles.
Kenny
On Thu, 24 May 2001 11:45:30 GMT, "dub driver" <reev...@home.com>
wrote:
Colleen Wooten
a really stupid question. When the thermostat fails what opens the
flaps? I see how the spring closes the flaps, but I don't get what
happens if the t-stat fails.
Just curious.
Bryan
71 - Bus - no flaps engine built in AZ
64 - Bug no flaps - but I have all the parts except the t-stat and
bracket
88 - Fox
Tom Mink
Colleen Wooten wrote:
> Thanks for the page, its quite helpful. But I have, what I hope is not
> a really stupid question. When the thermostat fails what opens the
> flaps? I see how the spring closes the flaps, but I don't get what
> happens if the t-stat fails.
>
The flaps stay shut and you overheat your engine.
Tom Mink
Kenny the GRAND CYCLOPS OF LIFE wrote:
>
> The flaps are there to regulate airflow to allow the engine to come to
> operating temp quickly and massively reduce engine wear. Flapless
> engines never run for 100,000 miles.
Sure they do. Mine certainly did.
Speedy Jim
Not quite true.
The thermostat bellows is pre-formed to the extended position.
The gas/liquid inside is in a low pressure state (vacuum)
when cold; this keeps the bellows contracted.
In the event of even a tiny leak in the bellows wall,
atmospheric pressure allows the bellows to expand to its
full extended position, thus opening the flaps. It's truly
fail-safe.
Speedy Jim
http://www.nls.net/mp/volks/
KWW
I have a leaking thermostat. It is in the contracted position.
With my present engine setup, the default (spring) position has the flaps
open...
I will look at the diagrams again, but I don't see how the flaps would fit
onto the
thermostat (which only bolts to one side of the engine) unless I put the
thing together
the way I have...
"Speedy Jim" <vo...@nls.net> wrote in message news:3B0D3F...@nls.net...
Colleen Wooten
Bryan
james
John Henry <johns...@sprintmail.com> wrote:
>Love to see his data.
>
>Where was the temp taken? Under load, or at idle. High rev's low revs.
>
>(Hint: You wanna convert me? Let's see the temp at the plug base of #3 at
>sustained load.)
Further, I want to see it at different altitudes and ambient temperatures!
Does the guy in Texas consider that he might be servicing cars that spend some
of their life in the Rockies or the Northwest?
Somebody posted on the vintagebus list about an infrared thermometer
they use. I'd like to see real metrics from that. Buses on a hot,
hilly trip with and without flaps.
I have no flaps on my new motor. The new EMPI shrouds and head tins
aren't even drilled for them!
I will say this -- even in Phoenix AZ, it takes longer than I'd like for
the motor to warm up. The problems caused by running too cold might not
be as dramatic as the problems caused by overheating, and it might not
even really be an issue in TX, NM, AZ, CA... That doesn't mean it's not
a problem in Maine or Oregon...
Dennis Wik
else that could make it run to hot in over 75 degree weather like it did
last year. A clip had cme off a flap lever by number three and it was
stuck about 1/2 open. Needless to say, I will put up with any problems
from a to cold motor since it will never have flaps again. Dennis
James W. Lindsay
Shows what you know. This might happen in a water-cooled application, but
not in the Type 1 engine. The thermostat is a sealed unit, expanding as it
heats up and contracting as it cools down. It holds the flaps closed
against the tension of the linkage return spring on the backside of the
shroud. It does *NOT* "force" the flaps open when it heats up.
I repeat:
The return spring is trying to hold the flaps open all the time. The
thermostat's job is to hold the flaps *closed* until the engine warms up.
Should a leak develop in the thermostat (eg: a crack in the bellows), the
thermostat loses its internal vacuum and can no longer hold the flaps
closed. As long as the spring is intact, the only thing that would keep
the flaps from opening when a thermostat fails is mechanical binding of the
link rod that connects it with the flap assembly on the right side of the
engine.
The thermostat, linkage, and flap assemblies aren't exactly examples of
simple construction. Their addition to the Type 1 engine adds a definite
cost increase to the overall price of the car (which might not seem like
much, but certainly adds up over the colossal production run of these
cars). If they weren't necessary, VW wouldn't have installed them. Cars
destined for Africa had thermostats & flaps, so the German engineers must
have thought that they served a purpose.
Finally, there is an important fact that few people mention in the pros vs.
cons of thermostats and flaps: the current "thermostat & flaps" is actually
a *second* generation temperature regulation device for the Type 1 engine,
with earlier engines using a large "valve" that restricted airflow through
the fan air inlet hole on the back of the shroud. IOW, this design is an
improvement after many, many years of actual customer field testing. If
"thermostats & flaps" weren't necessary, VW would have dropped the whole
idea instead of improving upon it.
----------------------------------------------------------------
James W. Lindsay Vancouver, British Columbia, Canada
Website: http://members.home.net/jlindsay ICQ: #7521644
----------------------------------------------------------------
You need professional help. May I suggest Jack Kevorkian?
----------------------------------------------------------------
Tom Mink
because I have not had one (nor flaps) on any VW engine I've owned over the
last 20 years. I've also never overheated one. But what do I know, I'm a
moron.
Tom Mink
Gregg Holmes
air-cooled flat 4 then Porsche. Heck, if the flaps aren't needed then
why do they think they need all the tin and the fan? I need to get into
the replacement engine business.
Dave AKA Nor-Cal VW's
The VW was used in Desert climates in WW-2 and, didn't overheat. This
design was relatively unchanged for the life of the Air-Cooled Engines.
Keep the flaps. Plain & Simple.
The only other things that I know to work to help cool a VW engine Are
the T-3 AKA Hawaii Tins, These replace the little shield in between & at
the base of the cylinders with a substantial cover/ Deflector that wraps
around both Cylinder bases.
Decklid offsets work Provided that all of the Rubber Engine Seals are in
good shape prop the Decklid with the Deck lid off sets or like the
Cal-Look cars via the bottom of the deck lid.
It's interesting that this subject has come up as I've been testing my
65' Drag car with it's street duty. So far on a 96 degree day and Stop &
go driving & freeway for 20 miles with my CR. gearbox, My head temps
were 260F and my oil was 168F with my Berg 4 quart sump Average Exhaust
Temp at head was 680F. This engine has all of the required tins &
Deflectors, No flaps as it's a racer and not a driver ( My 67' Has them)
and no metal around the engine! I never ever went over 4000 RPM in it
and I'm not trying to meltdown my engine, just Checking temps. I use my
Calibrated Omega Temp meter With Various Surface mounted Temp probes and
one dipstick probe.
Dave.
--
Dave AKA Nor-Cal
Santa Rosa, Ca
One of the many great Daves in RAMVA!
Check out my home on the web
http://www.norcalvws.com
Inky
<SPAMSU...@pacbell.net> wrote:
>What data do you have to back up that statement? Show me something that PROVES
>that flaps lower head temp. I don't recall seeing it. I'm not saying it aint
>true, but everyone is so quick to jump on the flap bandwagon, I'd like to see
>your with/without data, please.
I don't think the argument is that they lower head temp. How could
they (same fan and air flow with or without)? It's just with the flaps
closed, the engine warms more quickly and an engine at operating temp
wears slower than one that is cold. Once the flaps open, the temp
should pretty much like there are no flaps at all.
-- christian (blood type VW positive if anyone needs a transfusion)
'71 bus -- Turtle
'70 bus -- Snail (non-running project car)
>dub driver wrote:
>
>> your "mechanic" is an idiot.
>>
>> "KWW" <kwalke...@nospam.aircooled.net> wrote in message
>> news:Nk5P6.15442$CD5.7...@news2.rdc2.tx.home.com...
>> > Here in TX I am a bit concerned about heat in an aircooled motor. A
>> local,
>> > reputable VW shop owner told me yet again yesterday that he pleads with
>> > customers to allow him to remove the flaps on rebuilds because they
>> restrict
>> > the airflow...
>> >
>> > I noted reading that they direct the airflow even when opened all the
>> > way.... He countered that he's measured head temperature and it is lower
>> > with the flaps out. Is it cylinder temp that differs without the flaps?
>> I
>> > decided to keep them in, though I have had no luck finding a working
>> > thermostat, but that's another story... For now they are locked upon by
>> the
>> > spring.
>> >
>> > Clock starts today! I've got to get her running and passing inspection
>> > before the end of the month!!! Thank God for Memorial day! If I fail you
>> > will be able to spot me at any show - I'll be the one who looks like he's
>> > been sleeping in a dog house (hopefully not doghouse cooler) in the back
>> > yard for a few months...... ;)
"... the..."
-- Madonna (the singer or the Virgin Mary,
take your pick)
Geoffe Elias
saying that one shouldn't put T3 lower cylinder tins in a T1 (I guess upright)
engine.
If what I heard was true, then why would they issue such a bulletin?
I had that in mind when I built my engine. So I just used the standard lower tin.
Geoffe Elias
'74 Super Beetle
'98 Acura Integra
website: http://www.geocities.com/u982008/veedub/
Dave AKA Nor-Cal VW's
Your guess is as good as mine on this one??? I personally prefer this
style and have never read a service bulletin for this. I also don't know
whether or not it helps cooling or hurts cooling.
Now that i think about it, I omit that mention of using T-3 tins for a
upright engine for cooling purposes unless there's someone that had data
to back this up as I do not have this data.. But, the Deck lid offsets
for summer use work extremely well for me and, I also forgot to mention
that I use Dual 2 barrel carbs and need the additional air that this
modification provides.
Dave.
Jan Andersson
Gregg Holmes wrote:
>
> I love it when self proclaimed experts think they know more about the
> air-cooled flat 4 then Porsche. Heck, if the flaps aren't needed then
> why do they think they need all the tin and the fan? I need to get into
> the replacement engine business.
I am :-) 4 more engine carcasses rolled in yesterday. I'm supposed to
try and save at least one or two of them. Gotta get my hobby to support
itself..
Jan
John Willis
wrote:
>I don't think the argument is that they lower head temp. How could
>they (same fan and air flow with or without)? It's just with the flaps
>closed, the engine warms more quickly and an engine at operating temp
>wears slower than one that is cold. Once the flaps open, the temp
>should pretty much like there are no flaps at all.
Yes it is the same fan and the same amount of air being pushed. The
difference is without the flaps to properly direct the airflow there
is little to no cooling BETWEEN the cylinder heads (and you must have
the little air dam on the bottom, between the heads installed as
well).
Those pesky Germans knew a thing or two about design. Yeah, there are
some things we can improve upon using today's technology (or even
decades old technology, look at ignition modules) but the cooling on
one of these stock engines ain't one of them. Start ripping off
components because some self-proclaimed "expert" says so and you will
lower the life expectancy of your engine.
Mileage may vary.
~~~~~~~~~~~~~~~~~~~~~~~~
John Willis
jdwi...@airmail.net
Jan Andersson
And the ill effects won't show until 50k miles later or something. "Hell
I removed the damn flaps and it runs just fine, and has run perfect for
the last 5k"
The difference is, do you want to rebuild the engine at 100k or 50k? Do
you want to replace the heads with new or just do a valve job?
Jan
John Henry
"James W. Lindsay" wrote:
Ie: The annular cooling ring that my '36 hp has. Did you know the very
earliest engines had manual "valves" that you used to adjust the intake
aperture for the fan? A "Seasonal" setting...
> IOW, this design is an
> improvement after many, many years of actual customer field testing. If
> "thermostats & flaps" weren't necessary, VW would have dropped the whole
> idea instead of improving upon it.
Good point(s) James
>
>
> ----------------------------------------------------------------
> James W. Lindsay Vancouver, British Columbia, Canada
> Website: http://members.home.net/jlindsay ICQ: #7521644
> ----------------------------------------------------------------
> You need professional help. May I suggest Jack Kevorkian?
> ----------------------------------------------------------------
--
John Henry
Tom Mink wrote:
> I stand corrected on the results of a failed thermostat. I didin't know
> because I have not had one (nor flaps) on any VW engine I've owned over the
> last 20 years. I've also never overheated one. But what do I know, I'm a
> moron.
>
That's "maroon", right Ant?
Gregg Holmes
Thom Fitzpatrick wrote:
>
> Ok, those of you with your pulse so firmly on what VW "intended,"
> please explain m-code 002 - preheat flap delete
>
> Also, 911's don't have any sort of pre-heat flaps. Does the 356/912 engine?
>
> -- Thom
> All-VW Auction! - http://www.vintagebus.com/auction
Taylor
get your headliner in, windows, and anything else that needs to get done
before inspection. I'm in McKinney, so I shouldn't have too far to go Email
me at: timt...@ti.commmm and let me know.
--
Tim
'73 Bug (ol' blew)
"KWW" <kwalke...@nospam.aircooled.net> wrote in message ...
James W. Lindsay
> Ie: The annular cooling ring that my '36 hp has. Did you know the very
> earliest engines had manual "valves" that you used to adjust the intake
> aperture for the fan? A "Seasonal" setting...
Kinda like the seasonal flapper door on the aircleaners of early Hyundai
Ponies...
----------------------------------------------------------------
James W. Lindsay Vancouver, British Columbia, Canada
Website: http://members.home.net/jlindsay ICQ: #7521644
----------------------------------------------------------------
May I please be excused? My Brain is full.
----------------------------------------------------------------
Nachi11744
Well, yes. There was a contraption to blow hot air at the carb intakes to
prevent icing, it had a bellows thermostat just like VWs, only it lived behind
the fan shroud and *sensed* engine room temp, so as the air heated up, it shut
off the hot air stove from the heater (J ?)tube, it is like *carb heat* on
small aircraft piston engines.
Nachi
bruce
> Colleen Wooten wrote:
> The flaps stay shut and you overheat your engine.
Actually its just the opposite. The bellows that is the thermostat,
contains alcohol. When the thermostat fails, its because the alcohol
leaked out. The free state of the bellows is fully expanded, or flaps
wide open. Anybody actually seen an engine with the flaps stuck shut?
Are flaps needed? Well, not according to VW themselves. Today, the
new Bugs being made in Mexico have no flaps, and no thermostat. Part
of the reason is that they are operated in a warm climate where it
doesn't make a lot of difference whether the flaps are there or not.
Your mechanic in Texas isn't that wrong for removing them. However if
the car was to run up north, they are definitely needed. That's why I
am going to retrofit them into my 2001 Bug.
Rusty J
asks in part:
<snip>
The free state of the bellows is fully expanded, or flaps
wide open. Anybody actually seen an engine with the flaps stuck shut?
I have, on a baywindow Bus (NOT mine, it was at a garage). The owner WIRED
THEM SHUT after the thermostat failed. Evidently he thought that the failure
mode of the thermostat was "flaps closed" and therefore secured them in the
opposite position.
The vehicle, not surprisingly, was in the garage for an engine rebuild.
Rusty
Ogden, UT
The '80 Westy Formerly Known As The Vanagon Valdez
(4000 miles on rebuilt 2.0L T4, still no oil slick :)
Mike Fritz
and watch what way the flaps sit, they are open, not closed.
--Mike
Tom Mink wrote:
--
The content of this message contains my ideas, experiences, and general
information I've heard or read.
I will usually specify whether the information was heard, read, my idea, or
from experience.
It is up to you to be the judge of how valid the content of my messages are.
abuse@[127.0.0.1]
u...@ftc.gov
Mike Fritz
would be like if your propane tank had a hole in it. All the liquid is
evaporate and be all gone.
The thermostat is pre tensioned, when it leaks, it expands. I have experience
since before I found a new thermostat from http://www.aircooled.net. I would
buy these whenever I found them at the junk yard, they would expand once, leak,
and never shrink again.
Mike
KWW wrote:
--
Gregg Holmes
Jan Andersson
expand as much as they would when heated up. Puncture=inside pressure
equals outside air pressure. Heated=liquid inside boils (at 65-70C) and
the vacuum inside is not only gone, pressure grows beyond that of the
outside air pressure and the bellows expandsfurther due to the excess
pressure.
Yes I did poke a hole on a good old thermostat to see what would happen.
I also tested the opening speeds and temperatures. Dip them in hot water
and see them start expanding just about immediately.. then they are
good. Don't leave them in boiling water, hold them in just long enough
to see them expand. Fully expanded, they should fill the space they sit
in, inside the bracket.
Jan
Jan Andersson
when I realized my own projects were being neglected.. money was coming
in, but nothing was happening to my own cars. Could not go on like
that.. this time I'm gonna try to keep that in mind.
Jan
Erik Meltzer
"James W. Lindsay" wrote:
> On Fri, 25 May 2001 10:02:59 -0400, John Henry wrote:
> > Ie: The annular cooling ring that my '36 hp has. Did you know the very
> > earliest engines had manual "valves" that you used to adjust the intake
> > aperture for the fan? A "Seasonal" setting...
>
> Kinda like the seasonal flapper door on the aircleaners of early Hyundai
> Ponies...
No need for anything so Far East to find something like that.
Most of the '70s VW waterboilers I've seen and owned so far
had a similar setup, and I seem to remember something like it
even from my '70 Euro Bug.
Airhowlingly yours,
Erik.
--
"Bill Gates has apparently paid the Rolling Stones 8 million pounds
for the right to use 'Start Me Up', the song better known for its
catchy refrain 'You make a grown man cry'." -- Douglas Adams