Casting Four Individual VW Heads

To All:

It appears that personalities and other factors overwhelmed the
subject that I thought it best to start anew.

One of those other factors is my physical condition -- more
specifically, the amount of pain I have to deal with and the
limitations placed on me by the physicians, such as limiting the
amount I can lift to about 25 lbs. Cheating isn't wise since I'm
liable to crush another vertebrae. Increasing my pain medication is
also unwise, since it causes to pass out... only to have the pain wake
me up due to some crazy angle of my neck or back... which causes me to
reach for the pain pills AGAIN... round & round we go...

----------------------------------------------------------------------------------------------------

The objective is to produce TWO unique castings -- one forward, one
aft -- for the two barrels on each side of the VW engine.

Volkswagen presently uses ONE casting, flipping it end-for-end when
used on the opposite bank of cylinders. By splitting the single head
into two individual castings, we can move the exhaust stack to a new
position that is lower than the outlet on the present head, thus
allowing MORE FIN AREA to be cast onto the ends of the individual
heads.

Since these heads are not for vehicles, there is no limitation on the
height of the fins. If the heads WERE for bugs or buses they would
have to fit UNDER the stock tin-ware, reducing the maximum fin height
to about one inch.

Based on the parting-line flash of new, stock heads, they are cast
using two molds. To cast INDIVIDUAL heads it will take at least THREE
molds of FOUR different types. Anyone having actual experience with
finned aluminum castings is encouraged to offer their opinion.

I have drawings & photos of VW heads that I'll be happy to post to
some address where they might be available to all -- and would
appreciate comments as to where such a place might be. But no
Bluesky, please. I'm trying to solve a problem; I've no interest in
creating another Chat Room.

-Bob Hoover

On Jan 16, 5:08*pm, " wrote:
To All:

It appears that personalities and other factors overwhelmed the
subject that I thought it best to start anew.

One of those other factors is my physical condition -- more
specifically, the amount of pain I have to deal with and the
limitations placed on me by the physicians, such as limiting the
amount I can lift to about 25 lbs. *Cheating isn't wise since I'm
liable to crush another vertebrae. *Increasing my pain medication is
also unwise, since it causes to pass out... only to have the pain wake
me up due to some crazy angle of my neck or back... which causes me to
reach for the pain pills AGAIN... round & round we go...

---------------------------------------------------------------------------*-------------------------

The objective is to produce TWO unique castings -- one forward, one
aft -- for the two barrels on each side of the VW engine.

Volkswagen presently uses ONE casting, flipping it end-for-end when
used on the opposite bank of cylinders. *By splitting the single head
into two individual castings, we can move the exhaust stack to a new
position that is lower than the outlet on the present head, thus
allowing MORE FIN AREA to be cast onto the ends of the individual
heads.

Since these heads are not for vehicles, there is no limitation on the
height of the fins. *If the heads WERE for bugs or buses they would
have to fit UNDER the stock tin-ware, reducing the maximum fin height
to about one inch.

Based on the parting-line flash of new, stock heads, they are cast
using two molds. *To cast INDIVIDUAL heads it will take at least THREE
molds of FOUR different types. *Anyone having actual experience with
finned aluminum castings is encouraged to offer their opinion.

I have drawings & photos of VW heads that I'll be happy to post to
some address where they might be available to all -- and would
appreciate comments as to where such a place might be. *But no
Bluesky, please. *I'm trying to solve a problem; I've no interest in
creating another Chat Room.

-Bob Hoover

Bob,
I have done some experimental metal casting work, but nothing to the
extent you’re proposing; however, such a concept is within reason.
Quite rightly the mold design and preparation are the most significant
aspect of this project, once made though and good foundry can produce
the castings. The end user can than do their own clean up milling work
or if desired such work may be done by the seller. Beyond this I’ll
honor your request for no blue sky flights of fancy, but I hope you
consider posting your drawings on your blog.
Regards
Joe S.

On Jan 17, 8:15*am, Copperhead wrote:
Beyond this I’ll
honor your request for no blue sky flights of fancy, but I hope you
consider posting your drawings on your blog.
--------------------------------------------------------------------------------------

Yo, Joe.

Thank you. But there's Blue Sky... then there's bluesky, in which a
nine-page article is based on a 'minor detail' such as steel which
happens to float. Or a Gasoline Pill. Or... you know what I mean. I
am MORE than willing to go Blue Sky when it involves nothing more than
nudging Mother Nature in the right direction... such as finding the
fellow who is casting those Aluminum Crankcases, and finding the
Chinese shop which is casting those remarkable crankshafts, and buying
them lunch, with the object being a crank that's about five inches
longer and the crankcase to house it. Because we simply don't have
enough bearing area to pull more than about fifty ponys out of the VW
crank for a MINIMUM of 1000 hours. But there IS enough bearing area
on... what? I know they're out there -- I've seen their shells in the
trash out behind the DeSoto dealer's shop. (Yeah, it's been a
while... But the point is that the BEARING means there's a ROD that
will fit it. And I'm all for THAT brand of Blue Sky.)

If all goes well, this afternoon -- Saturday the 17th of January,
2009, Steve Bennett and I will sit ourselves down across the table
from each other and come up with the Master Plan for the Invasion of
Homebuilt Land.

I will be wearing my Lucky Shirt.

There are New Batteries in my camera.

There will be at least one Calculator on the table.

If you can think of anything I've forgotten, include it now.

-Bob

On Jan 16, 6:08*pm, " wrote:

...

The objective is to produce TWO unique castings -- one forward, one
aft -- for the two barrels on each side of the VW engine.

...

Since these heads are not for vehicles, there is no limitation on the
height of the fins. *If the heads WERE for bugs or buses they would
have to fit UNDER the stock tin-ware, reducing the maximum fin height
to about one inch.

Based on the parting-line flash of new, stock heads, they are cast
using two molds. *To cast INDIVIDUAL heads it will take at least THREE
molds of FOUR different types. *Anyone having actual experience with
finned aluminum castings is encouraged to offer their opinion.
...


My experience is not with casting but with fin design. Fins that
are longer than necessary will reduce the cooling.

Think of it this way: As you move along from root to tip the
temperature in the fin drops. If it drops to the same as
the air temperature before you reach the tip, all of the fin
between that point and the tip is wasted. Actually worse
than wasted as cooling air passing over that outer part of
the fin doesn't cool anything, as you're wasting air too.

That's an extreme situation, but the point is that there is an
optimum length for cooling fins given a fixed massflow of
cooling air.

And as mentioned before, tapering the fins in thickness from
root to tip helps to maximize the cooling and minimize the
weight too.

--

FF

On Jan 17, 5:17*pm, Fred the Red Shirt
wrote:
On Jan 16, 6:08*pm, " wrote:







...

The objective is to produce TWO unique castings -- one forward, one
aft -- for the two barrels on each side of the VW engine.

...

Since these heads are not for vehicles, there is no limitation on the
height of the fins. *If the heads WERE for bugs or buses they would
have to fit UNDER the stock tin-ware, reducing the maximum fin height
to about one inch.

Based on the parting-line flash of new, stock heads, they are cast
using two molds. *To cast INDIVIDUAL heads it will take at least THREE
molds of FOUR different types. *Anyone having actual experience with
finned aluminum castings is encouraged to offer their opinion.
...

My experience is not with casting but with fin design. *Fins that
are longer than necessary will reduce the cooling.

Think of it this way: *As you move along from root to tip the
temperature in the fin drops. *If it drops to the same as
the air temperature before you reach the tip, all of the fin
between that point and the tip is wasted. *Actually worse
than wasted as cooling air passing over that outer part of
the fin doesn't cool *anything, as you're wasting air too.

That's an extreme situation, but the point is that there is an
optimum length for cooling fins given a fixed massflow of
cooling air.

And as mentioned before, tapering the fins in thickness from
root to tip helps to maximize the cooling and minimize the
weight too.

--

FF- Hide quoted text -

- Show quoted text -

Without a doubt the concept of a longer case and crank shaft for
increased bearing surface coupled with an improved head casting with
relocated exhaust valves and increased fin space is long past due. The
Corvair aircraft engine has now seen the introduction of a fifth
bearing surface as well as forged crankshafts becoming available, but
still in question as to long term reliability. Me, I’d be more than
willing to purchase improved VW “aircraft” engine parts for a build
project. Without a doubt others would to as such an engine would be
fantastic.

Joe S.

And as mentioned before, tapering the fins in thickness from
root to tip helps to maximize the cooling and minimize the
weight too.
--------------------------------------------------------------------------------------------------

It's not just a 'nice-to-have' feature, the draft or taper is an
absolute necessity, first for successful casting, then for EFFICIENT
cooling. Transfer of heat to the atmosphere causes the air to
expand. If the air channels are not tapered the 'fatter' air quickly
REDUCES air-flow through the fins and the engine begins to overheat.

-Bob

On Sat, 17 Jan 2009 10:18:42 -0800 (PST), "
wrote:



If all goes well, this afternoon -- Saturday the 17th of January,
2009, Steve Bennett and I will sit ourselves down across the table
from each other and come up with the Master Plan for the Invasion of
Homebuilt Land.


why does steve bennett's name ring a bell? is he 'great planes'?

On Jan 18, 4:00*am, Stealth Pilot
wrote:
On Sat, 17 Jan 2009 10:18:42 -0800 (PST), "

wrote:

If all goes well, this afternoon -- Saturday the 17th of January,
2009, Steve Bennett and I will sit ourselves down across the table
from each other and come up with the Master Plan for the Invasion of
Homebuilt Land.

why does steve bennett's name ring a bell? is he 'great planes'?

Yes, that's the man, he's already marketing a great deal of VW engine
kit option's for aircraft. If we're really lucky enough perhap's he'll
be willing to do a test marketing run on improved VW head's and such.

On Jan 18, 2:00*am, Stealth Pilot
wrote:

why does steve bennett's name ring a bell? is he 'great planes'?
-----------------------------------------------------------------------------------------------

Yes, unfortunately we failed to connect -- I was waiting for him to
call, while he had already gone to the restaurant I'd suggested and
was waiting for me there. After a couple of hours he called to say
he'd run out of time. And there I was, thinking he was still in San
Diego.

-Bob

"Fred the Red Shirt" wrote in message
...
On Jan 16, 6:08 pm, " wrote:

...

The objective is to produce TWO unique castings -- one forward, one
aft -- for the two barrels on each side of the VW engine.

...

Since these heads are not for vehicles, there is no limitation on the
height of the fins. If the heads WERE for bugs or buses they would
have to fit UNDER the stock tin-ware, reducing the maximum fin height
to about one inch.

Based on the parting-line flash of new, stock heads, they are cast
using two molds. To cast INDIVIDUAL heads it will take at least THREE
molds of FOUR different types. Anyone having actual experience with
finned aluminum castings is encouraged to offer their opinion.
...


My experience is not with casting but with fin design. Fins that
are longer than necessary will reduce the cooling.

Think of it this way: As you move along from root to tip the
temperature in the fin drops. If it drops to the same as
the air temperature before you reach the tip, all of the fin
between that point and the tip is wasted. Actually worse
than wasted as cooling air passing over that outer part of
the fin doesn't cool anything, as you're wasting air too.

That's an extreme situation, but the point is that there is an
optimum length for cooling fins given a fixed massflow of
cooling air.

And as mentioned before, tapering the fins in thickness from
root to tip helps to maximize the cooling and minimize the
weight too.

--

FF

------------------------------------------------------------------------------------------------

Agreed. So considering the thermal properties of something like 356
aluminum, what would be the most efficient geometry for cooling a cylinder
head? Length, pitch, taper, etc.