what every boy needs - yeah seriously

On Jan 8, 3:56*pm, Monk wrote:

A Subaru?
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Not bad. But it's going to come down to the Bottom Line. And in
that regard, the individual heads are the winners. Why? Because we
can do the machining ourselves.

First off, we can forget about lost-foam or anything more exotic than
green-sand, simply because there aren't enough of us. So we stick to
standard, readily available valves, valve guides, valve seats and
studs. The fins make the castings pretty tricky but if it was easy
you would have seen it years ago.

There's a couple of directions we can't go but if we borrow a page
from the Corvair we can position our exhaust stack just about anywhere
and still have a good seal. Most of us have MIG, which means we can
do the stack-extensions. And since it's a new casting we can provide
the boss for the hold-down bolt.

Here again, borrow a page from the Corvair (or from GM) and we end up
with a 'rocker arm' that actually works. The tricky bit is that it
does NOT need to be aligned on a shaft... we can literally put a valve
anywhere there is room. And that means at any angle as well.

Domed or hemi-shaped chamber won't buy us anything. I'm pretty sure
of that, based on some work I did in that area about 30 years ago.
But that's actually to our advantage. By keeping the combustion
chamber simple we keep our valve-train geometry simple. AND YES, we
run juicers.

Exhaust outlet to the stack is probably a rectangle, as with the
Porsche. We put the wiggles into the exhaust stacks, which we make
out of Monel or whatever, secured with that bolt we stole from the
Corvair.

So we make a L-head and an R-head; mirror images. We do the best we
can with the fins but recognize our limitations and leave the most
difficult of them as CUT fins: Rather than try to cast perfect fins in
a couple of high-risk areas, we settle for a quarter-inch bar of
aluminum that's configured for easy SAWING, which we do as part of the
flash clean-up.

-R.S.Hoover

wrote in message
...
On Jan 8, 3:56 pm, Monk wrote:

A Subaru?
---------------------------------------------------------------------------------------------------

First off, we can forget about lost-foam or anything more exotic than
green-sand, simply because there aren't enough of us. So we stick to
standard, readily available valves, valve guides, valve seats and
studs. The fins make the castings pretty tricky but if it was easy
you would have seen it years ago.

So we make a L-head and an R-head; mirror images. We do the best we
can with the fins but recognize our limitations and leave the most
difficult of them as CUT fins: Rather than try to cast perfect fins in
a couple of high-risk areas, we settle for a quarter-inch bar of
aluminum that's configured for easy SAWING, which we do as part of the
flash clean-up.

-R.S.Hoover

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

I've alway thought it would be more practical to CNC saw all the cooling
fins. Seems a bit extreme at first glance, but if you go to the time or
expense to fabricate patterns to cast the heads, we must be talk about doing
more than just a couple of sets. So the programming cost might well be worth
the cooling efficency of extremely detailed cooling fins.

On Jan 8, 10:30*pm, "Maxwell" #$$9#@%%%.^^^ wrote:
wrote in message

...
On Jan 8, 3:56 pm, Monk wrote:

A Subaru?

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

First off, we can forget about lost-foam or anything more exotic than
green-sand, simply because there aren't enough of us. *So we stick to
standard, readily available valves, valve guides, valve seats and
studs. *The fins make the castings pretty tricky but if it was easy
you would have seen it years ago.

So we make a L-head and an R-head; mirror images. *We do the best we
can with the fins but recognize our limitations and leave the most
difficult of them as CUT fins: Rather than try to cast perfect fins in
a couple of high-risk areas, we settle for a quarter-inch bar of
aluminum that's configured for easy SAWING, which we do as part of the
flash clean-up.

-R.S.Hoover

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

I've alway thought it would be more practical to CNC saw all the cooling
fins. Seems a bit extreme at first glance, but if you go to the time or
expense to fabricate patterns to cast the heads, we must be talk about doing
more than just a couple of sets. So the programming cost might well be worth
the cooling efficency of extremely detailed cooling fins.

I disagree, sand casting would be easier than milling from solid
block. Just sculpt your head out of wax cover with sand and pour your
casting. A little grinding here and there and there you have it. OK,
not that simplistic, but you get the gist.

"Monk" wrote in message
...
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I've alway thought it would be more practical to CNC saw all the cooling
fins. Seems a bit extreme at first glance, but if you go to the time or
expense to fabricate patterns to cast the heads, we must be talk about
doing
more than just a couple of sets. So the programming cost might well be
worth
the cooling efficency of extremely detailed cooling fins.

I disagree, sand casting would be easier than milling from solid
block. Just sculpt your head out of wax cover with sand and pour your
casting. A little grinding here and there and there you have it. OK,
not that simplistic, but you get the gist.

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

I didn't suggest milling from billet. Just milling the cooling fins. The
overall head with valley for the rockers, combustion chambers, ports, etc.,
should be green sand cast.

It's also not possible to green sand cast over a wax investment. Even if it
were simple enough to sculpt your heads out of wax, which it's not, you
would have to investment cast them.

Sand casting the heads and machining detail not practical with the green
sand or air set process is the only practical method for producing a limited
number of parts. Tooling cost for wax or foam investment casting would be
too prohibitive.

On Jan 8, 11:21*pm, "Maxwell" #$$9#@%%%.^^^ wrote:
"Monk" wrote in message


It's also not possible to green sand cast over a wax investment. Even if it
were simple enough to sculpt your heads out of wax, which it's not, you
would have to investment cast them.

While sand directly over wax isn't practical there are hybrid methods
of lost wax and sand that the hobby casters can do with good results.
As for being simple to sculpt the heads in wax ...........depends on
your definition of simple.


Tooling cost for wax or foam investment casting would be
too prohibitive.

If your thinking conventional production practices you might be right,
but there are home brew methods that while slower work just fine. We
aren't talking GM production numbers or that level of automation.
====================
Leon McAtee

On Jan 8, 7:30*pm, "Maxwell" #$$9#@%%%.^^^ wrote:

I've alway thought it would be more practical to CNC saw all the cooling
fins. Seems a bit extreme at first glance, but if you go to the time or
expense to fabricate patterns to cast the heads, we must be talk about doing
more than just a couple of sets. So the programming cost might well be worth
the cooling efficency of extremely detailed cooling fins.
------------------------------------------------------------------------------------------------------------------------
Dear Maxwell, et al

(more for the et al's at this point)
What makes this NOT a ' blue-sky & bull**** ' kinda project is the
fact we can pick up a telephone and have the key components sitting on
our front porch in a matter of HOURS. Such as:

Pistons & cylinders, crankshafts, camshafts, valves, valve seats,
valve guides, carburetors, electronic ignition components, electrical
system components... and so on right down the list.

In fact, the existence of the Roto-Way type heads... most folks think
of them as 'Scat-type'... provides 'Proof of Concept' -- meaning this
IS NOT a new idea. What's 'new' is coming up with an isolated head-
design that is amenable to air-cooling.

Historically, when the real engine manufacturers ran into the thermal
limitations of cast aluminum (**) they way they tackled the task
serves as our instruction manual. They tried liquid cooling and
machined fins but finally achieved the desired power-to-weight ratio
by going to FORGINGS for their aluminum heads.

(Forged aluminum is denser; it can couple more heat to the atmosphere
than a casting can. [and if one you grammarians jumps on that...] ).
Indeed, comparing the American & British efforts makes a damn good
adventure novel -- one in which the British should have won (ie,
because of their slide-valve engines). But buried in that 'novel' is
methods tried & discarded not because they didn't work but simply
because the goal was for more horsepower than those methods could
provide. And to be fair here we really need to include the Japanese
14-cyl radial... which was using the so-called 'Singh Grooves' in the
early 1940's, allowing them to run on 70 octane tractor gas.)

In fact, we can even use the Lycoming O-145 as a good model of how NOT
to do things. (Yeah, it produced 65hp... but only when you spun it up
above 3000 rpm. Stuck on the nose of a Piper 'Cub' it was a TERRIBLE
powerplant, simply because it produced all of its thrust in a narrow,
high-velocity slug of accelerated air into which the fuselage of the
Cub was buried. And as we know (and Lycoming seemed to forget), drag
increases as the SQUARE of velocity. But AFTER the war, when a bright
young fellow named Mooney came along with a sleek little single-place
design, the O-145 finally came into its own... because there was
simply no comparison to the induced drag of a Cub and a Mite.

So what's our engine gonna be? It's going to be what it ALREADY IS, a
set of 94mm jugs atop an 84mm Chinese crankshaft. But the difference
is in the HEADS. And it's not even the WHOLE head we're talking
about, just the outer portion that is associated with the exhaust
stacks. This is the HOTTEST part of the VW engine. VW's engineers
did some truly remarkable things to ensure the CORNERS of the engine
got the MAJORITY of the cooling air. Unfortunately, when you try to
do that using RAM-AIR instead of a blower, you run into all sorts of
problems, most of which can be resolved by simply increasing the AREA
of the cooling fins.

And how do we do that? (Someone asks) ...or, Why hasn't someone done
that? (another asks)... and in both cases the answer is pretty much
the same: We do it by altering the shape of the exhaust outlet, and
YES, someone has ALREADY DONE THAT... if you're familiar with the
Porsche engine.

The point here is that it's not a big change, in engineering terms.
Nor even an especially difficult change. The main problem is that all
previous efforts were aimed at CAR engines, which presented some space
limitations that they simply could not resolve if they wanted the
engine to fit in the car. Bottom Line: They came up with a new car-
body that provided enough room for the 'fatter' engine -- 'fatter'
because it had more fins. And put that fatter engine into airplanes,
too. Which means we're not quite the ground-breakers we think we
are :-)

So what's the basis of our 'success'? Easy! We simply re-design the
exhaust to dump out the BOTTOM of the head, as GM did with the
Corvair... and which VW could NOT do with the VW engine. When the
exhaust stack is moved outta the way it gives us access to the upper-
outer corner of the head for each of the jugs, and that is where we
install our additional fins. Not only do we add additional fins, we
increase the size of the fins that are already there, so that our
maximum PEAK output comes up to something on the order of 80hp, whilst
our maximum SUSTAINABLE output is about 60hp (Standard Day
assumed).

Does this give us a 'thousand hour' engine? Hell no! Lookit the
bearing area. At that level of output you'll be lucky to get a TBO of
500 hours. Of course, replacing every bearing in the engine will only
run you about sixty bucks.

Sure sounds easy, eh? In fact, if it's so damn easy you gotta wonder
why I haven't already done it. Surprise! I already did... sorta. We
called it the 'Fat Fin' head and tried to accomplish what I've
described here by TIGing on additional fin area to stock heads. Which
didn't work for a lot of reasons, but there were some examples that
DID work... until the fins warped or the valves overheated or any one
of a dozen other things. Plus the biggie: Fat Fin heads would not
fit in a VEHICLE. And without that market, they were little more than
a joke... some crazy ol' guy wanting to put a VW engine in an
airplane, for crysakes!

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

How do you get in touch with OTHER 'crazy ol' guys?' Back then, you
got Pope Paul to put a notice in the magazine. Remember all them
notices? Yeah. I don't either.

But now we got the Internet.

Tell you what... Somewhere in my drawings I've got a stock VW head,
sorta -373'ish (that's a VW part number... don't sweat it). I'll dig
it out, convert it into a .jpg and post it on my blog. Then you can
blow it up to near-full-scale and print it out. One it's printed, you
can start fooling with the location of this & that... moving the
exhaust stack... which is when you'll discover that a push-rod and an
exhaust stack will NOT peacefully co-exist :-) But there's a couple
of ways in which they WILL... expect they put one hell of an angle
onto the push-rod... and you gotta move the rocker-arm around... stuff
like that. THAT'S what we're talking about here. Once we can move
the exhaust stack WITHOUT trashing the push-rod, we can increase the
cooling-fin area by about 25%... mebbe more.

Best of all (mebbe) is that we'll come up with a casting that the
average home machinist can turn into a cylinder head. And that will
only take another 10,000 words or so... plus a few hundred
pitchers... if anyone is interested.

-R.S.Hoover


And just for Flavor of the Month -- sump plate

On Jan 9, 9:28*am, " wrote:

And just for Flavor of the Month -- *sump plate
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Okay, okay... I sorta overlooked some asterisks and left you hanging
with regard to the Sump Plate... so cut me a slack, okay? I gotta
take some pills & stuff.

(...but the Sump Plate is souper simple: You move the sump's DRAIN to
one of the 'down-hill' corners of the sump, which allows you to
install a PERMANENT sump plate... outta aluminum if you want minimum
weight or outta steel if you want to use it as a base for brackets or
whatever. Got some pitchers to show you... if I can findem')

-Bob

As promised, three ILLUSTRATIONS of drawings depicting the later-model
VW dual port head. Posted to my blog: bobhooversblog.blogspot.com

Now I gotta go do my exercises. (My wife calls them 'Comic
Relief.' ( I got a TOUGH crew.)

-Bob

schreef:
Indeed, comparing the American & British efforts makes a damn good
adventure novel -- one in which the British should have won (ie,
because of their slide-valve engines).

[[off-topic, only of interest to historians:]]

Bob, you are writing history here as a US'an crediting a US patent to a
non-US'an! Indeed Mr. Charles Yale Knight, first holder of sleeve-valved
engine patents, was born in Indiana, USA, in 1868, at least that's what
I learn from http://en.wikipedia.org/wiki/Knight_Engine

Then again, his idea was based upon early concoctions by German Mr.
Otto, and then again his ideas were most succesfully implemented in
Europe, in some British aero-engines (Bristol Centaurus and its
predecessors) but also in the notorious luxury Minerva cars from Belgium
- that factory was close to my home, indeed the allies only nearly
missed killing my mother when trying to bomb the factory in May 1943.


KA

jan olieslagers wrote:
schreef:
Indeed, comparing the American & British efforts makes a damn good
adventure novel -- one in which the British should have won (ie,
because of their slide-valve engines).

[[off-topic, only of interest to historians:]]

Bob, you are writing history here as a US'an crediting a US patent to a
non-US'an! Indeed Mr. Charles Yale Knight, first holder of sleeve-valved
engine patents, was born in Indiana, USA, in 1868, at least that's what
I learn from http://en.wikipedia.org/wiki/Knight_Engine

Then again, his idea was based upon early concoctions by German Mr.
Otto, and then again his ideas were most succesfully implemented in
Europe, in some British aero-engines (Bristol Centaurus and its
predecessors) but also in the notorious luxury Minerva cars from Belgium
- that factory was close to my home, indeed the allies only nearly
missed killing my mother when trying to bomb the factory in May 1943.


KA

Yeah an American invented it, but it took Harry Ricardo and crew to make
it really sing.

Charles