VW Heads Designed for Aircraft- Poll

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Value of purpose built VW aircraft heads

  • Why bother. Who would try to use '30's auto technology to fly.

    Votes: 1 4.2%
  • It's an interesting idea but what we have now is good enough.

    Votes: 2 8.3%
  • If they were close in cost AND better I'd probably use them

    Votes: 11 45.8%
  • It's been needed for a long time. They will make the VW a far better option.

    Votes: 10 41.7%
  • It would be the best thing to happen to EABs in the last 2 decades

    Votes: 0 0.0%
  • Why bother. Who would try to use '30's auto technology to fly.

    Votes: 1 4.2%
  • It's an interesting idea but what we have now is good enough.

    Votes: 2 8.3%
  • If they were close in cost AND better I'd probably use them

    Votes: 11 45.8%
  • It's been needed for a long time. They will make the VW a far better option.

    Votes: 10 41.7%
  • It would be the best thing to happen to EABs in the last 2 decades

    Votes: 0 0.0%

  • Total voters
    24
  • Poll closed .

Aviacs

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Doggone B & S vanguard heads - if only they had put the ports in the correct position!
I think the rest could have been machined to fit. Though they are not excessive with finning, either. 20 HP/cylinder continuous is in the right ballpark. At slightly higher revs.

They might well be a good option for opposed twin VW based.

:)
smt
 

Hot Wings

Grumpy Cynic
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Doggone B & S vanguard heads - if only they had put the ports in the correct position!
If only these near sighted engineers of the industrial engines and the VW had just taken the time to consider that some of us would like to hang them on an airplane.

Life would have been much easier, and more fun............at least for us.
 

Bill Volcko

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Does anyone make valve rotators for type I VW heads? Are there any valve rotators that can be adapted to type I VW heads
 

Hot Wings

Grumpy Cynic
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Not really needed on the VW bug. Set the rocker offset per specs and they rotate just fine. If you want a little more put a steel shim under the spring.........and make sure the springs are installed 'right side' up.

More than you wanted to know about valve rotation:
 

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Bill Volcko

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Mar 1, 2020
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My heads came assembled, therefore I'm assuming they are right side up. How can one tell? Original VW rockers had adjusters with a rounded contact with the valve stem. If they were set up correctly the valve would rotate. These stock adjusters were a wear item and had to be replaced regularly or suffer the consequences. They then came out with the "Ford" or" Courier" type, which I have. a captured ball with a flat ground on it to contact the valve stem. I set them up according to instructions and after 40 hrs there is zero evidence of rotation.
 

Hot Wings

Grumpy Cynic
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How can one tell?
If they are stock VW springs they are wound asymmetrically. The close together coils go next to the head. This design reduced the reciprocating mass and introduces a rising rate spring pressure that helps avoid resonance as well. Most aftermarket springs are simple coils.

The stock valve adjusters shouldn't be a wear item. The rub surface should be hardened, but there are/were a lot of junk parts on the market that aren't. The tip then mushrooms, pits, or both, and the valve adjustment loosens up much faster.
A light scratch with a file will tell you if the tips are hardened. With the stock spec tips the adjusters will develop a slight polished wear arc that makes setting the lash a little more difficult with a feeler gauge the next time. The arc will be in a slightly different place for each setting. I've seen stock adjusters last thru a couple of rebuilds but I got to the point they automatically went into the iron bin with the rod bolts and exhaust valves. The time needed to sort thru the old ones took longer than simply using known good new parts.

The Swivel Feet adjusters do cut down on the valve rotation forces, and they do stop the valve stem contact surface from cupping and give a little more arc when using high lift cams. Per spec valve stems don't cup with stock adjusters and the keeper grooves don't 'pull' which leads to having to file the groove burr to get the valve out.

Getting good parts was a real problem 20 years ago and I doubt much has changed. I bought all of my valve adjusters, and most of my VW specific hardware, from the Metric Man because they were the only wholesaler that had consistently good adjusters - even then I checked each batch. Unfortunately they appear to no longer be in business.
 

Bill Volcko

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Your VW knowledge is impressive! I am just trying to get an Aerovee to be reliable. At this point all parts are aftermarket. Still learning.
 

Aviacs

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Oct 21, 2019
Messages
342
Keeping VW head thoughts in one searchable place...

Whatever happened to the watercooled GP heads that were sold for a while?
Some hidden defect turn up in service?
Were they effective but too costly?
Ineffective?
(perceived?) too much extra weight?

If the heads were effective and durable, does anyone know which pattern and casting process was used?
It's probably known by now that i am a fan of conventional matchplate patterns and no-bake moulds, shell cores.
Was that process used, or were they also going lost wax?

smt
 

Vigilant1

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Whatever happened to the watercooled GP heads that were sold for a while?
Some hidden defect turn up in service?
Were they effective but too costly?
Ineffective?
(perceived?) too much extra weight?
I don't know the specifics, but they may have been made by/for "Rotaway" or "Rotorway' (like the helicopter company).
IMO, there's not much potential for increasing VW Type 1 continuous HP with liquid cooling. The magnesium case is already subject to cracking after long use at 75hp, it will happen a lot faster at higher power levels. Bearing saddles in the case wear out, too. So, for more continuous HP, you'd probably need to use aluminum cases (more weight and $). Other engines start to look more attractive.
If we just want longer engine life and better reliability at 75-80 HP, I think we can get there with improved "finnage" and, perhaps, additional oil flow through the heads via a dedicated system (so, liquid cooling but without the weight and cost of a separate glycol loop). Likely, better fins are enough.
 
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Hot Wings

Grumpy Cynic
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I knew they had some prototypes but I didn't know they actually sold any H2O heads?
For the complexity of what I remember I don't see any need for lost wax. Cope/cheek/drag should do it with 3 cores?

H2O would be nice but it leads to complications the market just isn't ready to accept..........Just my 2 Satoshi worth.
 

Vigilant1

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I knew they had some prototypes but I didn't know they actually sold any H2O heads?
Yep, GPAS sold the liquid cooled heads for a short time (a year or two). Together with the GPAS reduction drive (so engine RPM greater than 3600) or direct drive + higher CR, the liquid cooled heads were intended to allow higher continuous HP.
I have heard 3rd hand that Steve Bennett wanted to develop them further and work out (unspecified) issues, but that this didn't happen.
 

Aviacs

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If we just want longer engine life and better reliability at 75-80 HP,
^^^^^This^^^^^

Although i am not averse to aluminum case if it, too would increase reliability through better rigidity.

I think we can get there with improved "finnage" and, perhaps, additional oil flow through the heads via a dedicated system (so, liquid cooling but without the weight and cost of a separate glycol loop). Likely, better fins are enough.
Is someone here capable of designing such a head, perhaps relocating the ports, and making it as a single, as has been mentioned?
Supposing someone were dumb enough to consider making patterns & core boxes?

smt
 

DaveK

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Heat pipes can move an impressive amount of heat. I’ve toyed with the idea of attaching heat pipes to the heads in the hottest areas and having them run to the top of the heads to be in cool air. If made of alluminum they could be welded / brazed straight to the head. Would have to select a proper working fluid, but that shouldn’t be hard.
 

Vigilant1

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When it is complete, this new head will need to be tested in flight. Thoroughly tested.
Most users will probably use them in tractor installations, but there will be pushers, too.
For safety and efficiency, what is really needed is a twin engine, push-pull VW testbed that would allow these new/prototype heads to fly while a more traditional VW engine is available to get the plane safely back home in case of trouble. Pops already has a design mostly worked out, and he might soon have the second needed engine.
Just sayin..... ;)
 

Pops

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When it is complete, this new head will need to be tested in flight. Thoroughly tested.
Most users will probably use them in tractor installations, but there will be pushers, too.
For safety and efficiency, what is really needed is a twin engine, push-pull VW testbed that would allow these new/prototype heads to fly while a more traditional VW engine is available to get the plane safely back home in case of trouble. Pops already has a design mostly worked out, and he might soon have the second needed engine.
Just sayin..... ;)
I'm waiting for someone to build it. Did I see your hand go up ? Yes, believe I did :)
Have two engines on the bench. The engine from the SSSC and the flywheel drive VW engine project, also the VW engine in the mud ( pipe/sand) buggy that I built this last year and also 2 more that are disassembled.
 

Aviacs

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Looks like 4 cores?
I am not a professional pattern maker, though i have made professional patterns and core boxes. :) (Pro= they made commercial products cast in multiples that sold reasonably well. In one case, they would still be selling except my last foundry went out of business and the patterns were stolen or destroyed. The parts were large and the margins low, i have not been inspired to make new patterns, and the "competition" has caught up selling similar models.

Starting with that "qualification" I only see 2 cores so far, depending how the finning works out to orient the combustion chamber in relation to the parting line. I "imagine" there will be another, or couple more, cores for the pushrod channel once that is worked in, so if you were including that; then "yes". OTOH I'm assuming shell cores, not paste-up. Modern foundries don't want to work with paste-up cores, and the cost per casting is an impressive factor higher cost. Shell cores will also give very smooth dimensionally uniform, essentially "lost wax" surfaces, say, in the induction and exhaust ports.

Looking harder at your drawing, i'd almost go out on a limb and suggest one shell core could do the whole negative space.
They do shrink and can slightly tear coming out of the shell core box, so overall dimensions and locational tolerance could be a factor. As would, again, the finning and parting line(s) to determine available geometry to position the core prints in the pattern. (IOW, it could be possible to blow the entire core as a unit in 3D space. However, if the points where "the ends" must fit to the 3d space of the primary pattern don't admit (nearly) parallel entry, then one or the other might have to have to be broken down into smaller interlocking components).

I don't assume i'm telling you anything new, but there may be others following along. :)

smt
 
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