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DOHC L6, Was somebody looking for the Goerz-Paeco DOHC L6 Head ?


Vintageracecar

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Maybe because I'm a pattern maker the casting seems to be the least of the problems. Cams,timing chain and gears, lifters etc are all going to be harder to come up with. Also people qualified to bring a raw head casting to a finished product probably aren't looking for any hobby projects.

 

And thanks to Tony instead of concentrating on the bid I should be working on i've given the casting approach some more thought. And I really think this is feasible.

Acquire a copy of the prints.

Develop the 3D model.

Carve a traditional cope and drag pattern for air set sand for the exterior of the head. This will cut down enormously on the cost of the 3D printed sand and shipping.

Have the water cores and air passage cores 3D printed. The benefits to printing the cores are huge. first and foremost your not constrained by the limitations of a traditional core box. Since each core is printed separately any changes are just a matter of redrawing the model. Also because it's a continuous 3D print there are no part lines and the sand is super smooth. To put this into perspective I would design the intake, exhaust and combustion chamber as one continuous chunk of sand. The finish and precision of this method can only be matched by investment casting. Also this gives you tons of freedom to individually design each heads internals.

Here is a shot of a sample of some sand I had printed. I was doing some restoration work for the King Lunalilo Tomb in Hawaii and was curious how the sand would look. I sent them a STL file of the crown scan and they printed this.

file.jpg

 

I was really blown away by the detail it picked up. So you can see the possibilities for this.

First step get the prints.

Second step find a machinist. Preferably one that want's a twin cam L6 head :)

Third step source cams and assorted hardware.

Fourth step develop 3D model for casting. (me)

Fifth step have machining model and prints developed from casting model with proper tolerances and such.

Step six patterns and castings (me)

Step seven Machine castings

 

So fill in all the steps except for four and six and this could happen. There's makers and takers in a deal like this. Makers donate labor takers donate cash.

 

Derek

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Reproducing this head could be much more cost effective using selective laser melting in the future. The technology is advancing rapidly. The prices are dropping each year for 1-off and prototype parts. Similar material properties and finishes to investment casting. Unlimited complexities. Amazing stuff.

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Tony,

S20 head is not symmetrical. The inlet and exhaust ports are a similar shape and with a similar manifold bolt pattern, but the inlet side has multiple water passages for the inlet manifold to mate up with. Similar situation with the OSG TC24-B1 too: It has the external coolant log running along the top of the exhaust manifold, and that mates up with the coolant passages in the block.

 

Switching of the exhaust and inlet sides on both heads would require a complete re-design of the coolant passages, with the knock-on effects needing to be dealt with too ( oilways, bolt holes etc etc ).

 

Alan T.

 

PS, pics of my 432R replica project's 'K3' S20 head for reference:

 

s20headinletside.jpg

s20headexhaustside.jpg

 

Alan,

Too much pedantry there---the reference was that the Paeco-Goertz head was symmetrical, AS SUCH you could place the intake or exhaust on EITHER SIDE---so putting the intake on the RIGHT SIDE like an S20 or OSG is possible.

Likewise, putting the Intake on the LEFT SIDE like a 1MG from a 2000GT Toyota is ALSO possible.

 

The head as cast is perfectly symmetrical in both intake and exhaust port configuration, no difference. You can make the head in any configuration you should want.

 

If there was a mad hybridizer out there wanting an L-Block in a 2000GT, this head would allow that intake/exhaust configuration just as easily as and S20 or OSG setup.

 

I did not say the S20 or OSG heads were symmetrical, just that you could make this head into a similar configuration because it is a blank slate.

 

 

Seriously, did you honestly think I would ever say the S20 or OSG castings are symmetrical?

 

I'm somewhat hurt...cool.gif

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RE-Derek and lifters, cams , gears, valves etc...

 

There was some talk, I don't remember the size of the holes already machined into this head, but I think I posited at the time that this head (given the period it was made) would likely accept Toyota DOHC Buckets and shims for the valve actuation and adjustment. Frankly that is easily adapted, it's just a bore. Possibly the cams from a 1MG or 5MG...or perhaps a Jag? Cams are cut from billet and ground, since I can come into a place and say "can I talk to Ron" that for me is pretty much a done deal, though any cam grinder would likely be able to do it...just setting up the machine for the valve centers. Same bumpstick offset as an RB I would suppose. Remember the KA Sectioned head used a lot of off the shelf parts including cams.

 

Which is why I say making ANOTHER head instead of using this one would be a better idea. The casting would likely be a better quality, and then you could start from square one with MODERN buckets (smaller diameter, less friction, better parts availability BETTER METALLURGY FOR NON ZINC OILS!!!) Valves are no biggie, Ferra makes what you want, just tell em!

 

See what got started...

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Alan,

Too much pedantry there---the reference was that the Paeco-Goertz head was symmetrical, AS SUCH you could place the intake or exhaust on EITHER SIDE---so putting the intake on the RIGHT SIDE like an S20 or OSG is possible.

 

No such thing as "too much" pedantry. It's infinite. Quite rightly too....

 

OK, I see what you mean now. But I originally read it as you implying that the S20 and OSG TC24-B1 heads are symmetrical in inlet and exhaust, and I just want people to understand that this is not the case.

 

Don't want to damn this 'Goerz Paeco' thing with faint praise, but it won't be legal for use in most of the race applications that would most like to use it ( unlike the factory 'Safari' E4621 FIA 'head and 'LY' crossflow 'head ) and is therefore something of a white elephant as far as race use is concerned. Just like the OSG TC24-B1 in fact.....

 

I'll cheer it on from the bleachers, nonetheless.

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....and is therefore something of a white elephant as far as race use is concerned. Just like the OSG TC24-B1 in fact...

 

Yeah, unfortunately. I had a customer that was interested in the B1 and he had the wherewithal to buy one. But we couldn't find a place for him to play that didn't include Z06-R Corvettes, Nissan GTRs, and Porsche Turbos. He asked, "Why would I spend 6 figures on an engine guaranteed to lose?" He bought a GTR instead. I would too.

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To say that head has a lot of work to make functional is more true than I could care to swallow. Even if I had the budget (which I am FAR from being able to see in my near future currently), I'd start over with something else. I personally DON'T like it's symmetry. I DON'T want my valves, let alone port volumes to be the same from side to side. I don't like the extremely low port floor that looks to be a solid 90 degree surface relative to the deck. That port probably has some crazy geometry going on inside there. And check those chambers out! To say they need some work... well that'd be an understatement.

 

All of the big issues are fixable, but considering that it'd never be legal in competitive racing, you have to ask "why"? With what I see as roughly the same amount of work you could mold a I-6 KA head, or even adapt the RB head to L bore spacing dimensions. The RB would be more work as it would require some oil/coolant passage work, but certainly not impossible to overcome.

 

In the end, to make this head work, even with over the counter buckets, cams, gears, etc you're still making something work that to my eyes doesn't look that desirable. Maybe I'm just missing something here.

 

 

Oh, and ALL THAT SAID!!!!! (please use this next paragraph to read my attitude about the previous statements). I think this head has some interesting history in it that's worthwhile, and that the more we can learn from it the better. It's great that there's still drawings around for it which I'd LOVE to see. And if someone wants to make one, AWESOME! I applaud anyone who wants to go through all that work and make it happen. I just wouldn't do it myself. :-D

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Listen I'll be the first to admit this is still and will probably be a pipe dream. But as technology advanced things that were previously absurd become feasible.

The only way i would consider getting involved in this is if it used off the shelf components. That just makes sense.

Also keep in mind what I'm pushing is being done right now by ford, chevy etcetera. This is how they are prototyping their stuff. When ever I quote out manifold or head work this is how I propose it. By printing the cores you can keep tweaking things until you get it the way you want it. Then after you have a workable design in both performance and cast ability you commit to traditional core boxes for production.

By 3D sand printing the cores the combustion chamber and ports can be tailored to each head. As long as it fits inside the outer shell your good to go. The thing I like about this design is it looks right for the car. So if you can design an exterior patten that looks period correct and custom print the internals what's not to like!

 

 

Derek

Edited by Derek
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Yes, the thought that back in the early 70's someone was working on a DOHC...Not idly chatting on a desk blotter with friends.. Someone worked it out, drew it up, made the forms, cast it, started machining, and then...

The project ends up in estate sale and is sold lock-stock-and-barrel at a parts swap meet in San Diego 20 years later.

This work is PREDATING THE TC24B1 by A DECADE!

That is kind of cool. Likely the guy was old, and died without it being completed. I can only ponder why it stopped where it did, ill health?

If you ask "why" the passion escapes you, which is sad.

This is the spark from someones imagination that was one HARDCORE enthusiast.

Maybe the milquetoast set here wanting bolt-on solutions and stuff to be stocked at Autozone or it doesn't get done... I can see them asking "why"... Why climb Everest? Why race?

I mean we have people here who remake tubular components...Yeah, we had someone even cut up a head...

But gentlemen... This is "Worlds Fastest Indian" type shite! This is mad scientist in the shed toiling to odd hours of the morning coming out to eat breakfast and clean the carbon from his brow reeking of cutting oil and castor beans...

THIS IS FABRICATION!

Truly, it doesn't exist, so the guy decided to MAKE ONE!

To me, this is one step beyond mere adaptation. Cutting and piecing what is already done...that's one thing.

This is returning to Vulcan, the god of hellfire to break the resolve of the metal at a molecular level and force it from it's natural form to a form you proscribe.

This is not "adaptation", this is "CREATION" -- something men are supposedly incapable of doing!

For me, that elicits a monster-raging Viagra blue-steel wood!

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  • 1 year later...
  • 2 weeks later...

Drop another $8K and I might consider it as Wall Art next to my S20 Valve Cover...

 

Interesting snag 'o quotations in the eBay 'vert!

Only thing I can say to the claims is "but they're complete and functioning heads, if it's so easy to do why haven't you done it 'over the last decade' you've owned it?"

 

It was a fishing expedition. He caught a carp. Interesting as it may be this is as marketable as a DOHC Borgward Head Conversion, save that Borgward Owners aren't as cheap as Z-Owners!

Edited by Tony D
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All this talk about RB heads, KA heads, Goerz Paeco heads, laser printing and all this......   Start off with a merc 104 head.  bore spacing and head bolt spacing are dead on.  all you would need to figure out would be the chain drive, coolant passages and oil.  What ever happened to MAG58 anyway?

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