The Flathead threads by Lucky 1974 and Grimlok got me thinking about something. Would it be possible to build your own heads out of sheetmetal? To make 8 port OHV heads? Or even 8 port OHV/OHC heads? I have read that early Crosley engines were completely built out of sheetmetal, and sheetmetal would be softer than cast iron but not as soft as aluminum. What do you guys think? Is it possible? Would it make sense?
I haven't seen an early Crosley up close, but the early Ford V8-60 was a "Tin Side" block. I think this was a way to cut production costs. The early 60 was a cast iron block but the outer sides had a sheet of tin welded on to cover the open water jacket area, I think Crosley was the same. This saved on casting cores I believe.
maybe seperate pieces of built up forms using steel plate that bolt together with hand cut dead soft copper sheet gaskets to create jacketing
Yeah, or Mig welded together. It would look square and boxy, and it would take a lot of machine work. But it would be pretty cool if it can be made to work, right?
A stack of aluminum plates with the required ports machined into each before assembly... and then welded and finish machined, would look like this...
Doc, that is more or less what I am talking about. Exept the ports would be pieces of tubing that get welded to the backside of the combustion chamber, before the sides and top get welded on...
use your medium and techniques, sheet and plate hammered and welded. no reason why it can't be done. if your skill was in whitteling billit or pouring molten metal the end result would be virtualy the same contain and control heat and pressure, just engineer it to do those things efficiently. Paul
VERY nice Type 40 Bugatti! They differ fron the Type 37 in the lower crankcase, I've been inside a few. The cambox is an aluminum casting the rectangle shaped blocks are cast iron. Back to the original question, I don't know how a sheetmetal combustion chamber would stand up.
You are right Paul, I guess I look it with the material in mind that I am used to working with... 37Kid, if the Combustion chaber wall was thick enough to hold the pressure, with a water jacket on the other side, it should be OK, or dont you think so? Also would the complete finished head be really prone to warping, or would it be stabile enough, if its thick enough in the right places?
Something tells me this has been done in Germany or in the aircraft industry. I just think about all the stress around the tubing you'd have to weld in around every head bolt, and spark plug bosses. Someone did cast two piece heads for a flathead years ago.
[ QUOTE ] Someone did cast two piece heads for a flathead years ago. [/ QUOTE ] It was either Kong or Navarro. They machined two aluminum plates & bolted them together. There were some minor sealing issues & the later heads were cast. Of course, a flathead is easy - you're talking overhead! Still, might be an option. How thick will your sheetmetal be in the chambers?
I dont know, I'd have to cut up a couple of cast heads to see how thick they are. I'm guessing 3/16 or 1/4...
go for it man anything is possible if you think about it long enough if i could afford it id be working on stuff like that right now i love trying to think of ways to make flatheads better then a FLAT head just imagining all the things that were going through those guys heads over a half century ago and having the skills and the resources to fiugure it out.....that intrigues me to no end good luck zach
I had that same idea as well !! I thought of using Aluminium plate (thick) for the walls, combustion chamber etc. Thick wall aluminium tubing for the ports, a piece similar to a 90 degree exhaust piece that can welded in at both ends. Then I thought why has this not been done before as on paper it seems simple (). The only down sides I can see is that it would be differcult to mount the 'push fit parts' like valve seats and valve guides. You would have to weld bosses in for these which by the time this was done it would just be a solid block of metal! You would defferently have to have something substantial for the heads bolts to bite down on. Finally another problem might arise with the combustion chamber in that there wouldn't be one!
I think the hardest part would be to build the ports. They need to be strong enough to handle the pressure and heat ( the valve spring pressure is right on them ), and they need to flow well ( why else make the head...) Maybe the way to make those would be to cast a brass hammerform to beat redhot 1/8 plate steel over, with a seam down the middle... The combustion chambers would not be that difficult, and you could even eliminate them altogether by turning it into a Heron head ( dome in piston...)
It COULD be done. Stress relieving after final welding would be a very good idea,before final machining. You would need enough material in the right places so the valve seats didn't move around. Cast Iron is not vary stiff,neither is Aluminum, so a mild steel head has to be possible;but it would be ALOT of work. Buy a TIG welder and try it. A shitty old Briggs and Stratton would make a cheap test mule.
The heads on those OHC[rotary valvetrain] engines were a solid peice Billet not cast, with no water jackets....would you incorporate water passages in the design of these?
I know you're talking sheet fabbed rather than machined, but fwiw in the June 2002 R&C there is a little write up on an Ardun-esque 2 piece billet banger head. They use 2 piece to mill water passages etc. I'm guessing they don't have a 5axis machining center. Article says two pieces are joined by "secret process". I'm guessing maybe doweled and furnace brazed. Definitely not welded. Contact info given is H & H Engine Building 818-248-2347 www.handhantique.com
I've got this factory cutaway of a Model T Ford engine. Here are some photos of the head just to give you a view of things.
Metalshapes,this is from the new book Vintage American Road Racing Cars,might give some food for thought.Sorry I'm not smart enough to put it all into one post.
I don't see why it couldn't be done.. I'd start by taking a stock head (or heads) and cut them up in every direction imaginable to get a clear view of the internal structure. Then duplicate what you see with plate and tubing. When finished I'd stress relieve it before machining ( that's already been said). I'd also make a head gasket out of thicker dead soft copper and use studs instead of bolts. Take pictures while you go along and we promise not to apply for a patent before you do. Frank
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