I can't afford a wild 12 port head for my 235. But I have an idea. Why can't I machine one from a large block? Two pieces. Bottom half seals the combustion chamber, top half houses valve springs, both halves have half a port machined out. Sealing up the exhaust side could be difficult, but are there major reasons it can't work? If it blows up, I'm out a 235. Big deal.
All you need is the proper machinery, good machining knowledge, lots of time, and a big chunk o' metal. Oh, and a sense of humor, if the whole project goes sour.
Maybe not so crazy - you should check out an Inliner named Bob Corbett in Denver. He runs a front engine rail with a 302" GMC block and a custom machined 12 port cross-flow aluminum head. Sure, it took a few tries, and lots of machine shop time, but he's got one! Later,
2 words: water jackets Seriously, you probably could make a top and bottom half, bolt together to form water jackets. cutting up a scrap head would show how much and where to put water.
What about the late Kay Sissell's idea of welding two SBC heads together for a hp crossflow? Seems like there was info on the HAMB re this in the past.
I'm not sure this would work on a 216/235 but its for a 292/250. these engines have the same bore spacing and port arrangement as a sbc...cool all the same!http://www.customdesignperformance.com/leo/cylinder_head.html
Well, it doesn't HAVE to be a Chevy head. Another make with the same bore centers as the 235 would work. I doubt the bolt pattern is the same for the Chevy V-8 and 292/250, so those guys will have to do some drilling in the head and/or block as well. Heck, V-6 heads would even work. Might be easier to macine the ends off and tie the water jackets together with V-6 heads. Wouldn't be any welding on the ports that way. Maybe one of the small V-6s will have the same bore centers as the 216/235? And who cares if its even one of the Ford V-6s??
They did fill and mill quite a bit on the block to prep. how cool would dohc v6 heads be on there? maybe thats too much work...
Alot of the stuff being posted here about cutting up a SBC and making yourself a mean 6 is covered fairly indepth within the pages of this guy:
I have a 235. I WANT to make my own parts. more than to go fast, to say I did. I am looking for machining/tech support, material to use, etc. who has made a head for a I6 from scratch? I've read about the supercharged 2 stroke GMC, and Wayne's 12 port. But how do you do it? Surely I can figure it out.
I think the idea is great! Assuming, of course, that you have the means (read: equipment and knowhow). There have been a couple models of Flathead Ford heads made as you suggest--bottom half with combustion chambers and block sealing surface on bottom side and water passages and bolt bosses on the top side. The top half has the remainder of water jacket on the bottom and outer surface on the top. Bolting them to the engine seals the two halves together. All you need to is extrapolate from there. The Hudson Boys who run in XO and XXO class at Bonneville have done a similar thing with Hudson Hornets but all their "watering" appears to have been accomplished by cross drilling and plugging. Just make sure you plan it all out thoroughly before you start carving-that chunk of aluminum ain't gonna be cheap. quote=53sled]I have a 235. I WANT to make my own parts. more than to go fast, to say I did. I am looking for machining/tech support, material to use, etc. who has made a head for a I6 from scratch? I've read about the supercharged 2 stroke GMC, and Wayne's 12 port. But how do you do it? Surely I can figure it out.[/quote]
Does the stovebolt forum have any info leading to what you want to accomplish. Info that can be brought over here. The HAMB is so much easier on the eyes to use!
Just a crazy thought. Does the BMW 535 head have the same spacing? That would save a lot of machining if it did. Ed
All I can say is good luck!!! I've been resaerching the same issue, and you are prety-well on your own for trying to find other stuff thats compatible with the stovebolt 6 head. There the question of the water holes, that make other head impossible to fit on the block. Laminating a head is do-able, but to use modern cam profiles is really difficult do to the abscence of roller rockers. There are 4 different types of rockers used in these engines, so to get a set of rollers made is a difficult and expensive proceedure, if you can find some-one to make them. Maybe you should try some old school methods on a stock head, stuff like angle planning the head to increase compression, porting and filling the ports, high lift rockers, powerglide valves, and a recognised camshaft design, and THEN if your still willing, go make a laminated head . My $0.02 worth. I can give you some ideas as to what to do to improve the design of the head.
That idea is not all that "out there". I'd say it was very doable if you have the equipment and/or the coinage to have it done. The best material would, of course, be 6061-T6 aluminum. If you were going to attempt something of this nature, you might as well get as much bang for your buck as possible. Something like a 4-valve, dual overhead cam with pent roof (hemi) combustion chambers would be fairly easy to design, with the plugs centered in the chamber between the valves. You could use a pair of conventional I-6 camshafts lying side by side, but only using the intake lobes on one side and the exaust lobes on the other. Of course this head would necessitate new intake and exaust manifolds, timing case, valve cover and numerous other small parts. The rockers would have to operate both valves off the single lobes, and would probably be best in a shaft-mount arrangement. It would be an enormous undertaking, but it could be done. The hardest part would be getting the water jackets sealed up, while still allowing the plugs and valve guides to penetrate both halves of the head. Some good heads to study would be the Cosworth Vega and the DOHC Quad-4 heads. The Quad-4 places the cams directly over the valves with a light weight lifter of sorts acting directly on the valve stems. You might be able to utilize them in the new head and save some time and money. One thing is for sure. The 4 valve technology sure flows some air. Two small valves flow a lot more than one larger one. I have an 89 4-door Grand Am with the DOHC Quad-4 that royally spanked a Porche Targa. You shoulda seen the look on the guys face. Priceless... Anyway there's some food for thought. Keep us posted if you take the plunge. I'm a machinist by trade and will be glad to help you out if I can. R S
I e-mailed a guy who did something like this. heres the reply. looks like using stock-ish valvetrain geometry is the way to go. All that's left is everything.
Ok you've opened it up for discussion - now give us some more about this cars that does 7's, and the guy who runs 200+ @ B'ville.
http://flatheaddrag.com/99slc.html http://www.draglist.com/lists/jfd-et.txt http://www.flatheaders.com/Chevy6.html somewhere in here, can't find it now [SIZE=-1]linksmanager.com/draglist/[/SIZE]
LOOK into one of those australian ford 250 inlines they have crossflow heads on them . the heads will fit right on to the us ford 6 cylinder engines
Funny that. I've got one in the garage right now, packaging it up to ship it off to one of our very own HAMBers right now.
Is the 4.2 Vortec (Atlas LL8) straight 6 bore spacing the same as the 235? I don't know as I am having a hard time finding that kind of info here or at Inliners (or GM as they don't support it in the aftermarket). Dual overhead cams and cross flow (exhaust on one side intake on the other). If it could be made to fit that would be a large improvement performance wise, with a lot less machine work. Which should be less expensive than a block of aluminum that big. My $.02
I can measure the bore spacing of the Stovebolt head if you have the spacing of the 4.2 Vortec. If its the new Chebby engine, a bunch of Inliners members went thru the factory whilst at an Inliners International convention, so one of them should have picked up on the bore spacing.
Harlod Johanson made his own 4 valve model A head. Took him about 5 years, but he had other projects at the time. If he can I would think someone else can. Just two more cylinders.
Just to clarify, the Aussie Ford 250 head that will bolt right onto a U.S. 200 or 250 is a cast iron 12 port NON-crossflow design (all ports on the right side). The later Oz 250 cast iron and aluminum crossflow heads are for a somewhat different block. They can be adapted onto a U.S. block, but it will take a lot of custom fitting. Mustangsix on here was able to get one to work, but it took a while. Later,
I have been doing so much research the last few months that I'm loosing track (too many different subjects). I was reading some in Bill Fisher's book and some of Roger Huntington's book today and one of them claimed the I-6 Chevy's had the same bore spacing as the SBC V8 (supposedly where the V8 got it from). The best I remember that is 4.4". I just posted a question on Inliners about the bore spacing of the 4.2 Vortec. I found some other sites that claimed it has a 103mm bore spacing (4.055"). I don't know if I trust that as the sites in question couldn't agree on actual displacement, HP, TQ, Wt, etc. If that is the case though, it won't fit (Dammit !!!). I did however find a site that shows a guy welding heads together off a 3.4 DOHV 60 Degree V6. Cross flow, 4 Valve, Aluminum. Pretty neat tech even if it's not complete yet. The DOHC 60 degree was the one in that family (IIRC) that did not have the intake as part of the valve cover rail. He's putting it on an OHC Pontiac I-6 and claims the bore spacing is the same on the 60 degree V6, the SBC and the OHC Pontiac I-6. So, if I haven't gone completely nuts and the info is reliable (cause no one ever screws up on the Internet ) the bore spacing on the Pontiac OHC I-6 and the 235 should be the same. Now, if only the head bolts would line up. All that would leave is how to drive the cams as the Chevy's had no provision for this. Hmmm, worm gears, a drive shaft from the cam gear (in the block) to one of the cams in the head and chain the cams together? Or maybe I have been around radial aircraft engines too long and too many Brit cars?
I think if you're going to weld heads together you should at least start with good ones to begin with. I'd look at possibly sectioning a couple of LS1 heads. Fantastic flow rates, easy to find, and pretty darn cheap. I'm not sure if the Oz Ford Crossflow head will fit a stovebolt. The bore centers are only 4.080" and the head is a little short, I think. But, if it could work, those are dirt cheap in Oz. The biggest drawback is that you will then need a custom cam since the intake and exhaust layout is completely different that stock. One other technique that might work is something we've been doing at work lately. We build models in layers, then prototype them by cutting those layers out of paper or metal and then laminating them together. So, instead of a billet head with a top and a bottom, you have a "billet" head with 20 layers of sheetmetal .
I have seen demo footage of that, very impressive. Could you seal the lamination's tight enough for a running part, or would you use it to make tooling to cast a solid piece? And yes any of the LS or newer V8 Vortec Aluminum heads should flow more than the 3.4. I just figured that the 3.4 (207 CID) making 210 or 220 (or whatever) stock with all the smog BS and still being able to wind past 7K it would probably size out well for 235 CID at less than 7K with better than stock induction and headers. Of course if you use any of the V8 stuff you don't have to worry about inventing a cam drive and only need 1 custom cam.
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