Inliners International Forums General Discussion Hi Performance New hybrid head?

Has anyone ever worked on using two 181 or 151 heads to build a hybrid for our 6s. It would seem that the bolt holes are in the right place, cylinder spacing is right,and the water jackets line up. I don't know if there is a safe place to slice them. They'll take the same valves the 6s will. The valve train is in the right place. I don't know how the ports work out. It seems like the 151 cross flow might work. Any thoughts? What am I missing? Beater

The aluminum "Iron Duke" race head GM used to sell will work. I think Brodix still has a head they sell that is similar. I know a Comp guy that did it for the big sixes with the GM head. There hard to find used, and you probably wouldn't want to cut them up to do it....$$$$$

But what about the 3 different reasonably priced and readily available 8 port 181 cast iron heads? They make 140 HP from a 181 ci 4 cylinder. That would be equal to 190 HP from a stock 250 six. At least one of them uses 1.95 intakes and I think 1.6 exhausts. All head bolts and push-rods would be in the right place. Water jackets line up. The cross flow "Iron Duke" head is thin and fragile and restrictive, so I hear, buy it will fit. Way easier and cheaper than the V8 option. It would solve the Siamese port thing and make MPI a real choice. Just thinking. Beater

Thats true, just welding or furnace brazing the head sections back together is the biggest obstacle. But its doable.

Looking at the gaskets that jalopy45 posted the cuts would have to be made between two intakes on both ends. I suppose you would cut to the outside and mill back to the finished length. there doesnt appear to be any extra room but once it;s back together you don't need extra. I need to find a junk head to cut up. There should be lots of them around. Beater

You know, the early hybrid heads were all cast iron and that's exactly how they did it. Cut, milled back and brazed. With the brazing alloy's we have now, I think it would be quit doable and gets away from the problems encountered with the V-8 head hybrids.
Leo does touch on the subject of using the Mercruiser heads (pg.112) and Sarge Nichols and I have talked about it. The limiting factor seems to be airflow for those who are interested in all out competition and head gaskets. For street use, it would be great (IMHO)

Good luck!!

Stock gaskets might work or a copper gasket in the stock pattern. Thanks Armond, I'll check p.112. Beater

Here's an aluminum we could cut up but we need two.

There is always the Brazilian 12 port head to consider for the 6's...

Wow, Armond is right! How did I miss p. 112 in "The Book". There are pictures and everything. Advantages are as I thought everything lines up. Disadvantage is that no one has really worked on getting them to flow. They have flow as well as the stock Mercruiser head which makes good power. They would really work with MPI. What is involved in furnace brazing? I may change the 292 plan or at least have a phase #2 plan. Thanks again Armond. Beater

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Anyone know if induction brazing has been attempted on these heads or the hybrid heads for the big Ford six?

When I did furnace brazing(on smaller components), the braze/flux was already added to the joints in either a strip of the correct thickness to get the gap correct or a paste with tooling to hold the gap correct. The furnace is heated to below the melting temperature of the braze and held, allowing the component temp. to normalize. Then, the furnace temperature is ramped up into the brazing temperature and allowed to soak for a set time. After, temp is dropped below the solidification temp and cooled at a set rate.

Furnace brazing is no small feat. The furnace atmosphere may need to be controlled as well. I did pretty well with tack welding components in position(proper gap & alignment) on low volume test runs to avoid tooling costs, but they weren't cast iron.

Thanks guys. This is an interesting process and I've been reading about it. I see it is not something I'm going to do at the pizza place next door on my lunch hour. I my try to find a place around here that does it. Holding the parts in place could be tricky.

I'm not entirely sure furnace brazing is necessary. As there are no oil passages or structural members. I think you could use a parting compound on the top edge of the block. Then, using the block as a jig, use a rosebud to heat the two halves, then just braze the joint. Wait till it cools (slowly) unbolt it and do the bottom edge. The rods we have now, everdure (silicon bronze), weldco 17 (nickel silver), etc. Flow very well and can be TIG'd instead of torched. Something to consider. Weldco 17 has a Tensile strength of up to 95,000 psi, which is stronger than cast iron. I wonder if one of those Brazilian manifold T. Lowe has kicking around would bolt on? They have 6 intake ports.

This may be a stupid question (Hey... it's my specialty) but do the two halves of the composite head need to be welded together?

If the head is cut and then milled back to a specified clearance as suggested by BotP above, grooves could be milled into the cut ends to help with sealer retention. Alignment dowels could be provided for the mating surfaces as well as for the deck.

The matching surfaces will be only holding only coolant pressure, which wouldn't seem to be an insurmountable chore.

An inline six block tends to wiggle like a fish. If you left the two pairs unjoined you will be creating a stress riser by virtue of asking the block to bear the brunt of this wiggling motion instead having the head to stiffen the long block. I'm guessing the bores in cyls #3 and #4 wouldnt stay round long and block failure would soon follow, depending, of course, on the power level being developed. Then again, if you aren't looking for huge power increases in the first place there is no need for a hybrid head.

Have you seen the head I made using two stock heads slabbed (like a sub sandwich)and stacked together to raise the ports [shown on http://www.fordsix.com]? Maybe something like that could be done on a stovebolt.

Linky no worky.

http://fordsix.com/forum/viewtopic.php?f=2&t=47841&hilit=raise+ports

http://fordsix.com/forum/viewtopic.php?f=2&t=33048&hilit=like+a+sub+sandwich

Here's some related threads, couldn't find a pic though.

Granted, an unwelded split head would have no inherent beam strength. However, it does seem that it would be possible to regain that strength without the necessity of going through the furnace brazing or welding process.

An oversized intake/exhuast flange matched with a dummy strap bolted to the bosses on the back of the head may be enough. Either could be further strengthened with an inverted L shape to increase web depth.

The top of the split head halves could also be milled flat so that a girdle plate could sit atop the entire arrangement, mounting the valve cover on the girdle.

One of the reasons that omitting the brazing/welding process for the adventurous low-dollar builder might be advantageous is that damage to or over-porting of one of the halves would be much less financially traumatic.

I'm not clear as to where the cut is made? What functions of the head are bisected, beside the ports?

Panic, they would split just as the hybrid V-8 head does. Right between two ports. The only thing opened up is the water jacket.

Meant this one: using two stock heads slabbed (like a sub sandwich)and stacked together to raise the ports

Note that the floor of the ports can eb easily welded up, eliminating any "lump port" inserts, when the head is sectioned. Also, porting now becomes easier due to better access. Go for it.

Or buy mine.

Man, you guys are getting out there! Cutting heads in half length ways top to bottom? CNC, Doug, Armond, Panic, Flyer, 68 this is great! Panic where did your furnace brazing post go? Armond I wondered about the necessity of welding the halves together. When you think that it is necessary to use a torque plate just to insure the bores are round I think think they need to be stuck back together. Would other braces work? Thank you all for adding to this discussion. Beater

Has anyone ever taken a chevy 6 head gasket and compared it to some of the european performance 6's like the Jaguar, Ferarri or Mercedes etc.? It might be easier than fabricating a head. I've seen Porsche V8 and subaru 4 heads adapted to SBC's because the bore spacing matched and they both showed some promise in the performance area. Just need to find someone who woks in an auto parts store?

I know someone who works for the 3rd largest corporate parts store where the computer catalog goes all the way back to '62. The stocking head gaskets don't even include a Chevy 6 or 4. Porsche, Ferarri, Mercedes? It ain't what it used to be. There is no longer an in house listing for "engine parts" No valve, piston, rod #s or specs. Sets and kits. Thank you for calling "Flash Lights Are Us" how can I help you? Beater

It was just a curiosity question but if you look at some of the heads like this Mercedes on EBay 24 valves, big ports , http://cgi.ebay.com/ebaymotors/Mercedes-...sQ5fAccessories

Most of those foreign makes are much smaller dimensionally than the 6's we have here. They are more common in size to the smaller Ford 144 & 170 engines. The Chevy 194-292 and Ford 300 are a lot larger of an engine externally. Most of the import stuff has real low hood lines and short front ends.

Jalopy45,
You can start here but no guarantees since there is a lot of values missing.

At one time, I'd considered attempting to cut and adapt a pair of early 50s DeSote hemi heads to the 292... Bore spacing is only a few thousandths off. Unfortunately, the guy I knew with the barn full of early hemi parts has gotten out of the business.

The DeSoto would be a lot of work.
DeSoto bore spacing is 4.3125" vs. 292 at 4.400" = .0875" error for each successive cylinder.
The DeSoto heads are all smaller bore than the 292, but will require domes because of the large chambers.
The head bolts are going to be bad because they're also the DeSoto rocker stand bolts, but there's some front-to-back wiggle room.
The easiest fit is to have the DeSoto intake facing the pushrod side of the 292, but because of the difference in cam locations the pushrods might have to pass through the block to reach the rockers.

Hmm... I must have read some erroneous information re the DeSote bore spacing; I recall something like 4.385, in which case the error wouldn't be too bad.

Because I lost the source for the parts, I never got as far as actually looking at one to compare. Given the constraints, that is probably a good thing.

Just start with two 2" slabs of billet aluminum, CNC everything where you want it, rifle drill it in a couple of places for cooling, and sandwich them together with dowel pins. Done deal. Plus you can take it apart to modify/ repair it.

Yeah, that would be the easiest way to do it. Norm Fricks has done it countless times with various Flathead engines. I might play with that idea this winter.

Never mind.

As I remember from an SAE paper about NASCAR engine design moving the location of the intake valve by as little as .040" can affect flow by as much as 10%

Not only moving the intake will make a BIG difference in intake flow,an incorrect valve job can ABSOLUTELY kill airflow,,also the throat area being cut correctly.
Or having too wide of a seat will kill flow.

MBHD