I started mocking up my Ryan Falconer head for my 292. I don't know how much push rod angle is acceptable. This is my approximate angle.

more pics.

The valve positions in the head, from the front cylinder:
Ex In Ex In Ex In Ex In Ex In Ex In
The lobe positions on the cam:
Ex In In Ex Ex In In Ex Ex In In Ex

Three of the cylinders (#1, 3, 5) will work properly, three (#2, 4, 6) will not work at all.

I would request a customer list from the manufacturer of people that have actually installed them on an inline Chevy 6 cylinder and have them successfully running without issues!

Using a 300° cam to make the numbers easy:
#2 cylinder's intake cam lobe will open its exhaust valve @ 40° BTDC, descend for 180°, and close it @ 80° ABDC (40 + 180 + 80 = 300). The vacuum from the falling piston will fill the cylinder with exhaust gas from previous cycles and compress it.
#2 exhaust cam will open its intake valve @ 80° BBDC, rise for 180°, and close it @ 40° ATDC (80 + 180 + 40 = 300); there is no exhaust for the rising piston to expel, but it will pressurize the intake manifold.

I never pretended to know what I'm doing here. I build dry ice manufacturing plants for a living.I don't think anybody has tried to do this before so that's perfect for me. I'm sure that people like panic forget more about this stuff before lunch than I will ever know. Most of my entire build (53 3100) is stuff people said I couldn't do. I'm standing on the shoulders of giants. I have been getting advice from Mike Kirby and Leo Santucci and many others. Leo is familiar with the head and said he had never done one because of the cost. It may not work out, I have no idea but I have to try. If it doesn't work I will just have to buy the rest of the V12 to go with it. As far as the cam cant they make it anyway you want? Isn't it pretty much a stick with bumps on it? When Crower made my billet crank they ask me how I wanted it. It's been my experience that if you pay they will make it.The engineering and design part is usually at least as much as the part. The good news is the next guy that wants a billet crank for a 292 won't have to pay those cost and will get it for about a half of what I paid. Maybe the simplest thing to do is buy their cam or copy their specs. I don't know enough about this stuff but am no where near giving up. Thank you for you advice and time. I'm eventually going to have to find someone to actually do the work and that's the scary part.

cant they make it anyway you want?
Yes, that's all you have to do, you can use your roller lifters again (tell the cam mfg. what you have).
This is the same thing that many 12 port head buyers 70 years ago had to do: when the valve positions don't match the original engine the cam is changed.
The next question: how to select the right grind (and intake and exhaust lobes may be different), complicated because of the supercharger. Falconer may have experience with boost on the V12... good place to start.
Although your cam can't be reground (not enough material in the lobes) it's worth money to another builder.
In his defense, Falconer may have asked you if you're aware of what's needed, and assumed "yes", and certainly didn't mean to mislead you or misrepresent the product.

You may find a magazine is interested in running a feature on this when it's done.
You're going to be the "go-to" on this!

I've gotten some requests for an explanation.
This "valve position vs. cam lobe" is unrelated to siamese or individual ports, cross-flow or reverse-flow, and even occurs in V8 engines.
Cams are made with the unfinished lobes close to their final shape and "clocking" (rotation) and cannot be re-ground, adjusted, advanced, etc.: you're stuck with it.
The cure is a billet ($$) cam (unless there have been many with the same request, such as the Chevy 4-7 firing order swap).

The stovebolt, Gen-3 250 etc., G.M.C. all use this common pattern:
ex in in ex ex in in ex ex in in ex

My custom billet solid roller cam from Crower was $435.42
lifters $362.78
rocker arms $344.55
These are for my iron race head.

I have no idea what rocker arms the Falconer head needs, are they stud or shaft mount?

Stud mount I believe. They are still making the stainless steel roller rockers. I had them ship the The rest of it to start looking at it. I now see what you mean about the cam. I think I can get a cam made to get around that? I'll take some pics today and show some other hurdles. I took a picture of the 2 heads together to show the valves but apparently I have forgotten how to post them. Sometimes you just have to walk away.

At the cost of the cam, the quality of the head design was substantially improved.

And your putting that On What motor?? I mean I can tell it is a 6cly head . But those bores won't/Don't match up in anyway because it is so much shorter. From the looks of the photo.
Never mind I back read , you have a 292 But from that photo with them side by side I Just can't see how That is even going to work.
It just don't match the Bores.

This is a great thread. For clarity sake I have taken all the attachments and put them into the Photo Library and then linked them here in order.






Not sure what is going on with the last photo (which leads to Twisted's question) . . . but the previous images show the head on the block.

For me the troubling thing is what to do about those push rod angles . . . With roller lifters the push don't need to spin but with heavy spring pressures how does one keep them from flexing?

Moreover, the push rods are leaning out of the plane of rocker motion. This will cause a sideways thrust (instead of just straight up) - effecting rocker ratio and potential stress/wear.

Still working on the push rod angle. Leo Santucci told me when he does SBC chevy heads the push rods end up outside the block. They make offset lifters and all kinds of funky push rods with angled ends. I need to call Mike Kirby next week. Leo told me Mike did a cantilever lifter somehow. With all you smart people I'm hoping this can be done. It will be be cool if we can pull this off. The bore spacing is the same. Thank you for your time.

Many production engines have angled rockers with the valve stems rotated in 2 planes (and intake & exhaust not parallel): BBC, Ford Cleveland/Boss, Ford 385, Chrysler polyspheric. The 235 has valves parallel in the crank axis plane, but not parallel across the head.

Maybe this was posted earlier: are the valve stems parallel to each other? I assume they're at an angle to the bore axis (so are the stock 292 etc. heads, but perhaps not the same angle).

mick35 - Thanks for posting all the info on your build. I've looked at the Falcon engine over the years and understood that the V-12 was based on two Chevy inline 6's, and that the Falcon heads would fit a 250-292 Chevy 6. Now, with you taking the initiative to actually step up and purchase one, we all get to see what it would take to get one working on a real running engine.

With what you've shown so far, the only similarity between the Falcon head and the Chevy 6 seems to be the bore spacing and maybe the bolt pattern(?). Otherwise with the pushrods outside the block, using the Falcon head looks more like using two (or more) V-8 heads welded together. A lot more work than I originally thought it would take.

I've never been a big fan of using welded V-8 heads on a Chevy 6 mainly because of the awkward way the side cover has to be made. I've got a Ford 6 engine with a head made from three welded 351 Cleveland heads that has the same issues with pushrods. I didn't originally build the engine, but have pretty much set it aside after spending a considerable time trying to get it useable again. One issue was trying to seal all of the oil leaks around the pushrod cover. Invested more than one tube of RTV.

So, when I've thought about doing one of these head swaps (and maybe you've already considered it) is to also convert it to an overhead camshaft. Lots of advantages and probably more or less the same amount of work. The Falcon head is a good candidate because the valves all appear to be inline and you'd only need to use one camshaft. And you already need to build a custom camshaft anyway.

Pete Aardema used to do a lot of overhead conversions, but I don't think he is still around.

https://www.hotrod.com/articles/hot-rodd...inder-behemoth/

And I've also heard of circle track racers in the 50's converting stock GMC heads to overhead cams, so it not something new.

Just a thought.

Now that it's on the block That looks SO much better. So odd how is liked in that one Photo.
At this time do you have a Idea as to how far off the top of the cover needs to be? And the bad part is that is the oil drain back side. And from the Photos it does not look like enough head surface to seal the side cover at the edge of the head. Or am I not seeing it. In the photo's?

Those are some WILD looking motors alright.

mick53 can you send me a photo of the underside/edge of the head that hangs off the block. Or post a photo. The header flange area
looks as if it may take up some need space.

I may? have a idea already It would be a kinda Odd looking cover.
PM sent

The advantages of OHC were not readily understood by the hot rod public 70 years ago. It does free up some power from the drive, and reduces component weight and compliance (you can't buy good GMC rockers last time I looked), but that's the whole list.
The GMC head won't produce power much above an RPM limit easily reached with pushrods.
In theory, OHC allow the valves to be in better positions w/r/t their ports (and no pushrod holes!) but SOHC requires rocker arms.
The staggered bore pitch (like the 235 but larger) makes adapting a better head even more of a headache than the Falconer: bolt, water locations, chamber overlapping the head deck (like the 235 does now).
If I wanted a serious (but not legal in XXO) GMC I would be looking at a big inch 4 valve DOHC engine. The GMC average bore pitch looks like 4.45" (3 @ 4-3/8", 2 @ 4-9/16") or 113mm. The Nissan V6 (including GTR) is 112mm. Centering the #3 & 4, the error adds 1mm for each cylinder in both directions.
The TB48 L6 engine may also be close with the advantage of a single casting but the bore is huge at 3.917".
The Toyota DOHC L6 FZ also looks interesting.

I'm going to post a series of photos. I hope I don't get in trouble for posting too much. Here is a comparison of the head gaskets on the wrong head.

They are still making the rockers but going off the grooves in the intake this is what I have. These are the springs that came with it.

Here is the push rod angle. The photos are deceptive. As best as I can measure the angle from front to back varies from 1.5 deg. to 3.5 deg. In and out is a consistent 9.5 deg.

How do you know the PR angle until the rockers are installed?
What diameter tube is that, looks really small.

My idea was to the intake come down flush with the machined edge on the bottom of the head for a nice edge on push rod cover. Hogan will be making my intake. To deal with the water flow my idea was to just cover up the holes on the head and machine the thermostat housing in the end of the head. Ryan (Falconer) said that was not a good idea because the water would be to hot when it got to the front. So now my idea is to have Hogan make with the intake a way to plumb it out to a thermostat housing. Or maybe just A/N fittings to a remote thermostat? I fully appreciate all the help and the fact that nobody has made fun of me yet. This could be built by forum and we can all be a part of it.

Those are just some old push rods I have laying around. There are little recesses in the intake and that's where I put the push rods. Some of them have holes so it's pretty close to the angle in and out. That's the biggest angle.

mick53,

I wouldn't worry too much about folks making fun of you for trying to do this. This is a dream project for many of us which we could never afford to carry through to completion. It seems that you have the desire and wherewithal to get this done.

Panic and Twisted6 got you on the right track with the camshaft. Nothing that can't be fixed with enough $$$ thrown at it. The lifter box is just a matter of having the fabricator make something that will seal it up and clear everything. Not easy, but doable.
For the rocker arms, I would want to have a Falconer piece or pieces to use for mock-up. Much easier to visualize what needs to be done if you can see where the existing parts fall short.

While an overhead cam might circumvent some of the challenges of the pushrod/rocker arm configuration, it presents problems of it's own. Since the rpm of this motor is going to be limited by piston speed, most of the advantages of an OHC are lost.

I'm along for this ride.

CARRY ON!

I don't think anyone is making fun of this project, but are just giving our thoughts on how to proceed if we had the $$. I bet all of us has fantasized on what our ultimate engine would be.

So to continue - If money is no object, why not a custom block to incorporate the pushrod cover, etc? The 292 Chevy block has already been made in billet by LSM Engineering:

http://www.lsmeng.com/Billet-Blocks2.html

And/or LSM can design the valvetrain and rocker arms too:

Capability
At LSM we have the expertise needed to make camshafts and
valvetrain systems work. We utilize internally developed advanced
computer modeling software to analyze valvetrain motion that can
handle your application from standard pushrod to desmodromic
applications. LSM has the answer to your camshaft needs whether
you need the latest big bearing camshaft, or want to experiment with
profiles or firing orders.

I bought this truck (53 Chevy 3100) in 1980 when I got out of the Navy. When I decided to go full Monty on it I put my retirement off three years ago to put my income into this build. The engine is backed up with an TKO 600 built for 1000 HP and a mid shift kit. Duel disk clutch and Frankland Quick change with Bicknel torque arm and Gleason Torson diff. Keeping leaf springs. 12.88" Wilwood 6/4 piston Nickle plated calipers. Electric P/S and A/C to keep the engine compartment clean and simple. I'm also running a secondary Ron Davis remote drag radiator with electric pump primarily to cool it after shutdown

what kinda price tag does the IGOR block carry? And I am guessing that it needs block plates to install. As I see no motor mounting points. Also what is the bore on that motor.
That would look nice sitting in my ChevyII

PS. it was nice chatting with you mick53

Never inquired about the cost. I was just impressed that it had been done and they didn't have any problem making more.

Nice thing about a custom billet block is that they could add any detail you'd want including motor mounts.

As far as bore size, when I ran an aluminum Duggan engine, it had a 4-1/8" bore. That's probably the max with the stock 292 bore spacing.

You know what they say, "If you gotta ask then......."

The cam could be made. At first look, the pushrod angle does not look severe. One of the hardest parts would be the custom side cover. One that joins the head and factory side cover area on block.
Looking at that billet block has me thinking. Might have to draw up a small one and play around in the CNC.

Mick53,

You had me @ 'Quickchange'!


Bruce Schneider
Gearhead's Quickchange Exchange

They told me base price on the igor block was $15k. Waiting to hear from them it may not be a water block.

Tom - Can you beat that quote???

I saw several billet aluminum 4 cylinder Chevy race blocks at Joe Deppe's place when I bought the Duggan 12 Port Head casting patterns from him. He said it cost him just $2500 each to have them made. So a 6 cylinder shouldn't be a lot more to have done.
The LSM blocks dont have the same bore spacing as the factory blocks do because they are 4.250" bore. So a longer crankshaft and cylinder head will also have to be made also. Every component in them is custom and has nothing in common with the production 6 cylinder except it has 6 cylinders.

Casual 6
Yeah I heard it was close to what you said. when I first hear about IGOR I did a little digging found what they spent on that Build. Yeah that's a Dream build right.

Your right on that Scott Everything they did for that motor was custom Just for Racing. Yeah but did those Deppe block's have water jackets Or pretty much a solid block Running a Elky.

Yeah mick53 I know But by the same token If you don't ask Ya Never know . lol

Also if that motor is a solid piece of billet How did they get a water jacket in it?

I have seen billet water blocks made in sections.

They also have wet sleeves in them and have water flow around them. That's how the 4 cylinder blocks were done. Kinda' like how a diesel is. Removable liners that interlock in the deck. But most billet blocks I've seen are solid and intended for short duration racing and for use with Methanol or Nitro as a fuel.
The IGOR block and other components were a true one off, and there really wasn't any other way to make them for it's intended purpose.
That makes a cast block more advantageous because, while many things can be made billet, I do it professionally for a living everyday, many things just aren't practical to be made that way.

here are the flow numbers on my head. 340 CFM I / 220 CFM E according to Leo.

That's looking sweet!

Is that someone else's shop? Looks like a Precision Matthews lathe.

Interesting - a ported 4200 head with 1mm OS valves will flow that also....

Glad you started this and hope it is still progressing. An awesome look at what it 'really' takes to put this together.

I was looking at an LS head cut/weld, it even has 4 bolts per cylinder like the 292. Then I laid the LS gasket on the block and everything looked good.... except one row of bots were outside the solid area of the block.
The bolt lay out of the originals does not really suite cross flow heads. The SBC head conversion sort of works around it, but the passenger side of the block simply does not have enough room for pushrods and free flowing ports. The canted push rods on your set up give some guidance on how to get around it.

I've given some thought to OHC conversion, it would not be particularly difficult on the block side, but as noted a totally new cross flow head based on LS ports with repositioned bolts would be needed to take advantage of it.

But keep on going!