Can you imagine a billet Cobra with a billet block? More and more, it is beginning to appear - thanks to the amazing innovation at Kirkham works - the heyday of the Cobra is now, right here in the 21st century!

EDIT: Make that a billet Cobra with a billet block AND a flip front!

Hey Buz, I could not agree more! I think we will see not only Kirkham step it up, but the other major players. The cobra world does seem to have a shot in the arm. Darren

Hey Buz, I could not agree more! I think we will see not only Kirkham step it up, but the other major players. The cobra world does seem to have a shot in the arm. Darren

Thanks for the kind words!

When we were looking through the F1 book we noticed they use wet sleeves. As we got thinking about it we realized we sleeves must have a better thermal transfer than dry sleeves because the heat has a thermal barrier as it tries to cross the boundary between the iron sleeve and the aluminum cylinder bore. Arguments were raised the sleeves could not be stable. However, the stresses on an F1 motor are beyond anything in the world we work in so that was dismissed. We figured, "Why not try it."

We added webbing in the valley because we completely removed all the support for the cylinder banks when we hogged them out.

The block is billet so we can change anything we want. We are not locked into any casting.

The final weight, with the sleeves and the girdle, should be about 95 pounds.

David
:):):)

Thanks for the kind words. We will see what the future brings. We have lots of other projects on the burners.

David
:):):)

Caught the attention of the FE Forum.

http://www.network54.com/Forum/74182...illet+FE+block

http://www.network54.com/Forum/74182...illet+FE+Block

Thanks for the heads up and the links. I'll head over there and answer questions as well.

David
:):):)

You know you're going to want to get David to make you a set of Kirkham billet SOHC heads to go with the block. ;)

You never know what is on the drawing board... **)

David
:):):)

Here is a video of us doing the final design tweaks and the final CNC programming of the block girdle. We got the idea of a mains girdle from looking at an F1 block. Also, and critically, we were able to cut the size of the billet down to keep the hardness in the center of the block as high as possible.

David
:):):)

So David, with all this F1 techy stuff, are you going to be able to spin it up like an F1 engine;)?

Very impressive machine work... it will be interesting to see how that mating surface for the girdle performs under load.

David, not having the technical background/knowledge, from both a cost and design point of view, basically, how does machining and casting compare to arrive at the desired end product, as a continuation of KMU Aluminum 201 ?

.......sure is impressive.

F1 engines at red line are music. It is amazing what those engineers have done over the years.

The girdle should perform well. That basic design is used on many high performance engines.

David
:):):)

Castings are very difficult to get right. There is a ton of engineering and experience that goes into making a casting. You simply don't pour metal down a hole and hope for the best. Sprues, runners, risers, gates, temperature, fluidity, chilling, out gassing, on and on. There are many, many variables in casting. Any small problem in any of them can make a BIG problem in the casting. It is not uncommon to throw away 2, 3, or more castings for every good one you get in a complicated casting when you are starting out. One of the big problems is many times you never know if a casting is good until it is fully machined and you find a big surprise (like a hole) on the final cut.

Machining from billet eliminates most of these problems. It does present its own set of problems, like stress relieving (which is a problem castings have as well--you just can't seem to get away from it) but largely the problems are eliminated.

The strength of a casting vs. a billet (referring to typical alloys here) does not compare--especially at temperature (temperature referring to the temperatures we usually run into with automobiles). Castings soften very quickly in the 250 degree range, which is not uncommon for engines, heads, and calipers. As the temperature goes up, the stiffness (and strength) goes way, way down.

David
:):):)

David,

What will the final version of the engine look like in terms of other trick items??

Some items I could think of would be dry sump oiling, Kirkham billet aluminum flywheel, billet hemi style heads with coil on plug and distributor-less ignition with hidden ignition wiring, billet valve covers and intake manifold, ????

So far it is looking pretty awesome. Working at your place would be a dream job for a mechanical engineer like myself. I am beyond envious of Sandwich !!!

We have thought about dry sump, but the cost is pretty high for not much gain (in terms of street use). The Kirkham billet flywheel will certainly make an appearance. I have long dreamed about a distributor-less ignition, but that is just floating around in my head right now. Billet valve covers and a billet intake are on the drawing board.

Our guys seem pretty happy working here. I am not sure why an employer would want unhappy employees. Seems pretty dumb to me.

David
:):):)

It seems our billet block has attracted a lot of attention. The Land Speed guys are carrying on a conversation about it as well. Rick Byrnes emailed this to their group. He said I could post it.

The land speed guys stress their engines more than anyone else. F1 lifts for the turns. Drag Racing (don't want to put those crazy guys down) only hold it for a few seconds--granted those few seconds are like a bomb). But the land speed guys hold the pedal to the metal for 5 miles--flat out--100% of "I'm giving her all she's got, Captain!" They hold that at 200, 300, 400 miles per hour. Truly a breed apart of classic good old American garage engineering. Those guys have a "can do" spirit few can match.

His email to the group starts here:

"I have a little experience with Alum castings. Mostly die cast and Semi
permanent mold, and some with Iron castings.

In aluminum no experience with parts as big as a cylinder block, but having
tested smaller parts ( 4.6L Front cover) that were cast, verses billet, I
found the
mechanical strength of the billet part FAR better than any casting which is
full of air bubbles of various sizes.
Almost regardless of alloy. (I no longer have any data), the density of
the material is so consistent in a billet part, and with stress relieving
and additional heat treat the block will be indestructible. (and very
repairable.)

Besides, they do it because they can.

If you consider this the rapid protyping and very limited production (1 copy
per week or less) I'll bet the cost per piece will beat cast parts including
tooling and the learning process for vents and sprews.

Way back I did a 2.3Liter block for Ford SVO. I was working with and visiting
our engine plant and casting center at Taubate, Brasil on a regular basis.
We modified old water jacket cores, and added lots of iron to the main webs
and skirt, Siamese bores and .750" deck. In all added 26 pounds of Iron.

My point is
The casting/learning process required over 1000 parts to get 200 good usable
blocks. Many times the airbubbles/voids would not show up till almost the
end of the machining process.

I have visited Kirkhams, and looked at their parts. They produce
extraordinary products and I think they are bringing the FE into the present
time. They are using current technology to update the classic powerplant.
I don't think there is much of an economic slump for the folks that can
afford the Kirkham products.

The Billet 427 sure is a perfect engine into their roadster or Daytona
Coupe. Absolutely over the top."

Rick Byrnes

Hi David, loving the machine porn! I do have a question though. It looks like the rear main is machined for the factory type seal. Is this so?

Yes, it is the factory type seal. If anyone has any better ideas, we are all ears! We looked and looked at the seal and didn't see any obvious way to improve it without changing the crankshaft.

On the bright side, the block is billet (not a casting), so we can change it rather easily :D

David
:):):)

The block is amazing, next will be to upggrade the old fe head with a new super high flowing billet head, think of that block, state of the art, with brand new state of the art heads, lots of power to be found in them heads.