Billet Aluminum FE Block (Coming Soon!)
Provo, Utah. February 19th 2006.
Fellow Car Nuts,
I am VERY, VERY happy to announce the new Kirkham Billet Aluminum 427 engine block. I have wanted to do this for years and we finally had the opportunity to make one of my dreams come true. We did extensive engineering and design work to take out all of the excess weight we could find. If you look closely at the intake galley, you can see we even surface machined the lifter area to take out all of the weight possible. The picture you see is of a wooden block that was used to prove the CNC tool paths and tool clearances. We have a 2nd wooden block we are finishing right now in the machine. Our first ALUMINUM block should be done this week. We will assemble and run the block to make sure everything works. We should be in production in 4-6 weeks. We had special FORGED billets of aluminum made for the starting blanks. This is the block we have all been waiting for! Finally, big block acceleration with BETTER than small block handling. I am so excited I can hardly stand it.
Thoughts behind the block:
A couple of years ago we had the idea to make billet brake calipers. I was tired of all of the problems we were having with the castings--long lead times, porosity, sand inclusions etc, which led to a big pile of junk calipers that we had spent a lot of money machining on, but were useless. But the biggest complaint we had with the original calipers was the cast aluminum flexes excessively under heavy braking--especially if the calipers are hot after a few laps. Not that anyone felt there was anything that could be done, they just thought the brakes on an original Cobra stunk and that was it.
There had to be a better way.
After much research, we found the thermal characteristics of cast aluminum are terrible. The modulus (stiffness) of cast 356 T-6 is quite low (at room temperature) and its stiffness at braking temperatures makes you wonder if Playdough wouldn't be a better material choice. Combine that with the porosity that naturally occurs in all castings (porosity=holes=no material=very low stiffness) and you get a caliper that flexes more than an early morning aerobics class.
There HAD to be a better way.
We have very advanced CAD/CAM capabilities here at Kirkham Motorsports and so we thought we would give making billet aluminum calipers a try. The programming was intense, but in the end, we "surface machined" the calipers so they look IDENTICAL to an original cast caliper. The calipers had to look identical to originals to pass tech in Europe where after-market brakes are banned from competition.
When we finished the calipers we sent them out to a customer in Europe to test at the demanding Nuremberg circuit. The tests were unbelievable. Our customers were AMAZED by the qualities of our billet brake calipers. During actual racing conditions, they were able to REDUCE brake master cylinder sizes, DECREASE pedal travel and experience NO caliper fade for the entire race. But, most incredibly, they were able to use braking points a full 15 meters LATER than the competition (almost 3 car lengths!). The calipers worked so well, after the race, our customer's car was hauled back into tech to see if he was running "cheater brakes." As our calipers look identical to original calipers no one could tell they were billet. Bottom line--the billet calipers simply don't flex as much as cast calipers--especially under the conditions (temperature) that the calipers are actually used at.
So...I got thinking...
I explained to one of our customers the advantages of the billet calipers and asked him if he would be interested in a billet engine block. He is having us make the ultimate Killer Car and simply wants the best that can be made (within reason). He gave me an enthusiastic YES and so, characteristically, I jumped into the deep end of the pool--with out checking for any sharks or alligators before hand.
A billet block presents some very difficult challenges. Water is, of course, the big challenge. How do you get the water from here to there without leaking? Well, I got thinking about Caterpillar engines and some of the old time engines I have seen in the past. They all had bolt-on water jacket plates. I figured if Caterpillar could bolt water jacket plates on the worlds biggest, toughest engines...then, so could we. (You can always see further standing on the shoulders of giants.)
Problem 1, keeping the water in the block--solved--sort of. There is still quite a bit of extremely difficult machining to get all of the water passages to "communicate" with each other. Now, next problem...keeping the water OUT of the cylinder bores.
You have to cool the cylinder bores to cool the block, but you obviously don't want water to leak into the bores. So, you basically have two choices to solve the problem--wet sleeves or dry sleeves.
Caterpillar uses wet sleeves. In a wet sleeve motor, the water actually touches the cylinder bore sleeve. The block casting is bored out straight into the water jacket. The cylinder sleeve is pressed in with o-rings in both the top and the bottom of the block to keep water from leaking into the cylinders and causing all sorts of havoc with your motor--and your wallet. The sleeve actually only touches the block on the top and the bottom of the block. Because water surrounds the sleeve all the way around the bores this is a very effective method of cooling the engine--think bulldozers in Phoenix.
A dry sleeve block actually has the block metal all the way around the sleeve. When the block is bored out to accept the sleeves, you never (hopefully) hit water. (Good thing in Saudi Arabia--bad thing in dry sleeve engine blocks). So, to cool the block, the water has to cool the block material, pass across the sleeve/block boundary, and then cool the motor. If that sounds like a heavy, bad idea for cooling a block it is--in theory--but in practice, many millions of very successful blocks are done this way.
A more interesting question is, “Why put sleeves in a motor at all?” Well, it is cheap and it works. Additionally, because there is extra material around the sleeve in a dry sleeve block, the bore is actually stronger as block material itself supports the sleeve.
Nevertheless, a particularly vexing problem with sleeves (wet or dry) is the different coefficients of thermal expansion (how much something expands when it is hot) between aluminum and iron. The coefficient of thermal expansion for aluminum is around 2 times greater than it is for iron. That means aluminum grows twice as much as iron when it is heated up--and engines get hot. This problem is compounded by the fact that iron sleeves (which don't grow much) are surrounded by an aluminum (which grows a lot) block. I have seen cylinder sleeves literally fall out of bores when the engine is hot. (You see lots of interesting things on a dyno).
Isn't there a better idea?
Nikasil. Nikasil is a silicon carbide coating that is plated on to the cylinder walls. It is extremely hard, some what porous (holds oil very well) and wears like, well silicon carbide. Nikasil was invented in WWII for aircraft engines. Actually, the process was top secret for a long time. If you remember, in WWII whoever won in the air won on the ground and such performance enhancing modifications were very closely guarded secrets to prevent the English from speaking German.
The thermal conductivity of Nikasil is extremely high. That means it is very efficient at cooling the motor. Nikasil is also extremely light. Cast iron sleeves are very heavy. Isaac Newton proved 350 years ago F=MA and if we can reduce the M (mass) that goes a long way toward improving the A (acceleration). (F stands for force, or in our case that can loosely be correlated to the force or power of our engine). So, as weight goes down, "power" and "acceleration" proportionally go up. This works on humans too--but since making the block 80 pounds lighter is easier than making me 80 pounds lighter I decided to put the block on a diet instead of me.
The whole point of this experiment is to take all of the weight possible out of the motor while keeping it reliable and durable. There is a tremendous amount of material left in most block castings simply because they don't want to take the time to remove the extra metal. If you look closely at our gallery on our web page, you can see in the intake valley we removed all the material we could around the lifters. We did the same process all over the entire block. That is how we got the block so light.
A particularly cool understanding of Newton's laws occurs when we drop the pedal coming off of turn 24 at Miller Motorsports' track and see the wide open straight away (3/4 mile of pure glory) in front of us. Where else in this world can you run out of courage before you run out of straight?
A more subtle understanding of this sinks in when at the end of the straight you realize you can turn (lateral acceleration) much harder if you don't have all of that weight pushing you off of the track--something I am personally familiar with. That is why lighter cars, as a general rule, handle better. Our cars will pull over 1g of lateral acceleration in hard corner. That means you, and your passenger if you have one) will experience the same amount of force trying to throw you out of the car as you feel pulling you down in the seat. It is an unbelievably cool sensation to feel the car turn harder than you thought possible.
We hope this new billet aluminum makes all your dreams come true.
- FORGED billet aluminum
- water cooled
- 4.25 inch, Nikisil lined bores
- 1 piece bottom girdle with integrated main caps
- Will take standard heads, bell housing, intake manifold.
- Anticipated price $4,995 (final pricing will be determined when we see how many actual hours of spindle time it takes to make the block).
- weight 79 pounds!!!
Here are the weights of other common engine blocks:
- original 427 cast iron block (with caps) weighs about 190 pounds.
- cast aluminum Dart 351 small block weighs 100.8 pounds.
- billet aluminum Kirkham FE block (with caps) 79 pounds!
Click on the pictures below for larger images.