momarkmach1,
Nikasil is commonly used on almost all motorcycle engines. ALL race engines use it now. It is a coating that is deposited on the cylinder walls so they can take the friction of the piston moving up an down in the bore.
The coating is completely renewable. We are hoping to be able to get 1/2 a point of compression out of the motor (11:1) and still be able to run on pump gas. But, that has yet to be seen on the dyno tests. The cooling of the aluminum block should let us get away with it. But, all BS goes out the window once we have it on the dyno.
As I talked to Mike Lefevers and Dave Dralle, everyone seems to think with turbos the engine could easily stand 1500 hp, but who cares at that point? If it stands up to 700 I would be thrilled. That is way more than I ever care to use.
MKIV,
Send me along one of those cranks...or better yet, send me the CNC code to make it!
Rsimoes,
Currently max bore is 4.25. Max stroke is 4.25, but we hope to be able to stretch that to 4.375.
Byots,
Yes, the 79 pounds includes the girdle (main caps). I am very sure the Shelby block is heavier than 130 pounds...but, admitedly, I have to check. It has been quite some time since I have weighed one and my memory may not be correct. I do seem to remember, however, I posted the weight of an aluminum block some time back. Maybe I'll do a search and see if I can find it.
I will post the weights of various motors tomorrow. I do have them listed on a spread sheet. We weigh motors and cars all the time.
Lew,
I'll trade a block for a few shoes any day. But I am not sure my wife (or your's) would! I look forward to getting your car back for a diet.
Rick, Sal,
The wood makes a MESS in the CNC mill. I look more like a cabinet maker than a machinist now! Wood chips everywhere! But who knows what we will do.
Mike,
No sleeves. You run the pistons right on the Nikasil. That is one of the reasons it is so light.
Billet certainly is far stronger than castings on most things. Of course, with a casting you can make cores and do all sorts of strange things that for a given project may make a casting better...turbine blades come to mind. BUT, when it comes to aluminum, a billet is almost always better. (I can't think of anywhere it a casting would be better.) The properties of cast aluminum (regardless of the alloy) are quite low. Far lower than you would suspect. At any temperature castings loose their strength and rigidity very, very quickly. At engine and brake caliper temperatures, less than 1/2 of the original strength remains while 6061 remains largely unaffected.
Porosity is the monster that you have to deal with in castings. Where there is a hole...there is no strength. So, you have to make it very, very thick to compensate for fatigue, etc.
David
