Hank,
Thanks!
acschlary,
I decided against the splayed caps because I didn't see them used in F1 motors. Actually, the one I saw only had 2 bolts on the mains. (mrmax, I will comment more on F1 motors later).
mr bruce,
Thanks for the link!
quickjack,
I do agree.
rsimoes,
Thank you for your kind words. You car is looking KILLER! It will be done in a few days.
mrmax,
You said,
Quote:
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Originally Posted by mrmax
David, you keep mentioning F1 motors while they are wonderous, they only are 3.5 liters (about 210 cubic inches). Pistons the size of maybe a 12 ounce soda can and most likely similar weight. Sure they spin up to 20k rpm but are not likely to produce stresses like 4.25 bore slug and rod combo.
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I imagine you may not be familiar with F1 and the incredible technology that goes into the sport. I have been fascinated with F1 technology, manufacturing, and technology for as long as I can remember. There is NOTHING like it on earth. (Well, perhaps the space shuttle, satellites, and military aircraft--but certainly no automotive engineering).
Just to keep things in perspective, Ferrari is rumored to have spent over $500,000,000 last season alone. (Now, we are talking military size budgets). I have customers who supply F1 with critical components. I have been to their shops, I have talked with the guys who make the parts. I have seen them make the parts. I even have some of their parts. I have seen their secrets (no, I can't tell). I can tell you it is unbelievable. If I could make something 1/10 as nice as some of the parts I have seen I will die and go to heaven straight away. I even keep some F1 parts on my desk to remind me EVERY DAY what the goal is. Interestingly, an F1 rear hub (steel) for $5,000 and it weighs 3.32 pounds (just weighed it) for a cost of $1506/pound.
Below, I have quoted directly from the F1 site.
http://www.formula1.com/insight/tech...fo/11/467.html
"The engine and transmission of a modern Formula One car are some of the most highly stressed pieces of machinery on the planet, and the competition to have the most power on the grid is still intense.
Revving to over 19,000 RPM a modern Formula One engine will consume a phenomenal 650 litres of air every second, with race fuel consumption typically around the 75 l/100 km (4 mpg) mark. Revving at such massive speeds equates to an accelerative force on the pistons of nearly 9,000 times gravity. Unsurprisingly, engine failure remains one of the most common causes of retirement in races." (Rumors are they are actually over 10,000 G's now)--added by David.
A typical engine (that we are used to in our cars) will turn about 6,000 rpms. The G loading according to this website
http://www.eng-tips.com/viewthread.cfm?qid=85349
is about 1,100 G's for a Chev 350--about 1/10th of an F1 engine. (I haven't checked his math, but it looks right on a cursory reading from my past experience). Granted, that is a Chev 350 and our blocks have longer rods and strokes (bore and weights don't have anything to do with the calculations) but let's double the Chev's 1,100 G's and say our monster Billet 427 generates a generous 2,000 G's and we are and still only 20% of an F1 motor. Their engineering is simply amazing.
The stresses on a engine go up with the SQUARE of the RPM's according to this formula. See link.
http://www.engineersedge.com/engine_...automotive.htm
Further, to add to the F1 block's misery, F1 engines are stressed members of the car.
Now, how does this equate to ribs?
Well, a Porsche flat 12 CAN'T have any ribs--by definition--you can't put ribs between cylinder banks that are on opposite sides of the crankshaft. They even have BOLT on jugs! Merlins (60 degree V-12) don't use ribs and they bolt their jugs on too. If F1's needed the strength to hold the heads together and keep the block from twisting, they would tie the heads together. But, they simply run the intake runners straight up out of the head ports and let the heads hang off in space unsupported. Stiffness between cylinder banks simply CAN'T be a problem in the applications we are talking about. How did I decide what to do? I just looked at what was out there, discussed it with very knowledgeable people, and made a decision--admittedly, standing on the shoulder's of giants.
Now, John Force making 10,000 hp, pulling 5 G's??? when he launches probably needs ribs (and a diaper) as I imagine he IS distorting the bores.
David
