Say I have the head design for a v8. Could I add more cylinders, just from the perspective of the top end? Specifically could this be done for an overhead cam engine? Or if I have the heads from a v6- could I add a cylinder to each head? Obviously I wouldn't be tacking another cylinder's worth of stuff on- I know I'd need to recast everything from scratch. But would the basic design remain the same?
Specifically with a v6 to a v8 in a longitudinal installation you'll probably find cylinder 5 and 6 tend to overheat if you just copy the 3 and 4 geometry over.
The second to last cylinder in a bank is the one most likely to run hot, and the problem gets worse the longer the bank.
You'd also expect problems with camshaft torsional stiffness, and of course you will need a new crank, hence possibly new mains.
Any old goon can design it for you, but if you want a design that is likely to work and give you a commensurate boost in power output (given that so far you haven't suggested any specs) be prepared for sticker shock.
I would want to extend an engine 2 cylinders long to 3. At this point would there be significant cooling problems? I would love to keep the same power per displacement. I just have no idea how much this would cost- $1000s, $10,000s, $100,000s, $1,000,000s, ect. Any estimation?
brilliant find. OK, I'm going to guess that butchering two engines into one, that is, finding a way of cutting and joiining the heads and block,is of the order of 50k, plus new cams, plus a crank design. The latter would take a couple of weeks to draw up in the spirit of this design, that is, no sophisticated analysis, so 5k, and 10-30k to make.
Frankly i'd expect an engine designed like that to go round under its own steam, but main bearing life, and red line, are very much open to question I am amazed they put one in an aircraft.
If you actually want a properly engineered design then half a million would be a start, for a set of drawings and calculations. A real production engine program like that would be 100 million or so including tooling.
Obviously all these numbers except the last are WAG.
If I was to copy over the design for more cylinders, without changing the design to keep this supposed problem with the second to last cylinder running hot, what would be the result?
the second to last cylinder will run into det first, all other things being equal, and it'll be the one that seizes. i wouldn't worry about it overmuch, other things will get you first.
