Boat Designer vs Car designer

Hi Guys,

If you are a boat designer, please do not attempt to build a car.

There is a difference you know

 

looks like a mock-up, or perhaps a frame to make a fiberglass body.

 

The bloke eventually decided to take the wood out and put some other stuff in it. One can see he's got too much money, and not from South Africa for sure, nobody here has that kind of money except government officials and they don't build anything, and there are too many potholes for a car like that.

Never the less an excellent job. If that was a boat of the same size it wouldn't have fitted in the work space

Oh yes, it must have been built in a place where there are lots of pipes

 

looks like a home made Lamborghini.

 

That's a tried and true technique. I've done it with MDF and foam. The last was a sand rail body.

 

Thats one mean looking engine with its fancy plumbing for an exhaust !!

 

Looks to me like this guy could have built a car or a boat.
What were you yammering about?

 

Those exhaust headers are 180 degree scavenging and tuned. These, by their nature have to have this spaghetti look to them, particularly under a body like that. I've seen a lot worse.

 

So what does all that mean ??

 

It looked like he knows car building.. thats pretty much how hand made car is done IMO
BR Teddy

Like PAR said it..

 

tuned usually means the length all match and are selected to optimize power at a particular rpm range. Looking at the length of them I would say they are going for as much torque as possible in the lower rpm range.

"scavenging" is the term used to describe the effect of tuning the exhaust pulses so when the exhaust valve opens you have a low pressure node right at the exhaust valve so it speeds the removing of the exhaust gases, and actually can pull more of the exhaust out of the chamber than the piston can actually push out alone. the low pressure pulse comes from the natural harmonic of the gases going out of the header, the rpm that this occurs at changes with exhaust pipe length.

The difficulty is to make all that length of header tubing fit within the space available, so that is why is it such a tangle mess of pipe. quite a bit of welding bending and cutting of short little bent tubes to make a custom header like that. Production headers have each tube bent with automated machine so they only need to be welded at each end.

 

Great job done there!! Probably would not perform very well in a crash-test, but nevertheless it is a really nice piece of mechanics.

Those tuned exhaust pipes also look gorgeous, I would put a transparent hood to let the world see that artwork!

 

Petros has it down pretty good. Scavenging can take place, just by placing one pipe next to the other, but it's more efficient if you pair cylinders 180 degrees apart in the firing order, so their sequence in the reciprocating order, will best benefit each other. This trick will improve mid and upper RPM range performance. It does depend on how the crank is arranged, but in American V8's use a "cross plane" design on each cylinder bank, which delivers uneven exhaust pulses. The really impressive thing about this arrangement, and the reason I mention it is a typical 180 V8 header setup requires ridiculously long primary tubes. On this engine they are able to snake around, over the transaxle, so the runs are shorter than typical, which equates to good power at the RPM range this trick is most effective. I've seen this tried on Mustangs and Camaros, where 50" long primaries wiggle down around the full length of the transmission, K frame, etc.

I disagree in that this wouldn't fair well in a crash. It looks to have a couple of aluminum tubs and substantial A and C post hoop triangulation, which will make a stiff and strong chassis. Obviously the engine is high output, the ZF transaxle looks inverted (the fast setup) and has quad trailing links with coil overs and quad struts, so it's intended to be very tunable and handle some serious HP. I wouldn't have used the Lamborghini Countach body, as there have been several much better looking bodies since, though we don't have a date on the image, so . . .

 

Well, PAR...

 

The plywood form buck is used to fit aluminum pieces shaped by an English Wheel, right?

A guy in another forum did a rare racing Jaguar from the 1950's this way.