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The Buchka 242 Fake Racecar

Thanks Pat. The tube sizes and basic geometry are from the FIA Group N manual. Not building it to fit into any certain racing class, just trying to make a safe cage that won't become a box of spears in the event of a roll-over or collision.
 
More tubes:

2013-01-10%252023.00.48.jpg


2013-01-10%252022.51.58.jpg


2013-01-10%252022.51.43.jpg


The tube that goes across the front of the windshield is bent and notched, just needs a little more trimming to fit in. The first batch of DOM tube is now all used on the car. Probably going to need an extra 60-80ft to finish up the entire cage structure.
 
FYI, you really should grind the fishmouths back until they are full thickness. Welding them like that, you either need to back way off on the pedal in order to not burn the edge of the tube away because it is so thin, which means the effective weld cross section and tube wall thickness of that part of the joint is much less than nominal. Or, you have to "chase" the melting away edge around the pipe which is also not great.

Awesome to see progress though! :cheers:

More tubes:

2013-01-10%252023.00.48.jpg


2013-01-10%252022.51.58.jpg


2013-01-10%252022.51.43.jpg


The tube that goes across the front of the windshield is bent and notched, just needs a little more trimming to fit in. The first batch of DOM tube is now all used on the car. Probably going to need an extra 60-80ft to finish up the entire cage structure.
 
FYI, you really should grind the fishmouths back until they are full thickness. Welding them like that, you either need to back way off on the pedal in order to not burn the edge of the tube away because it is so thin, which means the effective weld cross section and tube wall thickness of that part of the joint is much less than nominal. Or, you have to "chase" the melting away edge around the pipe which is also not great.

Awesome to see progress though! :cheers:

Thanks for the tip Kenny. I've encountered both of those issues before. I just don't do much tube fitting so grinding the fishmouths back never occurred to me. *facepalm*

how do you bend the tubes?

Siliconesand and Fire? Or do you have a bender?

JD-Squared Model 3. It's a really high quality machine.

http://jd2.com/p-32-model-3-bender.aspx
 
Bit of a change of subject -- do opposing pistons share a common crank throw (odd-fire) or is it an even-fire crank? I know there's a balance shaft to deal with the 60 degree/V8 dynamic balance issues, I assume it's also odd fire and the balance shaft deals with that also. All of that to ask -- what's the exhaust note sound like on one of these?
 
Bit of a change of subject -- do opposing pistons share a common crank throw (odd-fire) or is it an even-fire crank? I know there's a balance shaft to deal with the 60 degree/V8 dynamic balance issues, I assume it's also odd fire and the balance shaft deals with that also. All of that to ask -- what's the exhaust note sound like on one of these?

The crank pins are split, making it even fire. You can see the pins here:

photo%25202.JPG


This is the best exhaust video I've been able to find. I think it sounds good.

<iframe width="640" height="360" src="http://www.youtube.com/embed/rSDtrCxpKKI" frameborder="0" allowfullscreen></iframe>

Noble M600 videos aren't really indicative because of the turbochargers.
 
I've heard the V8 uncorked a few times, when replacing cat-back exhaust systems on them at the dealer. Sounds pretty bad ass, unfortunately couldn't drive it around like that, but revving it sounded wicked. Really wanted a Bertone that sounded like that...:-(
 
I couldn't help myself so I hung the front wheel on there with a piece of string. It's a little too high where it's sitting but it paints a good picture. Gave me a real boost of motivation.

2013-01-12%252023.34.23.jpg


Measured the cams:

2013-01-11%252015.35.55.jpg


lift%2520chart.PNG
 
The crank pins are split, making it even fire. You can see the pins here:

photo%25202.JPG


This is the best exhaust video I've been able to find. I think it sounds good.

<iframe width="640" height="360" src="http://www.youtube.com/embed/rSDtrCxpKKI" frameborder="0" allowfullscreen></iframe>

Noble M600 videos aren't really indicative because of the turbochargers.

Cool! Any pics of the balance shaft wackiness?

Thanks!

-Ryan
 
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