#151
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On the subject of airflow, many including myself have made the rookie mistake on their first racecar of thinking that 1/4" screen being much larger than standard window screen should be a good choice for airflow in front of the radiator. It is not, it will overheat in no time, it takes 3/8" or better. An experiment of putting a room fan in front of a standard screen and blowing through it will reveal that virtually no air goes through it. This is the same concept that gun silencers use. Even though that screen has probably 80% open area, it has nowhere close to 80% air passage, but other shapes or sizes could have much better to equal passage and airflow. That is the lesson here, open area and airflow do not always equate equally.
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Charley Strickland |
#152
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Full Sized Miura Rendering
As I get closer to needing the think about the Miura bodywork, I thought it was time to get a full sized rendering to work from. Here it is hung on the garage wall.
Superleggera (AKA Mark from Modena West) recommended and helped me with this by providing a high resolution picture as a starting point. I added a 4 inch grid of 1 pixel wide lines over the picture in Photoshop prior to printing. These lines make it real easy to take measurements directly from the printed picture. I converted the picture from color to black/white thinking it would be cheaper to print that way. It wasn’t as the business where I had it printed could only do a 48 inch wide print on their colored printer. The car is 44 inches high so I couldn't get it full sized on narrower paper. It’s printed on heavy, glossy paper so it should be fairly durable. Getting it printed wasn’t cheap but I’m sure having this hanging on the wall for reference will be well worth the cost.
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Joel Heinke Be original; don't be afraid of being bold! |
#153
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Wow, that should really help save a lot of time and take a lot of guesswork out. Did think about printing it up in the larger scale that you're building too?
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Marcus aka. Gojeep Victoria, Australia http://willyshotrod.com Invention is a combination of brains and materials. The more brains you use, the less materials you need. |
#154
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The print is the larger sized Miura version I'm building. It is 104" wheelbase (versus 98") so the 4" grid lines right up on the wheel centers. I'm already taking measurements off the picture wheel centers for the chassis structure for mounting the radiator
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Joel Heinke Be original; don't be afraid of being bold! |
#155
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Artwork is full-size -- ie: 1-1 scale.
Advantage of the 1-1 sized artwork is obviously as Joel is doing -- the measurements are the same to the real thing. Other perk is as one starts building the structure for the bodywork itself, just move the artwork behind the car and (from a distance) eyeball them together for general lofting and as the aluminum skin is created. Thus the human eye is just doing a "comparison" between forms. Much better results occur versus "just eyeball engineering it".
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• me: Mark • home: Dry Heat, Arizona USA • quote: What did you design or build today? • projects: Curve Grande and the 11Plus Le Mans Coupe |
#156
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Perfect.
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Marcus aka. Gojeep Victoria, Australia http://willyshotrod.com Invention is a combination of brains and materials. The more brains you use, the less materials you need. |
#157
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Quote:
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John EK Holden V8 |
#158
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Chassis Front Extension Fabrication
The Miura chassis needs to be extended forward to provide a radiator mount and a mounting point for the tilt-up front end body work. In other words, a chassis structural mount for everything in front of the front suspension. The current Miura chassis ends just in front of the steering rack and it needs to be extended about 2 ½ feet forward. The chassis extension needs to be strong and rigid so the front clip won’t flop around on rough roads or from wind gusts. In addition, I’d like to mount the battery up front so I’ll also be looking to make a battery box integral to the new chassis extension.
The chassis extension will connect to the existing chassis in 6 places. I’m designing the extension as a “bolt-on” in case it needs to be removed at some point in the future. ¾” by 1 ½” rectangular aluminum tube is being used for the structural parts. The first step was to locate mounting points for the bottom four tubes such that they would not interfere with the steering or suspension. The topmost two tubes (not included yet) will serve as triangulation for the middle tubes. The two bottom tubes are welded to ¼” plate for mounting and for the middle tubes I inserted ½” aluminum blocks into the ends so they wouldn’t get crushed by the bolts going through them. The bottom tubes are mounted under the A arm pivot points so they would stay clear of the suspension and steering. Because of this inboard mounting point, they needed to angle outward for alignment with the middle tubes. Next I put a series of pie cuts and welds in the bottom tubes to provide more ground clearance in front of the radiator and to line up the front portion with the middle tubes. I then scouted up an old battery to use for the battery box design. There should be just enough clearance for the battery terminals under the spare tire if the battery box bottom is placed at the same level as the chassis bottom. I’m locating the battery on the passenger side in order to offset a portion of the driver’s weight in the car. I’ll post more updates as I make progress.
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Joel Heinke Be original; don't be afraid of being bold! |
#159
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while building that structure, think about how you will support / attach the headlight assemblies and hinge points for the tilted nose.
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• me: Mark • home: Dry Heat, Arizona USA • quote: What did you design or build today? • projects: Curve Grande and the 11Plus Le Mans Coupe Last edited by Superleggera; 10-28-2018 at 02:58 PM. |
#160
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Quote:
Speaking of headlights... look what I was able to obtain recently. Yes, two complete headlight units from a Fiat 850 Spyder. The good news, they cost me less than half of what I was quoted from a Fiat parts source in Italy. The bad news, I probably paid as much for these headlights as a complete, running Fiat 850 sold for in the '60s. I tried finding some Porsche 968 or 928 headlights but didn't find any that were going to be all that much cheaper than the Fiat units and I don't think they would have looked correct anyway. The glass on the 850 headlights is oval shaped and the Porsche lights have round glass. It's a subtle difference but I think it would have been noticeable given these sit right up on the most visible part of the front clip. My thought is that the headlights on my Miura will mount in the framework that's part of the tilt-up bodywork and thus not on the chassis framework. Can someone who's familiar with the original Miura confirm that is where the headlights were mounted?
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Joel Heinke Be original; don't be afraid of being bold! |
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