Australian Belly Tank

[Sumner]

One note though on that thought is on page 128 right before section 3.4 he talks about a Yakel body, which looks somewhat like a lakester to me and he mentioned that type body on a b'ville type car (I couldn't find a picture) that went 248 mph on about 160 hp (I'd like to know which car this was).  Anyway the body had a drag of about 0.17 at a ground clearance of 10.2 cm (4 in).  The drag decreased about 6% when the body was lowered to a ground clearance of 7.6 cm (3 in.). This seems to contradict what he says elsewhere in the book.

Well maybe I can answer my own question.

   

Looking at the Lynn Yakel designed Larsen/Cummings car I can see why lowering it helped with the drag.  It has a pretty flat  bottomed/wide body that would respond to keeping the air out from under it.  Now most of the solar cars have a similar shape, but the wheels/tires they run allow the body to be raised quite a ways off the ground, which is pretty impractical with a car like the Larsen/Cummings streamliner.

I think with a narrow/rounded body (tank) car it is best to keep it off of the ground by at least 5-6 inches.

c ya, Sum

[Dr Goggles]

......nice car , canny competitor...I like this quote from F.L about rear engined cars

"?You?re sitting so far forward, you don?t know what?s happening back there. That?s why I built a slingshot?my streamliner. If the rear wheels move an inch, your butt moves an inch and a quarter.?

I've been struggling through "The Leading Edge" .........it's , um ,dry...

So you'll be looking down on us Sum' ?, I just hope we're passing you at that moment ..............  

[Sumner]

   

Fred Larsen said ?You?re sitting so far forward, you don?t know what?s happening back there. That?s why I built a slingshot?my streamliner. If the rear wheels move an inch, your butt moves an inch and a quarter.?

They say a front cockpit car is harder to drive or at least you find out you are in a bad situation late in the game   .  For those of you that would like to read the Rod & Custom article about Fred Larsen you can find it ( HERE).  Harv thanks for reminding me of it   .  

I've been struggling through "The Leading Edge" .........it's , um ,dry...

I didn't do too bad in math in school, but I skip most of it in that book.  Makes it much faster to get through to the conclusions   .

So you'll be looking down on us Sum' ?, I just hope we're passing you at that moment ..............  

How high is it to the top of your car?  I'm about 35 inches to the top of mine with the bottom 6 inches off the ground.  I don't think they allow passing on the salt   , besides I'll be about 12,000 miles ahead of you or behind you     .

c ya, Sum

[Dr Goggles]

you wrote " besides I'll be about 12,000 miles ahead of you or behind you"

D..oops I mean, Touche!  

[Reverend Hedgash]

Thanks for the posts on ground clearance everybody.

The decision for this year will be to cut back to our 50mm (2 inches)  height from the ground as planned to just get the thing there and moving.

It is a relatively easy operation to lower the axles in the future to raise ride height if required and the base of the car will remain the same relative to everything inside. (Its dictated by our bum in the seat too, both of us are 6 foot one and so getting us to fit in the front was a juggle of many figures. )

We feel that the roll bar treatment of many contempory belly tanks has been their weakest feature so have really concentrated on getting the looks of this right, and making it as low as possible. Its lines will be expressed in the canopy and in the future livery.

The windscreen is yet to be made, any information given here would be greatly appreciated. We are thinking that the process will be to make a mold and have something vac formed over it.

Other thoughts were a sailplane canopy if one flukes our dimensions.

For this year we will get a motorcycle windscreen as a temporary measure with some polycarbonite bent over to fill the gap and secured with straps.

You will be looking over us Sum, by an inch and a half. Our dimensions are as follows:

At 50mm ground clearance our heighest point is 880mm (34.6inches) from the ground which is roughly the top of our rollcage.

The original tank is 810mm (31 inches) at its widest point one third down the length and is 4200mm (165 inches).

We are running 28inch Goodyear Landspeeds on the back which run at about 27inches the centre of which sets our centre line forthe tank at 13.5 inches.

We have 26inch Mickey Thompsons at the front and with our axle Holden stubs arrangement have the front axle just below centre.

Our track width is the original ford rear end width, although when we had the wheels made (ford with kombi rims) we had the rims offset to better hide the drum brakes at the rear and to minimise track width.

We had our front axle made to match the track of the rear axle.

We had a lot of discussion over whether to make the rear track narrower by chopping the axles in order to help directional control but decided keeping the wheels in line were better for streamlining and something we could do later if needs be.

Also the advantage of keeping the wheels wider should reduce the effect of the turbulent air from the wheels on the body's airflow. Also it should help stability in a spin.

The penalty of increased frontal area is marginal as it is a few inches of rounded axle only.

Reverend Richard Hedgash

[Sumner]

   

The windscreen is yet to be made, any information given here would be greatly appreciated. We are thinking that the process will be to make a mold and have something vac formed over it.

If you look at my "links" on my site ( HERE) you will find one link on vacuum forming and another on blowing a canopy.

I'll also PM you a couple paragraphs related to the subject I have.  I'll have this same problem ahead of me, but I'm not very close to having to solve it at the moment.

I'll be anxious to see how you guys do with the car.  Good luck,

Sum

[Reverend Hedgash]

Thanks Sum for the windscreen bumpf. Good stuff in there. I wonder how optically pure doing it this way is though?

We have had a diversive set back:

Building a car is one thing, then there is the trailer to put it on (in) but we didn't expect we had to rebuild the bloody tow truck as well!!!

Its been a bad Christmas break for the truck.

Firing badly, hole in the extractor, and using way too much gas (Runs on natural gas not gasolene). The engine was tested and found to be low on compression and the decision made to finally replace the donk. Have gone for a chevy 350V8, new carb and electronic dist. with Vortec head, roller rockers etc.  Will ebay the old one.

Dr Goggles pulled out the old engine today and found the clutch also needs replacing. sheesh.

Now this truck was my home for three and a half years so I have a lot of fond memories of it (and some crap ones too) so I having decided to bring it up to speed, I have decided to do it properly.

Its a 350 Custom 30 Chev tray with a step through motorhome on the back. Sleeps four and has shower kitchen and toilet.

Have been meaning to do a number on the interior but nothing really done as yet. Focusing too much on the belly tank.

Shall paint the Reverend Hedgash Dr Goggles racing team logo and maybe some flames on the white body too. Crossed racing flags at the front. Has some very nice striping done at present. A little more Urban Cowboy than von Dutch...

Still, should trick up nicely to be a salt lake push truck / team headquarters and home away from home.

Shall post images of engine install as we go.

Its a never ending list to get there isn't there?

Reverend H+.
Financially exhausted!

[Dr Goggles]

$@#^@@!$%@   ....second motor I've hoisted this week in the team daily drivers.....correct on all counts though 'Gash.........the transplant'll be done tomorrow God( he drives a Chev apparently) willing..it should be good for roll-backs with the new mill..ta for the blow mould info Sum' you're a right fount. Got sunburnt today and it's 35 tomorrow

[Seldom Seen Slim]

Rev. Hedgash -- you say you had a natural gas vehicle -- but do you still have one, now that you've gone through all these changes?  I ask because my '89 GMC Jimmy has a natural gas setup that I haven't used since they took away the only compressors for 200 miles.  that was at least fve years ago.  If you wanted something from the old beast -- I'd be glad to think about sending it your way.  I've got the two gas bottles, for instance -- unh, I think they're 10L each (range of the vehicle was about 80-90 miles on CNG).  They're located inside the cab of the vehicle -- won't have any corrosion or nasty crud on 'em.  

The gas injection system and all electronics are still intact, too, although I doubt they'd be worth a whole hell of a lot -- the conversion was made in the early 90's, and so is probably a few generations out of date.

Sure did like CNG as a fuel, though -- at 100,000 miles the factory spark plugs were still fine -- still white, still had sharp edges on the electrodes.  I replaced 'em mostly 'cause I wanted to have 'em as souvenirs to show folks.  Too bad I didn't buy that small compressor and install it at my shop -- fuel with no road taxes is WAY cheaper than what you buy at the gas station.

If you want the tanks or are interested in anything that might be on the truck, let me know.  I use the truck (on gasoline) as my snowplow truck, so you can't have the motor, though. . .

[Reverend Hedgash]

Thanks for your offer Seldom, very generous indeed.

Unfortunately I probably didn't make clear that our truck runs on LPG (liquid Petroleum Gas) which you may know is a bit different to the stuff that you are talking about.

I am continuing to use the set up, in fact it is duel fuel in that I can run it on both LPG and petrol. LPG is much cheaper than petrol in Australia.

I have to do this because although LPG is available pretty well Australia wide, the last station from Lake Gairdner is 250 km away, so a round trip is 500km plus the daily running and the truck just doesn't have this range.

(For those coming petrol is available at the station property at Lake Gairdner.)

I have two 60 litre tanks for the gas and one 40 litre tank for the petrol. That gives me room to move and ability to refill from jerry cans etc.

The engine is now in the Chev,  Dr Goggles had to work in 40plus degrees centigrade (over a hundred degrees F) for the past few days under the truck. As soon as you put a tool in the sun it became too hot to handle.

42.5 degrees today.

The old extractors are stuffed so new ones being considered.

Thanks again Slim.

Reverend H+

[Dr Goggles]

...just like one of those bad dreams where the beastie is after you and your legs ..just ...don't...want....to....work...fast....enough...Speedweek looms at Gairdner and nothing has happened on the car for over a week..re-motoring the Chev' outdoors in searing heat sapped my energy something severe...Sunday was 43 degrees C ( that's like 200 F, well almost) and all I could do was look at the 'tank and mutter to myself , I sat in it and it all seemed wrong     .... As the arch conundrist Jack D said...we Aussies need more events during the year to develop our rides....last years meet seems like weeks ago but having to wait until 2007 if we don't get the car there this year is doing me head in!!!

If praying is your thing keep us in mind

[Dr Goggles]

We've buckled . The Jarman-Stewart bellytank won't be going to Gairdner 'til 2007 . I doubt there are many of you who watch this board who don't understand the pressure , expense and effort of designing and building something by yourself out of your own pocket .

We all need a holiday and there's no better place for one than Lake Gairdner during Speedweek.    

In the dumps but in a way relieved too , call us weak , we don't care we'll be there next year and by then we'll be well sorted .So hang it on us now ,we need a good laugh .

Dr Goggles ( no , the Doctor is OUT!)

[JackD]

A lifetime work is just that and deserves all the time you have
 over what ever length it takes for your satisfaction.
  Don't be consumed by it.
You are not playing to anybodys schedule but your own.
The idea is to get it ready for an event but never call it finished or you will be.

[Reverend Hedgash]

It is true.

We have decided after more than two years of weekends of hard work and a desperate escalation in work rate over the past few months to acheive a runner for 2006 that it will be not in the interests of the sport or us to rush the completion of this project.

We have always designed with the triangle of Safety - Speed - Beauty foremost in our mind.

Although we didn't expect to be hitting big speeds this year, just hoping for a run, we feel that with so much to do we would significantly reduce the craft of the project, potentially the safety and definately the beauty if we worked desperately to get it ready over the next month.

It wouldn't be the Land-Speed Racing way, hey?

Thanks everyone for the input thus far. We will definately be pestering you for another year now as rookies.

It is a great obsession. We are both devastated but know it is right.

We can lighten up a bit now and spend a bit of time getting ready for the trip to the salt sans car (a two day road trip), finishing the truck, developing our menu, building some nifty things for the salt.

For example we saw the fantastic blender with the motorcycle handle throttle on Mark's video of Bonneville. Hilarious.

Can also find the time to watch the Ack attack run which will be a real treat.

Thanks for your comments Jack. Take it at our own speed, yes.

I can enjoy it more and not be so stressed about it now the decision has been made. That is what it is all about.

Reverend H+

[JackD]

You guys are going to be vicious spectators that I wouldn't wish on anybody.
 Armed with a camera, a curious eye, and the time to use it.
 As part of your probation we expect a full report.
 Take a lot of pictures, we can turn them over when they get here.
How else are we going to know you were not just having fun while we have to stay home.
You must realize the blender deal is for medical use only, but you do have a Doctor and a Chaplain along.