Author Topic: MS LIBERTY a Wild Weasel's belly tank  (Read 1097225 times)

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Offline SPARKY

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Re: Rat-a-Tack AA/GL
« Reply #120 on: August 19, 2011, 10:25:49 PM »
Rex,  I wish I could say I planned it--- but the inside of the tires will be about 33-34" inches apart, to clear the 30" dia. frt. body---what I don't know is just how wide the body will be at the rear tires  it will be tapered some, but behind the rear axle I have a water tank---if all goes well this Sunday I can give you a more definitive answer
Miss LIBERTY,  changing T.K.I.  to noise, dust, rust, BLUE HATS & hopefully not scrap!!

"Security is mostly a superstition. It does not exist in nature, nor do the children of men as a whole experience it. Avoiding danger is no safer in the long run than outright exposure. Life is either a daring adventure or nothing."   Helen Keller

We are going to explore the racing N words NITROUS & NITRO!

Offline SPARKY

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Re: Rat-a-Tack AA/GL
« Reply #121 on: August 19, 2011, 10:27:48 PM »
Buddy, congrats on the new Grand--and congrats on the new GRAND RIDE!!! :cheers:
Miss LIBERTY,  changing T.K.I.  to noise, dust, rust, BLUE HATS & hopefully not scrap!!

"Security is mostly a superstition. It does not exist in nature, nor do the children of men as a whole experience it. Avoiding danger is no safer in the long run than outright exposure. Life is either a daring adventure or nothing."   Helen Keller

We are going to explore the racing N words NITROUS & NITRO!

Offline SPARKY

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Re: Rat-a-Tack AA/GL
« Reply #122 on: August 20, 2011, 09:26:11 AM »
Rex,  I "think" you are right about your comparison with 77 and 608 bottoms. Bow waves off the frt of tires led me to the nose shape of the old car and the choice of the round bottom on the new.

On 4411 when we ran it as a Lakester with the tires out, it had a fairly large"sun burst" salt pattern behind the tire where the widest part of the body was real close to it.  I have read and searched a lot trying to grasp some insights as to the air flows that would have caused it :?
Miss LIBERTY,  changing T.K.I.  to noise, dust, rust, BLUE HATS & hopefully not scrap!!

"Security is mostly a superstition. It does not exist in nature, nor do the children of men as a whole experience it. Avoiding danger is no safer in the long run than outright exposure. Life is either a daring adventure or nothing."   Helen Keller

We are going to explore the racing N words NITROUS & NITRO!

Offline Tman

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Re: Rat-a-Tack AA/GL
« Reply #123 on: August 20, 2011, 11:08:57 AM »
Sparky, wish I could have sat down for a chat on the salt since we are also building a lakester. Too many people spread out over too much real estate!

Offline gearheadeh

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Re: Rat-a-Tack AA/GL
« Reply #124 on: August 20, 2011, 01:32:35 PM »
Sparky,
I know you spent some time with the 608 lakester, did you ever notice that after a run there is a big build up of salt right in front of the rear wheels? You don't see it on Seth's car and I think the difference is that Seth's car is round in section which allows the air to pass between most of the wheel/tire and the body where as the 608 car is flat sided and the air is completely restricted from going between the wheel/tire and the body. How far away from the body do you plan to make your wheels?

As Pork Pie says "It doesn't much matter how you open the hole, it is all about how you close the hole"
Pork Pie      Wendover KOA August '06

Rex


Iam not anysort of expert nor do I have any Kudo's of Records to point at. But there is a theory I have whenever looking at successful Liner designs. There is no reason for my theory that I can point at, just a sort of straw poll of my own.
Every one looks a 2 basic things when it comes to areo(now many more with these boundary layer heat/cold ,suck/ blow things).
 
1 is frontal area
2 is Wetted area

Now Iam proposing that we think of the side profile as if the car was traveling perfectly sideways at speed!
I think this is why a traditional tank is so successful. Any cube or flat sided car has by nature a sharp radius when it changes from flat side to flat top and it is these sharp radius that are causing problems!
40 is the old age of Youth, 50 is the young age of the Senior years.

Offline Rex Schimmer

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Re: Rat-a-Tack AA/GL
« Reply #125 on: August 20, 2011, 01:35:47 PM »
Sparky,
My thinking and I think Dr. Goggles agrees is that there is really no need to have either of the axles on a lakester very narrow. The thought being that the tires have a pretty big volume of aero affect and when you have the wheels close to the body the tires and body can aerodynamically interact and probably not to your advantage. I have seen some CFD plots of open wheel cars where the front wheels appear to cause a low pressure area between the wheels and the body (Bernoulli effect?) and I would question if this is a desired affect.

I did take another look at your 3D CAD dwg of the rear of your car and with your pinching of the rear of the car you do appear to probably have some additional tire to body clearance depending on the wheel base you settle on.

Rex
Rex

Not much matters and the rest doesn't matter at all.

Offline SPARKY

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Re: Rat-a-Tack AA/GL
« Reply #126 on: August 20, 2011, 01:44:22 PM »
Rex, The "sun burst" from the 4411, exhaust, and " my precpetion" of tire bow waves led to that decision :?
« Last Edit: August 21, 2011, 10:03:37 PM by SPARKY »
Miss LIBERTY,  changing T.K.I.  to noise, dust, rust, BLUE HATS & hopefully not scrap!!

"Security is mostly a superstition. It does not exist in nature, nor do the children of men as a whole experience it. Avoiding danger is no safer in the long run than outright exposure. Life is either a daring adventure or nothing."   Helen Keller

We are going to explore the racing N words NITROUS & NITRO!

Offline SPARKY

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Re: Rat-a-Tack AA/GL
« Reply #127 on: August 20, 2011, 01:49:05 PM »
gh 'eh,
 as I understand  :-o  the flat bottom CAN give one downforce at the expense of more drag  I will be running more lead with the new car.
Miss LIBERTY,  changing T.K.I.  to noise, dust, rust, BLUE HATS & hopefully not scrap!!

"Security is mostly a superstition. It does not exist in nature, nor do the children of men as a whole experience it. Avoiding danger is no safer in the long run than outright exposure. Life is either a daring adventure or nothing."   Helen Keller

We are going to explore the racing N words NITROUS & NITRO!

Offline SPARKY

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Re: Rat-a-Tack AA/GL
« Reply #128 on: August 21, 2011, 10:16:12 PM »
Jon, and I had a tedious day in the shop. We took the mock up motor out and squared up the motor plate on the mill and droped the back of the eng another 5/8". We now will have to "nibble outer edge of the starter housing to get it in and out. This lowers the eng enough that we should be able to get a tall deck block in with out bulging the upper skin. We will have some carb sticking up though.  I feel several bingeengineering sessions wil be necessary to solve that one  :cheers:  :cheers:

We put the PG in with its 1' drive shaft. We will have to move two of the lower hoop crossmembers slightly, they are just tacked,  for the difference of the trans pans and trans mounts---we are now as low as we can get to the lower skin with out "bumping" it.  Looks like the WB will be 207" which it was on the old car  :-o strange  :?
« Last Edit: August 23, 2011, 09:06:49 AM by SPARKY »
Miss LIBERTY,  changing T.K.I.  to noise, dust, rust, BLUE HATS & hopefully not scrap!!

"Security is mostly a superstition. It does not exist in nature, nor do the children of men as a whole experience it. Avoiding danger is no safer in the long run than outright exposure. Life is either a daring adventure or nothing."   Helen Keller

We are going to explore the racing N words NITROUS & NITRO!

Offline bucketlist

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Re: Rat-a-Tack AA/GL
« Reply #129 on: August 23, 2011, 01:14:02 AM »
Sparky,
My thinking and I think Dr. Goggles agrees is that there is really no need to have either of the axles on a lakester very narrow. The thought being that the tires have a pretty big volume of aero affect and when you have the wheels close to the body the tires and body can aerodynamically interact and probably not to your advantage. ...

Rex

The book "Aerodynamics for Racing and Performance Cars" by Forbes Aird discusses this, "interference drag", and yes, the closer an outside obstruction is to the body, the greater the resulting Cd. The unstreamlined shape of the front tire creates a turbulent wake that affects air flow over the car body downstream. I wouldn't know how to guess about the rear. Probably depends on if the flow has separated into turbulence, which it might not on aerodynamic bodies. But with the turbulence from close front tires, one might not have the magic boundary layer one expects with the aero body.

I'm no expert, I read the book (over and over) and am just trying to apply what I think I learned to a slower brick.
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Offline SPARKY

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Re: Rat-a-Tack AA/GL
« Reply #130 on: August 23, 2011, 09:18:25 AM »
What drives us all crazy---there are NO Hard and fast rules---what works on a Lakester may not apply to a Liner with almost the same body---would be my guess--YMMV

I spent about an hour listening to a ROADSTER guy telling me about his two days in the tunnel with his car and about 20 perceived made up before, ideas to try, things he had made in advance. One was wheel spacers made that he could take the wheels out up to 6" inches there was an interaction between the wheel spacing and "other Mods he was trying . Things at the front of the car and on the rear influenced his final choice of wheel spacing.  IE right up against the body---

This is only to say it is all "A PACKAGE"---
Miss LIBERTY,  changing T.K.I.  to noise, dust, rust, BLUE HATS & hopefully not scrap!!

"Security is mostly a superstition. It does not exist in nature, nor do the children of men as a whole experience it. Avoiding danger is no safer in the long run than outright exposure. Life is either a daring adventure or nothing."   Helen Keller

We are going to explore the racing N words NITROUS & NITRO!

Offline SPARKY

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Re: Rat-a-Tack AA/GL
« Reply #131 on: August 28, 2011, 09:54:14 PM »
Joey, John & I had a good day in the shop,  got the Hyprid Pro out and spread the tubes in the seat back enough for the straps to get in side and over the "HP". RE coped with our trick home made notcher--wo does it work seet with the mis matched tube  Sizes..

We will work some more  later on the cage---

We are trying to get upper rails in so that we can get the frame off the jig and see if we can get the tank around it :-o.  We took another inch of the mid plate --trying to drop the eng as much as we can so the carb will not stick up so much..  We will also run with open stacks at first just simpler and faster to get going. We are begining to get a feel for the fuel and dry sump tank shapes..
Miss LIBERTY,  changing T.K.I.  to noise, dust, rust, BLUE HATS & hopefully not scrap!!

"Security is mostly a superstition. It does not exist in nature, nor do the children of men as a whole experience it. Avoiding danger is no safer in the long run than outright exposure. Life is either a daring adventure or nothing."   Helen Keller

We are going to explore the racing N words NITROUS & NITRO!

Offline 38flattie

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Re: Rat-a-Tack AA/GL
« Reply #132 on: August 28, 2011, 10:05:35 PM »
Sparky, it's sounds like you guys are making great progress.



Of course, pics would verify the progress..... :-D

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http://youtu.be/89rVb497_4c

Offline SPARKY

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Re: Rat-a-Tack AA/GL
« Reply #133 on: August 29, 2011, 10:11:25 AM »
John, takes the picts, when I recieve them, I resize them and try to post.

I am very pleased with how far down we now have the tall deck, we will now have to put one of the raised port heads on it and see if we can get the stacks out or we will have to  raise the frame rail in the eng. bay.
« Last Edit: August 29, 2011, 02:14:02 PM by SPARKY »
Miss LIBERTY,  changing T.K.I.  to noise, dust, rust, BLUE HATS & hopefully not scrap!!

"Security is mostly a superstition. It does not exist in nature, nor do the children of men as a whole experience it. Avoiding danger is no safer in the long run than outright exposure. Life is either a daring adventure or nothing."   Helen Keller

We are going to explore the racing N words NITROUS & NITRO!

Offline SPARKY

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Re: Rat-a-Tack AA/GL
« Reply #134 on: August 29, 2011, 02:15:34 PM »
Jezz it is pretty evident that I reside in Beerhaven also!!! lol
Miss LIBERTY,  changing T.K.I.  to noise, dust, rust, BLUE HATS & hopefully not scrap!!

"Security is mostly a superstition. It does not exist in nature, nor do the children of men as a whole experience it. Avoiding danger is no safer in the long run than outright exposure. Life is either a daring adventure or nothing."   Helen Keller

We are going to explore the racing N words NITROUS & NITRO!