LocostUSA.com

I was thinking about the fuel tank system in the C6 Corvette. I'm not sure what kind of pump system they use to get fuel from one side to the other. In my mind, I had imagined two tubes connecting the two tanks, one at the bottom and one at the top so that pressure should equalize as fuel flows, but I think multiple tanks is too much work.


I was looking for examples of the Lotus Elan frame. Gosh, the rear shock towers on that thing are tall, but with new coilover shocks, they could be made considerably lower. In my picture search, I came across pictures of the Delorean, of all things. It apparently used the same basic concept, with each end of the backbone frame shaped like a Y and a triangular fuel tank stuck in the front end behind the steering rack. I'm having a hard time coming up with anything very detailed or high resolution but from posts I've read, it seems that the transmission tunnel for the Lotus Elan was boxed, so top, sides and bottom. Was the structure simply formed and welded plate or was there some underlying structure? I do expect that my car will be heavier than a 4-cylinder locost, but I'm also going to be using a 400hp V8. I'm looking at the double-Y shape of the backbone frame and am trying to think of ways to incorporate a pair of 3" diameter tubes to tie the front to the back, to define the width of the vehicle and to work toward establishing some side protection since this thing is almost exclusively going to be used on the road. There are no tracks less than at least several hours from here.

As I was searching, I also came across one page that made me laugh. http://www.airshiptg.org/ Among other things, the company appears to be developing a car with spherical wheels, each in a maglev housing so there is no physical contact between the car and the wheels. There vehicle of choice for the project is a Delorean.

I'm starting to work on collecting parts for the project, although my Jeep bled for me this morning, so I need to focus on that for the short term. The water pump went out on the way to work this morning. A wobbling fan and throwing antifreeze everywhere.

It seems that the Lincoln Mark VIII, some Thunderbirds and Cougars had 28-spline axle shafts in the 8.8" IRS, while the Mustang Cobra had 31-spline axles. Higher spline count means more contact area and greater strength even though the splines themselves are smaller, but I'm disgusted how expensive 31-spline axles cost. The only place I've found them for sale is at "The Drivehsaft Shop" for about $1800 for a pair. Re-manufactured 28s can be had for $75 each. I'm thinking that I will settle for the cheaper/weaker axle shafts and upgrade them later if something breaks. That is unless I can find junkyard units that need refurbishing.

Charles,

the 31 spline axles are stronger because the axle has a larger OD. The additional area allows more of the same size splines.

Moser Engineering can make axles to your specification for about $250/pair without the joints. The easiest thing to do is send them a stock axle and provide an overall length measurement. It is okay to reuse a good joint. Rear joints seem to last forever.

Factory Five sells replacement axles for their IRS cars, which are 18" long, cheaper than Moser, and are fully assembled with new joints. However, the ones I bought had a very sloppy fit at the spline, so I resold them to another miata v8 guy. I discussed the issue at length on the miata.net and with Factory Five, who receive a box of axles at a time from their supplier, which I believe to be far east. They may have it sorted out now or it could have just been an issue with that specific production run. Just FYI.

I was thinking about the custom axle route and that seems to make the most sense. I got a catalog in the mail today from Strange Engineering, but since I've settled on independent suspension, very little in their catalog benefits me.

I started to play with Solidworks today, trying to decide if the features of the application justify the cost as it relates to my project. It gave me a migraine. The very first thing I did was trying to make a simple pipe section, but quickly learned it's not the same species of animal as Lightwave 3D. I'm used to being able to subtract shape B from shape A, but Solidworks doesn't work that way, so I'm working through tutorials. I watched a couple youtube videos for frame modeling, but they didn't really go into the keyboard shortcuts they were using to accomplish tasks. Very unhelpful.

After my 8.8" housing gets here and I get a chance to go pick up my engine block, I'm going to work on a backbone for the frame. I will have a pair of 2.5" or 3" tubes that run from steering rack to differential and spaced to define the width of the transmission tunnel. It should help establish a rolling chassis similar to below:

There will be a crossbeam at the steering rack, one at the transmission support and one at the differential. The rest of the "locost" frame will be assembled around the tubes. As the battery will be in the back, wires will likely route through a smaller conduit inside one of the two large tubes. Much later on, the transmission tunnel will be a bolt-in unit, kind of like this:

I like the bolt in transmission tunnel idea.

I need to try bouncing some ideas off something other than the wall behind me. I looked through some other posts and found a linked picture to a TVR Chimaera restoration. So, using the two images below, here are my thoughts so far:

The primary structural elements of my frame will be a pair of 3" tubes along the bottom of the car, defining the transmission tunnel. These tubes will run from the steering rack to the differential. The tubes will have two welds so that the space at the engine bay can be wider than the space at the rear diff. Just behind where the engine meets the transmission will be a low hoop of square tubing. A similar but lower hoop will be at the front of the differential. The transmission tunnel will then bolt in place fore and aft, as well as to the two 3" tubes. I want an aluminum sheet on top of the 3" tubes, below the tail of the transmission and under the driveshaft, with this aluminum sheet to be insulated top and bottom. Exhaust will tuck along the sides of the engine block, past and under the transmission and between the two 3" tubes, then bend up and over the differential. Behind the differential, the frame supports form a triangle with a point at the top. Exhaust tubes should stick out the back on each side of that point and connect to a pair of oval-shaped mufflers, with inlet and exhaust on the same side, exhaust tips exiting just above the lowest point of the frame.

The first potential problem I see is that this makes the fuel tank sit kind of high in the vehicle, above the differential and suspension components, and the exhaust. Along the bottom of the car, most of the exhaust heat should be reflected down, but there might be a hot spot at the drivers elbow, unless I go with a pair of straight mufflers tucked right under the differential.

Your taking on a big project, nothing wrong with that. You want to avoid making it too big though by taking on too many things.

Staying closer to a Locost frame would help you, I think. There's a couple of points here.

In your case, after looking at the pictures of the frame for the Sondegaard you provided, you should make the frame taller by several inches. Consider a top rail that is perhaps 6 inches taller at front and more like 10 at your shoulder. You can look at the picture, and use some of the wood or PVC stock you bought and set it up on a table with a seat mock up.

Don't think of a Locost frame as something with a tunnel tacked on. It sometimes looks that way and there is history to your point but that is not the proper modern approach. The bulk of the stiffness in a Seven comes from the tunnel. So they should be designed carefully and the car grown outwards from it. This is not always done properly and you can see the tunnel tubes not connecting directly with others. You can (should) do this properly for your design. You will need the motor, transmission and diff to do this.

The larger then normal tubes at the bottom of the car (ladder frame etc.) are for designs that don't really have more frame. We have history that is showing that 1.25" 16 gauge is sufficient. It is more important for the upper tubes to be strong, that's where more of the load is. The car hangs from the springs and the top rails. The part of the frame at the perimeter is good for peace of mind and for supporting your body work. Lotus Elans like in your picture are beautiful cars, but I wouldn't want a motor scooter to t-bone me... I think it raises the level of effort for your body too, it must be much stronger. In the case of the frame I am talking about the body is more of an add-on. Heck you could drive it for a year while you do the body work.

For this construction to be strong enough, the basic need is for bracing to be in the right places. and good design for where you have brackets etc. You could go up one gauge for the main tubes, but .120 is over the top!

Have fun and don't get discouraged it just may take a little while to get answers sometimes.

Well, I don't expect what I'm working on to be a small project. Start to finish will be a number of years. I'm currently reading about suspension geometry, center of gravity and roll axis. My first thought is that a roll axis should be fairly level, but that doesn't seem to be the case. I've read that the vehicle should have a rake to it, the front roll center lower to the ground than the front to produce a bit of understeer. The front roll center should be close to but not below the ground. Using a wishbone suspension front and back, there should be a wide range of adjust-ability. I have a question about vertical alignment of the rear spindles in relation to the differential. Spindles will of course move up and down as the suspension cycles, but must the spindles be in the same vertical axis as the differential, or can the spindles be moved a couple inches to the rear, effectively moving the differential forward? I'm trying to think of ways to make space to lower the fuel tank, thereby lowering the center of gravity.

That's typical but there are probably several things going on here. Like the height of the center of gravity of items at the front of the car compared to the back and all the other tradeoffs. I think I'm tired so that last sentence came out a lot shorter then I meant it to! It may be the explanation you read is a particular style. So don't make too many final decisions early and try to keep open minded. It's hard and that why it becomes a big project. I think that Caterhams for example have higher roll centers then I would have expected, but will have to look at that again. If you have IRS you tend to have lower roll centers, but I suppose that doesn't always hold true.



No, it is not a requirement. There are specs for the allowed total misalignment and they should be respected. It's also good to be a little conservative in this area. Our cars probably have less suspension travel then a sedan, so some of that would be available to do as you describe. There are examples of stock cars that do this, but can't recollect one right now. It really is just one or two inches. If you fabricate your own tank, it can be bigger by being the right shape to fit the space.

I got back from my ski trip last night. The trip was supposed to be a time to get together with old friends that I haven't seen in a while, but it ended up different than expected. Three of my friends came up from Oklahoma and I met them in Silverthorne, Colorado. We then moved on to Copper Mountain for 4 days of skiing and snowboarding. I was a bit nervous the first few times getting off the lift because I've not been on a snowboard in two years, but after a while, it seemed normal again.
The first day was a lot of fun, although a bit tiring. I weigh almost 30 pounds more than I did two years ago, but I found that the added weight gave me more control over the board. Between the four of us, we had no falls and no bruises. That night, We went to a restaurant at Copper for sushi. Good stuff.
The second day was similar to the first, but in the last half hour, I took a bad turn, hit hard and broke my tailbone. That pretty much ended it for me.
The third day, I stayed off the board, going shopping and doing laundry instead. On the way to Copper, I picked up a Mopar Small Block book from Barnes & Noble, so I did a fair bit of reading. At about 2:00, I got a call from one of the others that Jeremy, another member of our group had taken a bad fall on his skis and was taken to the medical clinic. Last year, he tore his ACL, had surgery, went through physical therapy and was in shape again. He wore a metal brace on his right knee for added support. He had been moving down a narrow trail and hit a bump he didn't see. His feet came out from under him and he landed on his back, between his shoulder blades. When he landed, his knees came down to hit him in the face, his knee brace cracking his goggles. He had a bruised lip and a scrape on his forehead as his goggles moved up. A passerby helped him up and he managed to ski down to the lift, although in pain. When he got down to the lift, he opted to be strapped down on the sled and towed down the mountain behind a snowmobile, and to medical. They took x-rays and found what looked like a compressed vertebrae and took him by ambulance to Frisco, CO. They did a CT scan and an MRI and found that he had a compression fracture of the 11th thoracic vertebrae. Looked at from the side, the front of that vertebrae was 40% shorter than the back.
We spent the fourth day packing everything up and loading up the vehicles before going to visit Jeremy. The doctor scheduled him for 5:00pm surgery. We spent most of the day sitting in his hospital room visiting. His surgery took about 90 minutes and he's in recovery now. He will probably be held through the weekend and released Monday, although he's hoping to be released sooner. His mom and fiance started driving up Thursday afternoon and planned to be in Frisco by Friday afternoon, when the other two in our group would drive back to Oklahoma. I stayed in Frisco until Jeremy went into surgery, then started my way home. I ran into a blizzard north of Denver and after Ft. Collins, I saw NO northbound traffic except for myself. Normally, a 4 1/2 hour drive ended up just over 6 hours.

Yo Charles-
So, let me summarize... The four of you went snowboarding/skiing... Two of the four wound up injured, one in the hospital.

Dude, take up a safe hobby, like auto racing!!!

Yeah. Safer, that's the ticket. Actually, it probably IS safer than flying down a hill with nothing more than clothing to protect.

Jeremy is a car guy too. He still has his first vehicle, a 1987 Chevy S10. The thing has survived food-poisoning-induced blackout rearendings and rolling down a hill into a tree during a fishing trip. Several years ago, he rebuilt the truck, swapping in a ZZ4 350ci V8. It's now garage-kept and goes out only in fair weather.


When my friends and I were in the emergency room waiting area, there were two other accident victims brought in. One didn't make it. I heard a lady on the phone telling someone about the other, a man in his 40s who hit a tree, stating that if he hadn't been wearing a helmet, he would have been killed. As is, he suffered a broken clavicle, five broken ribs and a punctured and partially collapsed lung.

I'm heading off to pick up my engine block next weekend and have a decision to make. I have a couple books about building Mopar Small Blocks and big inch Mopar Small Blocks (strokers) and everything more or less made sense until getting into valvetrain. After that, there are so many mix and match possibilities that it's hard to keep things straight.

Building a 408 stroker, I need to decide whether to get an LA-style or a Magnum block. Every time I get far enough to formulate the question, I get confused. The only difference between the two is that the Magnum block oils through the lifters and pushrods instead of using an oil passage between the block and the heads. You can put Magnum heads and intake on an LA block. I'll have to go back and look for the paragraph that stated it, but it may be that the metal around the lifter bores on Magnum engines is taller than on the LA engine. If I use an LA block, I'll convert to mechanical rollers and if I use a Magnum, I'll use hydraulic rollers and hollow pushrods.

The only reason this is even a question is cost and distance. I can get an LA block for $250 and drive 142 miles to get it, or $200 if I drive 209 miles to get it, but I can get a Magnum block for $150 and 184 miles.

I say get the Magnum. the torque curve is much broader, the idle is smoother for a given cam duration and the aftermarket is pretty strong nowadays for it.

Just think, you'd actually be able to reach the sensor on the bellhousing too

I was starting to lean toward the LA block, but after doing some checking, I think the Magnum block would work fine. Lifter bores being different was the potential problem. I specifically want this cam: http://www.summitracing.com/parts/CRN-698801/ So, it's still going to take some funky engineering to accomplish. I still need to verify whether or not a cam from an LA block will fit in a Magnum block. LA heads on the Magnum block.

Mopar Magnum engine block from a 1994 Dodge Ram 2500. Magnum block was never in a passenger car
4.030" bore x 4.000" stroke, forged crankshaft, H-beam rods and pistons
Mechanical roller cam and mechanical roller lifters
Mopar W5 heads and hopefully a W2 single plane intake and 750-850cfm 4-barrel carb