Mid engine fun

Are you one of those confused people who can't make up their mind?
Ol'fogasaurus
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Joined: Mon Nov 13, 2006 10:17 pm

Re: Mid engine fun

Post by Ol'fogasaurus »

There are edge margin tables on-line but, in some cases, it is hard to discover which table applies.

Holes are done in two ways; the simple hole in the material and flange holes, e.g., a hole with a flange on it that are designed to add strength when material is reduced. Flanged holes are usually set at either 45° or 90° but there might be others I have not run into (designed to... 60°?). The 90° flanged hole is stronger than the 45° as under certain circumstances the less than 90°can "seam" (a fairly sharp bend in the flange) or fully bend up in based on the direction of the loading iis being applied.

Minimum distances between holes is usually 2 1/2 dia. but the distance will be longer with flanging as you are bending material and the bends have to be a certain minimum distance apart or the bends can weaken up.

A hole too near a stiffening or mounting flange also can weaken that flange up.

If you were doing two or more parallel lines of flanged holes, then a whole new way to go is needed.

For what it is worth.

Lee
DeathBySnuSnu
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Re: Mid engine fun

Post by DeathBySnuSnu »

Well as the structure of the chassis was 100% prior to adding any hole parts.....that makes the hole parts primarily decorative......it fools people who don't know better into thinking it is an actual race car.

It did make me feel better about the construction to tie the open ends of the C and Z shaped channels (which have no holes) together.....at least I know the open ends can not spread.
So overall I would say 90% decorative and 10% structural peace of mind.
Ol'fogasaurus
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Joined: Mon Nov 13, 2006 10:17 pm

Re: Mid engine fun

Post by Ol'fogasaurus »

DeathBySnuSnu wrote: Tue Mar 01, 2022 9:29 pm Well as the structure of the chassis was 100% prior to adding any hole parts.....that makes the hole parts primarily decorative......it fools people who don't know better into thinking it is an actual race car.

It did make me feel better about the construction to tie the open ends of the C and Z shaped channels (which have no holes) together.....at least I know the open ends can not spread.
So overall I would say 90% decorative and 10% structural peace of mind.
I would suspect it is stronger than it looks after my discussion.

My work using this kind of stuff had a higher workload than a buggy might get. I mention things so people know more than they would otherwise... besides it was my job to look at and "double check" stuff like this.

Even after being retired, for over 20 years now I still not only react this way and since the rooms I worked in had several hundred workers in the rooms I usually worked in but when in quiet areas the silence bothers me when concentrating on something so noise is often added... against my wife's need for quiet :roll: :lol: .

Lee
DeathBySnuSnu
Posts: 191
Joined: Mon Feb 09, 2015 4:45 am

Re: Mid engine fun

Post by DeathBySnuSnu »

One of the mock ups.
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Ol'fogasaurus
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Re: Mid engine fun

Post by Ol'fogasaurus »

If you mess correctly with the carb stacks you might be able to play music as you drive or are parked and bored :wink: :roll: :D .

It does look like an interesting build, but the engine does look pretty close to the driver and passenger, e.g., noise and heat for instance. Other than that. it is looking interesting. Also a cage is going to be part of the closeness of the body and running gear.

In the bottom pix showing the hood, it sits low like my black buggy does so supporting the top and bottom ends of the front beam looks tight. I got the bottom support in but the upper tube to the firewall won't work "on mine anyway" as the FG it so thin.

I'm fighting similar area problems with my black buggy.
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This is my black buggy when I was building it for the street. Ann event stopped that, and it now being converted to a sand buggy (assuming it ever gets done that is).

I am assuming that the fuel tank will be in the rear, is that correct?

Lee
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Last edited by Ol'fogasaurus on Sat Nov 12, 2022 7:27 pm, edited 1 time in total.
DeathBySnuSnu
Posts: 191
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Re: Mid engine fun

Post by DeathBySnuSnu »

You are correct......it will not be nice.

No doors
No windows
No heat
No ac
No power steering
No power brakes
No auto trans
No cushy shocks
No dashboard
No instruments
No mufflers
No comfy seats


What I do have...
A v6
5 speed trans
Stiff springs
Sway bars
Tube chassis
Racing harness
Race seat
Giant tachometer

And the bare minimum to be street legal in my state.
Technically being a pre 68 I don't have to have seat belts but I do have the six point harness.
Dot windshield.
Wipers
Headlights and taillights.
Turn signals
Brake lights
Licence plate light
Horn

I did get the beam lower by using drop spindles, adjusters, and a pie cut.
So I do have top bars on beam.
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Ol'fogasaurus
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Re: Mid engine fun

Post by Ol'fogasaurus »

:) I wasn't trying to be a smart ass on what I said.

All states have different requirements for licenses and ownership papers... of vehicles I was not addressing that. But... for insurance purposes a clean title is usually required by the insurance company. Not sure about the requirement for racing but for off-road it is a requirement in most states (from what I understand) and federal lands [again, as I understand the requirement. To ride the Oregon Dunes for a type 2 vehicle [a rail or a buggy for example], it is a requirement and a suggestion for those who the requirement does not cover).

I was more into the basic design phase and room for things such as "form, fit and function (inspecting other's drawings as well as my own drawings was my job for more than 35 years before early retirement {the Dr. jokingly gave me bad info on how long I had to live not knowing some of my history ["2 years to live" back in the first week of January 2000).

If you were going to race it vs. on the street, then one needs to look at things a bit differently in order to make those in the toy safe as well as others that could come into contact (a potential joke but not intended as such) with. If this is to be on the street or dual purpose, then other things should probably be looked at differently.

Kerfing/pie cuts are OK and I used them a lot but should have a "doubler" over the area where the pie cuts were made because the cuts disturbed the grain pattern reducing some of the tube's strength.

My main computer is down and waiting to be looked at so I can't post pix (assuming you want any).

Lee
DeathBySnuSnu
Posts: 191
Joined: Mon Feb 09, 2015 4:45 am

Re: Mid engine fun

Post by DeathBySnuSnu »

It does have a title and a vin and I still have them and in my name since 1977.

None of the tubing is pie cut.
Lots of fish mouths and bending.
The z channel the body mount rails are made from are pie cut, doubled and then closed in with the hole plates to form a box section.

The pie cut I referred to is inside the re-used beam yoke.
It is a common modification to add castor and to lower.
Re-using this piece of a pan gave me a starting point for the rest of the fabrication.
DeathBySnuSnu
Posts: 191
Joined: Mon Feb 09, 2015 4:45 am

Re: Mid engine fun

Post by DeathBySnuSnu »

It will basically be a race car that I drive on the street.
It will probably never get raced....as I am in my sixties and I am slow now.

Besides....I have something else to go actual organized racing with......here down south we drag race in the dirt.
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Ol'fogasaurus
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Re: Mid engine fun

Post by Ol'fogasaurus »

DeathBySnuSnu wrote: Sat Nov 12, 2022 12:19 pm The z channel the body mount rails are made from are pie cut, doubled and then closed in with the hole plates to form a box section.
The term "Z channel" is a term I never have heard used before, so I looked it up.

I have seen the shape before but never heard the\that term used/associated before. I did look it up using several different dialogues and the answer wasn't what I had expected/hoped for. As a matter of fact, I have never heard a name attached to that shape of metal before plus I have never heard of it being used in this kind of high stress situations before.

A "doubler" attached against the long/wide part of the "Z-shape does make sense, but I am at odds as to its use. I don't doubt strength depending on several things.

Anyway, I hope for the best on its use. I wish I could be of more help.

Lee
DeathBySnuSnu
Posts: 191
Joined: Mon Feb 09, 2015 4:45 am

Re: Mid engine fun

Post by DeathBySnuSnu »

Using "channel" instead of beam might be a regional thing. Around here it is listed in all the raw materials books as z channel. You see it a whole bunch in larger construction such as steel buildings like factories, Walmart, ect.

The doubler is only at the pie cut bend area and also is the attachment point to transition to round tube.
And then it is the round tube chassis that is the stressed members.
Ol'fogasaurus
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Joined: Mon Nov 13, 2006 10:17 pm

Re: Mid engine fun

Post by Ol'fogasaurus »

DeathBySnuSnu wrote: Sat Nov 12, 2022 8:10 pm Using "channel" instead of beam might be a regional thing. Around here it is listed in all the raw materials books as z channel. You see it a whole bunch in larger construction such as steel buildings like factories, Walmart, ect.

The doubler is only at the pie cut bend area and also is the attachment point to transition to round tube.
And then it is the round tube chassis that is the stressed members.
In my looking up of the "Z channel" that is pretty much what I got out of reading about it too; their conversations delt with mostly roofing and other light and heavy centralized construction use.

For my 2 buggies pan's support I did origionally look at using "C channel" to start with but there was the weak spot mostly for torsional reasons, so... I switched to center seamed rectangular tubing (the seam can be in the center of the longer side, or up to the three-quarter area or in the center if top of the tube. Since I am not an engineer, when I did check with engineers I worked with/assigned to, while they didn't know squat about VW pans, I did get some advice (not much) that did help me out.

The VW Unibody pan, have a design with the tunnel being the primary support design with the body bolted to it which gives additional strength (reduced on a convertible) and stopping torsional problems with the flat pan, IOW, the body can rack (twist) easily, or the pan can start to sag w/o the body on for support, not only fore and aft but torsion-ally also. One of the problems the owner of a VW salvage lot told be that the area between the Napoleon's hat/firewall can sag some over time which is another reason for the body lift for support and clearance. I would not use square tub for strength on the pan but maybe a 1" X 2" thick-walled rectangular tube. My black buggy build here has those pix and some of these reasons there too.

The body's top covers side to side loading as well as front to rear loading and the pan/body twist loading also goes thru the roof of the body. A well-built body lift using rectangular tubing does handle a lot of the loading. The commercial body lifts are usually thin walled "C-channel" which, when combined with the pan and the body does some work but also rusts out quickly (on my blue buggy I was given a body lift but the only part of it I could use was the Napoleon's hat and it needed to be rebuilt also.

"C-channel" like the "Z-channel has weaknesses with the flanges as they would/could need additional strength needed also. If you look at the pan's body mount flanges you probably will see a slight down bend radius and that is to keep the flanges from bending up or down or tearing depending on which way the bend on the pan goes (also the pan's flanges, as I remember has those minimal bends also.

The heavier grade of "C-channel" and "Z-channel" could still have the flanges distort under big loads which is why I went for the tube. I have seen the stiffening flange damaged from over-loading of the material

When I did the "pic-cuts"/"Kerfing" to do the bend, the grain of the inside of the tube was disturbed (cut away) then welded hence the U-shaped doubler with holed drilled in the center and at the ends so the doubler would be weled in the center hole to the body lift then the ends clamped over the body lift, then pulled in place by the clamps then the doubler's end holes would be welded to the lift then finished off by a complete perimeter weld to add strength to the doubler.

The seamed side of the tube is, as I understand it, not quite as strong as the other side, and I had the potential of being run into I put the seam on the inside of the body.

I have seen a fair amount of Bajas, and mostly early style rails bent up pretty good and still, the newer style rails can be introduced into and have to take a heavy beating also causing dam(N)age.

Anyway, for what it is worth...

Lee
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