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Planning a mid engine build
Divano Veloce - 16/3/15 at 04:49 PM

Hello all,

My name is Matt and I live in Australia.

i have been lurking for a while as i plan and research a project car. I love the late 60's formula cars but am unlikely to ever be able to afford one. As there isnt much to them I figured that i could always build one....

This leads to the question -> what are you going to do with it..??? In many parts of the world theres FIA appendix K which says replicas can compete with originals (more or less) as long as they are true to the original design. In Australia, motorsports governing body says NO to replicas in the class where 60's formula cars compete. This leaves me with club sprints and hill climbs....

It also liberates the design and build away from using period components and fabrication techniques. For instance, i could tig weld the frame instead of nickel bronze braise... I could use a locost approach to the build.

Soooooo..... assuming that CAMS dont change their mind (which they wont) I might as well build a locost BT21/23/28 copy. These cars were mid engined usually 4 cylinder 1000cc (F3) or 1600 (F2) ford motors, v8s for F1/tasman, hewland tranny, spaceframe with fiberglass body.... Front uprights triumph herald or magnesium, rear uprights proprietary magnesium.

Challenge no. 1 is the frame. They're pretty simple things and i have mapped out all of the structural elements of a couple of variants in cad based on detailed photographs. The problem is i have no scale. I'd really like to spend an hour or two with a car sans body to determine all the dimensions and member sizes etc... but owners of these cars are a bit protective. You may say so they should be because thats proprietary intellectual property. Ok, then should i copy a Birel or Titan instead and have a second hand rather than first hand copy??

Anyway I'd really like some dimensions of a BT21/23/28 so i can verify what i have determined from hours spent analysing photographs...

Next big thing is the motor. I dont think i could afford a Ford or Lotus twin cam. I would like something that suits the period but is a bit more readily available, like an Alfa twin cam. Not as much power but cheap as chips. Thoughts on this choice? Whatever i use it will have to be dry sumped

Transaxle.... It seems that i have not much choice here but to fork out for a hewland.... Any alternatives that have the input shaft below the output shaft (ie, flipped?)

For uprights, brakes, hubs, steering i am open to suggestions, preferrably something i can source from local wreckers

I am looking forward to starting this build and sharing the experience here!

Kind regards,

Matt

[Edited on 16/3/15 by Divano Veloce]


Fred W B - 16/3/15 at 05:42 PM

Hi Matt

Welcome to the site, seems a great project you have planned. Most difficult thing is always the transaxle, if you want it cheap. The Audi 016 is the usual suspect.

If you have not seen it already, I am sure you will find this build of interest

Cheers

Fred W B

[Edited on 16/3/15 by Fred W B]


Divano Veloce - 16/3/15 at 06:02 PM

Thanks Fred,

i had seen that awesome build before! I think he started out with a vw tranny referred to as a 6 rib that was flipped (and required a dry sump motor) but eventually the build was finished with an audi trans and chev motor...

any idea on what is involved in using a "6-rib" VW tranny flipped?

[Edited on 16/3/15 by Divano Veloce]


designer - 16/3/15 at 07:04 PM

The 60's Hewland gearboxes were based around the VW box.


Myke 2463 - 17/3/15 at 08:38 AM

Try this http://www.stuart-taylor.co.uk for a few ideas


designer - 17/3/15 at 09:09 AM

This is a personal thing, but I have based the styling of my single seat on a 50's cooper 500, and if I was to do a 4 wheeler I would base the style on a late 50,s, early 60's F1 car. (Cooper T51) as they are larger than later cars and would be more practical to use on the road.

I love to BT23, but think it would be way too small for use on the road.

Just like Gordon Murray did with the Rocket.


Divano Veloce - 17/3/15 at 12:03 PM

Thanks for your replies and interest.

The car will not be road registered, purely a track toy.... I would probably attempt a traditional locost if i were to attempt registration for road use but through a prolonged campaign of "speed kills" and anti hoon laws it has become not only difficult with police, but socially unacceptable to enjoy spirited driving on public roads. So although i dont agree with this predicament i must abide by it so i'll save up my enthusiasm for the race track.

Anyone have experience with hewlands and adapting them to different motors?

(if i were smart id do a east west middy)


coozer - 17/3/15 at 01:12 PM

Hi Matt, regarding you last comment there, east west. Have you considered the Midlana?


Divano Veloce - 17/3/15 at 02:09 PM

im not that smart


coozer - 17/3/15 at 02:26 PM

quote:
Originally posted by Divano Veloce
im not that smart


Lol, get the book, looks dead easy, easier than a locost!


big_wasa - 17/3/15 at 06:21 PM

quote:
Originally posted by coozer
quote:
Originally posted by Divano Veloce
im not that smart


Lol, get the book, looks dead easy, easier than a locost!


I disagree. I think there is way more fab for the midlana and even more still for in board shocks.


TheGecko - 17/3/15 at 11:12 PM

Matt,

Can I suggest joining the OzClubbies forum (http://www.ozclubbies.com.au/). Although it's predominantly about Clubman's (i.e. Lotus 7 style cars) there's plenty of like minded lunatics there building other things. Kaspa with the BT24 replica that Fred linked to is a regular on there. My (long term) mid-engined clubman build is on there too - http://www.ozclubbies.com.au/index.php?/topic/396-the-gecko-mid- engined-clubman/

Also, don't be put off building a traditional (or not!) clubman. Depending on what part of Oz you're in, registration etc might be easier than you think.

Best of luck,

Dominic


coozer - 17/3/15 at 11:31 PM

quote:
Originally posted by big_wasa
quote:
Originally posted by coozer
quote:
Originally posted by Divano Veloce
im not that smart


Lol, get the book, looks dead easy, easier than a locost!


I disagree. I think there is way more fab for the midlana and even more still for in board shocks.


Yeah maybe but it looks dead easy to me mate.


coozer - 18/3/15 at 02:23 AM

Just need a tig welder!


kb58 - 20/3/15 at 04:14 PM

quote:
Originally posted by big_wasa
...I disagree. I think there is way more fab for the midlana and even more still for in board shocks.

Which is why the book gives the option of outboard suspension! The amount of fab is no different than a Locost, though perhaps a bit more due to the integral roll cage, but that's a requirement on my part regardless where the engine is, so it's a wash.


Texan - 20/3/15 at 04:25 PM

If I were to be building a little light weight 1 seater I'd use a motorcycle engine.

Great sound, great weight and then use a chain drive diff or, depending upon the engine, a mating adapter to mate the engine directly to a standard car diff, which would make it dead simple to build.


Divano Veloce - 21/3/15 at 03:37 PM

thanks for the suggestion Texan, i just plonked a hayabusa into the BT21 chassis that i have in CAD and it looks like it could fit sideways. That would be the best bang for the buck for sure! Given that every other avenue has some major cost or technical road block i think that this is the path i'll likely follow