Rear engined chassis

[peteypt]

Hi there.

I'm new to this forum, so please excuse me if this is in the wrong place

I've been building buggies for years now, for off road entertainment, and have for several years been repairing accident damaged cars / write offs etc etc along with some tuning work and mobile mechanic repair jobs.

After driving a friends Caterham 7 a few months back, I finally decided to buy the Haynes book and look at building a road legal roadster.

However, in these few months, I have yet to find a sierra donor near me for the type of money I want to pay, and don't particularly fancy collection from up country (I live in Devon) as the main objective of my first roadster is LOW cost. Hence BMW / MX-5 etc probably out of question form what I’ve seen so far – Plus I don’t mind trashing a sierra, but who wants to chop up a ‘nice’ motor? (apologies ford lovers :p :D)

Having a selection of engines and gearboxes in the workshop got me thinking, perhaps I could just take a gearbox apart and weld up the diff, place the lot transverse in the chassis and find a suitable rear wheel diff, but again this would end up with issues, and costs.

So I got to thinking, rear engined, rear drive, allowing me to use a common engine from a front wheel drive car. (like the Atom?)

Before I get out to pen and paper and CAD package, I was wondering if anyone else has done something like this with the Haynes roadster? I anticipate the back needs enlarging slightly, fuel tank moving forward and a general re arrangement of chassis for strength. Not the mention front / rear wheel unbalance and tendency to lift like a dragster? lol :rolleyes:

I have read a few threads in other forums etc from people with more aspiration than sense and also noted the often derogatory responses they get suggesting they are under informed and should go study a degree first, so to avoid that in this thread, I'll point out I have already been to uni, and walked away with a Beng Mech (hons). My current choice of work just reflects my preference hands on engineering to pen pushing theory (if I can help it) :p

I look forward to any input, or any tips from someone who has ‘been there and done it’ and of course I have every intention of documenting my build in one fashion or another to assist other builders who like myself are struggling to find a ‘cheap’ sierra donor and maybe want something a little different to the stock design.

Pete

[TQ_uk]

Hi Pete,

I'm totally on your wavelength here. If you haven't already, I suggest checking out some of the rear (mid) engined kits available for chassis ideas, such as the MEV range (Sonic/Rocket etc) which use Focus running gear, and maybe the MK Midi (although think thats bike engined).

HTH

Edit: the 'issue' I have with the MEV design is believe it uses Cortina geometry/parts for the front end, which to my mind is surely going to be even less available than Sierra stuff...

[peteypt]

Hey, yeah, I had seen the MEV kits when looking around.

They are all rear' engine jobs with what looks like gearbox to hub drive, minus the steering gear, which is up front. they don't look too much different from the Haynes, just with slightly different frames and more modern appearance.

The problem with them of course is cost though.

I was looking to spend around £500 on the build (not including the documentation afterwards), so they are fairly pricey.

I'm kinda in the frame of mind that I'd like to keep the haynes appearance as much as possible and keep the rear engine as a kinda 'mod'. I really love the classic shape, and would go ahead and build one as per book right away, but with my budget, I am really going to struggle with a donor rear wheel drive.

Talking to others, they are finding the same issues now with Sierras, and I guess an element of this would be that the cossies are being restored, and the rest are being bought in bulk by the big kit car producers? I've noticed that some companies are very interested to sell reconditioned units to use from sierras, but at a cost of over 1k for engine and running gear, and then ideally, you still need a donor for little tid-bits like steering, hubs, etc etc etc.

I was looking at sourcing a non running engine, finding a box and diff to suit (or machine some plates to make them fit) and then picking up other parts from various cars as need be, but it becomes very expensive, and also I'd like to keep some continuity in parts, so that If it needs a bearing or bush or joint in the future, there's only one car it came from, as opposed being from a large inventory of cars - i.e. peugeot hubs, ford steering, vauxhall this, daewoo that lol :D

Pete

[John.W]

Hi Pete welcome to the forum

Have you had a look at the Sylva Riot http://www.sylva.co.uk/riotSE.html it's a slightly shorter version of the Haynes but with a rear mounted engine, you might not want to buy a kit but it could give you some ideas for engine and suspension layout

regards
John

[flyerncle]

Its been discussed on here before and I suggested this, Roadster chassis,move driver and passenger into engine space and use seating area as engine space using Audi/VW engine and box as the length from front pulley to driveshaft is relatively short.

[Eternal]

Hay pete. To be honest anything can be done with enought time and cash. For 500 you wont get much done i dont think. I would say around 3k would be more realistic but probably a tad bit more.

[Talonmotorsport]

If your looking at £500 spend limit you need to be looking at the WR4 build on locost builders as it's an 'exo' chassis with no body work and is basicly engine, seat and wheels.

[fabbyglass]

£500 !!! ummmm well won't get far with that

[TQ_uk]

Hi again Pete,

I meant taking inspiration from MEV rather than buy a kit. If you're after the 'look' of the classic 7 are you aware of the Midlana project?

http://www.midlana.com/

There will be a book out in due course, but it floats my boat for all the reasons you state (i.e donor availability etc).

[will_08]

£500 thats twice as much as what Ron Champion managed with!!!! :o

[twinturbo]

I will be using my old Mondeo 24V, and building a custom chassis utilising as many donor parts as possible but not where it would ultimatly compromise the end result...


If you want a realy interesting spin on the engine option look up correls 4x4 build

TT

[Tilly819]

right first thing first lets get some terminology right, technically all the kits etc that have been mentioned as rear engined are actually mid engine since the engine is in front of the rear axle.

second i am right in the middle of designing such a car using the duratec 2.0 and the IB5+ gearbox from an ST150 it wont be a 7 style body but the underlying concept is similar. It is very doable and i would encourage any people thinking of doing it to go ahead but be warned designing a car is very much a case of picking 2 of the following at the expense of the third.

Do it Fast
Do it Right
Do it Cheep

Pick 2

tilly

[twinturbo]

Shiz..

I was going to do it cheep and shi.....


:D





your right that it would be mid engined as the drive line sits behind the engine mass.. Unlike them 9xx tail waggers from Mr P..

TT