Build Table Build

Made good progress this weekend putting together the build table. Started by putting the wooden top together so I had a flat surface to lay the steel box section on to weld it together.

Lighting and Welding Practice

Today I replaced the single light bulb in my garage with two fluorescent strip lights. This has made such a massive improvement to the light that I can actually see what I'm doing now!

  

Last week I had some metal box section arrive which gave me the chance to start welding practice. I haven't welded anything for over 15 years and quickly realised I am going to need a lot of practice :-)

Its a good job I have small welding project to practice on. I have designed a build table which will be used to build the chassis upon. Hopefully by the time I have welded the table my welding skills will be good enough to start welding the chassis. If not I'm going to find a welding course.

Chassis Design - Continued

Over the last month I have done a lot of design work on the chassis design. As now I am able to measure the parts from the BMW I have been able to finalise parts of the design such as the rear suspension.

The rear suspension will use the BMW hubs and bearings but the upright will be fabricated from sheet metal. I have also decided to use the same handbrake method as E36 with brake shoes within the disc actuated with cables the the brake lever. For the caliper I have decided on Wilwood Dynapro Singles (See Design & Components section).

As I am getting close to being able to start fabricating the chassis I wanted to confirm that the body work would look right over the chassis I have designed. Because the BMW M44 engine is quite tall I had to increase the height of the bonnet section whilst trying to maintain the correct lines. I am really pleased how this has come out as I was worried that it may not look correctly proportioned.

After much contemplation I have decided to make my own nosecone. I realise this is going to be difficult but I think the end result will look much better as I can get the clean lines I want.

 Rough dimension-ed sketch of the engine to make sure it all fits in OK.

Engine Removal

Very busy day today! Earlier this week I purchased the mild steel box section for building the chassis and as it was going to be delivered today I took a day off work. I had decided that whilst I was waiting for the delivery I would finally finish removing the engine.

 

Chassis Design

Over the last few weeks I haven't done a great deal of work on the BMW; however I have been doing a lot of work on the design. Having the donor has meant I have been able to measure the engine and draw up a very crude representation in my CAD software. As soon as I tried to fit the engine into my original chassis it became clear I had under estimated the size of the engine and there was no way it would fit. Since then I have had to re-draw most of the chassis again. This also means I will have to check the suspension geometry as the front pickups will be further apart now.

Differential removal

Last day of the christmas holiday today so was determined to get as much done as possible, starting with removing the diff. Took rear wheels off (cursing that I hadn't loosened the nuts when it was on the ground!), removed the rear anti roll bar for better access to the diff and then had another go a the bolts that beat me before. As they had been soaking in WD40 for the last two days they came of much easier this time. Next I got to use my new Torx socket set to remove the drive shafts from the diff, which was surprisingly easier than I had expected. Finally removed the three mounting bolts and the diff was out.

Diff on the way down.

Very dirty diff on my work bench.

Once the diff was out I removed the rear half of the propshaft. The BMW propshaft is in two pieces and as access the the bolts holding the front half the the gearbox was so difficult I decided to leave it in place and remove it when I remove the engine and gearbox.

Suspension geometry - Part 1

After giving up removing the diff from the BMW I decided to work on the design. As I remembered to measure the steering rack I was able to start planning the suspension geometry.

Whilst static the wheels are 1 degree in negative camber.

In cornering the body rolls 3 degrees before the outside wheel gains positive camber.

As I have chosen to use a relatively short swing axle length (SAL) of 1600mm to improve cornering geometry, the wheel geometry alters quite a lot in squat and droop. The images below are 50mm squat and droop.

Started to remove the differential

Did some work on the BMW today, not as much progress as I would have liked, but started to remove the diff. Originally I planned to remove the engine today but as I thought about it I realised I needed the car on the ground again prior to lifting the engine.

This is so that a; I don't need to lift the engine as high and b; I can roll the car half out the garage to have more space to maneuver the engine once it's out. With the new plan, I needed to make sure everything that needs to be done whilst the car is on axle stands, is done prior to removing the engine. Removing the diff was the most important job to do.

As mentioned, didn't get very far as I discovered I needed to jack the back of the car up higher to get underneath it, then to make access easier I removed the rear bumper, whilst I was at the back I also removed the rear lights (Ready for eBay) and then took an hour to remove just one of the bolts holding the prop shaft to the diff!

Preparation to remove engine

Removed the exhaust and heat shield in order to remove the prop shaft, disconnected all electrics from the engine, disconnected pipes connecting the engine to the heater. All that is left to do is remove the bolts on the gearbox mounting and engine mounts then crane the whole engine out in one piece.

The Teardown

At this stage I am not sure how much of the car I will end up using but currently my intention is to use the engine, gearbox, prop and drive shafts; and wheel hubs. I will use the differential for the build but intend to swap it out for with limited slip version at a later date, similarly the steering rack will be swapped with the quicker ratio version from a Z3. The first stage is to remove the parts I need from the car and then to remove parts I can sell on ebay before getting rid of the left over chassis.

Since I picked the car up I have been working on removing parts but as the car had an after market alarm and immobiliser system I needed to remove it before removing the engine so I could check the engine wasn't immobilised. After removing the dashboard, following wires all round the car and rejoining wires where the alarm was spliced I finally was able to remove the alarm system. A quick test and the engine fired up first time.

Once the alarm was gone I could start getting ready to remove the engine. I had removed the front bumper, grill and lights over the last week so next the car needed to be jacked up and the coolant and oil drained.

The beginning

On the 9th of December I collected my engine. I chose to use a BMW M44 engine, mine came with the rest of the car for free. I won my 1996 BMW E36 318is on ebay for £285, after explaining to the seller what I was using it for, she asked if she could buy the bonnet back off me so in the end I paid £250 for the car (Minus the bonnet).

Inspiration - Lotus Seven

Originally designed by Colin Chapman in 1957, the Lotus Seven was a two seat open top sports car. The design has been copied by many car builders over the years, the most well known being Caterham and Westfield.