Eighties Contest Entry: BMW 635CSi

[RallyRaider]

Sensationall stuff. I'm feeling a serious case of lathe envy here! How long does it take to machine something like that alternator?

[MPWR]

Lathe envy...

Originally Posted by RallyRaider

How long does it take to machine something like that alternator?

Good question. Actually, it usually takes longer to design a part than to actually machine it. The alternator was fairly complicated despite being small. The body was done in two parts, and each part took multiple steps as they had to be both lathed and milled. I'd say combined it took about an hour. Then when I decided to add the cooling fan, that took another 20-30 min to figure out what I wanted to do and make it. On the other hand, if you dont need to design anything, parts can sometimes be made very quickly. On the oil filter canister-



-I decided it would actually be quicker and easier to machine a new part than to clean up the mold seam and ejector pin mark on the kit part. I did the new part in easily under five minutes. Now I just need to cut off the old canister and replace it with the new one.

Time to mount the alternator (I told you it would be revealed, Stevenski). The alternator body will be mounted on a small steel rod- about 0.010" dia.



It fits into a small hole I drilled in the chassis frame. Here it is being test fitted.



Now for some mounting hardware. To make the mounting bracket, I started with some thin (0.020" dia) brass rod. I softened an inch or so by placing it in a lighter flame and allowing it to cool (annealing it), and bent it into the curve that I wanted.



Once I was happy with the shape, I put it on my mini-anvil and gently pounded it flat with a small peening hammer head (which was, of course turned on the lathe ). This is even better than PE brackets, as I can make any shape I want (easier to find and cheaper, too! ).



I then cut it off, and blackened it in Blacken-It.
(Creative, I know. )

Here's the alternator with the new mounting bracket.



Then, I just neeeded another mounting point- so a small piece of plastic channel rod will do the trick.



And here it is all put together.



The wires nicely hide the mounting rod.



A few CM PE fasteners were added for nuts and bolts.





There- much better than the plastic stub on the kit part, I think. It will get a drive belt once the engine is in place. So, on to more engine detailing....

[Stiwi]

Hi MPWR,

this Alternator is looking like a real one. Great work so far. But an alternator is never mounted onto a cars body or frame!! It has to be mounted on the engine, cause the engine is moving indepedent of the body or frame and this movement cound'nt be handled by the drive-belt. I hope you'll know what I mean. BMW used to use Bosch-Alternators so the wires have to go into the backside of the alternator.

Take care

Stiwi

[Shunter]

The alternator looks very realistic. It is a model on its own..

[agamo]

Awesome job as usual, always a great experience watching your work.

Great!

Regards

[mike@af]

Wow Andy, great work. Thanks for showing the step by step, its fun to learn something new.

[nugundam93]

Originally Posted by Stiwi

Hi MPWR,

nice project. I love those oldschool touringcars.

And I've found a pic showing the no. 10 car driven by Gerhard Berger in Spa 1986. Take a look at the side :

hahahahahahaha! so even at that time, gerhard berger's getting his share of weight jokes?

[Technoman]

Originally Posted by nugundam93

hahahahahahaha! so even at that time, gerhard berger's getting his share of weight jokes?

I think they are referring to the trim down the side of the car. The car is at an angle because of the camber on the track.

Great progress by the way!!

[nugundam93]

ahhhhh okay, i thought it was another berger weight joke.

[sportracer02]

Fantastic work

[Risko]

Wow, amazing skills, can´t wait to see it finished!

[klutz_100]

I'm in a quandry - as I know you, the 1/1 alternator is just where you put it (give or take a micon or two ). On he other hand, Stiwi's point does sound logical and reasonable. What's the deal?

Regardless of where it is or isn't, it's an outstanding example of modeling skill and I'm surprised that it only takes you +/- 1 hour :o

[MPWR]

Originally Posted by klutz_100

I'm in a quandry - as I know you, the 1/1 alternator is just where you put it (give or take a micon or two ). On he other hand, Stiwi's point does sound logical and reasonable. What's the deal?

Yeah, well, there is that. Logically, I expect Stiwi is correct. My first thought was to attach it to the engine- but the only place it would logically go is occupied by the oil filter. The kit part has the alternator outrigged in such a way that it could not possibly be supported by the engine- mounting it on the frame would have been the only option. So, I took my positioning cues from Tamiya, and recognise that it could be incorrect- but I really didn't know what else to do with it. The problem is I really don't have enough in the way of good reference materials to superdetail this engine. There isn't alot of guesswork, but ther is some. The other bit will be the plumbing of the semi-dry sump system. Tamiya of course didn't bother to include scavanger pumps. I've settled on a logical, probably defendable configuration, but it really is guesswork. I have no idea what the system Schnitzer installed looked like. So, maybe the best I can do is come up with something that looks good....

[malscar]

MRWR, just a few photos to help you with the detail. This is one of the Aussie JPS cars. Built all in-house so it will not be exactly the same as the Euro cars. Photos are big to keep detail which is why I used thumbnails here. If you have dialup they will take time.

The sump shot below shows the oil filter and just in front of it the alternator. What looks like a bracket seems to be bolted to a cast-in hard point on the side of the pan. Interesting concept. Note also that they have welded extra protection onto the bottom of the sump.



Next is the engine from above.



Then the front right suspension.



The diff area to help you with plumbing.



Finally a shot of the dash etc. All photos are from 'Australian Motor Racing Yearbook 1984/85 by Berghouse Publishing Group.



Hope this helps,
Mal

[Stiwi]

Originally Posted by MPWR

Yeah, well, there is that. Logically, I expect Stiwi is correct. My first thought was to attach it to the engine- but the only place it would logically go is occupied by the oil filter. The kit part has the alternator outrigged in such a way that it could not possibly be supported by the engine- mounting it on the frame would have been the only option.

The position where u've mounted the alternator is just the right area, but it has to be mounted completly on the engine. On malscar's second pic u can see a part of the back of the alternator one inch right of the A(the last A in ALPINA) on the valvecover.