Author Topic: Cosworth V8 1:12 scale  (Read 1639 times)

Offline Steve Crow

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Cosworth V8 1:12 scale
« on: November 22, 2020, 06:11:42 PM »
A few months ago, I decided to have a go at making a 1:12 scale Cosworth V8 DFV Formula 1 engine.

It will be a 2-stroke running on air (or CO2?) with a bore of 7.2mm and a stroke of 5mm.

I want to share my progress so far as I’m sure I will need some advice.

After making the drawings, the first thing I did was make card models of the main components.



 

This helps me visualise things and see if any screws interfere with each other etc.



 

The block started life as 1” square mild steel bar.



 

I sawed of a piece about 3” long and this was clocked in the 4 jaw and eccentric bosses, on the crank centre line, were turned at both ends. This gave me an accurate way of holding it while boring out the cylinders and milling the block to shape. In the picture below, the milling is part done.



 

The block, milled to shape. The bores are a bit rough but true. They will have brass liners anyway.



 

The block was drilled and tapped and the sump blank bolted to it.



 

The whole assembly was then drilled and bored out as one piece and the bosses removed.



 

More to follow….

Steve

Offline Steve Crow

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Re: Cosworth V8 1:12 scale
« Reply #1 on: November 22, 2020, 06:16:25 PM »
The next job was to remove some metal from the inside of the sump and the block to provide clearance for the con rods.

Here is the block, ready to be milled. Note the miniature brass V-blocks – very handy things. You can see they are numbered. This is to ensure repeatability when using them with a 4-jaw.



And here they are completed. The block now weighs 60g. The initial square blank weighed 370g. That might not sound a lot of swarf to you guys with big-boy’s lathes, but it made a mess of the kitchen table with my Sherline.



More soon.

Offline Vixen

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Re: Cosworth V8 1:12 scale
« Reply #2 on: November 22, 2020, 06:19:28 PM »
 :ThumbsUp: :ThumbsUp: :ThumbsUp: :ThumbsUp:
It is the journey that matters, not the destination

Offline gerritv

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Re: Cosworth V8 1:12 scale
« Reply #3 on: November 22, 2020, 06:23:11 PM »
Wow, this makes it real.

Gerrit
Don't confuse activity with progress

Online steamer

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Re: Cosworth V8 1:12 scale
« Reply #4 on: November 22, 2020, 07:08:45 PM »
Wow!  nicely done!    following along!   

 :popcorn:

Dave
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Damned ijjit!

Online crueby

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Re: Cosworth V8 1:12 scale
« Reply #5 on: November 22, 2020, 07:44:44 PM »
Beautiful work - I like the little v-blocks too, have to remember that one.

 :popcorn: :popcorn: :popcorn:

Offline Roger B

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Re: Cosworth V8 1:12 scale
« Reply #6 on: November 22, 2020, 08:00:35 PM »
Splendid  :ThumbsUp:  :ThumbsUp:  :)  :wine1:

I am also a user of CAD (cardboard aided design)
Best regards

Roger

Offline Art K

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Re: Cosworth V8 1:12 scale
« Reply #7 on: November 22, 2020, 11:13:34 PM »
Looks like a fun project, great work. Clever use of the brass V blocks to hold the block for machining.
Art
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Online Dave Otto

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Re: Cosworth V8 1:12 scale
« Reply #8 on: November 23, 2020, 01:02:01 AM »
That is some nice table top machining there!
Your parts look very nice!

Dave

Offline Ramon

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Re: Cosworth V8 1:12 scale
« Reply #9 on: November 23, 2020, 08:31:36 AM »
Very nice workmanship Steve - just shows what can be done on small kit when the desire is there  :ThumbsUp: :ThumbsUp:

I look forwards to seeing this progress further in coming weeks

Regards - Tug
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Offline Steve Crow

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Re: Cosworth V8 1:12 scale
« Reply #10 on: November 23, 2020, 09:28:08 AM »
Regarding the little brass v-blocks - I use them along with this gadget for holding small square sections in the 4-jaw chuck.







Steve

Offline Mosey

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Re: Cosworth V8 1:12 scale
« Reply #11 on: November 23, 2020, 02:07:15 PM »
Spiders, I think they're called

Offline Steve Crow

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Re: Cosworth V8 1:12 scale
« Reply #12 on: November 23, 2020, 02:21:15 PM »
I made some endplates from 1/8” mild steel flat bar. These hold flanged bearings for the crankshaft, 4mm at the gearbox end and 3mm at the cam-drive end. There is raised boss on the back of both which are a snug fit into the crankshaft bore to keep thing nice and true.



The one on the left will house the flywheel and the one on the right, the cam gear train.



The sump and block were drilled and tapped 12BA to secure the endplates and everything was assembled.







Steve

Offline Admiral_dk

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Re: Cosworth V8 1:12 scale
« Reply #13 on: November 23, 2020, 07:44:53 PM »
Nice parts and progress  :ThumbsUp:

Getting the  :cheers: and  :popcorn: ready.

Offline Steve Crow

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Re: Cosworth V8 1:12 scale
« Reply #14 on: November 24, 2020, 11:33:17 AM »
I then fly-cut some steel to size for the cylinder head blanks and drilled and counterbored to suit the block. All in all, I had to tap 30 blind holes to M1.6 in the block. A bit scary.



I also cut to size blanks for the cam carriers. They can just be seen in the background.



Another shot.



Steve