Cosworth V8 1:12 scale

A fine challenge and beautiful work!

One of the most fiddly things on this build was hand fettling the bearing blocks so the camshaft turns freely with a minimum of play.

The cam shafts are supported by a sort of shell bearing. These were made by turning down brass bar to 2mm and boring out to 1.6mm.

These were then trimmed down to a semi circular C-section and burnished/work-hardened into place using a polished steel 1.6mm rod.

They are now held firmly in place by there own springiness.

I'm making all this up as I go along but it seems to be working fine.

Steve

Amazing work! Keep up the info on here please. I wish I had the time patience and skill that you have.

David

That is looking stunning Steve. As above keep posting pics.

Steve.

My next challenge is to finish the cam gear train. The principal gears are in place and running smoothly, I just need to sort out the idler gears.

Here are some sat in their final position.

Steve

So cool !! I wouldnt know where to start !

Superb workmanship and excellent documentation - thanks for sharing it

Tug

Absolutely BRILLIANT . Well done .

I am totally in awe. Yes, brilliant.

I have a similar-ish gear-driven DOHC V4 Honda motorbike. Ohh but those many and multiple gears make a glorious whine when they get wound up!

Edited By Hopper on 20/02/2022 12:31:02

It's time I resurrected this thread. I've had a couple of months off metalwork but I'm back into it now.

Yesterday, two years to the day from the first idea and drawing, I finally finished making all the major components.

I've completed the task I dreaded most. The valves, guides, tappets and springs - 32 of each.

The valves took the most time as they are rather small with quite tight tolerances. Each one needs 8 machining processes.

Here's 16 of them on a penny.

And a close up of one so you can see the slot.

At this magnification, you can see bits of paste from when I ground them into their seats.

Edited By Steve Crow on 28/05/2022 17:17:15

Here's how the valve parts fit together, open and closed.

The valve guides are brass and reamed with a 1.026mm carbide reamer (Jurassic Tools - great price). They are a friction fit in the cylinder head and the springs keep them seated.

The tappets are adjustable using the 3 holes and the slot in the valve using a tool that I have not finished yet.

Here is a tappet and an untrimmed spring. And a penny.

Steve

Jeepers!

Very impressive work.

Jeepers!

Very impressive work

[Edit: Duplicate post, but it bears saying twice, anyway.]

Edited By Andy_G on 29/05/2022 09:26:25

Here is one cylinder head with valve gear installed and a cam carrier behind it.

Valves, tappets and springs (and spares) for the other head.

Amazing workmanship

Can't wait to see her turning over