By continuing to use this site, you agree to our use of cookies. Find out more
Forum sponsored by:
Forum sponsored by Forum House Ad Zone

Cosworth V8 1:12 scale

All Topics | Latest Posts

Search for:  in Thread Title in  
Nigel Graham 203/12/2021 18:33:17
2133 forum posts
29 photos

A fine challenge and beautiful work!

Steve Crow06/12/2021 15:10:28
310 forum posts
191 photos

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.

cam1.jpg

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.

cam2.jpg

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

Steve

David George 107/12/2021 08:26:29
avatar
1839 forum posts
503 photos

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

David

Steviegtr07/12/2021 22:36:14
avatar
2432 forum posts
336 photos

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

Steve.

Steve Crow07/12/2021 22:58:48
310 forum posts
191 photos

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.

gears1.jpg

Here are some sat in their final position.

gears2.jpg

Steve

Die Hardenedbedway12/01/2022 17:05:15
avatar
30 forum posts
14 photos

So cool !! I wouldnt know where to start !

Ramon Wilson12/01/2022 17:52:00
avatar
1319 forum posts
382 photos

Superb workmanship and excellent documentation - thanks for sharing it

Tug

Engine Doctor ( Phil )20/02/2022 11:48:33
avatar
19 forum posts
1 photos

Absolutely BRILLIANT . Well done .

Hopper20/02/2022 12:28:59
avatar
6393 forum posts
334 photos

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

Steve Crow28/05/2022 17:16:14
310 forum posts
191 photos

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.

01.jpg

Here's 16 of them on a penny.

valve01.jpg

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

valve03.jpg

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

Steve Crow28/05/2022 18:32:22
310 forum posts
191 photos

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

02.jpg

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.

valve05.jpg

Steve

Andy_G29/05/2022 09:25:25
avatar
173 forum posts

Jeepers!

Very impressive work.

Andy_G29/05/2022 09:25:26
avatar
173 forum posts

Jeepers!

Very impressive work

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

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

Steve Crow29/05/2022 10:42:43
310 forum posts
191 photos

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

valve04.jpg

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

valve02.jpg

Ady129/05/2022 14:10:43
avatar
5090 forum posts
736 photos

Amazing workmanship

Can't wait to see her turning over

All Topics | Latest Posts

Please login to post a reply.

Magazine Locator

Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!

Find Model Engineer & Model Engineers' Workshop

Support Our Partners
Eccentric July 5 2018
cowells
Dreweatts
Rapid RC
Eccentric Engineering
Subscription Offer

Latest "For Sale" Ads
Latest "Wanted" Ads
Get In Touch!

Do you want to contact the Model Engineer and Model Engineers' Workshop team?

You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.

Click THIS LINK for full contact details.

For subscription issues please see THIS LINK.

Digital Back Issues

Social Media online

'Like' us on Facebook
Follow us on Facebook

Follow us on Twitter
 Twitter Logo

Pin us on Pinterest