Thread: Casting small engine parts

Hello all - first post here. You come recommended from a guy i found in a google search.
Anyway - i have a rare car engine that has some fancy valve rockers. Being rare - there are no others. I would like to cast some spares.
They are fairly small - each rocker is in 2 pieces and each piece will fit inside your hand. Ive attached an image of it all together but i dont expect you to make too much sense from it.
Does anyone know where i could get these pieces cast?
Thanks
Glenn

Glenn
Welcome
do you know what the material is? Cast iron or Cast steel? If iron you should be able to find someone down your way who could and would be able to reproduce these. If steel then it might be a different story. I can't help you with who though unfortunately.
There are still a few commercial foundries around but I believe a lot of them are not interested in small volume work. If the rockers are Cast Iron then you best bet would probably be a backyarder who knows what he's doing. Someone else here will probably be able to add more to this.
Whats the car?

regards
bollie7

Thanks bollie
Its a Ford model T racer. photos attached.
Now im gonna let you see something that not many people get to see - my ignorance! i have no idea what they are made of.
I would need someone to have a look. Personally - does it matter what they are made of?

An alternative option could be to take a stack of photos, and use an image-to-3D service (see this post) and create a CAD file of the part (confirm critical measurements and tweak the model to fit).

You then have something you can keep against future need, and when required, either get the part CNC'd in a moulding foam to make a part for casting, or CNC'd directly from billet - CNC Machine Shop | Custom Waterjet, Plasma, Laser Cutting | eMachineShop.com .

Wow - four valve heads! How old is that engine?

I wouldn't be surprised if the rockers are forged steel, like the car's front axle.
Not easy to replicate in the home workshop.

Jordan

Nadroj - its actually 16 valve. 1917 was the year of manufacture. Peugot made the first multivalve engine but this is considered so different to the Peugot model that this engine (called a 'Roof type A') is considered the first 16 valve car engine. They were an after-market engine solely for the Ford Model T.

Is there a difference between cast steel and cast iron? again showing my ignorance but would it make any difference for this type of application?

Ive seen the ability to take digitial measurements of pieces and turn them into plastic replications - is that the sort of thing in need here to start with?

Nice looking car.

Looking at the photo, the rocker assembly seems to be a mixture of castings and forgings. I'd be surprised if any of the higher stressed bits were cast iron in that application - could be wrong though.

Are you a member of the MTFCA (Model T Ford Club of America)? I am not, just a former T owner, but a friend and current owner of an OHV speedster (not a Roof head) passes on his MTFCA magazines for me to read. Within the last year or two there was a long feature article on the history of the Roof company and detailed description of the Roof heads.

Frank.

Originally Posted by wgipps

Nadroj - its actually 16 valve.

I mean 4 per cylinder. Most V8s have 16 valves too, but only 2 per.

Jordan

Hi Franks
I am on the MTFCA discussion board and am aware of 3 other Roof type A heads still going, and 1 in a museum somewhere. I read an article about them a while ago - i will see if it is one and the same.
Castings? Forgings? now youve got me stumped.

Hi Glen,
What sort of rpm do you have in mind?
I guessing not many so maybe cast would hold up?

Which ports are split? 2nd and 5th?

Stuart

Hi Glen,

I do a bit of backyard casting, but I'm not sure I can help. It's hard to see the shape clearly with the pictures, and I think making the pattern might be a bit tricky.

As for material, the sample part doesn't look like cast iron, it might be a cast steel alloy?

I wonder if silicon bronze would be suitable?

Any chance of a few pictures showing the shape a bit more clearly?

Beautiful restoration by the way.

Regards
Ray

We get small run castings done at work, not cheap but I'll find out who does them if you like?

Originally Posted by wgipps

Is there a difference between cast steel and cast iron?

Cast steel is exactly steel, but rather then rolled into beams and rods and billets is instead cast into shapes...

Cast iron is well, cast iron....

There is a third and fourth option..... They could be drop forged... But I would well imagine drop forging back then would have been a very expensive thing to do if it was even invented back then... Drop forging is the forging of steel between machined dies...

The fourth option is malleble iron castings.... Malleble iron is items cast as cast iron, then they go through a heating process in controlled conditions where most of the carbon is removed... resulting in a ductile iron metal...

There is a foundry in Bendigo that does ONLY cast steel. If you get the pattern sorted out, I could get a quote.
To put the difference of cast iron vs. cast steel vs. forged steel into perspective for this application (and simplistic terms), cast iron is brittle and won't tolerate much in the way of bending or shock before it cracks and falls apart, whereas cast steel has the ability to tolerate both bending (and will spring back up to a point) and shock.
Forged steel is "pressed" into the shape very hot by either a huge press or hammering. It has more inherent strength than the steel it was forged from because none of the 'grain' of the metal is cut or disrupted in the process and it is made 'denser' by forcing the molecules closer together.
None of this is technically entirely correct, but in practical terms it makes some sense.

Joe

Thank you guys. Ill tell you what im thinking.
1 - Get some better pictures of the parts.
2 - look at getting some 3D modelling and/or rapid prototyping done
From there, i can identify what process i need to employ and get some quotes.
How does that sound?