Tapping cast iron for poppin engine.

[ian_in_the_midlands]

I am having a go at making a poppin flame licker engine.
I have only made a simple Elmer's wobbler before so expect this to be challenging.
Expect plenty of questions to come.

The plans call for the cylinder to be tapped 2-56.
I plan to convert everything to metric, so will use M2 instead.
These holes will take screws that hold the cylinder to the standard, and hold the cylinder head on.

My questions are:
Are there any special considerations/potential problems when tapping cast iron with a small M2 thread?
Should I use tapping fluid with cast iron, or tap dry?

Thanks.

[Jo]

Cast Iron is a joy to tap and self lubricating

(This is assuming you are not using a recycled piece of CI full of hard spots  )

Jo

[ian_in_the_midlands]

I think it must be some good stuff. First time I have used it. Managed to cut 15 thin fins on cylinder without any problems.

[Bradley Simmonds]

95% of the time normal grey cast iron and 3d/sg/ductile iron is even better...you shouldn't ever really have a problem at all.  You can tell if you have got the goo stuff-ductile iron as when you machine it, it smells garlicy

[DavidA]

Spheroidal Graphite iron smells heavily of carbide if you first breath on it then sniff the surface.

If you get this result with cast iron,  then you need to change your mouthwash.

Dave.

[PJW]

Hi Ian, any pics?

[Bradley Simmonds]

Spheroidal Graphite iron smells heavily of carbide if you first breath on it then sniff the surface.

If you get this result with cast iron,  then you need to change your mouthwash.

Dave.

Ummm did i miss something?

[PJW]

Are you doing a build log on your flame licker, this is an engine I know little about. I enjoy machining Cast although it is a bit dirty to work with, I have made piston rings with cast and it is amazing how much you can open it after heat treatment, its like spring steel.

[ian_in_the_midlands]

I was not going to do a build log. I have little idea what I am doing, so it is very much a project to learn from.
It is a big challenge to me, and don't know yet if I am up to it.
I would hate to start the log and not be able to end it.

I will post pictures of any success following help on here.
The cylinder will be the first picture - assuming I do not mess up the drilling and tapping.

[ian_in_the_midlands]

The cast iron was purchased from Noggin Ends. I think it is Grade 250 Meehanite.
It turns very easily.

Will a tiny M2 thread hold in a material with such a grainy structure?

[Manxmodder]

I was not going to do a build log. I have little idea what I am doing, so it is very much a project to learn from.
It is a big challenge to me, and don't know yet if I am up to it.
I would hate to start the log and not be able to end it.

I will post pictures of any success following help on here.
The cylinder will be the first picture - assuming I do not mess up the drilling and tapping.

Look at it another way,if you log it here and get into difficulties then it is easier for more experienced members to guide you through any problems you may encounter.
A problem shared is a problem halved,so they say  ......OZ

[awemawson]

I find that a build log not only gives others an opportunity to help with problems but also helps me sort out my ideas logically..writing it out for others to read forces you to go through the process in your mind. I also find the logs a useful reference and several times have referred back to them on the forum to remind me what I did!

[dawesy]

good point andrew.
also there are some of us who are less experienced and may be apprehensive about starting a project like this, seeing you do it can help encourage us to have a go too.
remember he who has not made a mistake hasn't made anything 

[PJW]

Hi the engine shown in my avitar is a Webster ic engine, the cylinder is Meehanite, I found it so nice to use I am using it in my latest project, a Hoglet Jnr a scaled down V twin. Like yours this is a massive project for me & if I ever get it running I will be cockerhoop!
As I go I have started a build log & I will be sharing it soon.
I have had a lot of help from the forum members in the past so dont be shy of asking!

Peter 

[Manxmodder]

good point andrew.
also there are some of us who are less experienced and may be apprehensive about starting a project like this, seeing you do it can help encourage us to have a go too.
remember he who has not made a mistake hasn't made anything 

Lee,there are some days when I make nothing but mistakes and question whether it was a mistake to have even got out of bed .......OZ.

[dawesy]

OZ in glad I'm not alone there.
Lost count of the times I've gone into the workshop and things just don't go right so I end up kicking up and coming in

[ian_in_the_midlands]

As you predicted, it tapped surprising easily.
Fairly pleased with progress so far.

Off now to make the piston.

[PJW]

thats looking good so far

[dawesy]

Very nice

[Stilldrillin]

Fairly pleased with progress so far.

So you should be! That looks spot on.

I've never made a finned cylinder. We're all beginners, in some aspects........ 

David D

[ian_in_the_midlands]

Build log started as requested.
It will keep all my questions together.