My Flat Head Hit Miss Engine

[rdean]

As I said before I seldom make any drawings but this cylinder head is different from anything I have made before. All of my other cylinder heads I have made were round. Simple to layout the head bolts in a bolt circle for the head and the block but this one is rectangular. I drew this up in Aspire and included cutting the head gasket as well.

I cut the head gaskets first and boy am I glad I did. Somehow I got the gasket size 0.080 too short and 6 of the head bolt locations off as well.
I haven't found just where I went wrong but I redid everything and now it is right. My only loss was 1 head gasket so not so bad.
This is the way I cut my gaskets using a drag knife so I made several on my vacuum table.

Fits good.

I mounted a piece of 0.625 aluminum plate with a spoil board under it and milled out the combustion chamber. I made the chamber 0.200 deep but I am not sure that is right. I am shooting for a 5.5 to 1 compression ratio so it should be close. If it is too deep I can shave some off the head to raise it.

I then flipped the piece over and milled the top side of the head and cut it out.


Top done

Bottom side


It turned out just right after all.
All the bolt holes even lined up.

I put it up on a pedestal for show.

Ray

 

[Ben17484]

@rdean sorry for a bit of a side topic, but I see you have a round column mill. I’m looking at getting a better mill and see round columns come up at a reasonable price. I know the negatives of moving the z axis losing your position, but do you find that a major issue? I’ve read back through some of your threads and you seem to do great work, so it’s clearly not holding you back.


Sent from my iPhone using Tapatalk

 

[rdean]

Ben
I actually have two round column mills one is manual and the other I converted to CNC.
I very seldom move the head on the manual mill. I use a combination of R8 collets and or ER32 collets this allows for different length tools and depth of cut without moving the head. A little bit of planning goes a long way.

Today was valve day and all went well
I made two valve guides, two 5/16" valves, two valve spring keepers and one light intake valve spring.


Assembled


I will lap the valves before I install the valve guides it will be easier that way.
I can still do more laping later with the guides installed if needed.

Ray

 

[Arielht500]

Very interesting project, will be following along.

 

[rdean]

Glad to have you one and all!

Did some laping on the valves and then installed the valve guides.
I spent some time doing some cosmetic features on the cylinder block.
It makes it look more professional what do you think?



I also got a good start on the crank shaft but still a lot left to do.
Note the sealed ball bearing for the connecting rod end.



Ray

 

[rdean]

A short day today but it turned out fine.
I reduced the webs on the crankshaft and rough cut the shafts.
Also installed #2-0 taper pins on the connecting rod end of the crank. These were driven home with a liberal amount of loctite.


Tomorrow I will cut them off and file them smooth.

Ray

 

[rdean]

I had trouble sleeping last night so I went out to the shop early this morning. (It happens when you get old)


Finished up the crankshaft and painted it.
I cut out the side rails and the bearing caps.


Think I will take a nap.
Ray

 

[rdean]

Well today I bolted the bearing caps on to the side rails and bored both rails for the crankshaft bearings.



It turned out so well I decided to layout the holes for the side rails and cylinder block in a piece of 0.375 aluminum plate. The plate will be the main frame that holds everything together.
There are 18 #6-32 bolts that secure all the pieces together and this is where I usually run into some kind of trouble. Marking, drilling, counter boring, and taping this many precise locations usually causes me to wallow out the holes to make it fit. Not today only one hole was off by about 0.010 and I was able to shift things around and make it work.
A few pictures






Ray

 

[Chris Hamel]

Looks good. Really coming together.

 

[rdean]

Thanks Chris