Let's build a 4 cylinder

[rdean]

Thanks Ben I am not going to rush but do the best I can.

Ray

 

[rdean]

I changed the order of the build so I could first install the front cog belt pulley and make sure it ran true. Then I decided to make up the flywheel so it would be easier to turn the engine over after installing the o-rings.
I had an ugly piece of 4" round steel that I had tried to use on a different model a couple of years ago for a flywheel but it wasn't big enough for that model I think it may just work fine here.

I started by digging out 0.200 from both faces to thin it down on the lathe.


Then over to the mill to make some lightening holes to improve the looks.


The center flange was from a previous build also and required the center hole to be enlarged to fit this crankshaft.
Painted both pieces and left them to dry overnight.
Installed the belt pulley and the flywheel today.



What do you think?
Should the center taper lock flange be a different color?


This shows how I cut the grooves in the pistons for the o-rings.


Pleased to say all cylinders hold a vacuum for at least 30 seconds.

Thanks for looking
Ray

 

[Chris Hamel]

Looking good

 

[rogerl]

Ray:
Are you going to do an overhead cam on this engine?

Roger L

 

[rdean]

Thanks Chris

Yes Roger it will be much like the 2 cylinder engine I just finished only 4.

Ray

 

[rdean]

This shows making the cooling fins for the cylinder heads.
I cut the fins for all 4 heads before taking them to the band saw to separate them.


Truing up the heads after the band saw cuts.


A good start on 4 cylinder heads.


Thanks for looking
Ray

 

[rdean]

I drilled the holes in the cylinder heads for the head bolts, and the intake and exhaust valve guides. I won't drill the spark plug holes or the intersecting intake and exhaust ports until later.
The cylinder heads needed to have 0.200 taken off of one side for a flat surface to mount the cam shaft support brackets.


And the results.


I also made up 8 valve guides.

These guides are made extra long to give the valve stems more stability due to the overhead cam sideways push when opening the valves.

Thanks for looking
Ray

 

[rdean]

8 valves are roughed in and how I how I made them.
Valve stem is cut using the cross slide.
Valve stem 0.125 in diameter.


The valve face is cut using the compound slide set at 45 degrees.
Valve face 0.250 in diameter.


I made all the valves the same length and threaded the ends 6-32 for the brass push rods to screw on to.


Thanks for looking
Ray

 

[rdean]

The intake and exhaust ports are drilled at an angle in order to miss the head bolts. I would like to tell you that I made a special fixture to hold the heads at an exact angle of some degree but I didn't. I used a couple of 1/8" drill bits for support and some 5/16" square stock to get an angle I liked. The degree of angle is not important only that they are all the same and that they intersect the valve guides. I also taped the holes 1/4 X 28 threads.


I used a drag knife on the vacuum table to cut the head gaskets. Not a very good picture you can just see the ones that are already cut in the back row.


I made a plate for the cylinder heads to bolt on to in order to test the valves using shop air.


I started laping the valves.
Probably one of my least enjoyable jobs.


Thanks for looking
Ray

 

[Chris Hamel]

Looks like you had a productive day.