4 Cylinder Inline Engine

[rdean]

Been working on the pistons the last couple of days.
This shows cutting the o-ring groove in the piston.


And a group photo.


Slotting the piston for the connecting rod.


Drilling for the wrist pin.


Ready for the connecting rods.


I installed brass bushings in the piston end of the connecting rods but didn't get a picture.

Everything fits and turns smoothly.


Happy days.

Thanks for looking.
Ray

 

[Chris Hamel]

Starting to look like an engine

 

[rdean]

Thanks Chris
I did have to cut the block down some to get the compression ratio up where I wanted it.
I took off 0.025 to raise the ratio up to 6.2 to 1.
I must have added when I should have subtracted when drilling the holes for the wrist pins.
Ray

 

[rdean]

Cylinder head day.
Time to see if my calculations are correct.
First spot drill the hole locations.


Then on the drill press finish drilling through for the head bolts, intake, and exhaust holes.
Counter drill for the head bolt recesses and partially drill for the spark plug.


The spark plug hole gets finished later just before final assembly.

I am happy to say the 16 head bolt holes all lined up just fine.

Thanks for looking
Ray

 

[Chris Hamel]

It's always a good day when you trust your DROs and it all works out.

 

[Chris Hamel]

After posting the comment above, I realized you probably used the CNC mill to spot the holes. Regardless, it's always good when everything lines up.

 

[rdean]

You are correct Chris and even using the CNC there is still a possibility when drilling the holes that the bit will wander off some. I have never made a 4 cylinder head in one piece before. A couple of 0.001s off in each of the 16 holes could add up to a problem later.

Ray

 

[rdean]

I cut the cooling fins in the head today and drilled holes for the intake and exhaust ports.
Then gave it a little shine.


I think I am done making holes in the head for now.

Thanks for looking
Ray

 

[rdean]

I made 8 brass valve guides, these are longer than usual for me. I am planing an overhead cam for this engine and I noticed that on the other engines I had built with overhead cams the valve stems were subjected to some side loads. Making the guides longer should give the valve stems more stability.


Installed the guides.




Thanks for looking
Ray

 

[Tom1948]

True, longer guides equals more stability. Good thinking Ray. That little engine, the way you designed it should be capable of some high rpm;s.