Let's build a 4 cylinder

[rdean]

I have never built an engine with more than 2 cylinders before but I was really impressed with how smoothly my last engine the "Horizontal Twin" ran that I am going to try a 4 cyl version. I want to use three ball bearings on the crank shaft so that means I will have to make a built up crank. Now I haven't had a lot of luck with built up crankshafts in the past in fact I dread making them so maybe I need a different approach.

I started by carefully making the webs all the same length, thickness and width except for the outside two they are thicker. I drilled all the holes on the mill using ther DROs so I could could get them all the same spacing and in the correct location.



The holes were sized for a close slip fit so I need a way to hold the webs at exactly a 90 degree angle to the main shaft.
I put the main shaft in the lathe chuck at the desired length for the first web. Using a lot of Loc-tite 620 I held the web against the chuck jaws using the tail stock and a socket.



After about 15 minutes I removed it from the chuck and this is the result.


I also glued some of the rod journals before assembly using the same method.


I reinstalled the main shaft with the long end sticking out this time and started adding pieces.
I cut 10 spacer blocks to insert between the webs as each new piece is added and no I didn't forget to put in the center bearing.


This was all held in place overnight to allow the glue to really set up.
All the joints were drilled and tapered dowel pins installed before cutting out the main shaft spaces and trimming the rod journals.
Here it is after filing off the dowel pins and a little more cleanup.


It looks to be fairly straight but the real test will be when it is installed in the engine block.
Fingers crossed.
Thanks for looking
Ray

 

[Braeden P]

Can’t wait for this one!

 

[Boswell]

Looking forward to watching this build.

 

[rdean]

Thanks Braeden and Boswell glad to have you along.

Cut and assembled the main frame for the engine. I am using some thinner stock for this engine as I think I overdid it on the "Flat Twin". The side rails are 1/4", the end rails are 1/2" and the center support is 3/8".


This shows milling out for the main bearing caps.

Main bearing caps installed.


Next will be line boring the main bearings.

Thanks for looking
Ray

 

[rdean]

Indicated the block in the four jaw and drilled a 1" hole all the way through.


Using my biggest and longest boring bar I finished the hole out to size for the bearings.


I installed the crankshaft and was surprised to find it turned smoothly. I was expecting the shaft to be bound up or at least notchy but it's not. No straightening necessary and both ends run true.


Some times you just get lucky I guess.
Thanks for looking
Ray

 

[rdean]

I did some more cleanup on the crankshaft and gave it a coat of paint.



Drilling of the cylinder base bolt hole circles and access holes.


The crankshaft paint turned out so nice I thought I would paint the main block too. I put a wood dowel through the main bearing blocks to keep this area clear of paint and a way to hold the block.
I chose Allis Chalmers orange for a good color contrast.


That's all for a while as I am leaving today on a 7 day cruise.
The paint should be well cured by the time I get back.

Thanks for looking
Ray

 

[Boswell]

Have a great time off !

 

[Just for fun]

Looking good so far, have a great cruise!

 

[rdean]

Well I am back from the cruise but not in too good a shape yet. I never got off the ship and spent most of my time in my room.

The paint is dry and it turned out great.


I will probably start on the cylinders in the next couple of days but it depends on how I feel.
Thanks for looking
Ray

 

[rwm]

Ugg. Sorry to hear about your trip.
The engine looks great so far!