Let's build a 4 cylinder

[Boswell]

Than is one beautiful engine Ray.

 

[rdean]

Boswell I think you're right I only hope it runs as good as it looks.

Ray

 

[rdean]

On my models that require a throttle I have been kind of lax. It is usually at the end of a project and I just stick a piece of metal up somewhere to operate the carb throttle. This time I wanted to make a smooth operating and hopefully a nice looking one that is easy to adjust and stays in place.


I also had some time to start on the gas tank. I still need to make the clear ends and a stand for the tank but I ran out of steam for today.


Thanks for looking
Ray

 

[rdean]

I finished up the gas tank and made an aluminum stand for it.


All that's left is the spark plug wiring and getting it to run.
Maybe tomorrow

Thanks for looking
Ray

 

[rwm]

Sweet! I am wondering if he fly wheel is large enough for all the rotating parts? I would not know how to size this?

 

[rdean]

Robert I'm not sure either if it is big enough for a nice slow idle but I should know soon.

edit (sorry Robert I got your name wrong just getting old)

Ray

 

[rdean]

Well the engine does run but there are a few things that need to be sorted before the unveiling.

Distributor cap keeps falling off.
I have the dist cap held on with some electrical tape for now but when I am sure of the location I will a fix better.

Cylinder # 2 has a low output.
Cylinder #4 has no output.
I will pull the pistons and heads on #2 and #4 to see what is going on.

Cylinder #4 valve spring keepers/lifters are too short.
I will make longer lifters for #4 valves.

Fasten plug wires for neatness

Cylinders #1 and #3 are pulling fine so I am half way there.

Thanks for looking
Ray

 

[rdean]

I remade the valve spring keepers on cyl #4, lengthening them by 0.070 and realigned the cam shaft.
I couldn't find anything wrong with cyl #2 but I replaced the o-ring anyway.
Fastened the plug wires as best I can, they don't look too bad.

I put everything back together, started the engine and ran at least 6 tanks of gas through the engine today trouble shooting some new issues.

Cylinders #3 and #4 are firing nicely but # 2 is still weak.
Cylinder #1 has no spark and is pumping raw gas out the exhaust.
The cylinder would fire sometimes but not all the time which lead to the flooding condition.
I closely inspected the distributor and came to the conclusion that you get what you pay for. I may try to modify the dist first but if
that doesn't work out then I will make one of my own design.

I will be back.
Thanks for looking

Ray

 

[rdean]

I have made two major changes to the engine starting with the distributor.
I decided to try to close up the gaps the spark had to jump to get to the plug. The way it was made the spark had to jump over 0,050 in two places and then still have enough pep left to fire the spark plug.
This picture shows the rotor with the new copper wiper I installed that is 0.040 higher than the original. The bent up staple (that's what it looks like) was the original wiper and it was in bedded down in the plastic.
The spark now has a combined jump of 0.020 not 0.100 to make before the spark plug. Miss fires are a thing of the past.


The next change was the flywheel and as Robert had questioned earlier there was not enough mass for smooth running.
The new flywheel weighs over twice as much as the original and about the same diameter. You may ask why didn't I just go to a larger diameter and the answer is this is the only piece I had.



The engine doesn't like to run below 1200 rpms as there is a problem with the fuel distribution to the cylinders. Cylinder #1 is running too rich and cylinder #4 is running too lean. I will be investigating this issue in the future and I believe it has something to do with intake manifold.

I am not very good at taking videos so be kind.

Thanks for looking
Ray

 

[rogerl]

Ray:
That is amazing. What if you went with dual carburetors? This way you will only need to feed 2 cylinders per carb.

Roger L