Marks Holt 75

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I soldered the tank ends with silver solder and soft soldered everything else. The sediment bowl was cut from a glass test tube with a diamond wheel lubed with drops of water. After cutting the bowl's edge was smoothed with a diamond sharping stone. Before installing I filled the tank and checked everything for leaks.

Next I will be completing the fuel system with the governor and the linkage.



solder tank ends.jpg


Cutting Bowl.jpg


Drilling holes.jpg


Fuel Tank parts.jpg


Close up.jpg


Fuel Tank assembly.jpg
 
I soldered the tank ends with silver solder and soft soldered everything else. The sediment bowl was cut from a glass test tube with a diamond wheel lubed with drops of water. After cutting the bowl's edge was smoothed with a diamond sharping stone. Before installing I filled the tank and checked everything for leaks.

Next I will be completing the fuel system with the governor and the linkage.



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Very nice work. I really like the detail your sediment bowl adds.

Chuck
 
I'm making needles for model airplane engines by chucking music wire into an electric drill and grinding in the taper on a bench grinder, followed by a polish on an oil stone. So far it seems to work.

But I'm using 1/16" wire, not 1/32". (And yes -- music wire. Eventually I'll need to get serious and use proper drill rod).
 
I'm making needles for model airplane engines by chucking music wire into an electric drill and grinding in the taper on a bench grinder, followed by a polish on an oil stone. So far it seems to work.

But I'm using 1/16" wire, not 1/32". (And yes -- music wire. Eventually I'll need to get serious and use proper drill rod).

Look at using drill bits. Good steel and they come in all sizes. The problem i see in music wire is that it generally comes in coils so it isn't straight.

Mark
 
You can get 3 ft. straight lengths from places like Tower Hobbies that cater to the RC airplane crowd. I have some that is .024 and .032 and up, can't remember what the smallest size you could get is.

Ron
 
You can get 3 ft. straight lengths from places like Tower Hobbies that cater to the RC airplane crowd. I have some that is .024 and .032 and up, can't remember what the smallest size you could get is.

Ron

.008.

And I'm a member of that model airplane crowd (RC, CL, and FF). So when I think "music wire" I think three-foot straight lengths of drawn carbon steel wire that seems to run a hair oversize from its nominal diameter.
 
Hi

Well I had a great summer despite being in lock-down. Got out of the shop and out into the sun for a few weeks. Its Fall now and its wet out so I got myself back into the shop to work on the Holt project. This update shows the governor and the linkages connecting it to the carburetor.

Next is balancing the flywheels and making a starter clutch.

Mark T

Gov parts.jpg

Gov linkage.jpg

Gov fly balls.jpg

Gov2 linkage.jpg

Carb linkage.jpg
 
Hi

First let me thank you guys that left messages or left “likes” on my last post. It is very appreciated.

In the past when I made a starter clutch I used a one way bearing that a rod chucked into a drill motor would turn. The rod was hard to keep square to the bearing and so the bearing would soon fail. This time I am doing things a little different. The result is a starter clutch with a bearing that will stay aligned and not as likely to fail.

The bearing is a press fit into the part with the nut machined on the end. The shaft the bearing rides on has been case hardened. In the free turning direction the clutch turns butter smooth. In the drive direction the bearing locks up instantly. I think it looks nice.

Now I need to dissemble the engine a little to remove the front flywheel so that I can balance it and the rear flywheel as a unit. Before reassembly I will be timing the crank to the camshaft. And then it will be time to work on the distributor and ignition system.

Mark T

starter clutch parts.jpg


starter clutch.jpg
 
Hi, Thanks for following along. The end is near. Still have the ignition system to go and then the inevitable problems encountered when trying to start a new motor.

No photos this time, you will have to use your imagination.

The flywheels have been balanced. Before putting them back on the engine I made a protractor and set the camshaft timing to the crankshaft. I set cylinder one to start opening the intake valve at 20 Degrees BTDC. I then installed the big flywheel and the starter clutch. And I installed the spark plugs. Using a drill motor I rolled the completed engine over for the first time. Defiantly have compression and it sounds like a motor should. I need to fallback now and do some pickup work like a larger pulley for the water pump, some hardware replacement and some gaskets. And I still need to put water in the radiator and check the system for leaks.

Some time this week I will receive material for the distributor. I purchased an ignition system from Roy Sholl over at the S/S web sight Roy's CDI Ignition Systems . He shipped it promptly but was out of stock on the distributor wire with boot so I will be waiting on those. Roy is no longer running his web site as a business, but he is continuing to build some of his systems. He answered my email request for availability and cost the next day. And he shipped a couple of days after I sent an email placing the order. He trusted me to send the check.

Mark T
 

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