1/4 Scale IHC Famous 3hp

[maskell]

G day Jason,
I have been checking the 1/5 scale out from time to time and it looks as though it is comming along well. The carb on that one has helped me as I hadnt worked out how I was going to do that until I saw the bottom plate that bolts up.
Mine is a bit stop start as work gets in the way a lot, my average day starts at 6.00am in the workshop in town and I often don't get home intil 6.00-6.30pm and I do that 6 days so have to fit machining and learning CAD into that as well so it could take a while yet.
I should be doing the valves this week and make up a valve seat cutter from drill rod.
Thanks for looking in,

Lance

 

[maskell]

Well got a little time and made up the valves and did a bit more on the head
The inlet valve is still quite long as it is an atmospheric inlet and I am giving myself a bit of adjustment and will sort spring tension out when it is time for a run.
The exhaust is tensioned well as it sits but they still have the thread adjustment for finer tuning.

Lance

 

[maskell]

When making the valves I chose a no 6 -32 unc thread and found by cutting the thread on the valve with a 1'' button die then tapping the collet with the tap the thread is a bit sloppy, but there is no adjustment as the die is not a split one.
I made up this quick die holder to help the job along,
The bolts will be replaced with set screws when I get to town.

 

[maskell]

G Day everyone,
I have started on the ignitor and after turning the basic sizes in the lathe I set it up in the rotary table to find a centre and radius the diamond pattern.
From here the mounting holes also get drilled.
The ignitor has one fixed and insulated rod going through it with a fixed point contact surface and another that moves as the striker pushes it it makes and breaks causing the spark.
The hole for the fixed one is 9/64 and the fixed pin 1/8. I have drilled the holes and I was thinking of filling the fixed hole with JB weld or similar then drilling it out again. Is this a good idea? I have thought about making a bush out of nylon type material and then drilling it but heat may be a problem.
I'm open to suggestions.

Lance

 

[Jasonb]

The 1/5th version I'm doing has a lining machined from Teflon, I was going to try Corian as I have that available. The drawings show it as a elongated stepped bush so not sure how you would get on with just the hole insulated parallel with teh JB Weld, I suppose you could make a larger "washer" to slip over the rod.

PM also sent

Jason

 

[maskell]

Jason, The full size engine has a mica tube with mica washers under the head and as I restore old engines I have some of that but it is all too large and very flakey to deal with, I think it would have to be punched with a hole punch and not drilled.
I had not thought of teflon, thats where this forum is so great, you havent just got 1 brain (mine is hit and miss) to draw experience from.

Thanks Lance