Slide Valve Cylinder Castings
Slide Valve Cylinder Castings
Here is my first attempt at having my cylinder pattern cast. I had all the power and exhaust cores cast in. They didn't come out too bad, but I wanted to know if anyone had any experience with regards to the allowable fudge factor for the spacing between the ports. The plans do have a provision for a valve guide/plate, which will be machined out of cast iron, but if im already OK I would rathwr do without. Thoughts? Let me know.
-jlakes85
-jlakes85
-
- Posts: 1728
- Joined: Thu Jan 09, 2003 6:50 pm
- Location: Michigan, USA
Re: Slide Valve Cylinder Castings
Looks like you have big ports. What is this for?
Re: Slide Valve Cylinder Castings
Hi Marty,
This is for a 5" scale 15" gauge engine.
Regards,
John
This is for a 5" scale 15" gauge engine.
Regards,
John
Re: Slide Valve Cylinder Castings
I have plates made for my, yet unfinished engine, because of an error I did while machining. We stewed over it a long time weighing the plusses and minuses. Could find no minuses, (sense it was already screwed up) a plus was that down the road, no machining needed to the cylinder at rebuild time. Hense, when I made the "fix", I made spare set. If you need a pic... I can put one up here.
PS, I can offer this... next time I open the ports on a cylinder, I will plunge down with the end mill, make ONE pass and withdraw...I'll not make a return pass. (This ought to draw some smoke out).
Scotty
PS, I can offer this... next time I open the ports on a cylinder, I will plunge down with the end mill, make ONE pass and withdraw...I'll not make a return pass. (This ought to draw some smoke out).
Scotty
Re: Slide Valve Cylinder Castings
Not sure what the plans call for with spacing but the ports look OK to me. Can really only tell for sure after you machine the slide valve surface and see how it looks.
-Frank K.
Re: Slide Valve Cylinder Castings
You will be better using a slot drill rather than an end mill.
L
L
Re: Slide Valve Cylinder Castings
Hi Frank,
Spacing between ports in supposed to be 5/16, which is the same width as the power ports. Exhaust port is supposed to be 1/2 inch wide.
-John
Spacing between ports in supposed to be 5/16, which is the same width as the power ports. Exhaust port is supposed to be 1/2 inch wide.
-John
-
- Posts: 957
- Joined: Sun May 06, 2007 10:14 pm
- Location: St. Louis, MO
Re: Slide Valve Cylinder Castings
Did you incorporate machining allowance?
Given your ports being 5/16", I would say you would probably want 3/16" wide ports, as cast... Then for teh exhaust port, 3/8" as cast... So your cast spacing should be 7/16" between ports... It also looks like your cores may have broken, due to the odd shape of the left hand shape.
Given your ports being 5/16", I would say you would probably want 3/16" wide ports, as cast... Then for teh exhaust port, 3/8" as cast... So your cast spacing should be 7/16" between ports... It also looks like your cores may have broken, due to the odd shape of the left hand shape.
Re: Slide Valve Cylinder Castings
Rudd,
There were core prints for each port, about 2 inches tall, 2 degree taper on each side. On the cylinder bore side, i left about 2 inches of extra length for a core print. The exhaust passage was the most concerning, as one side dead ends within the cylinder, leaving only the valve face side for a print. I think the foundry guys glued that core in.
-John
There were core prints for each port, about 2 inches tall, 2 degree taper on each side. On the cylinder bore side, i left about 2 inches of extra length for a core print. The exhaust passage was the most concerning, as one side dead ends within the cylinder, leaving only the valve face side for a print. I think the foundry guys glued that core in.
-John
Re: Slide Valve Cylinder Castings
The steam chest bolts go down thru the plate into the cylinder casting.
How did you secure the false seats to the castings?
Scotty
-
- Posts: 44
- Joined: Mon Jan 21, 2008 6:13 pm
- Location: Menifee, CA
Re: Slide Valve Cylinder Castings
Here are some good pattern photos to reference regarding your exact casting outcome.