Briggs and stratton Model 5s Modification

This may help brother... easiest furnace there is

http://www.backyardmetalcasting.com/book_fp.html

That casting is pretty good. It has more definition than I thought it would.

Thanks lawren, probably going to make something better pretty soon before I try this again. I have some 12 volt car heater blower motors that I could rig up as a fan. I think it would work out nice if I can just get everything right at the same time. I think I could cast something smaller than the head using this method fairly easy. Maybe a finned valve spring cover. If I can find some styrofoam I might try a lost foam casting for that.

The other thing for this project is, I still don't know where I can get someone to mill me out a rod. I'm pretty sure I am going to buy a small milling machine soon, or a lathe, or both. It would be really nice for working on aluminum heads and things like this. In the past I've tried some stuff by hand but it takes hours.

a piece of plate glass, some 3m spray adhesive, and some sandpaper works wonders for making nice flat mating surfaces

I know it's doable, I did the opposed heads for my gtr project that way. Just takes a really long time. Also, I'd like to be able to mill out the combustion chamber, spark plug gasket surface, and tops of the head bolt holes. Then I could make a bunch of these if I wanted, or even make an entire billet head if I bought a block of aluminum.

Here's a head from a chinese engine I cut a lot off of, then I had to make room for the valves to open.


I did the areas over the valves with a dremel. It worked but it was time consuming and left a rough surface. Took a lot of checking to get it just right. With the mill I could cut those spots out no problem and have a nice smooth finish. With the 5s head, I want to do something similar, I was thinking when the valve is at full lift, have the bottom of the valve flush with the head. In other words, the valve will be up in a circular cut out in the head. Might not be a good idea though, maybe it would collect a lot of carbon in that area because of it's being recessed and probably cooler than the rest of the head.

oh I'm not dissing on the usefulness of a mill, I set up a cross slide on my drill press for light work. when I get set up up there, I'm planning on using a 6 cyl engine block for a mill bed, and a 4 cyl block for the mill head... the perfect 90 degree milled surfaces make for a great start to a DIY mill

Some testing to see how drilling the holes and plug hole would go. Drilled a pilot hole for the spark plug, then I milled a place for the plug gasket with an old wood bit. Works good, but I didn't bother getting it down far enough to be all the way smooth, since this head can't be used.


One of the head bolt holes drilled out.


Drilling the plug hole to the correct size before tapping. Most of the excess aluminum cut off. Finally got a small drill press at work now.


Plug hole tapped and holes drilled, cleaned up all the edges. Makes a nice conversation piece for the shelf.


1st attempt at a casting, 2nd attempt, and the real head. Soon I'll give it another try and see if I can get a usable part.

Pretty sweet! I didn't know a spade bit could cut metal, cool! Where'd you get a tap for the spark plug hole?

Thanks, I think the plug tap came from Napa. Just a 14mm x 1.25 I think. The spade bit dulls quick but it takes some of the aluminum off at least. Just have to go easy on it.

Here's some video of my casting operations. Found out afterwards from a guy in the comments, that with lost wax casting, the wax is only used to produce a plaster mold for the aluminum. It's not supposed to be used directly in the sand as I tried to do. I didn't realize this, so next time I'll try it with some foam instead. No wonder it didn't melt the wax out of the way...   On the plus side, I am now able to melt down a good amount of aluminum and keep it fairly hot. So I'm very close to getting it to work.

Getting closer!! Yah, wax to make the mold and melt the wax out, then pour in the metal. Billet fin valve cover would be cool.

If I'm not to busy maybe this weekend I can make another attempt but with styrofoam this time. For the cylinder head I still need to make a better wooden form. Next time I try the head, I'll lay it right side up on a flat board with the form around it, pack the sand in, then flip it over and take the head out, like your supposed to. Then hopefully I will get a better mold that way.

Doing some practicing with the milling machine. Working on a billet valve cover.