Home made sparkplugs

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Doug_C
Posts: 1254
Joined: Sat Jan 04, 2003 6:48 pm

Re: Home made sparkplugs PICS

Post by Doug_C »

Hello Ken,

The procedure to make the insulators was drawn out somewhat, only because it came in tiles of triangle shapes. I cut into strips on the band saw, then turned them into rods between centers on the lathe. That gave me some white, pink, brown and speckled gray insulators. [img]/ubb/images/graemlins/grin.gif"%20alt="[/img]

Having rods made it easy to use collets. I just machined the profile complete and drilled them through with a carbide drill. Then snapped them off at the .06 end.

If you look at the drawing attachment of the first posting, you will see the cross sectional view of the swaging tool in purple lines(lower right hand corner). I designed that to wrap the steel around the radius. The seal is created by the small angle face from drilling with the 118 deg point, along with the high temp loctite. The insulator is just a slip fit into the bore. As mentioned before. To much crimp will fracture the corian. The .290 dimension could be reduced to make swaging a bit less on pressure.

I purchased the tungsten electrode materials from a local welding supply as used for Tig welding. Typically about $3-4 a 6" stick. I have since found ebay is somewhat cheaper with the exception of shipping charges. It is not mandatory to use the tungsten, but I think it will erode slower. The tang is soft steel so spark polarity may play a role in what erodes first. Don't know if there is any gain in hotter spark or less chance of fouling the plug.

The insulator profile does not need to be this elaborate. Straight sides will work fine without the rings. Those give my boots something to grip on. The only critical taper would be on the business end, where carbon deposits could short out the plug internally.

I have heard of some purists actually making up molds for home made porcelain insulators. It becomes obvious why these plugs go for $12-$30 each when you get a lot of time invested into them.

DC
Anonymous

Re: Home made sparkplugs PICS

Post by Anonymous »

Doug-Way cool. How about some pictures of this radial? I have had fleeting fantasies of building a radial before, quite an undertaking.

Thanks!

Steve
Olympia, Wa
SKEricsson
Posts: 7
Joined: Wed Jan 08, 2003 1:37 pm
Location: Olympia, Washington

Re: Home made sparkplugs PICS

Post by SKEricsson »

Sorry, I forgot I haven't registered on this board yet! So, how 'bout them pics????
Organized people are just too lazy to look for things.
Doug_C
Posts: 1254
Joined: Sat Jan 04, 2003 6:48 pm

Re: Home made sparkplugs PICS

Post by Doug_C »

Hi Steve,

Here is a web site on building this engine. I do not know if Bruce Satra is still producing the castings or not. I think it was Vernal Engineering that Bruce was a part of.

Very nice to deal with.

Check out this site. It has many other engine projects too. [img]/ubb/images/graemlins/shocked.gif"%20alt="[/img]

Ron's Model Engineering

DC
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