The Magnaport Spyder high flowing valve has been around for quite a while. At one time it was about the only other high flowing valve available for Spyder markers besides AKA Tornado valve at 1/4 of the cost. That has changed now as there are a few others available on the market but for the low cost factor, some still choose the Magnaport over more expensive versions. A couple of years ago, I was looking at a stock valve and pin and thought that it really wouldn't be that difficult to duplicate the configuration of the Magnaport with a few simple tools. When I was done, I came up with a reasonable result that was much higher flowing than the stock valve that cost me nothing more than a little bit of time. I will show you how to do the same in this article and give you a few tips on how to make it work a little better in your mechanical or electro frame Spyder.

Tools and Materials

There are a few tools and materials you'll need to perform this mod. Some you may not have but there are alternatives that will suffice. It may be a good idea to have an extra valve body and pin handy in case you have an accident.

• Stock Spyder valve body and valve pin
• Vice
• Drill
• Dremel and cutting disk
• Rough and fine file with 90* square edges
• Sandpaper
• Metal polish
• 2 small blocks of wood
• 2 plastic nuts

Modifying The Valve Body

This will be the most simple task of this valve assembly modification. Remove the 2 o-rings from the valve body. Make 2 small square pieces of wood to chuck the valve body into the vice. Make sure when tightening the wood and valve body in the vice, that the ends of the wood are flush with the chucks of the vice. Try to make the top hole of the valve body as close to 90* up as possible. This will help you make a nice straight cross cut into the top of the valve body. Be sure not to make any gashes into the front cup seal portion of the valve body or the cup seal will most likely leak once you're done modifying it.

If you have a dremel with attached cutting disk, it will help make the first portion of this modification much easier. If you don't, just use the thin flat side edge of the rough file to begin the cross cut into the top of the valve body. Start the cross cuts at the left and right ends of the existing hole in the valve body. If you start at the center it's much more difficult to dig into the sides once the cut has been made. If you're using a cutting disk, you will go through a few disks until you rid the hole of the sharp edges of the top area and don't forget to wear safety glasses. Try to keep the cuts as much 90* straight down as possible to get a nice consistent straight inside edge.  If using the dremel and cutting disk, you may want to occasionally turn the valve around in the vice because you'll notice that the disk cuts into the valve body easier on one side than the other. This is due to the rotation direction of the disk.

Once you get the sharp edges of the hole ground down with the cutting disk and the cross cut is pretty much flat, start using the thin flat side edge of the rough file to continue the cross cut. You'll get a better flat cut with the file than you will with the round cutting disk. Keep filing the material from the center of the valve body until you've reached the center line of the valve body. Be sure to occasionally check that the cut is as perfectly horizontal as possible while you're filing. Once you get to the center point of the valve, use the fine file lightly to remove the deep scratches that the rough file has made into the surface of the metal. Remove any sharp edges on the hole for the valve pin that you've created by the cross cut. Now use some fine sandpaper then metal polish for the final smooth surfaces.

Modifying The Valve Pin

The diameter of a stock Spyder valve pin is about 3/16". Most you'll find have about 1/64" machined from one side to let pressure through to the striker to recock the marker. I was fortunate enough to find one that had both sides of the pin machined already. For those of you that aren't that fortunate, you'll need to file then sand about 1/64" from the other side at a parallel angle the same length as the existing one. Lay the pin on a flat surface with the machined side down and duplicate the slot on the other side of the pin. Take care not to scratch the rounded surface of the pin or you will create drag on the pin when it's inserted in the rear portion of the valve body. After filing it to this dimension, use some fine sandpaper to smooth the file marks. You might first use a rough file to get most of the metal ground off, then use a fine file when close to the dimension you desire.

We will now remove material from the cup seal end of the valve pin. Thinning this portion of the pin will let more pressure flow through the front of the valve body to the striker and bolt. Insert the pin with attached cup seal in the modified valve body and mark the back most portion of the valve pin inside the gap that you just made in the valve body with a scribe or permanent marker. You must not remove any material past this point because it will create instability in the pin when the back portion is reciprocating in the valve body.

Using a lathe would be the ideal way to remove this material but since most of us don't own one or have access to one, using a drill will have to suffice for the greater portion of us. I would not suggest chucking either end of the valve pin directly in the drill because you will either deform the threads of one end or marr the smooth surface of the other.

Take the pin to a hardware store and find 2 thin plastic nuts that will thread onto the cup seal end of the valve pin. Thread both nuts all the way on the pin. Holding the first one threaded on stable, turn the other one on a bit more til the flat hexagon outer edges of both match. This will lock them together on the pin and give you something to insert in the drill chuck and not have to worry about marring any part of the pin.

Another manner to chuck the pin to the drill is by simply slipping a piece of rubber tubing over the threads of the cup seal end of the pin. This may not have as firm a grip on the pin as the nuts but you might try both and go with what suits you best.

When tightening this adapter in the drill chuck, you will have to: 

1.  Be sure not to tighten the drill chuck too tight because you may deform the edges of the plastic nuts though it will have to be tight enough to keep it in the chuck when applying the file.
2. Make sure that the pin is centered otherwise when filing the material from the pin, the pin will wobble creating a deformed or uneven surface on the pin.

Having a variable speed drill would be ideal if you have one available but if not a regular 1 speed drill will suffice. While turning the pin in the drill, use the thin flat edge of the file to remove the metal from the, flanged area of the cup seal end to the mark you made earlier. DO NOT FILE THE FLANGE OF THE CUP SEAL END OF THE PIN OFF. It is used to lock the cup seal to the valve pin and keeps the pin centered in the front flange portion of the valve body. Don't bear down on the file so much that it makes the valve pin off center in the drill. If the pin seems to have a wobble, loosen the chuck of the drill and once again center it. You will most likely have to do this a few times before you're done. If you do not, the diameter of the thinned area will be inconsistent. Drag the file across the designated area slowly back and forth consistently as well or you'll have the same result. Do not just thin one small area then move to the next because chances are you will have an uneven result. File it down to a 1/8" diameter. If you make the diameter too thin, there'll be more a chance of bending the pin and it will be pretty much ruined. After getting it to the diameter that you choose, use some fine sandpaper to smooth it out on the filed area only, then use some metal polish for the final smooth mirrored finish. Keeping the pin turning straight in the drill and patience will yield the best end result.

Tips When Using Your Home Modded Magnaport Valve

I would suggest using a soft material aftermarket cup seal such as the Lapco to be assured of a good seal when using these types of valve assemblies with your Spyder, especially when using them with the higher rate of fire electros. With the higher flow rate of these types of valves, you will most likely need to change the spring combination you're currently using to counteract the increased flow.

Technical Information