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P-Mag MAP plumbing question?

BASE1127

Active Member
I'm installing a set of P-mags this weekend and I can't figure out the best way to plumb in my MAP tubes. My MP gauge uses a tiny (maybe 1/8'' OD) line connected to the primer port on the #1 cylinder. I have no idea where to look for hardware to tee into such a small line.
I have a plug in the primer port for my #3 cylinder, but it's not budging and I don't want to force it. Does anybody know what type/material barbed AN fitting would let me plug in the 1/8'' ID MAP tubes supplied with the P-mags?

If anybody has pictures from their install, that would be helpful as well!
 
Try Clippard

I had the same issue when I installed my P-Mags. I have a braided hose (-3) from the cylinder to a manifold mounted on the firewall. In the manifold, I installed a couple of 1/8"NPT-to-barbed fittings from Clippard (www.clippard.com). I don't recall the specific P/N, but there is a wide selection so you can probably find something to meet your needs. Clippard supplies the barbed fittings used in the P-mag.

Good luck,

Dean Pichon
 
Cylinders have two 1/8 NPT holes on top and bottom at the intake side. Your current line occupies one of them. Try using one of the other 7. Plan on using a #3 nipple or elbow, but first drill and tap 10-32 for one of the P-mag style barb fittings. Get one from E-mag, find a barb tee to fit the hose and hook it up. You could also use a steel braided hose so the tube isn't attached to a warm barb, and run the hose to a similarly tapped AN tee mounted off-engine.

John Siebold
 
Don't forget to put something in the MAP line to smooth the power pulses. Otherwise, you will have no idea what MAP the P-mags will use to set the timing.

Do a search, there are a lot of good suggestions already on this forum on how to restrict the MAP line.
 
aquarium air

fittings may work for the small lines and listen to Bill R. he knows P-Mags.
 
Hey Pat, I hope all is well with you! We were in Midland for Thanksgiving but never made it out to the airport to see who was around. How's the -8?
 
One other P-mag tip, support the vacuum lines with appropriate sized Adel clamps. Zip ties will simply clamp the lines shut.

You can see how I did it in this picture. Look closely and you can see the Tee fitting that drops down towards the right P-mag.

To time my P-mags, I pull the hose off on the firewall side of the Tee and insert a small section which I can blow on.
 
One option is to run the MAP from the cylinder to a manifold on the firewall where you can use different fittings to feed both the gauge and pmags. I purchased a nylon tee at the local big box hardware store. I used the tee to split the line for the pmags.


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