A

ao.frog

Well Known Member
Hi.

I've a Superior IO-360 with dual P-mags and I think I need a cap plug.

The RPM-indicator get's it's tach signal via a wire from the P-mags (I think?) so the tachdrive-port on top of the aft side of the engine won't be need. ( I think)

Therefore I suspect I need a cap plug of some sort to screw on the tach plug? I mean; that tach plug needs some cover of some sort, right?

I've searched this forum but can't find some info on this?

Any idea where I can get a suitable cap plug?

Sorry for the possibly dumb question guys... (and gals....)

Thanks!
 
Doesn't have to be any particular cap.

There are cap plugs available, but they are only "dust" covers. The shaft has an internal oil seal. The cap is just to keep foreign matter out of the tach drive.
 
Here you go...

ao.frog said:
Hi.

I've a Superior IO-360 with dual P-mags and I think I need a cap plug.

The RPM-indicator get's it's tach signal via a wire from the P-mags (I think?) so the tachdrive-port on top of the aft side of the engine won't be need. ( I think)

Therefore I suspect I need a cap plug of some sort to screw on the tach plug? I mean; that tach plug needs some cover of some sort, right?

I've searched this forum but can't find some info on this?

Any idea where I can get a suitable cap plug?

Sorry for the possibly dumb question guys... (and gals....)

Thanks!
Click to expand...

VAF thread:
http://www.vansairforce.com/community/showthread.php?t=21497&highlight=tach+cover

Part:
http://www.aircraftspruce.com/catalog/inpages/tachcap.php
 
You need a tachometer drive cap. I believe Van's, Aircraft Spruce, and Avery tools all carry them. From Van's, it's part number: IE RC-1 CAP.

Guy
 
Thanks guys!

I REALLY appreciate this forum!

Thanks for the info guys. I'm just about to place an order to Vans this weekend, so I'll include the cap too. Problem solved in less that 10 minutes!

(Guess I've also to be more creative when searcing the forum and not giving up so easliy....)

Thanks again!
 
Tach Drive Caps

Chief Aircraft sells one for $6.95.
Aircraft Spruce has one with four tabs so you can safetywire it wherever it happens to be convenient.......$19.95.

I ordered the one from Chief. It does the job.
 
I was given one of the Aircraft Spruce ones by the SOCAL group last fall - it is truly "Presentation Quality"....;)
 
mrreddick said:
Chief Aircraft sells one for $6.95.
Aircraft Spruce has one with four tabs so you can safetywire it wherever it happens to be convenient.......$19.95.

I ordered the one from Chief. It does the job.
Click to expand...

Let's see - that money will buy a good six pack or a case of beer. Dust cover or beer, hmmm. My plane doesn't have a dust cover, hasn't for the last 800 or so hours. Beer was good.

Seriously, cover not needed.
 
tach drive

I am just beginning my FWF so this question is also of interest to me. I assumed that I would need the tach drive to send tach information to a gauge, probably on an EFIS.

Searching the archives I found that it is difficult to arrange for the tach signal from both mags to be read by the EFIS, making a mag check difficult or impossible for both mags. It seems that some guys prefer to use a hall sensor on the tach drive fitting to provide the tach signal to their EFIS or gauge. This costs a bit more but makes the wiring less tricky.

If I have misunderstood, I am sure that others who know more about it will jump in to correct me.

so, you might want to use the tach fitting instead of covering it.
 
Last edited:
tonyjohnson said:
I am just beginning my FWF so this question is also of interest to me. I assumed that I would need the tach drive to send tach information to a gauge, probably on an EFIS.

Searching the archives I found that it is difficult to arrange for the tach signal from both mags to be read by the EFIS, making a mag check difficult or impossible for both mags. It seems that some guys prefer to use a hall sensor on the tach drive fitting to provide the tach signal to their EFIS or gauge. This costs a bit more but makes the wiring less tricky.

If I have misunderstood, I am sure that others who know more about it will jump in to correct me.

so, you might want to use the tach fitting instead of covering it.
Click to expand...

I use a toggle switch to alternate my tach readout to my EIS.
During my magcheck at runup, I just toggle to insure both mags outputs are correct.
 
Last edited:
DanLandry said:
I use a toggle switch to alternate my tach readout to my EIS.
During my magcheck at runup, I just toggle to insure both mags outputs are correct.
Click to expand...


I just run my tach signal off of one mag. In all my years of flying, I've never had a mag check fail because of a "minor" difference between the Mags - it is usually a fouled plug (which is instantly apparent from the significant difference in sound), or a plain old dead mag (in which case the engine stops running). yes, I could miss something very subtle - I've just never encountered what tat might be.

Not advocating this for everyone, just saying that there's another way of looking at it!

Paul
 
I just started the installation of my ECI engine and also had to put a cover over the RPM hole. I called American Aircraft Engines who built my engine and they sent a cover over. My only caution is that either you need some way to secure with wire or be prepared to use a bit of Loctight.
 
AlexPeterson said:
You mean the whole thing, seal and all was removed? If so, that is a different issue altogether.
Click to expand...
Yep, all gone. I had to replace the accessory case so I could install a fuel pump and didn't feel the need for any of it. Here's a picture of my cap, note the safety wire to the vacuum pad stud:


tonyjohnson said:
I am just beginning my FWF so this question is also of interest to me. I assumed that I would need the tach drive to send tach information to a gauge, probably on an EFIS...
Click to expand...
It all depends on your EFIS. The Dynon units accept two inputs and the P-mags don't drop the tach signal when you check them. In my installation, no switch is required and the tach never even waivers when switching between mags.
 
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