JPI 900 install

[Mooney-Shiner]

Hello, esteemed board.

I currently doing owner-assisted JPI 900 install.

The instructions prescribe the equal distance for EGT probe placements on the exhaust stack. I was going to re-use already factory-installed EGT hole on stack #3. However, if I replicate the factory distance for other EGT probes, I would have to install the #4 probe over the slip joint. This would go against the JPI installation instructions ("no install at the slip joint").

After speaking with A&P, he told me that welding shop can weld shut the original hole so we can install the probes at the different distance.

Is there any specific way that this welding should be done? The probe opening is pretty small.

I will use this thread to bring up my other questions and suggestions through my installation.

[Aerodon]

Yeah, I would get it welded, not difficult.    Then plan ahead for all cylinders.  I like drilling the holes on the inside, biting back at about 30-45 degrees.  Makes it much easier to route the wires along with the CHT wires.  And protected the probes from mechanical damage.

 

Aerodon

[KSMooniac]

I concur with Don.  You want all of the probes equidistant from the exhaust flanges, and of course out of slip joints.  Pay attention to how the probe wires will be oriented and plan accordingly for a tidy installation.

[Mooney-Shiner]

2 hours ago, Aerodon said:

Yeah, I would get it welded, not difficult.    Then plan ahead for all cylinders.  I like drilling the holes on the inside, biting back at about 30-45 degrees.  Makes it much easier to route the wires along with the CHT wires.  And protected the probes from mechanical damage.

 

Aerodon

Thank you for all of the ideas!

I will do the inside install of probes, and use the tensioning rod of the lower baffling(in photo below) to attach the wiring and keep the probe wiring away from ignition wires.

[Mooney-Shiner]

On 10/24/2023 at 10:29 AM, Aerodon said:

Yeah, I would get it welded, not difficult.    Then plan ahead for all cylinders.  I like drilling the holes on the inside, biting back at about 30-45 degrees.  Makes it much easier to route the wires along with the CHT wires.  And protected the probes from mechanical damage.

 

Aerodon

Don, do you have a photo with the inside install of EGTs and your wire routing? Can't find anything worthy on world wide web.

Took the #3 stack to the welding shop, more to follow

[Aerodon]

1 hour ago, ukrsindicat@yahoo.com said:

Don, do you have a photo with the inside install of EGTs and your wire routing? Can't find anything worthy on world wide web.

Took the #3 stack to the welding shop, more to follow

Not the best picture, everything is hidden.  I use yellow painters tape to provisionally locate each EGT and make sure i am not 'painting myself into a corner' with slip joints, baffles etc.  A right angle drill with a short bit works well, otherwise you might have to take the exhaust off.  Distance from cylinder is not super critical, I worry more about getting a nicely mounted probe.  Half an inch is not going to make much of a difference in EGT and you are looking for trends and peak rather than absolute values.

 

Aerodon

[Mooney-Shiner]

That looks like a very clean install!

[0TreeLemur]

Here's a shot showing how we ran the EGT and CHT lines on our C above the intake spider and away from the plug wires.

 

[Mooney-Shiner]

Thank you for the feed back, guys!

The install is coming along.

Did a dry-fit of 900 on the manufactured alum plate above radio stack. Pretty happy with the fit. Eventually, I'm thinking about cutting a carbon fiber board to cover entire right side of the panel to cover all of the holes and bare aluminum.

Installed the ground wire to the engine as RX'd. 

Current head scratcher for me is the red power wire. The JPI instructs to "connect red 20GA wire(power) to the master solenoid at the battery to avoid the line drop when cranking. 5 Amp circuit breaker (CB) required." My master solenoid is located in far right side of the cabin and it has 1 CB that is not connected to anything ("Radio 15 Amp"), both of my radios CBs are on the separate avionics bar, connected to "Avionics" switch.   I'm planning on using this Radio spot to install the dedicated 5amp  CB for my JPI 900 EDM.  

This is what the CB similar to Radio 15 amp CB looks like from the rear. Where can I source these kind of CBs? 

Should I install the modern push-pull breaker?

Also as for inline 1 Amp fuse for the Amperage wires to shunt, where do you place them on the JPI wires? Closer to the  instrument, or closer to the shunt?

Thank you for all of the support and encourangements!

Yuriy 

 

 

Edited November 5, 2023 by ukrsindicat@yahoo.com

[Mooney-Shiner]

Removed the "un-employed" Klixon circuit breaker B7A 15Amp photo below.  Now need to replace it with 5Amp CB to make it a dedicated CB for JPI900. 

What would be a good source for this replacement? I saw 2TC2-5 CIRCUIT BREAKER on Aircraft Spruce, and wonder will it fit.

[47U]

1 hour ago, ukrsindicat@yahoo.com said:

What would be a good source for this replacement?

Read the part number off the 3A circuit breaker for the ADF and order that in the 5A spec.  That would reasonably be expected to match the removed breaker so that it fits seamlessly on the buss bar.

Alternatively, 55 year old original equipment circuit breakers probably should all be replaced.  The plastic (bakelite?) housings are all brittle and can fall apart with the simple act of removing the terminal screws (in my experience).  It’s better to plan and replace them all in advance rather than to be in the middle of a project and be held up because you have to source more parts.  

[Mooney-Shiner]

19 hours ago, 47U said:

Read the part number off the 3A circuit breaker for the ADF and order that in the 5A spec.  That would reasonably be expected to match the removed breaker so that it fits seamlessly on the buss bar.

Alternatively, 55 year old original equipment circuit breakers probably should all be replaced.  The plastic (bakelite?) housings are all brittle and can fall apart with the simple act of removing the terminal screws (in my experience).  It’s better to plan and replace them all in advance rather than to be in the middle of a project and be held up because you have to source more parts.  

THank you. "ADF" 3 is being used for the GTX 320 transponder, but the adjacent Radio 15 is not being used by anything. I pulled this CB and tried to match it to push-pull CB in terms of size, but I can't find anything matching in terms of rear clearance (1.350"). Since I don't want to break apart the existing bussbar, I'm planning to get a regular modern push-pull 7274 Klixon and will build the a jumper wire to the existing bussbar.

[Mooney-Shiner]

After some pondering, I decided to replace all 7 CBs with modern 7277 at $24-sh each to adopt the bar to the new pattern.

My PSM CBs are pretty ancient, and some are damaged.

Also, I decided to install the shunt fuses for ammeter closer to the shunt. 

 

[47U]

3 hours ago, Mooney-Shiner said:

After some pondering, I decided to replace all 7 CBs with modern 7277 at $24-sh each to adopt the bar to the new pattern.

Excellent decision.  When I went down this road, I discovered the outboard-most CB is very close to interfering with the fuselage tube.  You can see the vinyl hose in your picture that I’m sure is there to prevent arcing on the last CB.  The 7277 is just a little longer, increasing the possibility.

I angled (rotated) the last CB in the mount slightly to gain a little more clearance from the fuselage tube.  It looks really close in the picture below, but I also replaced the vinyl hose protection which is more clear, so it looks like it’s the fuselage tube itself.  The best solution I think, would be to leave that hole empty, if you have space for that CB somewhere else.

[Mooney-Shiner]

Hmm, makes sense. I just ordered all of the CBs from Spruce, but will see if I can procure alternative 5 amp CB that has more rear clearance  since I crawled into that snake nest.

Thank you for huge help, 47!

[Mooney-Shiner]

Moving along with the install since holidays.

All the EGT/CHT probes are in, CB replaced with modern pull CBs,  and now the fun part - fuel transducer. I know that the fuel lines attached to transducer using 180 inch LBS https://www.jpinstruments.com/shop/fuel-flow-transducer-231/, but what about the rest of the fuel line? Like the fuel pump to the hose connection and the servo to hose connection? I looked through Lycs SERVICE TABLE OF LIMITS AND TORQUE VALUE, but couldn’t find it there.

Also has anyone tried to seal the transducer fire sleeve with Band-It Clamps as per manual? I ordered the clamps on Spruce, but have no such tool.  I found this tool on Amazon, but its pretty pricey for doing just two clamps. https://www.amazon.com/Center-Clamps-50pack-Diameter4-stainless/dp/B0CRRHNPYG/ref=sr_1_2_sspa?crid=1K65C08DNYWKK&keywords=band+it+tool&qid=1706411178&sprefix=band+it+%2Caps%2C172&sr=8-2-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9hdGY&psc=1 

Any insights are welcome.

 

 

 

[laytonl]

 

@Mooney-Shiner,  I’m getting ready to install a JPI edm-930 in my ‘92 M20J.  Were you able to use the existing ammeter shunt, or did you replace it?  It’s a pain to access and was hoping I could just swing the existing wires over to the edm930.

Also, any unusual “gotchas” during the install?  Lee

[KSMooniac]

I replaced the shunt in my J during my EDM-900 installation, and yes, it was a PITA.  I had to remove screws through the fuselage that fastened a supporting shelf...if your paint is nice, you might want to purchase a tool that cuts through the paint on a screw cleanly, to prevent chipping and flaking.

It was a long and tedious installation, but I'm glad to have done it, and would choose JPI again if I had to switch planes.

[mhrivnak]

I also replaced the shunt in my J. It had different specs than the one JPI sent. I managed to do it without removing external screws, but it was challenging and an exercise in patience.

[Mooney-Shiner]

1 hour ago, laytonl said:

 

@Mooney-Shiner,  I’m getting ready to install a JPI edm-930 in my ‘92 M20J.  Were you able to use the existing ammeter shunt, or did you replace it?  It’s a pain to access and was hoping I could just swing the existing wires over to the edm930.

Also, any unusual “gotchas” during the install?  Lee

Layton,

The shunt replacement is pretty straight forward on non-moded F model. Its right by the avionics access panel.

The crimping of oil pressure and fuel pressure connector pins can be a little tricky. It will false read if not crimped right. Also I keep a much of the service loop of wire as possible just in case that you will need to move things around in the future. Especially, on the EGT/CHT wires since you can't butt-connect two of those wires (supposedly). The RPM sensor mounts on the mag opening closer to the  mag flange. Those are some "gotchas" that got me.

[laytonl]

Thanks. Hopefully, it will go smoothly.  Lee

[Carl Everitt]

Can you tell me what probe you used for the CARB TEMP function ? Could you also send a picture of the port on the carb (M20E).

Thanks,

 

[Mooney-Shiner]

18 minutes ago, Carl Everitt said:

Can you tell me what probe you used for the CARB TEMP function ? Could you also send a picture of the port on the carb (M20E).

Thanks,

 

Carl, I have IO360

[kortopates]

Can you tell me what probe you used for the CARB TEMP function ? Could you also send a picture of the port on the carb (M20E).
Thanks,

 

Carl, if you fly an M20E you don’t have a carb but have an IO-36O.


Sent from my iPhone using Tapatalk

[Carl Everitt]

Very embarrassed out that post, but thanks for the response.

Carl