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Engine Selection Question

Lizard Lips

Active Member
I am to the point in my RV-14A QB that I need to start thinking about which engine to use. I've pretty much narrowed it down to the Non-Certified Lycoming IO-360 200HP and the IO-390 210HP. Both engines will probably serve me well, but am I asking for additional expenses with the IO-390, such as alternator, electric fuel pump and other accessories? I know the 360 has been around a long time and supposedly most of the kinks have been worked out. Is the additional 10 hp you get from the 390 really worth the effort and expense?


On another matter, I do not find a Firewall Forward Kit shown on the Van's website. Do I need to call Van's for FWF selection guidance?

Joe
Longview, Texas

RV-14A Tail section complete
Arion Lightning LS-1 Flying
 
Joe---most of the FWF kits we've done for builders were for the Thunderbolt IO390, with the AFP FM150 servo. Several have opted for Pmags, both single and dual, and a few have opted to have the B&C backup alternator installed.
Only slight differences in hoses.

Tom
 
Not sure I understand. You will have the same accessory expenses with both engines.

Some thoughts:
- I flew an RV-14A with the IO-390. My take was the plane needs those extra 10hp.
- The Van?s RV-14/14A FWF kit is specific to the IO-390 with the standard injection system. AirFlow performance will work but requires some mods to the FWF kit (not hard, but required).
- The Thunderbolt IO-390 engine with a pMag is a good deal. I got a new IO360M1B from them with one PMag and the other mag hole empty. It now has a second pMag mounted.

Carl
 
Either works

Joe, I haven?t flown an ?A?, but i have flown the factory RV-14 with the 200hp io360; and i?ve been flying my RV-14 with the stock IO-390 210hp. They?re both awesome, but there is no ?additional trouble? fitting the 390, and I love it. As for the firewall forward kit, they definitely have it and sell it; I just ordered it when I ordered my prop and engine from Vans. I went with a B&C alternator but otherwise their ffw kit with no regrets.
 
Joe - I think I was the first person other than factory pilots to fly both the 14A and the -14, and gave both of them a good workout. Realistically, it was hard to tell the difference between the one with the 390 and the one with the 360 - its a great airplane either way!

Just my experience.

Paul
 
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As I understand it, 14/14A were designed with the IO-390 in mind, and the plans/parts pretty much revolve around that design. Prices aren't hugely different. While the IO-390 is a newer design than the IO-360, it's now (in "certified" version) being used in production aircraft - STC for some Mooneys and Cessna Cardinal, and now is the standard engine for Cirrus SR-20.

All that said, the IO-360 has a very good reputation and there are a lot of them around.

It's a chocolate vs vanilla kind of problem..
 
- The Thunderbolt IO-390 engine with a pMag is a good deal. I got a new IO360M1B from them with one PMag and the other mag hole empty. It now has a second pMag mounted.

The data is creeping in...the angle valve 390 doesn't need or want a whole lot of ignition advance. The 390 is also a higher CR, 8.9/1, so less detonation margin. If you insist on using a p-mag (rather than an EI with a user-drawn advance map), be sure to install the retard jumper.
 
Search for "RV-14A FIREWALL FWD. KIT" in Vans' Order -> Parts and Accessories.

Found the RV-14A Firewall Forward Kit on Van's. Thanks for the lead. However I did not see a listing of included equipment/accessories. I am confused about what additional things I will need, if any, to obtain in order to make my engine installation "complete".
 
The data is creeping in...the angle valve 390 doesn't need or want a whole lot of ignition advance. The 390 is also a higher CR, 8.9/1, so less detonation margin. If you insist on using a p-mag (rather than an EI with a user-drawn advance map), be sure to install the retard jumper.

The IO-390 should have its timing set to 20°, the P-mags with the jumper in defaults to 26.6°.

The engine manufacturers "clock" the P-mag the extra few degrees. However, I strongly recommend they be set to TDC and programmed to the proper firing angle with either the EICAD program from Emag or with our EICommander.

Here is a presentation I gave on Ignition Basics .

Any of you installing or have installed an IO-360 or 390 angle valve engine, free to contact me, if you have any questions about timing the P-mags for your engine.

As I said above, the engine builders tend to clock the P-mags, which is OK. However, if the builder moves them, or installs a second one, all bets are off.
 
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One other thing

The P-mags have a Max Advance setting.

For new or freshly overhauled engines, I suggest setting that to the recommended standard magneto timing value. That way, if you have a high CHT issue, it is most likely a result of baffle leaks and not timing. After you see a drop in CHT's, typically around 10 hours, you can change it and let the timing advance as manifold pressure drops off.
 
The P-mags have a Max Advance setting.

For new or freshly overhauled engines, I suggest setting that to the recommended standard magneto timing value. That way, if you have a high CHT issue, it is most likely a result of baffle leaks and not timing. After you see a drop in CHT's, typically around 10 hours, you can change it and let the timing advance as manifold pressure drops off.

The p-mag manual states you can revert to standard mag timing by using the jumpers and disconnecting the manifold pressure tubing from both p-mags. Would it be advisable to do the initial engine break-in, when cht may be highest, in this mode? :confused:
 
The p-mag manual states you can revert to standard mag timing by using the jumpers and disconnecting the manifold pressure tubing from both p-mags. Would it be advisable to do the initial engine break-in, when cht may be highest, in this mode? :confused:

It depends. With the the MAP line disconnected, they won't advance down low but as you climb, the ambient pressure drops off and they will advance.
 
The IO-390 should have its timing set to 20?, the P-mags with the jumper in defaults to 26.6?.

The engine manufacturers "clock" the P-mag the extra few degrees. However, I strongly recommend they be set to TDC and programmed to the proper firing angle with either the EICAD program from Emag or with our EICommander.

Bill, confirm please. Assume an owner or mechanic does not use the EICAD program, and does not have an EI Commander. Further assume the owner or mechanic sets timing using the TDC mark per the manual.

No jumper; what are the base and max timing values?

With jumper; what are the base and max timing values?
 
"clocking" p-mag

Bill R. >> "The engine manufacturers "clock" the P-mag the extra few degrees."

For clarity and my level of understanding, I am guessing that "clock" the P-mag means that the P-mag timing is set via a computer interface rather than clocking it like a slick mag.

And re, "if the builder moves them, or installs a second one, all bets are off." What does 'moves them', 'installs a second one', and 'all bets are off' mean?
 
Bill R. >> "The engine manufacturers "clock" the P-mag the extra few degrees."

For clarity and my level of understanding, I am guessing that "clock" the P-mag means that the P-mag timing is set via a computer interface rather than clocking it like a slick mag.

And re, "if the builder moves them, or installs a second one, all bets are off." What does 'moves them', 'installs a second one', and 'all bets are off' mean?
No Jeff, you are mistaken. They do not mess with the firmware. They put the jumper in and then turn the engine a few degrees (not teeth) and blow in the tube. If you reset the timing to TDC, then it is off by a good bit.

However, Barrett does have one of our EIC's in their dyno room and can "tune" the P-mags to your engine, if you ask them really nice. I am not sure if they have done this or not, but they have the capability.
 
Bill R. >> "The engine manufacturers "clock" the P-mag the extra few degrees."

For clarity and my level of understanding, I am guessing that "clock" the P-mag means that the P-mag timing is set via a computer interface rather than clocking it like a slick mag.

Clocking means positioning the flywheel at something other than TDC for the "blow in the tube" timing set procedure. For example, if one wished to retard the timing 5 degrees across the entire timing map, position the flywheel at 5 degrees after TDC, rather than at TDC.

And re, "if the builder moves them, or installs a second one, all bets are off." What does 'moves them', 'installs a second one', and 'all bets are off' mean?

That goes to my questions in the previous post. I think a lot of them are being run too advanced, particularly in the case of 382's, 390's, and 400's.
 
Bill, confirm please. Assume an owner or mechanic does not use the EICAD program, and does not have an EI Commander. Further assume the owner or mechanic sets timing using the TDC mark per the manual.

No jumper; what are the base and max timing values?

With jumper; what are the base and max timing values?

Dan, your comment about a mechanic who is not familiar with the P-mags is exactly why I recommend they get set to the proper configuration with either our EICommander or the EICAD program from Emag.

A couple of things first, all the numbers I am going to present assumes the P-mags are set to TDC.

Startup Mode: Below 400 RPM's the P-mags fire at 4.2 degrees past Top Dead Center (TDC) for Version 40 and above. Pre version 40 fires at TDC, which has caused some kickbacks, damaging starters and starter rings. Get your P-mags in for the upgrade & inspection, if you are pre version 40!

Low Power Idle: Regardless of the settings, at low RPM's, the P-mags will move the timing to closer to TDC to help with the idle, 19.6 degrees in some cases. As soon as power is applied, the P-mags will move to the max power setting.

"A" Curve (Jumper In):
High Power / Takeoff setting: 26.6 degrees
Max Advance: 35.0 degrees (The P-mags advance 1.4 degrees past the Max Advance setting.)

"B" Curve (No Jumper):
High Power / Takeoff setting: 30.8 degrees
Max Advance: 39.2 degrees (The P-mags advance 1.4 degrees past the Max Advance setting.)

Customer configurations:
It is difficult to recommend a setting as it seems every engine is slightly different. When creating a custom configuration with the EICAD program or using an EICommander, no jumper is used.
The following are configurations that our EICommander customers have had good luck with:

Stock Parallel 8.5:1 compression engines (Either 320 or 360):
High Power / Takeoff setting: 25.2 degrees (Advance Shift: -1.4)
Max Advance: 30.8 degrees (Max Advance: 29.4)

Stock Angle Valve (Either 360 or 390):
High Power / Takeoff setting: 19.6 degrees (Advance Shift: -7.0)
Max Advance: 29.4 degrees (Max Advance: 28.0)

If any of you have any questions, feel free to email or call.

bill (at) repucci (dot) com
7O4 6O7 - four 57 too
 
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Changing P-mag Configurations

If you elect to change the P-mag's configuration with the EICAD program from Emag, be sure to take a screen shot (the Snipping Tool works good) and put a printed copy in your engine logbook.

If you are running an EICommander, the configuration will be stored in the EIC.

Should you ever send a P-mag back for service, it will be reset to factory defaults and you will need to reconfigure it to your desired settings.
 
Thank you Bill.

Readers note; you can't correctly time a p-mag on an angle valve engine using only the basic timing set procedure. You must...

(1) clock the flywheel position to retard the whole timing map, or

(2) use the EICAD program to program a timing shift, or

(3) use an EI Commander to do the same.

Moderators, a copy of Bill's post(s) really should be placed in the Electronic Ignition section as a sticky. It wasn't such a big deal when 90% of the P-mags were going on parallel valve engines, but the RV-14 changes things.
 
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You have to request access to the EICAD program from Emag.

They removed it from their website after a -14 builder had difficulty configuring their P-mags and complained. (All user error.)

We are in the process of updating our website with info about the new EICommander, available from SteinAir. The classic EICommander is still available from Aircraft Spruce.
 
Thanks, Bill

You have to request access to the EICAD program from Emag.

They removed it from their website after a -14 builder had difficulty configuring their P-mags and complained. (All user error.)

We are in the process of updating our website with info about the new EICommander, available from SteinAir. The classic EICommander is still available from Aircraft Spruce.

It was probably my complaint. User error? My ***. Good luck, anyone wanting to use the EICAD program.
 
If any of you are going to install P-mags, I recommend you bring a separate ground, send, receive, and tach signal into the cockpit and terminate those wires in a female DB9 connector, one for each P-mag.

That way you can connect to the P-mags with a laptop, from the cockpit. Or, you can make a harness and connect an EICommander to them.
 
It would be nice if a program to monitor the p-mags was available that would allow the data to be displayed on the G3X. The VPX has its own screen. I don't have panel space for an EI Commander.
 
Joe,
There is no substitution for horsepower. You can always pull the power back, lean, and match fuel flow to the smaller engine and get the same speed in cruise (at ALMOST the same FF - you are carrying a slightly heavier engine - but both have a similar SFC), but takeoff/climb performance won’t be the same - better with the -390.
As for the PMags - the jumper is installed from the factory. Only remove the jumper for a more aggressive advance on lower compression engines (below 8.5:1).
Don’t forget - the cheapest thing about owning/flying your own airplane is the fuel. The only possible reason I can think of for using an IO-360 v.s. an IO-390 is the cost of the engine. The difference needs to be well north of $5K, and most of that difference is resale value. There is value in the increased performance, ease of the build, and possible future maintenance, but those things can’t be quantified. If I were looking at at choice to buy 2 RV14’s, everything was equal (build quality, time, equipment, aesthetics), but one had the 360 and the other had the 390, I would pick the 390. I think most would agree.
 
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EMags v.s. SDS...

EMag doesn?t offer the ignition advance control that SDS does. Even with the EI Commander, or the EMag program as used in an EMag ignition system, you don?t get the same controllability that you would with SDS (or a couple other automotive based EI systems). What you do get is an ignition system that is self supporting - like a standard FAA approved magneto ignition system (although it?s not FAA approved as yet). The other EI ignition systems depend on the aircraft electrical system architecture for redundancy, and that?s why none of them will most likely never be approved in standard category aircraft, as a stand alone ignition system, unless there is a self powered ignition system - like a magneto - as the second ignition system.

If you think you might want to control your ignition advance for greater fuel efficiency in flight, and are willing to accept the reduced redundancy by accepting dependency on two critical aircraft systems for engine operation, then pick the SDS ignition system, or other automotive based systems ((EFII, Ford EADIS, etc). If you want improved efficiency through variable timing in a self powered redundant system, but without the controllability you get with SCS, etc, then go with the EMag system. If you want proven dependability in a less efficient fixed timing ignition system that you have to overhaul every 500 hours, then stick with standard FAA approved Mags.
 
How do the PMags compare to SDSEFI?

Please use the search function, this has been discussed at length on many other threads.

Moderators, please remove the posts in reference to this subject. We are trying to address a specific issue. - Thanks
 
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J...As for the PMags - the jumper is installed from the factory. Only remove the jumper for a more aggressive advance on lower compression engines (below 8.5:1)….

This is bad advice! (Sorry Scott.)

See the timing configurations listed earlier in this thread.

30 degrees advance is not acceptable for 7:1 compression engine. (150 hp O-320.)

If you are running an engine that is not designed for a timing within the two standard configurations, you will have to clock the P-mags or adjust the timing, as already described in this thread.

Everyone, if you do not understand ignition timing, please do some research. There is no quicker and easier way to damage an expensive engine then by setting the timing to the wrong value.
 
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