[Bob Martin]

I'm installing the primer system from Vans (electric) in my RV-6.
Vans kit doesn't recommend or supply a switch to activate it, I guess because it should be a simple install. The switch draws 6 watts which is under one amp by my calculatons.
What are others using to activate the pump?
How are you labeling it?

Seems a push button would be the easiest, just push/hold/release.
there seem to be lots of push buttons available, like a PTT button but these seem small, even though they are rated to handle one amp.
So I was wondering what other have done??
and did you just label it.......

Primer
O
Push to Prime

Wondering here.......Thanks for your help.

 

[alpinelakespilot2000]

Bob-
I'm currently thinking about my primer switch plans as well. If you're limited on switch space, Bob Nuckoll's has a suggestion to use a three position switch for the primer and boost pump. From bottom to top: off (bottom position) - boost pump (center position) - primer (momentary up position). I don't think I'm going to do this because I'm not limited on space and because I want the primer over on the far left since the only time I use it is on start-up. I want my boost pump over by the flap switch and throttle. Just another option though for you to mull over. I'm interested to hear other options too. Good luck.

 

[rvpilot]

Guarded switch

Here's the one we've been using, from ACS:

OFF-(ON), 5 AMP
Mounting Hole: 1/2"
Aluminum Guard
P/N 15-112 $8.40

Wire it so it's only active when the fuel pump is switched on. While it's hard to see in the picture, the guard helps to prevent it from accidently being pushed. Guard also helps in quick identification.
Just one solution, many others I'm sure!

 

[Ironflight]

Guarded Momentary Toggle

Mine is exactly like Bill stated above, and it's locate just to the left of the Boost Pump switch, directly in front of the throttle on my -8.

Paul

 

[Bob Martin]

Switch

Thanks for the information guys!
Wiring so that the primer can only function while the boost pump is on, is a great idea that I hadn't thought of. Just another built in safety feature.
Thanks again.

 

[bsacks05]

Mine is installed per 'lectric Bob's suggestion. One toggle for boost and momentary position for prime. Works great.
In the early hours of my phase 1 at about 800 agl, I accidentally hit the primer thinking it was the flaps. I am not sure why because the boost/prime is on the left of my panel and flaps are towards the middle above the throttle. Engine sputtered for a split second and really got my attention! Since then I installed color coded covers on all toggles and after 70 hrs can now hit the correct switches without looking.

 

[drill_and_buck]

Switch or Push button

Awhile back there was a discussion about the ability to use your primer lines to keep the engine running in the event that there was a problem with your main fuel delivery system.

If you have a multi cylinder primer system you might want consider going with a toggle switch rather than a push button.

With a toggle switch you could leave the solenoid valve open to continuously deliver fuel to 3 cylinders.

Mike Draper
RV-8 Finish

 

[Bob Martin]

Primer switch

Awhile back there was a discussion about the ability to use your primer lines to keep the engine running in the event that there was a problem with your main fuel delivery system.

If you have a multi cylinder primer system you might want consider going with a toggle switch rather than a push button.

With a toggle switch you could leave the solenoid valve open to continuously deliver fuel to 3 cylinders.

Mike Draper
RV-8 Finish

Thanks for replys.
I do have a 4 cyl primer system.
The primer pump/solenoid does 25 psi I think.
Not sure if the 'system' would actually run the engine if left on???
seems the chance of inadvertnatly leaving the toggle "on" would be a bigger risk than using the button in an emergency.
But maybe the toggle under the red cover would reduce the possibility of leaving the toggle switch on?

 

[mdoyle]

I had decided to not install a primer system, but I have recently heard the discussion about the alternative fuel delivery possibilities in an emergency, so now I'm reconsidering my decision. I've not seen a picture of an installation, where does the Van's primer system get plumbed in? I believe my Aerosport engine came with primer lines installed. I haven't unwrapped the engine yet to look.

 

[Bob Martin]

Primer install

I had decided to not install a primer system, but I have recently heard the discussion about the alternative fuel delivery possibilities in an emergency, so now I'm reconsidering my decision. I've not seen a picture of an installation, where does the Van's primer system get plumbed in? I believe my Aerosport engine came with primer lines installed. I haven't unwrapped the engine yet to look.

Mike,
The primer system starts at the top of the gascolator with 1/8" fitting and routes with copper tubbing (normally) via tee, etc to the 1/8 port on the Intake side of the cylinder head. There is a port on top and another on the bottom. The top one is usually used for Fuel Injection. sometimes you will see the manifold pressure tapped off a lower port, otherwise they are plugged up.

Vans kit is designed with flare type fitting and 1/8" copper tubing enough for two cylinders as well as the electric solenoid.

It does really help to look at one to visually understand it.
The hardest part seems to be where to mount the fittings, like the tees or in my case a 4 way spliter. Remember to bend up a coil for vibration between the engine and the firewall side of the installation.
Hope this helps
Bob Martin

 

[mdoyle]

Thanks Bob, I might go ahead and order the parts from Van's. I 've never flown an airplane with an electric primer, I've always had the plunger type.

 

[Bob Martin]

Elec primer

Thanks Bob, I might go ahead and order the parts from Van's. I 've never flown an airplane with an electric primer, I've always had the plunger type.

The electric part keeps the fuel line plumbing out of the cockpit too.
I know we have lots of fuel lines already in the cockpit, but less is better.
With Vans kit, you will still need a way to mount the solenoid and associated wiring and switch. Vans solenoid comes from ACS is a Parker B2DX62 6 watts 25 psi. Good Luck

 

[terrykohler]

Bob:
Aircraft Spruce sells a push button switch (SPB01) for under $5.00 which works well with the vans solenoid. Leave off the rubber cover and you're got a bright silver button that doesn't take up much space and only activates the solenoid when pressed. When you install the primer system make sure that you have a loop in the line going out of the solenoid and into the cylinders. With the valve mounted on the firewall and the engine moving on its mounts, a straight line will be prone to fracture.
Terry

 

[Bob Martin]

Push Buttons

Bob:
Aircraft Spruce sells a push button switch (SPB01) for under $5.00 which works well with the vans solenoid. Leave off the rubber cover and you're got a bright silver button that doesn't take up much space and only activates the solenoid when pressed. When you install the primer system make sure that you have a loop in the line going out of the solenoid and into the cylinders. With the valve mounted on the firewall and the engine moving on its mounts, a straight line will be prone to fracture.
Terry

Thanks Terry, I was looking at that one (SPB01) and
15-112 @7.95 thought I'd order both and choose one once I see them.
Thanks for the recomendation.

 

[DHeal]

Electric primers are nice because they help to keep some fuel lines out of the cockpit, but what happens when the primer solenoid sticks? You can't electrically or physically deactivate it because it's stuck. You can't modulate the fuel flow with the mixture control because the primer is bypassing the carb. Likely a very over-rich and uncombustible mixture results. Now what?? Use your main fuel valve as a crude mixture control??

 

[Bob Martin]

New info?

Maybe you know something I don't?
Not sure if they stick.
If it did, surely it would be at start up and one wouldn't fly unless everything checked out.
Do you know how it works?
Enlighten us, please.

 

[terrykohler]

Bob:
The primer (solenoid) is typically mounted near the gascolator and fed out of the top port. With Van's setup, two lines come out of the solenoid and route to a cylinder on each side. To prime, you need to turn on the aux fuel pump (boost pump) to pressurize the system. Actuating the solenoid allows the fuel to flow thru the two lines to the cylinders. Without the boost pump on, the lines don't get fed. If the solenoid were to stick open (haven't heard of that happening), due to a failed valve or momentary switch, it would only continue to supply fuel if the boost is operating. If the engine is running, the engine driven pump PULLS fuel from the gascolator and would not fill the primer lines. Hope this answers your question.
Terry

 

[Bob Martin]

Feeding the primer system

Bob:
The primer (solenoid) is typically mounted near the gascolator and fed out of the top port. With Van's setup, two lines come out of the solenoid and route to a cylinder on each side. To prime, you need to turn on the aux fuel pump (boost pump) to pressurize the system. Actuating the solenoid allows the fuel to flow thru the two lines to the cylinders. Without the boost pump on, the lines don't get fed. If the solenoid were to stick open (haven't heard of that happening), due to a failed valve or momentary switch, it would only continue to supply fuel if the boost is operating. If the engine is running, the engine driven pump PULLS fuel from the gascolator and would not fill the primer lines. Hope this answers your question.
Terry

Thanks Terry,
Yes, "the lines don't get fed" and "Pulls fuel" did it for me.
I guess I was thinking the system was/maybe pressurized. But after thinking about it, it is only pressurized when the boost pump is on.
Thanks for clearing it up.