Wanted to do a write up for a repair of your Sullivan smoke pump when it springs a leak and a simple pump mod to keep your plane interior clean.

Sullivan smoke pump are prone to leaking where the pump shaft enters the pump body. Sullivan uses a plain o-ring seal that will leak in time. If your looking to become a serious smoker, I highly suggest a Powerbox systems smoke pump.

Changing the pump head is a simple task and can be done for about $18.

The pump head in a Skywriter smoke pump is identical to the pump head in a Sullivan streamer field pump. Swapping a leaking pump head is a simple task when pulled from a new Sullivan field pump typically about $18. Just open each case, and free the motor and pump from the case bottom. Carefully work the motor and pump head loose with a screwdriver to break the gorilla glue free and replace the pump head. If your pump was already leaking, now is a good time to add a drain hose from the bottom of the pump. This line can be run through the bottom of the airframe and leaks will drip from this line before filling the pump and eventually your airframe when it decides to leak again.

Drill and tap for a 10-32 pressure tap in the area of the pump case between the motor and pump housing so that you can add a drain line out the bottom of the pump and out your airframe. You will be able to spot a leak when you see fluid in this line before you see it dripping from some other area of your airframe. The attached photos are showing the mod to a Sullivan streamer field pump, but the same idea applies for the Skywriter pump. Once the pressure tap is added, use RTV sealant to glue the motor and pump head back into the pump case and install the pump cover.

This will extend the usable life of the Sullivan Skywriter smoke pump and keep internal leaks from ruining a day at the field.

What are the options for check valves? Having trouble finding available options to be shipped here to NZ

I would stay away from diaphragm style plastic check valves.

Sullivan S756 or SUL756 check valves are machined from aluminum, use a Viton seal and operate a low cracking pressure. Definitely the best option if your installing check valves near nozzles (within an inch or two) as suggested on multi cylinder setups. Engine heat is not a factor with them.

Be sure to install in the proper orientation as noted below. Sullivan packaging does not indicate direction if you purchase from them. Also be sure to double check that there are no metal shavings inside or that they are not glued closed from the assembly process. I have had several check valves with both conditions right out of the package. I have brought this to the attention to Sullivan and have gotten replacements. NEVER use a check valve if you discover a metal shaving inside one. Not worth the risk trying to clean it out. Also be sure to filter your smoke oil when filling your onboard tank from your field can.

I sell them and go one step further and include the directional insert, ensure that they are not glued closed, and free of metal shavings.

Installed on my da50. Will give me more smoke time than the stock one due to running more efficiently as I can only fit a small tank

Originally Posted by ampEater

Installed on my da50. Will give me more smoke time than the stock one due to running more efficiently as I can only fit a small tank

Not sure if the 'direction' of the nozzle directly at the motor exhaust has been discussed previously in this thread but wondering if it's the best way to go? Wouldn't the force of the engine exhaust overwhelm whatever 'fan' pattern spray the nozzle gives you and make it no better, or perhaps even worse, than droplet injection when it comes to smoke production?

It should spray at about 45 degrees up and away from the nozzle, hence I've angled it at the 45 to spray across the port

I have one setup with a bit of spray toward the engine, and I note two things you should know.

1. The smoke works well this way!

2. However, there is also a discernable change in how the engine runs with the smoke. I suspect I'm losing some RPM over this, and the engine will definitely quit if the throttle is too low.

It has been noted by modelers such as myself with telemetry that pointing in the direction of the exhaust port is not ideal. On a DLE 111 and 170 I lost over 400 rpm's with fluctuations throughout the throttle range and had some seriously bad sounding exhaust, on two Valachs it would near bouts shut the engine down. That has been my experience yours may vary.
My method now is to run the engine up to operating temp and with an infra red find the hottest point on the muffler, that is where I point the injector. And sometimes it is surprising where that actually is.

Originally Posted by acerc

My method now is to run the engine up to operating temp and with an infra red find the hottest point on the muffler, that is where I point the injector. And sometimes it is surprising where that actually is.

+1 Robert....the same method that full scale guys use

Originally Posted by Hinckley Bill

+1 Robert....the same method that full scale guys use

Lol, where ya think I got it from, I am not that smart so I got to cheat....

By all means fellas, if your experiencing an rpm loss greater than a couple hundred at WOT then nozzle placement or spray direction can and should be changed. This can be as simple as rotating the nozzle by means of loosening the locking nut and turning the nozzle in the desired spray direction before tightening the locking nut again.

The suggested installation instructions of pointing toward the engine in a 45° angle across the port window but not up and into the cylinder or onto the piston face is a default nozzle location as different muffler styles can and will have a variety of mounting options. Customers are welcomed and encouraged to discuss via email what would work best for each application and their smoke expectations. For modelers not having a heat gun, nozzles placed in this orientation are subject to the highest velocity exhaust gas and the highest temperature from being closest to the combustion point within the engine. I agree, a heat gun if available at the hottest point in the exhaust system would be ideal.

Checking the spray pattern when fitting the nozzle but before the muffler is mounted back on the engine is very important. Spray is intended to spray at a point over or under the muffler inlet opening creating a misting wall of oil over the entire muffler inlet opening, but not actually out of the muffler during this test. Some light misting out the muffler opening is normal, while the full brunt spray coming out is not suggested.

As for the spray pattern breaking up due to the exhaust velocity, or retaining the fan spray in a smaller area. Think of something like a fire hose or garden hose sprayer tip set to mist. Both scenarios are taking a stream of fluid and breaking into smaller droplets to increase the surface area. This phenomenon also slows down the fluid velocity as it's expelled in relation to its speed in a column stream form. Many many micro droplets will have a larger surface area than that of a single drip and vaporize into smoke more readily. Overhead cooling mister cooling stations at an amusement park for example do the same thing. Increasing surface area and decreasing droplet size. They don't leave you drenched and the mist evaporates quickly.

4 strokes as ace mentioned are a little different animal and benefit from spraying away from the engine. This has been mentioned in other threads here on the forum as well.

I would think that the majority agree, forums like this or RC modelers as a whole are more than willing to share opinions or what works for them for what it is we do. Just one of the reasons I like this hobby so much.

Originally Posted by crankcase

I would think that the majority agree, forums like this or RC modelers as a whole are more than willing to share opinions or what works for them for what it is we do. Just one of the reasons I like this hobby so much.

The best thing about your posts is that you're willing to listen to input from folks and not automatically downgrade them because their thinking is different than yours...I commend any vendor who acts like this and will support these vendors whenever I can.

I agree 100% with you Bill. Very well said.

Hi;

I need an Atomizing Turbine Smoke Tube Kit. I'm assuming this would be all one would need for smoke installation for a turbine (Other than pump and tank).

Please let me know the shipped cost to 90265 and paypal address. Thanks

Originally Posted by ultimate65

Hi;

I need an Atomizing Turbine Smoke Tube Kit. I'm assuming this would be all one would need for smoke installation for a turbine (Other than pump and tank).

Please let me know the shipped cost to 90265 and paypal address. Thanks

Currently Turbine Smoke Tube kits are out of stock as I was having some quality issues with my welder. I have been looking into new welding services and am happy to announce that after a few months I am confident with a new laser welding service & now working to rebuild inventory.

I expect to have High Output smoke tubes back in stock mid Dec and Standard orifice smoke tubes to follow.

Prototype turbo prop smoke tube kits are getting good reviews and should be also hitting the website soon.

Depending on the size of your turbine, one or two smoke tube kits could be used. Smoke tube kits include smoke tube, universal mounting clips, kink free backing rod for bending into shape, safety wire, installation instructions & logo sticker. Your pump and plumbing setup will determine if a check valve or valves are suggested.

Tygon tubing will also be needed to feed the smoke tube from your pump available separately. Turbine smoke tubes do not require the use of high temperature smoke oil tubing on the feed line.

For ordering, you can email me direct at baddogsmokes@gmail.com or PM me here on the forum. PayPal invoices are then emailed to you. Payment forms are either PP or CC.