Gave up trying to fit a smoke device in the HSL due to lack of room so decided to try something else. Set up the twin small air pumps (1 per exit) and made some y joints to link them to the pump and exhaust outlets,. Works reasonably well and not too noisy. Breaks up the flow a bit and gives it an 'exhaust flow look'.
JB

A fan powered smoke unit (modified Heng Long) tried in the HSL. Not particularly good but it's output is reasonably scale(ish). As the fan (12v comp snail fan) just blows into the back of the smoke box without any positive connection, a fair bit of smoke escapes into the engine bay. The fan is hooked up to run with the cooling pump and is left on while running after the smoke (on off remote from the rotary switch) is turned off, and blows the residual smoke from the engine bay out the exhausts.

There are also the 2 small air pumps plumbed into the exhaust outlets via venturi pipe inserts, to blow the water out of the exhausts, (just on the waterline) as any water stops the smoke coming out (surface tension holds it in the pipe). Once I find a decent high volume small quiet air pump, I can do away with these and the fan, which should make things a bit better.
I've ordered some small 12v 40W printer elements to try another smoker idea, but they will be a while coming. Smoke will only be on for startup so shouldn't be too much of a problem.

I've almost become water/vaporlogged/glycerogged with all these experiments, and the other night I actually set off the smoke detectors,- house smells like a glycerine factory for hours afterwards,- but my skin's getting really smooth😂😂😂😂
JB

Trying air injection to break up the water flow. The air pumps I ordered finally arrived a week late but are too small to be of much use. I need a much bigger and faster volume of air to achieve what I want, which is for the water to almost be sprayed out in a mist. Might need to mod the water outlet by fitting fine tubes or stoppers around the inner smoke tube to build up a bit of back pressure, which might be another alternative
Unfortunately, as I've said before, you can't scale water, due partly to surface tension etc (why it either drips or runs out of a small pipe), so to make it fine you have to pressurize/vaporise it at the point of exit (ie garden sprayer) which is the hard part on a small scale. Lots of fun trying to perfect it though, and it keeps me out of trouble, and keeps the brain working - (although it's just asked for a pay rise due to all the work it's been doing lately!😂)

Tip,- if you run both videos at once you can see the difference between this and the last vid. It also breaks the smoke up.
JB

Using the e-cig element in the alloy box again but with the old smoker pump bored out and converted to a single outlet in line with the piston. Even makes a cool sound out the exhaust side!. Still waiting for my air pumps so just playing around in the mean time. Also trying glycerin and water 50/50 instead of baby oil. The pump doesn't shift much air ( slightly more blowing than sucking, - sort of pulsing back and forward) but if I blow down a tube I get clouds of smoke, I'll see what the air pumps do. Still only running on 2v.
JB

This version of a smoker box uses an E-Cig element in an alloy electronics enclosure.I gave the lid and box a 7mm haircut on the mill to reduce the size, (now 50x50x26, - was 50x50x33) but it could still be 1/2 the width. haven't found a smaller alloy box yet but might come across one, (only really needs to be 35mmx35mmx25mm The element is mounted on a bracket screwed to the bottom of the box (the box being the resevoir and neg) and against the outlet tube, and the pos wire runs through the side (in silicone tube) to the element.

The box is packed with cotton wool which is surrounding the element and soaked in smoke fluid (in this case baby oil) but leaving a passage through the center for air flow. I'm waiting for a couple of air pumps to arrive but I've used the old smoker unit pump again to demo the smoke and pulsing, (makes good smoke rings too)😊

The element is capable of taking 4.5v, but I'm only using 2v for the test and it smokes quite well. The pump is running on 7v but can be varied from around 3v - 8v. The large tubes are to allow for later exhaust fitting (water or dry stack). Once I get the air pumps I'll be running this one with the water again. I've done this (like Grahams version to be able to easily replace the element as the Heng Long smokers, while working ok (but noisy) have non replaceable elements, so if you kill one, it's off to file 13 at the end of the bench😉😁

The pump actually works quite well and if you mount it on sponge rubber it is reasonably quiet and could still be useful in a boat with a bit of interior room.

this hydroplane had to have major work done to strengthen both sponsons internaly as well as filling with expanding foam,this stops it from sinking in the event of a flip over and to put a little weight in the front to help keep the nose down.
fitted a tuned wrap to center pipe,water pump and also added extra fiberglass on the bottom because this was so thin it was flexing at speed and was hitting the bottom of the engine!!!!!. re-painted it too and put my own choice of graphics on.
I fitted the pulse water pump because I wouldn't be running flat out all the time and needed to cool the engine at lower rpm's,and the pulse water pump would do just that with twin inlets and outlets to keep the exhaust and engine head cool.

More of the Crash boat at our sea water creek and of Peter Dimberline taking a rest after an exhausting day at the radio sticks steering the model. After all, I only did the car loading, driving to the site, carrying fueling and starting, entry to the water and launching and taking the model out of the pond , cleaning and refueling etc to go again. You can see Peter is getting his stamina back. I only ever used 3;1 fuel and in later years 4;1 fuel, just how fast do you want to go? and I have defeated that(annoying) high whine of model engines with my muffler system. Needle valve is left alone and two or three clicks turn out/in in Summer or Winter is of no consequence, maybe too many fiddlers with model engines breaks down reliability? I usually wind the plug out 1 to 2 turns and start her dry and with one or two turns (electric starter belt now) of the flywheel and a fraction choke she STARTS at a bit above idle setting on carby , then throttle to idle disconnect plug lead and then screw in glo plug and lift model casually to pond and slowly place in water at IDLE. Just a bit of a mild throttle check / rudder function check, water outlet check, LOOK AHEAD and if safe clear release and gently open up.