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Laser Engines - Technical questions

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TartanMac18/12/2017 22:47:19
250 forum posts
157 photos

Just wondering if there is a way to reverse engineer the chicken hopper tank system. I am going to put my 150V in upright so the carb is a little high but the bonnet is not far off the same hight was just wondering if I could fit something shallow or low height wise with a tank underneath. Or can I have the fuel line at the top of the tank ? What would that do inverted ?

Jon - Laser Engines19/12/2017 08:55:49
5209 forum posts
237 photos

If the tank is low then you arent likely to have any problem. As long as its not miles out the engine will draw fuel without any trouble. If it is a problem, a pressure nipple would more than likely take care of it.

Steve Dunne19/12/2017 09:45:10
132 forum posts
57 photos

TartanMac - my FW190 has the Laser 200 V twin upright, fuelled from a tank over an inch lower that the carburetters line (with two clunks). It draws fuel fine in all attitudes...

Chris Walby19/12/2017 14:23:37
1115 forum posts
266 photos

New boy question No1 while converting my BH Speed Air from electric to Laser 70

Is it better to align the engine toward the top of the fire wall or the bottom as the tank can be moved to accommodate either position + I'll have to re-engineer the front wheel pivot anyway.



Question No 2

The SLEC tank shows/describes both vent tubes pointing the 70 does not need pressurized tank should I point one up and one down and just use them as fill (as vent facing forwards) and drain respectively?

Lastly the crankcase vent I assume just needs a short pipe pointing towards the ground?

john stones 119/12/2017 15:49:38
11174 forum posts
1507 photos
Posted by Steve Dunne on 19/12/2017 09:45:10:

TartanMac - my FW190 has the Laser 200 V twin upright, fuelled from a tank over an inch lower that the carburetters line (with two clunks). It draws fuel fine in all attitudes...

Oooh giz a go, lovely. yes

Jon - Laser Engines19/12/2017 15:52:02
5209 forum posts
237 photos

Hi Chris

If you can find them there might be some marks on the firewall in a cross pattern. These will represent the intended centreline and should be used for reference. If they arent there, mount the engine as high as you can. It will help with prop ground clearance as much as anything else. Having the crank in line with the middle of that red stripe on the fuselage is likely to be about right.

For the tank, you can either have a fill, a vent, and a clunk. Or you can have only a clunk and vent line with the pipe to the caburettor used for filling. I have done this many times as its easy to pull the pipe off, fill it, and pop it back on. My current 70 powered twin has this setup.

The crankcase drain line should just be vented away from the fuselage as described in the instructions

Joespeeder19/12/2017 18:18:04
40 forum posts
13 photos

Hey Jon,

Here are the shots of the Russian Storch.... lol

I just wanted to see how the 300v fit into the ESM Mig 3 cowl. I couldn't get it all the way forward into the cowl but you can get a general idea. I will make some cardboard cutouts to see how the 360v might fit. If I could get the 360v in there without cutting the jowls out of the cowl it might be an option.

The front edge of the blue tape is where the front of the firewall is inside the cowl.

Either way I can see CA soaked cardstock duct work will be needed to feed cool air to the jugs.



Would be very cool to have you join us for some warbird flying over here. I keep saying I want to go to the Goodwood Fesivtal of Speed so my coming over there may be more of a reality. Hmmm...







Edited By Joespeeder on 19/12/2017 18:30:17

Jon - Laser Engines19/12/2017 18:57:09
5209 forum posts
237 photos

that cowl really is a bucket! once the engine is in, you can open up those intakes on the side and use them for cooling air. Should work a treat.

Goodwood is also a nice idea, I have been meaning to go for years. There are plenty of airshows around that time as well so have a look at those if you do make it over

Joespeeder19/12/2017 21:30:39
40 forum posts
13 photos

Hey Jon,

Yup, those intakes will be cut open, and the rear of the intake "bumps" opened like the scale vents. Plus I'll open all the exhaust ports to vent the cowl out. I have several ideas so far and I'll post the details when I get there.

I used card stock on the La5,following your lead by opening the exhaust tunnels plus I have holes in the bottom of the cowl due to the mufflers. The trick part on the La5 is the scoop I made on top of the cowl. The front inlet is structured to blow intake air down onto the engine but there is a divider inside the scoop that blocks off the rear of the scoop from incoming air. The rear of the scoop is open to the inside of the cowl and to the rear of the scoop creating a suction and drawing out air from the top of the cowl by the firewall. The inlets to the jugs are card stock all the past the center line of each jug with only about 1/8 - 1/4 inch max clearance forcing the air past the jugs in a very directed manner. Card stock is very easy to shape and once soaked with CA is very tough stuff.

I'll do something along those lines on the Mig but it'll be a while as I have a D9 to build this winter and laser inventory should be up and running by the time I get to the Mig.







Edited By Joespeeder on 19/12/2017 21:38:26

Jon - Laser Engines19/12/2017 22:54:17
5209 forum posts
237 photos

Aww that intake looks so cool

John Stainforth20/12/2017 21:29:33
326 forum posts
39 photos


Surely one should not move the thrust line very far from its designed position?


Jon - Laser Engines20/12/2017 22:26:37
5209 forum posts
237 photos
Posted by John Stainforth on 20/12/2017 21:29:33:


Surely one should not move the thrust line very far from its designed position?


true, the red line on the fuselage should be about right. In truth though, a speed air isn't likely to care very much

John Stainforth20/12/2017 22:40:08
326 forum posts
39 photos


Many thanks with posting your really useful figures of your chicken hopper system. Just what I was looking for. I'm going to do some trials with similar set-ups on my engine test bed.

Paul james 823/12/2017 08:21:49
163 forum posts
47 photos
Posted by bert baker on 15/12/2017 22:33:47:

img_1772.jpgHi it has J11 0n engine lug as well as my initials

The carb is broken it is a 150 do you still stock this carb

Looks like an Irvine carb, you may find one of those if you look around. I fitted one to my Laser 75 as an upgrade from the ST.

Jon - Laser Engines23/12/2017 08:24:43
5209 forum posts
237 photos

That is one of our own carbs that we have used since about 2006. easy to replace

bert baker23/12/2017 09:36:57
1524 forum posts
317 photos

Is this the one reputed to give more power

Jon - Laser Engines23/12/2017 10:10:12
5209 forum posts
237 photos
Posted by bert baker on 23/12/2017 09:36:57:

Is this the one reputed to give more power

yes this is 9mm vs the old Irvine at 8.5. All 150, 155 and 180 engines since 2006 have had this fitted as standard and 120's have had it since 2012

trebor23/12/2017 18:49:41
1926 forum posts
216 photos

Thanks for the quick postage of parts, before, during and after pictures yes




I might invest in more piston rings as there was a load of difference between the old and new ones.

fly boy323/12/2017 19:31:09
3638 forum posts
22 photos

Hi Jon, I have a venerable Laser 62, runs faultlessly. Is there a recognisable difference between the 61 and the 62. Thanks

Percy Verance23/12/2017 20:51:53
8108 forum posts
155 photos

fly boy

The .61 was the first incarnation of Laser engine to be produced. The .62 is/was an altogether different beast, being smaller, lighter and more powerful than the .61. Jon might confirm, but I think the .62 was the same physical size as the old .45 and .50

I think the current .70 has the same mounting dimensions as the old .62

Edited By Percy Verance on 23/12/2017 20:54:24

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