Laser engine, how do you tell what size they are?

[martin collins 1]

I have just removed a Laser engine from a model i have just bought as i am fitting a petrol to the plane, the only markings on it apart from the name Laser are NHA   L does that correspond with the size of the engine? I am going to be selling it so would like to know what i am advertising, thanks for any help.

[john stones 1 - Moderator]

10 minutes ago, martin collins 1 said:

I have just removed a Laser engine from a model i have just bought as i am fitting a petrol to the plane, the only markings on it apart from the name Laser are NHA   L does that correspond with the size of the engine? I am going to be selling it so would like to know what i am advertising, thanks for any help.

 

A  picture Martin.

 

[martin collins 1]

[john stones 1 - Moderator]

NHA is owners initials, L I believe is year made, coincides with number plates.

Someone more knowledgable will identify size for you.

[martin collins 1]

Thanks John.............

[Paul De Tourtoulon]

Maybe someone could post a table with the owner's initials stamped on the engine with a list of what cc and

dates that they were supplied, it would help the never ending lists of 'what have I got "?.🤢

 

[J D 8]

    Very much doubt if any of the above is possible.

     Here is my take on the issue of a way to identify Laser engine size. This applies to The later models with the vertical glow plug hole.   It goes on number of barrel cooling fins and weight of unit including muffler.

  70  8 fins  580g

  80  8 fins  690g

  100 12 fins  810g

   155 13 fins  955g

   180 14 fins  1240g

   Previous models like my 150 has 12 fins and is 920g

  Another feature of post 2000 units is two screws holding the valve cover on but not sure when this change came about.

  I think the above engine is a 150 from the 90's if close to mines weight.

[Paul De Tourtoulon]

I have this,,,

[J D 8]

           Good one Paul, more for the older models, even the weights are in ounces.  John.

[John Lee]

If you use the Internet Archive https://web.archive.org/ you can see older versions of the Laser Engines website which give contemporary data for the models of that era.

 

EG from 2010 https://web.archive.org/web/20100213124011/http://www.laserengines.com/spec.htm 

 

[martin collins 1]

Many thanks for the replies but i am still confused, the weight does not equate exactly to any of the above, mine being 842g with the exhaust rubber tube and remote glow removed, it was flown on a 15x8" prop. In that last table provided by John Lee, height from crankshaft to cylinder head, is that from the centre of the crankshaft to the top of the rocker cover on the head as that measurement on mine is 101mm, or from the centre of the crank to the top of the cylinder head if you ignore the rocker cover which is 93mm on mine in that measurement! In which case it indicates it as a 120 OR a 150 with the width between the bearers the same as mine at 45 but the weight is nearer the 150.  But Paul`s sheet has similar dimensions to mine for a 90 though the weight is a bit less as mine is 29.70z as opposed to 28.5, is his sheet for newer engines as the 150 single is not shown. I am leaning towards it being a 120 or a 150 as shown in the last table, any thoughts from the collective? Wouldn`t it have been easier to stamp the engines with the size when manufactured!

Edited April 15 by martin collins 1

[J D 8]

        

26 minutes ago, martin collins 1 said:

28 minutes ago, martin collins 1 said:

Many thanks for the replies but i am still confused, the weight does not equate exactly to any of the above, mine being 842g with the exhaust rubber  Wouldn`t it have been easier to stamp the engines with the size when manufactured!

 

  Well 842g is pretty close to JL'S list above with 835g for the 150 of that generation. Do not expect the measure to be exact, manufacturing variance and your bit of rubber would make that up.

   

[Paul De Tourtoulon]

7 minutes ago, J D 8 said:

Do not expect the measure to be exact, manufacturing variance

It could also be over weight if it has been running on castor oil, adding another 10 grams to it.😂

[John Lee]

43 minutes ago, martin collins 1 said:

In that last table provided by John Lee, height from crankshaft to cylinder head, is that from the centre of the crankshaft to the top of the rocker cover on the head as that measurement on mine is 101mm, or from the centre of the crank to the top of the cylinder head if you ignore the rocker cover which is 93mm on mine in that measurement! 

 

It's from the centre of the crankshaft to the top of the rocker cover. If you look at the link I provided you would see this example:

 

[Don Fry]

I’ve just done some measuring. A laser 100 of that sort of era has 12 fins, and is 122mm from the bottom of the crank case to the top of the rocker box cover, ie distance off workbench to top of rocker cover.

laser 150, same era, 12 fins, 123mm, measured  as above. 
Note I seem to remember they shared a crankshaft, which makes some sense as the 150 is a lot bigger than the 120 in cylinder diameter.

[RottenRow]

Martin, the 120 was a squat engine (short stroke), the finned part of the cylinder was noticeably lower than its diameter. Here is a photo of my 120.

 

Yours is definitely a 150, an early one as it has the Super Tigre carb. You will notice that the finned part of the cylinder is much higher on yours compared to the 120.

 

Those shown on Paul’s paper sheet are the older ones with the glowplug at the front (the ones that Jon could no longer offer support for when the company was running).

 

Yes it would have been better if they had been stamped with their size during manufacture, one wonders why they were left anonymous.

 

Brian.

[martin collins 1]

3 hours ago, John Lee said:

It's from the centre of the crankshaft to the top of the rocker cover. If you look at the link I provided you would see this example:

I looked at you link John and didn`t even notice the diagram showing the measurement points! 🙄 . Your link plus Brian`s picture and description of the cylinder height difference have nailed it as a 150, if anyone is looking for one with good compression it is up for sale send me a pm. Thanks to all those that chipped in with information and thoughts.

[Andy Stephenson]

There were two versions of the 150. Earlier ones had a bronze liner and were nearly 2oz heaver than the later nikosil aluminium cylinder type.

[Jon H]

19 hours ago, martin collins 1 said:

 

 

Its a 100. 1993 manufacture. There is an outside chance its a very late 90, but i doubt it. 

 

Weights are meaningless as carbs changed, early engines had solid cranks, later ones hollow etc.  

[Jon H]

5 hours ago, RottenRow said:

one wonders why they were left anonymous

 

Dont look at me. i stamped the size on mine and in 1993 i was only 8 so not my problem. 

[Martin Harris - Moderator]

I don’t suppose there’s any way some of your identification clues could be recorded here for posterity?  Seems the accumulated forum knowledge was well wide of the mark this time!

[Jon H]

Well it looks like a 100...they look like that. if it looks like that its a 100 as that is what they look like. 

 

This is also a 100. 100's look like this

https://www.laserengines.com/product/laser-100/

 

You will note it looks the same as the old one, just not as square. 

 

What else...well 45mm case, 100mm tall...square case with no bulges above the mount rails for head bolts....small head, small carb, small exhaust....and it just looks like a 100. 

[martin collins 1]

The engine is a 1993 one judging by the L stamped on it, would a 93 100 have been this tall in the cylinder, the other one pictured by Brian is definitely shorter, obviously Jon is the expert in these engines so hopefully it can be identified between the two sizes. I still can`t grasp why the size was not stamped on them at manufacture to avoid this confusion?

[Jon H]

Martin yours is a 100, Brian's a 120 circa...ehh 96? sure why not. 120 has 45mm case, 90mm tall, bulges for head bolts on crankcase above mount rails, large head, large exhaust etc...and, it just looks like a 120 as that is what 120's look like. 

 

 

[Martin Harris - Moderator]

1 hour ago, Jon H said:

Well it looks like a 100...they look like that. if it looks like that its a 100 as that is what they look like.

 

Sorry, what I meant Jon, was would there be any possibility of listing identification clues for the whole range.