By continuing to use this site, you agree to our use of cookies. Find out more
Forum sponsored by:
Forum sponsored by CML

Laser Engines - Technical questions

All Topics | Latest Posts

Search for:  in Thread Title in  
Jon - Laser Engines23/12/2017 22:04:39
3471 forum posts
142 photos

Percy has it pretty much covered there.

The 61 was relatively long stroke and almost the same size as our current 80 in terms of its external dimensions. It was a powerhouse though and even now gives 60 4 strokes a run for their money. Its power to weight is not comparable to a modern engine however due to its large physical size. My restored 61 is a beast though and even though the wear on the rockers means its impossible to keep the valve clearances where they should be it goes like a train.

The 62 was developed from the 50 which was in turn developed from the 45. The 45 used the same bore as the 61, the 50 an intermediate size and the 62 the same bore as the 75 and 90. When the range was bored again in 92 we ended up with 70, 80 and 100 which remain in production today.

Trebor, rings are an interesting one as we had real trouble with them in 2016. The issue was not our fault but to resolve it we had to come up with a new method of production and the ring I sent you is of the current type. As you probably saw it has a very high tension and forms an excellent seal with the bore. This is particularly noticeable in engines that have many hours on them and the bore is somewhat worn. In any event the current rings, in combination with some other tweaks, have really improved the performance of the engines and I'm really pleased with how they are performing. I just need to make more of them.

Once I get back after new year I hope to really make some progress.

trebor24/12/2017 08:38:33
avatar
1427 forum posts
174 photos

Should I have buffed the liner with a greenie so the new ring might bed in better ?

Jon - Laser Engines24/12/2017 08:45:10
3471 forum posts
142 photos

if the liner looked clean then its not really a big issue. also the chrome/nikasil liners don't tend to glaze up like a steel liner. a little go with some went n dry or scotchbright wouldn't hurt it but its also not vital.

at the end of the day it comes down to the condition of the liner. if its grubby and slightly scratched then its worth a little treatment, if its pretty clean then its not super important.

trebor24/12/2017 09:30:45
avatar
1427 forum posts
174 photos

I think I was lucky, there was no play or scratches in the bearing surfaces. All I had was 2 small marks as the valves touched the piston top on one engine. They were the kind of marks you'd get by tapping a teaspoon handle on alloy and I couldn't see a problem with the valve seating as it was clean all the way round.

John Stainforth24/12/2017 16:15:57
141 forum posts
34 photos

Steve D,

Do you have experience with your chicken hopper system with laser V engines. I am presuming that one needs four tanks for two cylinders, or can the system work properly with one large tank feeding two small ones? (or even one tank feeding one small tank?) I was going experiment with all of these, but thought it would be simpler to seek expert advice first!

Ron Gray24/12/2017 16:25:34
644 forum posts
186 photos

As long as there are 2 separate feeds to the 2 carbs, so 1 main header tank feeding 2 small delivery tanks, or 1 main header feeding 1 delivery tank equipped with 2 clunk carb feeds I think it should work. Personally, I would favour the latter option.

Steve Dunne24/12/2017 16:39:03
avatar
37 forum posts
6 photos
Having thought about this a little, I am pretty sure that you will need two top tanks and two bottom tanks, otherwise the vacuum system won't work properly. It would be interesting to try it on the bench but I am pretty certain of the process logic.
Steve.
John Stainforth24/12/2017 16:43:25
141 forum posts
34 photos

Steve,

Thanks for the reply. I also got the impression I would need four tanks. I suppose it's time to get experimenting!

Edited By John Stainforth on 24/12/2017 16:44:44

Steve Dunne24/12/2017 16:47:01
avatar
37 forum posts
6 photos
Although on second thoughts perhaps one single top tank with one single bottom tank should work!
Two clunks in the bottom tank feeding the carbs will not interfere with the hopper logic.
Second thoughts are always better 😁.
Steve.
Ron Gray24/12/2017 16:50:16
644 forum posts
186 photos

Yup, that was my logic as well. If you had 2 bottom tanks I suspect that there would have to be a balance pipe between them in effect making them into 1, so why bother with 2?

John Stainforth24/12/2017 17:28:33
141 forum posts
34 photos

Steve and Ron,

Thanks for the ruminations. One snag I can see with a single feed tank is that it would need five pipes coming out of it!

Ron Gray24/12/2017 17:34:08
644 forum posts
186 photos

But that’s only 1 more than a ‘standard’ twin clunk tank, mine has 4, fill, vent and 2 feeds.

Ron Gray24/12/2017 17:34:51
644 forum posts
186 photos

But that’s only 1 more than a ‘standard’ twin clunk tank, mine has 4, fill, vent and 2 feeds.

Ron Gray24/12/2017 17:36:24
644 forum posts
186 photos

But that’s only 1 more than a ‘standard’ twin clunk tank, mine has 4, fill, vent and 2 feeds.

Ron Gray24/12/2017 17:40:03
644 forum posts
186 photos

3 repeat posts as a result of poor connection, mods can you clean up please?

Geoff Sleath24/12/2017 22:24:51
avatar
2274 forum posts
174 photos

While I was looking for tips on YouTube on stripping and rebuilding Lasers I came across this. It seems for some castor is not dead!

btw my YouTube name is Belper Flyer. They're my comments.
Geoff
bert baker25/12/2017 15:29:34
avatar
1026 forum posts
216 photos

Not long ago there was a mention of the laser head,

I saved this sectional picture of a laser head a few years ago and recently found it again img_1868.jpg

Percy Verance25/12/2017 20:14:42
avatar
6014 forum posts
109 photos

Ron, you didn't by any chance work for the BBC in a previous life?

Ron Gray25/12/2017 21:58:18
644 forum posts
186 photos

Hi Percy, afraid not, although I have appeared on TV a few times, but that’s another story!

Tom Sharp 226/12/2017 04:37:38
avatar
2630 forum posts
13 photos
Posted by Ron Gray on 25/12/2017 21:58:18:

Hi Percy, afraid not, although I have appeared on TV a few times, but that’s another story

Go tell us the story Ron

All Topics | Latest Posts

Please login to post a reply.

Magazine Locator

Want the latest issue of RCM&E? Use our magazine locator link to find your nearest stockist!

Find RCM&E! 

Email News - Join our newsletter

Love Model Aircraft? Sign up to our emails for the latest news and special offers!

Latest Forum Posts
Support Our Partners
Overlander
Expo Tools 14 July
electricwingman 2017
CML
Slec
Gliders Distribution
Airtek Hobbies
Wings & Wheels 2018
Sarik
Advertise With Us
Latest "For Sale" Ads
How has your building graduated?
Q: Did you start with ARTF and move to building from kits or vice versa?

 Started with ARTF moved to building from kits only
 Started with ARTF moved to building from plans only
 Started with ARTF moved to building from kits and building from plans
 Started with building kits or from plans and moved to ARTF
 I only build from kits or plans
 I only build ARTF
 I only build from kits
 I only build from plans
 Other (Please specify in thread)

Latest Reviews
Digital Back Issues

RCM&E Digital Back Issues

Contact us

Contact us