Laser Engines - Technical questions

[bert baker]

Is this the one reputed to give more power

[Jon H]

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

[trebor]

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

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

[fly boy3]

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

[Former Member]

[This posting has been removed]

[Jon H]

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.

[trebor]

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

[Jon H]

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.

[trebor]

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 Stainforth]

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 Gray]

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 Dunne]

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 Stainforth]

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 Dunne]

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 Gray]

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 Stainforth]

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 Gray]

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

[Ron Gray]

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

[Ron Gray]

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

[Ron Gray]

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

[Geoff S]

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 baker]

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

[Former Member]

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[Ron Gray]

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

[Former Member]

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