Martin McIntosh Posted August 5, 2016 Share Posted August 5, 2016 I believe that I used to get 7500 from a RCG50 but this has now dropped to 7000 on the same 23x8 wood for some reason. May be very old fuel. Getting marginal for large loops with my 28lb 96" Hurri. The problem with the 2 stroke is the noise. Quote Link to comment Share on other sites More sharing options...
Joespeeder Posted August 5, 2016 Share Posted August 5, 2016 Hi Jon, Very cool !! Would love to see you put a 15x8x3 on there. Do you think you'd get 7,200-7,300rpm ? What's the crank center-line to top of the valve cover measurement on the 120 long stroke? Great work ! Joe Quote Link to comment Share on other sites More sharing options...
Jon H Posted August 5, 2016 Author Share Posted August 5, 2016 Joe check out the dimension drawing for the 180 on our website. Its more or less the same physical size. and according to my calculations I would expect over 7500 on a 15x8x3 master prop but I have tried calculating 3 blade prop performance before and its a nightmare! Martin, we are talking 2 stroke vs 4 stroke so the two cannot be compared. Also 2 strokes respond well to exhaust tuning with many mufflers and pipes available. 7500 still sounds very fast for a 23x8 prop. As I said before I have seen first hand a dle 55 turning a menz 23x8 at 6500. DA50 owners seem to be looking at 7k on 22x8 carbon and 7k on 23x8 carbon when running a pipe. The Kolm ez50 petrol 4 stroke runs 22x10 @ 6300 according to the info I found online. From that I would expect about 6500 again on 23x8. But, as I say, once I have a prototype I will see where we are! Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted August 5, 2016 Share Posted August 5, 2016 OK, thanks Jon. Quote Link to comment Share on other sites More sharing options...
Former Member Posted August 5, 2016 Share Posted August 5, 2016 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Jon H Posted August 5, 2016 Author Share Posted August 5, 2016 Thanks for the positive comments. The big question is would anyone actually buy one? unless I sell 20 of them per year (minimum) its a non starter. The other issue is the price. It would be more expensive than the short stroke engine. Perhaps 10-15 quid more as its bigger/more material etc etc. I had not actually intended to put it into production as I was not sure if there was a large enough market, If people are serious about though it I can investigate getting it produced but I would need to present my boss with at least 10 firm orders to get anywhere. Edited By Jon Harper - Laser Engines on 05/08/2016 23:46:50 Quote Link to comment Share on other sites More sharing options...
Former Member Posted August 6, 2016 Share Posted August 6, 2016 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Terry Walters Posted August 6, 2016 Share Posted August 6, 2016 Ok Jon, just showing my faith in British industry and your valiant efforts put me down for one! I think there is a market for an engine like this. Terry Quote Link to comment Share on other sites More sharing options...
Jon H Posted August 7, 2016 Author Share Posted August 7, 2016 Noted Terry, I will see what I can do! Quote Link to comment Share on other sites More sharing options...
Alan Hilton Posted September 21, 2016 Share Posted September 21, 2016 Hi I have a question for Jon .Im thinking of a Laser twin for a 1/3 scale spacewaker .The cowl is just short of 7 " widenand quite deep .Which twin ? Or would a 180 work ? Alan Edited By Alan Hilton on 21/09/2016 07:17:54 Quote Link to comment Share on other sites More sharing options...
David perry 1 Posted September 21, 2016 Share Posted September 21, 2016 That long stroke sounds lovely. D Quote Link to comment Share on other sites More sharing options...
Jon H Posted September 21, 2016 Author Share Posted September 21, 2016 Posted by Alan Hilton on 21/09/2016 07:16:43: Hi I have a question for Jon .Im thinking of a Laser twin for a 1/3 scale spacewaker .The cowl is just short of 7 " widenand quite deep .Which twin ? Or would a 180 work ? Alan Edited By Alan Hilton on 21/09/2016 07:17:54 Hi Alan Using the specs of the SIG kit as a reference you could use anything from a 155 to a 300v. They quote 20lbs flying weight which seems a bit porky for a spacewalker, but you have plenty of wing to do the lifting. A great deal will depend of the flying weight and your desired level of performance. If you are able to build it light (18lbs) and just want to walf about the sky then the 155 or 180 would be just fine. The 160v or 200v would also do a great job. If however the model ends up at 20lbs+ and/or you want some more exuberant flights then a 240v or 300v are on the cards. I fly a number of 80inch warbirds and use 300's in the 20lb La7 and P39, and a 360 in the 23lb sea fury. All of these models have performance appropriate for their type with decent vertical performance for large loops. I also have a 1/4 scale stampe of about 14lbs that i fly with our 180 on a large prop. This flys very well at about 1/2 throttle with full power only needed for loops. Given that the spacewalker is between the two types of model above in terms of the performance i would expect the 240 or 300 would probably be my choice. Either will fit the cowling, both are very smooth running. You might get away with a 200v, but equally you might find it needing a little more. Looking a videos online some are using engines up to 60cc petrol which seems excessive. One was flying really nicely at 21lbs on an old ST3000 which our 240v will fend off on 18x8 props with an extra 200 or so rpm to play with. The 300 again would be really monster with all the performance you could ever want using a 20x8 menz wood prop @ 7400 or so. So, hopefully you are now less confused than before! Give me a call if you would like to discuss the options further. David, i like the long stroke sound as well. I just need to convince the boss to let me make/sell some Quote Link to comment Share on other sites More sharing options...
Ernie Posted September 21, 2016 Share Posted September 21, 2016 Hi Jon, What I really want is a beautiful piece of UK built machinery. It must start instantly, idle to perfection, and never falter. Hey, it's a laser ernie Quote Link to comment Share on other sites More sharing options...
Paul H Posted September 21, 2016 Share Posted September 21, 2016 I started my new Laser 150 on Sunday for the first time. The starter hardly had time to engage the spinner before it burst into life, after running a tank through and minimal adjustment I flew it gently and without a missed beat. You're not wrong Ernie Quote Link to comment Share on other sites More sharing options...
trebor Posted September 21, 2016 Share Posted September 21, 2016 I can't understand why you don't stamp engine sizes on, owners initials are no good in the secondhand market Quote Link to comment Share on other sites More sharing options...
Jon H Posted September 21, 2016 Author Share Posted September 21, 2016 Posted by trebor on 21/09/2016 14:27:00: I can't understand why you don't stamp engine sizes on, owners initials are no good in the secondhand market Yea dont even get me started on this. Suffices to say that i now stamp each engine with its size. I also try and stamp each engine i get back for repair as well but some have slipped through. Good to hear everyone else engines are doing their duty! Edited By Jon Harper - Laser Engines on 21/09/2016 14:48:29 Quote Link to comment Share on other sites More sharing options...
Alan Hilton Posted September 21, 2016 Share Posted September 21, 2016 Hi Jon Thanks for the reply what is delivery like on a 240 please .I have to sell some petrol engines to help fund a Laser so I'm not in a rush Alan Quote Link to comment Share on other sites More sharing options...
Jon H Posted September 21, 2016 Author Share Posted September 21, 2016 Hi Alan Its just as well you aren't in a rush. For numerous reasons I am totally swamped at the moment and it pains me to say lead times could be up to 10 weeks as I am so far behind. As one of the major obstacles to making headway (a broken machine) is now fixed it can get to work producing the large number of components I need. In the case of the 240 I only need the bearing housing and that will come through once the 70 and 80 bearing housings are done. Hopefully I can clear those small singles while the 240 parts are coming through, I can then do 300's and 240's together as they share a common bottom end. I do need to finish the 360's, 160's and 200's as well. 180's will have to wait until the machine is clear of the front housings and then it can make 180 crankcases, 120 crankcases, and then I can build those sizes.... There are also repair engines waiting for service too. The best plan is to give me a call tomorrow, or send me you number and I will call you. I can go through everything you need to know, make sure its the right engine for the job and get the order down. I wont take payment until the engine is ready, but at least you are on the board and no one can jump in front of you Quote Link to comment Share on other sites More sharing options...
Former Member Posted September 21, 2016 Share Posted September 21, 2016 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Phil 9 Posted September 21, 2016 Share Posted September 21, 2016 good news that the machine is fixed Quote Link to comment Share on other sites More sharing options...
Jon H Posted September 21, 2016 Author Share Posted September 21, 2016 Yes Phil, it means your 70 will soon be done. All I need for it now are the carb bodies (back from anodizing tomorrow) and piston rings. Once I have them its all good Quote Link to comment Share on other sites More sharing options...
Phil 9 Posted September 22, 2016 Share Posted September 22, 2016 Posted by Jon Harper - Laser Engines on 21/09/2016 22:34:53: Yes Phil, it means your 70 will soon be done. All I need for it now are the carb bodies (back from anodizing tomorrow) and piston rings. Once I have them its all good fantastic Quote Link to comment Share on other sites More sharing options...
Phil 9 Posted December 3, 2016 Share Posted December 3, 2016 a smaller laser for 40 size models would be nice Quote Link to comment Share on other sites More sharing options...
Derek Stevenson Posted December 3, 2016 Share Posted December 3, 2016 Phil, got a Laser 70 since I last saw you, runs like a Swiss watch, best engine tick over I've ever had, so good I added a 150 to the collection. Quote Link to comment Share on other sites More sharing options...
Phil 9 Posted December 3, 2016 Share Posted December 3, 2016 Posted by Derek Stevenson on 03/12/2016 19:56:06: Phil, got a Laser 70 since I last saw you, runs like a Swiss watch, best engine tick over I've ever had, so good I added a 150 to the collection. yes they are a bit good Quote Link to comment Share on other sites More sharing options...
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