Jon H Posted April 15 Share Posted April 15 8 minutes ago, Martin Harris - Moderator said: Sorry, what I meant Jon, was would there be any possibility of listing identification clues for the whole range. Ah look see, i try and help one chap id his engine and im back doing a job i no longer have for a company that no longer exists at half 7 on a Monday night. I dont mind helping out here and there but going through the entire range from start to finish would be like writing war and peace. Just the 150 alone has about 6 major versions to cover although many of the versions hardly differ visually. I have given details for the 100 and 120, the 150 is the same as the 120 just 100mm tall not 90. That's going to have to do for now. Quote Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted April 15 Share Posted April 15 Fair enough. I think we're all grateful for your continuing interest and appreciate that any help is a bonus. 8 Quote Link to comment Share on other sites More sharing options...
Paul De Tourtoulon Posted April 16 Share Posted April 16 It might be worth taking the head off and measuring the swept volume. Quote Link to comment Share on other sites More sharing options...
GrumpyGnome Posted April 16 Share Posted April 16 Or just believe Jon..... he's seen more Lasers than all us forumites put together..... 2 Quote Link to comment Share on other sites More sharing options...
Ron Gray Posted April 16 Share Posted April 16 48 minutes ago, GrumpyGnome said: Or just believe Jon That would be a first for Paul 🤣 2 4 Quote Link to comment Share on other sites More sharing options...
Chris Walby Posted April 16 Share Posted April 16 I must be really missing the point, but as its a pushrod engine if you really want to know, just take the head off and measure it? Its not like you will loose the valve timing. IIRC the valve timing is not that extreme so you could fill the cylinder head with oil (not castor!) at TDC, then turn to BDC, fill and the difference is the swept volume. If you can't be bothered with any of that then put it in a test stand and go through a few selected props, measure the RPM and compare with the Laser engine web site for the recommended prop for each engine (slightly more difficult for the obsolete engines, but do-able). PS, what did the original have on as a prop MC1 (assuming it was propped correctly)? 1 Quote Link to comment Share on other sites More sharing options...
martin collins 1 Posted April 16 Author Share Posted April 16 Prop was a 15x8 Chris. Quote Link to comment Share on other sites More sharing options...
Chris Walby Posted April 16 Share Posted April 16 Spec for the 100 Additional information DISPLACEMENT 0.99 cu in (16.21cc) BORE 27.7mm STROKE 26.9mm PRACTICAL RPM RANGE 1800-10000 RECOMMENDED FULL POWER RPM RANGE 7500-9000 RECOMMENDED PROPS 14×7-8 15×6-8 16×6 WEIGHT 810g Quote Link to comment Share on other sites More sharing options...
Mike T Posted April 17 Share Posted April 17 If you can remove the backplate, measuring the crank throw will give you your stroke and if you can get calipers on the piston skirt at BDC, that'll give you your bore. Pi x (bore/2)² x stroke gives you your swept volume. Quote Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted April 17 Share Posted April 17 Not on a Laser - the valve gears and cam followers prevent access to the crankshaft and piston so it’s much easier to remove the head to measure bore/stroke if it can’t be identified by other means. 1 Quote Link to comment Share on other sites More sharing options...
Mike T Posted April 17 Share Posted April 17 5 hours ago, Martin Harris - Moderator said: Not on a Laser - the valve gears and cam followers prevent access to the crankshaft and piston so it’s much easier to remove the head to measure bore/stroke if it can’t be identified by other means. I don't own a Laser (never will...), that's why I qualified with an 'if' 🙂 Still, it would be an easier method for most other engines - except that the manufacturers of most other engines sensibly cast or engraved their engines capacities on them... 3 Quote Link to comment Share on other sites More sharing options...
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