DonW Posted January 13, 2021 Share Posted January 13, 2021 1 hour ago, Matt Bacon said: Thanks, all! @DonW can you remember if there were specific circumstances to use one or other or both? Hard to see why you would ever NOT use both unless there were some downside... like increased fuel consumption. Though without integrated systems, it’s hard to see how the carburettor would “know” whether there were one or two sparks in the cylinder when the air/fuel mix got there... best, M. My father as an ex-Spitfire pilot was well used to checking magneto drop - the Merlin had two mags so they were checked independently to ensure the engine revs did not drop below a certain level for a set throttle setting when one or other was selected. Both were used for normal flight. He did a similar check of the coil and mag in the Lagonda, and always used to select coil only to start the engine from cold, as this made starting easier, but I don't know why! Otherwise both were used for the benefits of two flame fronts during combustion. There was the odd occasion when we were grateful for the set-up - I remember an occasion on a European trip where we had to rely on the mag alone to get us home. The Lag also had an advance / retard lever on the steering column so the timing of the spark(s) could be altered within a limited range, but he never altered the mixture since as you suggest all normal running was done on both. If anything fuel consumption was lower with both as the mixture was burned more efficiently. Quote Link to comment Share on other sites More sharing options...
DonW Posted January 13, 2021 Share Posted January 13, 2021 Thanks Bill - I was typing my latest reply when yours appeared, and gives a bit more useful detail! Here's an account of an accident caused by failure to carry out the mag drop check before take-off: https://assets.publishing.service.gov.uk/media/54230438e5274a1314000be3/Vickers-Supermarine_Spitfire_PR_XI__G-PRXI_05-03.pdf The Silver Ghost owner would have been at less risk if suffering similar mag failures! Quote Link to comment Share on other sites More sharing options...
Ace-Garageguy Posted January 13, 2021 Share Posted January 13, 2021 (edited) 1 hour ago, DonW said: He did a similar check of the coil and mag in the Lagonda, and always used to select coil only to start the engine from cold, as this made starting easier, but I don't know why! Very cool that your father flew Spitfires. The reason the Lagonda engine would start easier on the coil is that a mag has to be spinning to develop sufficient electrical oompf to light off the mixture. With the relatively slow cranking speeds of car starters, the rotational speed of the mag might be just borderline for starting, particularly with a somewhat flat battery in cold weather. Mags typically make more juice at higher RPM, hence their use on racing engines...and why push-starts were usually the norm back in the old days, to get the mag spinning fast enough to make a fat, hot spark. EDIT: Just for clarification, many old race cars didn't have onboard batteries or coils anyway, so push-starting a mag-equipped car (or using an external starter like some vintage Indy cars) was the only way to get them going. Edited January 13, 2021 by Ace-Garageguy Quote Link to comment Share on other sites More sharing options...
Matt Bacon Posted January 13, 2021 Author Share Posted January 13, 2021 Thanks Bill, Don... one of the parts NOT yet fitted in “Stage 3:the engine” is the starter handle! There’s no starter motor, so I imagine minimising the number of gears and linkages you had to hand crank around the the engine on a cold day would have been an important goal... The wiring of the magneto driven plugs is fairly simple: up from the mag between the two cylinder banks and outwards. The distributor/coil wiring is trickier: IRL the wires from the distributor go up to the front end of the engine and are carried to the plugs by a set of 6 “Pan pipes” which lead them to individual plugs. best, M. Quote Link to comment Share on other sites More sharing options...
DonW Posted January 13, 2021 Share Posted January 13, 2021 2 hours ago, Ace-Garageguy said: Very cool that your father flew Spitfires. The reason the Lagonda engine would start easier on the coil is that a mag has to be spinning to develop sufficient electrical oompf to light off the mixture. With the relatively slow cranking speeds of car starters, the rotational speed of the mag might be just borderline for starting, particularly with a somewhat flat battery in cold weather. Mags typically make more juice at higher RPM, hence their use on racing engines...and why push-starts were usually the norm back in the old days, to get the mag spinning fast enough to make a fat, hot spark. EDIT: Just for clarification, many old race cars didn't have onboard batteries or coils anyway, so push-starting a mag-equipped car (or using an external starter like some vintage Indy cars) was the only way to get them going. So now I know! Thanks Bill. Matt - it used to be possible to start a Silver Ghost by simply using the hand control that was also fitted on these cars to advance the ignition: " the lever controlling ignition advance had a wide enough range of movement to let the distributor points be flicked open and shut from the seat which was enough to induce a spark and start the engine .” No need to crank the engine at all! Quote Link to comment Share on other sites More sharing options...
Matt Bacon Posted January 13, 2021 Author Share Posted January 13, 2021 I'll have to have a look at the steering wheel more closely and see what's in the middle! So, moving closer to the moment of truth with the plug wiring: this is pretty much everything to complete the engine except the distributor and plug wires. Fortunately, the plug ends of the wire on the real thing just clip on from the side, so I can expose the metal on the top face, and superglue wire across rather than having to drill each plug. I need to drill the distributor (probably cutting off the projecting terminals and drilling down into the body). The magneto wires mount onto the stepped "shelves" you can see at the top of the brown part of the magneto, so no drilling needed there. The last piece of the puzzle, then, is to make the "pan pipe" structure that carries the wiring from the distributor side to each of its plugs. Fortunately, I have some thin brass tube and some superglue... Making it was surprisingly easy: thank capillary action for that. The tricky bit will be keeping it together while I fit it and wire it! Wish me luck... best, M. Quote Link to comment Share on other sites More sharing options...
Bainford Posted January 14, 2021 Share Posted January 14, 2021 Great job on this, Matt. It looks fantastic. And I continue to be very impressed with this kit. Quote Link to comment Share on other sites More sharing options...
peteski Posted January 14, 2021 Share Posted January 14, 2021 The engine looks really good Matt! As for the distributor, if I can drill out a 1:43 scale distributor, you should be able to handle the one in your 1:24 Rolls-Royce. Quote Link to comment Share on other sites More sharing options...
absmiami Posted January 14, 2021 Share Posted January 14, 2021 So. I’m rather enjoying this build. I think everyone is ... I took some photos of a Silver ghost display chassis w engine at Amelia - displayed maybe 7 yrs ago ... It appears to be this car or very close - would you like me to post a couple of them ? by the way I’ve built the Finecast Bugatti 59 and I’ve just purchased the Alfa Romeo P3 kit direct from their site. The Alfa, unfortunately, is a curbside kit - but it is the only choice in24th scale ... I’m a fan of their kits anyway ... have been for many years... Quote Link to comment Share on other sites More sharing options...
Matt Bacon Posted January 14, 2021 Author Share Posted January 14, 2021 Thanks, all... any pictures of an early Silver Ghost would be much appreciated... unless they show I've got it wrong ? So, I've bitten the bullet and started the wiring... and stopped. there's only so much I can do in one session before my eyes and mojo give up the "Ghost"... In these pictures, the "Pan pipes" are not fixed. I just wanted to satisfy myself that it can be fixed and stay below the line of the water pipe. The real pipe angles up much more steeply to the top of the radiator, but this has to stay low to make sure the bonnet top fits, which is definitely more than scale thickness. As you can see, half the magneto wires are in place at one end... Turns out, I CAN drill the distributor... without even breaking one .35mm drill bit! Another session or two to go, I think... best, M. Quote Link to comment Share on other sites More sharing options...
absmiami Posted January 14, 2021 Share Posted January 14, 2021 well - I'd say that your doing quite well don't bother separating the ignition wire tubes - enough is enough .. what a bonkers engine ... Quote Link to comment Share on other sites More sharing options...
absmiami Posted January 14, 2021 Share Posted January 14, 2021 I think you can tell that this display chassis had a different rear suspension layout Finecast was pretty careful with their research - I'm assuming that the this is a later chassis - as the Ghost was produced for years and almost certainly went thru lots of changes ... Quote Link to comment Share on other sites More sharing options...
absmiami Posted January 14, 2021 Share Posted January 14, 2021 nope you're gonna be mad at me - or maybe not ... the car that i photographed is a 1914 silver ghost - this is another shot of the same chassis I'm pretty sure that the kit instructions - famously vague - threw you off looks like the axle sits at the extreme end of the leaf springs and that the springs are attached to the chassis further forward. this matches the chassis drawings of the car that float around the internet ... now about that third leaf spring? maybe Finecast just enclosed a spare part //?? you may need a hand from some of our British forum members to settle this .... Quote Link to comment Share on other sites More sharing options...
absmiami Posted January 14, 2021 Share Posted January 14, 2021 my favorite Brit expression - Oh Dear ... Quote Link to comment Share on other sites More sharing options...
charlie8575 Posted January 15, 2021 Share Posted January 15, 2021 6 hours ago, absmiami said: my favorite Brit expression - Oh Dear ... One I'm quite fond of, myself. This build is gorgeous. Charlie Larkin Quote Link to comment Share on other sites More sharing options...
peteski Posted January 15, 2021 Share Posted January 15, 2021 I had faith in you Matt! Those wires look good! What a strange arrangement . . . Quote Link to comment Share on other sites More sharing options...
89AKurt Posted January 15, 2021 Share Posted January 15, 2021 Though I would never tackle such a subject or kit, read through every comment and picture. Looking great! Find an alternative to 5 minute epoxy? Quote Link to comment Share on other sites More sharing options...
Matt Bacon Posted January 15, 2021 Author Share Posted January 15, 2021 I’m not that daft @absmiami ! ? The back end is how it’s shown on the built model photos. And while I’m struggling to find a rear view pic of AX201 IRL, this is the (famously meticulously researched) Franklin Mint 1/12 model: best, M. Quote Link to comment Share on other sites More sharing options...
absmiami Posted January 15, 2021 Share Posted January 15, 2021 That’s a relief ! not ... daft ... I wonder if Rolls changed the susp arrangement depending upon the chassis length ordered by the customer ? Quote Link to comment Share on other sites More sharing options...
absmiami Posted January 15, 2021 Share Posted January 15, 2021 And there’s the third leaf spring ... Quote Link to comment Share on other sites More sharing options...
Matt Bacon Posted January 15, 2021 Author Share Posted January 15, 2021 The “Roi de Belges” body on AX201 is famously heavy, especially compared to later coach work. It might be a unique (or unusual) arrangement to ensure a compliant ride even with that heavy body full of people. Although the 40/50HP was in production a long time, it was a continuously evolving work in progress, and the rate of change was pretty high in the early years! best, M. Quote Link to comment Share on other sites More sharing options...
absmiami Posted January 15, 2021 Share Posted January 15, 2021 How much did this Rolls weigh ? Built like a railway car ... Quote Link to comment Share on other sites More sharing options...
Matt Bacon Posted January 15, 2021 Author Share Posted January 15, 2021 (edited) 2 hours ago, absmiami said: How much did this Rolls weigh ? Built like a railway car ... 3460 lbs with no one aboard and no fuel... That’s about 2 and a bit Model T’s. For context the modern Rolls Royce Phantom weighs in at 5640 lbs, so the 1907 Silver Ghost is 60% of the weight of the 2021 range topper... best, M. Edited January 15, 2021 by Matt Bacon Quote Link to comment Share on other sites More sharing options...
Matt Bacon Posted January 15, 2021 Author Share Posted January 15, 2021 Idly looking... the 1/12 Franklin Mint "die-cast" model, which is very impressive, seems to sell for less than $1000. Believe me, if I was charging for building this 1/24 scale model, it would be a LOT more than that by the end. Interestingly, the follow-on to the 1/12 Bentley from Airfix was going to be a 1/12 Silver Ghost https://www.vectis.co.uk/lot/2953-airfix-archive_149132 It would be interesting to know how much, if any of Airfix's research investment supported the Franklin Mint version... best, M. Quote Link to comment Share on other sites More sharing options...
Matt Bacon Posted January 17, 2021 Author Share Posted January 17, 2021 Right, that's it: "Stage 3:the engine" is now complete... Boy, am I glad to see that back of this bit... Still, it's a cool engine, and I understand much better how it works having built one. The wires could be thinner, but being black they have less visibility than they might, and I think the engine is much improved by having them in place... Now, on with the body.... best, M. Quote Link to comment Share on other sites More sharing options...
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