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I had a lot better look just now - with a pencil and paper - and it really makes no sense ....I assume (hopefully not Ass-U-Me) that it follows the Classic Beetle layout, with the inlets in the centre off the head and an exhaust at each end of it. In that case it's a Big Bang engine, where cylinder 1 and 4 fires simultaneously and likewise cylinder 2 and 3 .... To me it looks like the camshaft 'needs to be cut in the middle' and the having the one half turned 180 degrees and put back together ....
Just FYI, in most inline 4 cyl engines I have owned and worked on, many different makes and models, made in several countries, firing order is 1342 not 1324. There may be engines that use 1324 but I have not come across one as yet.
A Flat Four is not the same as a Straight Four ...!I agree on the firing order on a straight four - but the original question was for a flat four ....This time I actually searched the page and found this :https://www.cad-modelltechnik-jung.de/construction-plans-model-engines.htmlOne of the last drawings show the powertrain on this unik engine -> throwing ALL my assumptions down the drain Not only are the inlet and exhaust positions not where I thought on the rear two cylinders - but the crank throws are with a single 'pin / big end' -> making the pistons go the same way - instead of opposite directions ....I have never seen a full size engine with this layout - but it simplifies the build + make it more compact.I conclude that the camshaft is shown (in the drawing) with the pistons at either TDC or BDC. I will look at the last post before this to (hopefully) verify.
Coincidentally I just got delivery of the same plans. I'll wait to hear of any communication response you can pass along.When I've emailed him a few times in the past, seems like eventually he does get to them. Is it more the cam phasing you are wondering about or the individual timing parameters? I built myself a spreadsheet so I could digest this information (pertains to a glow radial) but eventually I could/will evaluate for this engine. I suspect, but don't know for sure, he sticks to similar recipe among his various engines.
I'll be watching along glorfindel. I'm just starting the same cad exercise myself.... and not trying to get too distracted from my radial build.- what is your rationale for changing the bore slightly from nominal metric to nominal imperial units by the little amount? Aren't the rings going to be sized based on resultant bore whatever it is (Trimble method), or do you have some other method in mind?- what features of the Edwards pushrod system are different or better than this design in your opinion?- not sure if you saw my inquiry post here on the forum about the Hirth coupling, but just wondering if you plan to adopt that feature on the crankshaft or have something else in mind.