cathurga

Jeff, I really dont know if the car timing light would work, but as mentioned, going through all that trouble when you could simply check the timing on each cylinder by using the wheel and timing light which is probably easier, and easier still if you have the engine on a bench. I actually mad a little wire reference indicator that I bolt to the cam cover, makes it pretty simple to set up and measure. I am travelling a lot at the moment, Spain last week, and Turkey this week, so just dont have the time....will have a bash when I am back, as my engine is in its box.

With regards to the tuning, I know that my HS needle is around 1.25 turns out, and I think the LS is at about 4.5, I never got it running so well when the timing was stock, so not really in a position to compare... On that Seafury in the video, we did 4 x 7 minute flights the other day, on a 450/500ml tank, and never refuled it once....and it was still at a quarter tank when we packed up,so I think it is running more economically....if that means anything.

Since you're flying it on an aerobatic, I understand that you need all the power that you can get, but I would be tempted to use a more powerful, 2-stroke for that sirt of application, considering they are able to handle overheating a little better than these engines, power/weight ratio and efficiency would be better,.....but the noise would be worse! lol!

Adrien, thanks for your input, as someone who is actively involved in making custom applications and ignitions for this hobby, its great to have you around to contribute. Building a hub with a ring would be the best option, particularly if you placed the magnets according to the true TDC of each of the cylinders. Next best option would be the sensor ring, as its easier to install than pulling a hub off.
Similar response I saw from Saito, there is no way they would ever admit to a design flaw like this.....so they will just absolve themselves of all responsibility.....hey, this is business, right?! We dont want them out of this hobby, but let them salvage their pride through the multiple returns they will see with smashed cylinders.....although they have mitigated the damage a little by 'redesigning' the pistons, not saying why, and reducing the compression ratio of the engines. Odd choice, but its theirs to make.... We might see in the future, a little sneaky sensor relocation in new engines....will keep an eye out for that :-)
34Deg BTDC is a good compromise for those that want the ultimate power, but I know from a technical standpoint, that increases in power normally come with some sort of compromise..and that could include a slight drop in longevity, and maybe a little more heat build up. I seek an easy starting model, that will fly my planes nicely and not be a pain in the butt....I am a tinkerer, but have never seen the advantage of running engines on the absolute 'peak' of the needle settings, I would far rather know that the engine is running at good power, without compromising on lubrication and overheating potential. I normally put overpowered engines in most of my planes (it seems the norm in this hobby) so dont really need to fly them on the red line. Actually, warbirds that had radials, were really low revving most of the time, so the Seafury sounds pretty good at lower revs, hurtling by...4T engines really do like a coarser pitch

Adrien, just a question for you; You mentioned that the ignitions do not advance the timing anymore after around 4000rpm, isthis correct? Since you have the option to reprogram your ignitions to remove the glaring timing error, would it not be possible to program the timing to keep advancing AFTER 4000 rpm? Maybe up to 34deg at 5500-6000 rpm? That would be first prize to keep the starting/low revs timing where it should be, and to allow max power at the top end....?

Just a thought, but I dont know how the programming curve/actions works, so I could be talking rubbish....