Originally Posted by Radial power (Post 12367943)

Thank you very much.

Oh, and another couple of little things that I forgot: these multicylinder engines have a lot of metal to warm up when compared to a single cylinder engine with the same displacement. And they also have much more cooling fin area to dissipate heat. So don't be surprised if the engine takes a while to fully warm up.

For the first runs I'd avoid using exhaust collector rings and instead I'd run the engine on a test stand with the 7 independent exhaust pipes. This way it's much easier to see if a cylinder is not firing: you only need to place your hand an inch or so behind the outlet of each exhaust stack and feel whether the pulses coming out of the stack are crisp, "hard" and hot exhaust pulses (indicating that the cylinder is firing) or much weaker lukewarm "puffs" (indicating that the cylinder is not firing). You can always fit a collector ring at a later time if you want to, when you are sure that you do not have problems with dropping cylinders.

Originally Posted by Old Fart (Post 12381227)

Nice flying sounds good

Originally Posted by Jennifer Curtis (Post 12382293)

tower has the Sirius 300 radial on clearance today. $2600

Jenny

Originally Posted by Radial power (Post 12384321)

I assume you mean the FR7-420 Sirius7, as the old Sirius 300 has long been discontinued.
It must have been a very brief price dip, as I have written a small program that checks for the price of that engine (and the FF-320) on Tower Hobbies every 6 hours to alert me via email of any price drop, and it noticed nothing unusual around november 9th. Price stayed at $3499.99 all the time.

Or it could be that there is a bug in my program, even though it clearly kept on logging $3499.99 the whole time :)

Originally Posted by tdevince (Post 12384327)

Tower does show they still have the FR5-300 in stock for $2499
https://www.towerhobbies.com/cgi-bin...&I=LXBY70&P=SM

I haven't seen a price drop on the FR7-420 yet either.

Originally Posted by BobH (Post 12389252)

That's a LOT of money for a 300 sized engine. You could buy a Saito FG60 for half the price.
Or if you prefer a UMS 777 radial..

Originally Posted by Old Fart (Post 12396078)

Hello bob a few years back i ran a 777 in on the bench for a flying friend.In the first hour the only way i could keep the bottom three to four cylinders running was to add 10% petrol to the glow fuel mix.

Originally Posted by partshunt (Post 12396081)

Compression may be the cause as it wont even fire intermittently, just nothing, nothing and more nothing. Any ideas?...Thanks.. Joe