ffkiwi

Greg you may be right-you may have a good 'un. I'm also cognisant that these-the Junior 1.5- were the first engines Cipolla produced-and presumably they had a learning curve to go through as well. Looking at mine, they are not as well put together as the bigger Cipolla 2.5, 3.5 and 4cc aircraft engines. Fratelli Cipolla were obviously trying to establish themselves in a fairly crowded Italian market that already had two high profile manufacturers-Super Tigre and Rossi-as well as several minor ones-Kosmic, OPS, CMB (I'm referring to the market as it would have been in the mid 1970's). It would make sense to start with a simple, low cost design to test the water before embarking on anything more ambitious. Subsequently of course their later T/R diesel and Combat glows were highly competitive in the 1980s [I used a Master 2.5 AAC std as an F1C engine in the early 90's-and it was right up there with a Rossi]. They were intended-in std form as beginners engines-though obviously in producing and selling a Competition model, the Cipolla brothers implicitly recognised the potential of the design. Both my PF7 glows go like stink-and on straight fuel-were a good 1000rpm better than a TD 09 on the same prop. On nitro the difference was even greater-and they were slightly lighter to boot! The Achilles heel was the glow insert-which were thin on the ground even in the 80's-and like hens teeth these days. Of course if someone nice like Jon Fletcher makes you up a Nelson head button-your problems in that area disappear............

I'm speculating here-but it would not surprise me if the diesel PF7 uses exactly the same piston and liner as the glow one, with the contra on the head, as opposed to the liner. Clearly the taper for an ABC glow-which nips just at or slightly before TDC, is less than optimum for a diesel. If my supposition is correct, then this would explain the starting issues that a number of people have encountered (not just me).

ChrisM
'ffkiwi'

ffkiwi

[quote]ORIGINAL: william hanshaw

Chris, Thanks for the good information and the two shots of your beautiful Delrin tank! I'll certainly be proud to make its home in my Spitfire! It's very easy to start and runs so well that it's my favorite engines in its size - at least in my limited collection!

Bill I've always regarded the Spitfire as a better engine than its Sabre stablemate-and I've run enough of both over the years. The Spitfire is an adequate sport 1cc-more powerful than an ME Heron or ED Bee, whereas the Sabre is a rather lack lustre 1.5 compared to just about all of its contemporaries. A number of people have expressed a similar opinion over the relative merits of the AM10 vs the AM15.

I lost my best Spitfire in a 40" Simplex just over a year ago............still waiting for that phone call from a local farmer, but it hasn't happened yet.

ffkiwi

OK Bill-here it is all done-the filler and feed vents took longer to do than the whole rest of the tank.

ChrisM
'ffkiwi'

william hanshaw

Hello, Chris.... Well the tank is a real beauty! Complete with aluminum fill/vent/feeder tube fittings, too! I can't wait to install it and run my Spitfire.

I assume I'm to use the bottom fitting to feed the engine's fuel input at the NV. Correct? Most other integral tanks I've seen,,in fact ALL I've seen, have had a fuel tubing-size hole near the top, so a fuel line from the carb can sweep around the cylinder and run into it, to the bottom of the tank. I guess I've just led a sheltered life!

If I use my DDD fuel which is tinted pink, it may show through the translucent delrin to show its level. Neat!

Chris as always, I'm indebted to you for your expertise and generosity. Thanks again, Your friend, Bill

ffkiwi

Bill-what I've produced for you is one version of the DC integral tank used towards the end of DC production. Yes you take the fuel feed from the tubular fitting on the underside. There are other tank versions-see pics below. There are spun metal tanks with tubular vents, nylon tanks with tubular vents, nylon tanks without vents-(just holes), clear acetate cylindrical moulded tanks, moulded flat sided tanks, and machined alloy tanks. My personal favourites are (i) the clear flat sided plastic tank with two top vents and a bottom feed-fitted to the earlier Merlins, Spitfires and Sabres-these could be removed and fitted externally on the model to give you a useful FF tank-even on models where you were using a different brand of engine! [the earliest versions of these plastic tanks just hand two holes in the top-one for the feed and one for filling] And (ii) the radial tank mount-available for the Dart .55cc, Bantam .75cc (which used the same crankcase as the Dart,but a different shaft and larger cylinder OD) and the later Wasp 0.8cc. These had the same mounting lug dimensions as the Cox reed valve Bee series-so could be interchanged easily-the only disadvantage occurs with the Dart, due to the single fixing bolt holding the cast tank backplate to the tank 'bell portion, these two can rotate with respect to each other-and if you flood the Dart, you can find the whole engine rotating-which is a real pain, as you have no option but to dismount the engine from the model, tighten the bolt and replace. [I've never had this occur with the Bantam or Wasp-being glows these have lower compression, and its harder to hydraulic lock them. If DC had designed a 2-bolt attachment for the tank backplate we wouldn't have this occasional problem-but then that would make production machining more difficult..........

ChrisM
'ffkiwi'

william hanshaw

Chris, thanks for the detailed information. Apparantly the manufacturer just kept on changing their design details through the life-cycles of their engines.

Is there some type of gasket seal or other compound that I might lightly coat the mating surfaces with to "fix" the tank from rotating in the backplate? Might be worth the trouble if tank rotation, especially during flight, is a problem.

Regards, Bill

ffkiwi

A paper gasket or thin fibre washer in that location certainly would not do any harm. Something like a manila folder is a good starting point for a 'paper' gasket-and use one of those circle cutters with a sharp blade to cut it out, unless you happen to have a set of suitable punches among your tools. I made the tank a very snug fit in the backplate recess of the backplate I used for reference. It may or may not be as snug in your engine backplate.

Chris M
'ffkiwi'