[Jollidude]

I have a Ziroli Harvard that will weigh approximately 25 to 27 lbs when finished, fiberglass fuse and built up wing. Most guys are putting in G-62s in this aircraft. I don't have a G-62 do you think a Quadra 42 will be enough for scale flight? I'm fully aware that it won't be a barn burner, but will be too underpowered? I don't have much experience with gas burners. What prop should I run on it? Any thoughts would be appreciated.

[Terry Gauvin]

Hey Jollidude, I've seen Zirolli's Harvard fly on G62 and a Q75 and it was a nice machine. I think you may be able to get a 25 pound cub to fly decently on a Q42 but I also think you will be extremely dissapointed with the harvard/Q42 combo. I would suspect it would be underpowered to the point that it would be an accident looking for a place to happen.

[rcav8tor]

it would be underpowered to the point that it would be an accident looking for a place to happen.

Jollidude... Terry is wright on.... The Q42 just won't do it.

The G62 is the engine of choice for this airframe...... And a gr8 airframe it is too. One reason the G62 is seen used so often is that it is the mandatory engine for the T6 class of air racing. Why not keep it legal just in case

There are other engines that would work well...such as the above mentioned Q75...

For a prop.... With a G62... try something in the 22/10 range.

Good luck with this airplane... should be a real hoot to fly...... all of Ziroli's plans do...

[JimMoss]

A lot depends on your wing area.

I had a 22 lb Big Bingo (Ace Kit) with a G-38 Zenoah in it.

It flew well but, you didn't want to pull the nose up to high.

Anything bigger would have been a balancing nightmare.

1425 sq. in. was the wing area on the Bingo.

Hope this helps.

Jim Moss

[nony]

The only Q42 that I have flown was a 25lb PT-19. Flight characteristics could best be described at "stately" and I think it has more wing area than the Harvard...

[Kevin McGrath]

I think you would be underpowered with a Q42 which is a heavier low power engine by todays standard,compared to a ZDZ,Brison,Fox etc........
I notice the Ziroli website calls for either a G62,or Quadra 74 for this model.It twere me Id go ZDZ 60,If the budget can stand it or used G62 if not.If the latter,make sure you are comfortable with starting larger fixed timing engines like the standard G62 or budget for a spring starter,or plug in electronic unit.

[AJCoholic]

If you do want to use a bigger gasoline engine, have a look on the RC Universe swap forum, there are lots of good used gas engines for sale. I have gotten a fox 3.2 and a Brison 4.2 off of there and both are excellent. I also sold my Brisson 6.4 twin on RCU.

Many G62's up for sale allways, many times youc an get the engine with aftermarket mufler, spring starter and other goodies for less than the bare engine from the hobby shop. Or, better yet look for a used Brison 4.2 (69cc) or other electronic ignition engine (fox, ZDZ, 3W, etc) as there are many listed daily.

Andrew

[Flypaper]

Harvards are notorious for tipstalling, easy to do with a weak engine. One of our clubmembers lost 2 this way,turned oround and built a 3rd one, he likes them so much. G62 powered.

[Jollidude]

Thanks for the help guys, I'll put the project on hold until I can get a bigger engine. Thanks for all the info.

Jollidude

[Ron Roy]

I have Nick Ziroli Harvard started, and have planned to use the Saito, two cylinder 300, 4.7 HP, with single carburator. Does anyone know what effect this will have on flight performance? The idea here is scale sound as well. I am also planning to add the C & M (or is CM) battery ignition. The idle will be under 1000 RPM, and hence more scale sound. I would like the valued opinions from those who have "been there, done that", or at least have a better understanding than I do. Thanks guys!