Large Model Association Forum

Advice please. Son Jason and I have recently acquired an almost complete Ziroli 51 which needs a lot of remedial work before flight. I have just had to make a new front bulkhead and reinforce the sideframes to take the bellhousing of a Xenoah 62.
As built the original bulkhead had no downthrust or sidethrust. Zero, zero. Have been able to borrow a plan from Paul Dudley and it shows no side thrust, but although the plan is a bit unclear it appears to show a tad of down thrust, no mention of dgrees.
The new bulkhead now has just a tad of down thrust and the spinner seems to match the top of the cowling OK.
Any advice please as to what is correct in practice from those who have flown them.
For what it's worth my CompARF P51, same size flies perfectly well on zero zero down/sidethrust
Thanks

John Webb 800

Hi John, the Ziroli P51 plan/instruction booklet advises that it has no downthrust and approximately 2 degrees of sidethrust. However this is based upon the engine size that the original design was based upon. I would think you need to apply a small amount of downthrust and sidethrust, probably 2 degrees of each as a guide.
Cary

Thanks Carey. At the moment I've got a tad of down and no sidethrust. Been talking to Stewart Clifford who has a lot of experience with the Ziroli. He reckons zero zero so it's all a bit variable. I think I'll stick with what I've done so far and see how it goes.

Thanks for your help

JOHN

I'd go with Carey's suggestion......no down & around 2 deg of side.

Phil