iflyg450

I need to swap out my YS 45 off my laser arrow because its needed on another plane.

So I was thinking that a OS 40 VF rear exhaust would be a good delta engine. I haven't been able to find much info on them. I have a chance to get one NIB,

MJD

My Feedback: (1)

I'm not sure it's a good engine for a thick winged delta or any thick winged aircraft though, because you're going to want to run 8" or smaller props and get the rpm up into ducted fan territory. The Laser Arrow is not the fastest or most slippery delta around, in fact pretty much the opposite - but a great flying delta it is indeed. On a thin wing delta menat for all out speed - Diamond Dust or Screamin Demon for example - it would be a holy terror. Get a CF FAI pylon prop spinning up in the low 20's and hang on, since you are now piloting a 180mph capable aircraft that disappears edge-on. You spend a lot of time banked or rocking the wings on the fast ones, least I do..

MJD

combatpigg

My Feedback: (3)

There might be some guys in the C/L Speed forums who have experience propping these engines. Steve Wilk at Eliminator props either knows something himself or knows someone who would know.
I'll bet it needs a FAI prop, or at the most a Q-40 prop. Does it have a factory tuned pipe already set to length?

MJD

My Feedback: (1)

From the little bit I've gathered so far it seems the DF .45's seem to get along with square to a bit oversquare props around 7.5" diameter. Is that QM prop territory or thereabouts? Steve was certainly on the ball when I spoke to him about .25 DF engine prop choices, and he has a whack of choices for .40's of all breeds. Elsewhere ILJ mentioned running 6.5x10's on DF .45's on F3S type stuff, but man you better have almost negative frontal area for that kind of prop.. [:-]

MJD

MJD

My Feedback: (1)

From what I've seen so far via Google, this may not be the fire breathing DF engine I was thinking it was from the VF designation - there's no "-DF" following it after all. One response posted on RCU from customer support regarding this engine said it was a relatively mildly timed engine, pretty much a .40 FSR with rear exhaust.

If that is the case, then it should pull props more suited to the Laser Arrow with authority. My comments were aimed at purpose-designed DF engines.

MJD

lfinney

My Feedback: (44)

this was a F1 engine to compete with the K&B and super tiger x40 engines, i bet it has plenty of deck clearance for high nitro, or even a second head and shims, a strong motor, but they were meant for high nitro, so have fun, i would start with some ys 20/20 fuel

iflyg450

Sounds like a good engine. The other airframe it could go in is my Mk Arrow buts it a larger pattern plane that requires a rear exhaust engine so I think the YS 45 would work the best.

lfinney

My Feedback: (44)

it would pull your pattern palnevery well, it will respond nicley to a tuned pipe as well

Roary m

My Feedback: (67)

The VF series were destroked versions of the FSR engines. They turn over very well; if you have a chance to grab the guy, just do it. Sooner or later he will come in handy. My last one was on an Ultra Sport 40 and it ran very fast.