Hi all. I am shopping for an engine for a Venus 40.

First, I have ruled out the YS-63s because of the price. I know this is probably the most popular engine, but I'm not considering it.

Having said that, which remaining engines provide adequate power without adding too much extra weight?

I'm thinking about a .70 4-stroke, or maybe an AX .46 (which my LHS sells for $95).

Is there a big enough advantage with the .70 to justify the cost and extra weight (about a 5oz increase over the .46)?

What about the AX .55? It's around 3.5ozs less than a .70 4-stroke, but a little heavier than the AX .46.

I assume a .52 4-stroke won't cut it, correct?

Thanks,
David

the ax 46 will fly it just great had gms 47 in mine and it was a rocket

Thanks, jetmech43. The .46 is the best buy, anyway.

i allso built one with an gms 47 , an for 69.00 from tower there hard to beat i thought it was an perfect match , and will balane with no added weight

the gms had alot of power, but couldnt get consistent runs out of it

I have also found the gms to be a little troublesome, but if you work with them enough they do run. I would go with the OS 55AX, it has to be the coolest engine out with a 40 sized frame. Now they should make planes a touch bigger to match, say a 58-59" wingspan Venus .

Thanks, everyone. Since I can get the AX .46 for $95 at my LHS I will go with that.

Yes, I wish there was a Venus half-way between the two they offer. I have seven .61's and I'd love to use one in a "modern" pattern plane. One is going in a BPA-type UFO and the other in an SPA Super Sicroly II (Prettner design), but it would be nice to have a 60"-62" Venus or equivalent.

David

I went a little silly and shoehorned a 61sf in the nose.

She fairly honks uphill

I'm sure it does! I worry about the structural integrity of these Asian arfs. I would definitely go in and reinforce the firewall and a few other areas if using an over-sized engine like that. There's a big difference between 5 1/2lbs of thrust and 8 1/2lbs of thrust on a plane that was engineered for .46's.

David

Dave,

If you have some inclination to scratch build, why not make the venus into a 60 size? It is quite simple to do even with no plans. Make sketches of what the existing 40 size is and enlarge about 20%

MattK

Matt, I've actually though about that. It would be very easy to do by just taking measurements and drafting it in CAD. I think I'll do it.

I wonder what the differences are between the Venus and Venus II. Something tells be it's not just a straight scaling up.

Thanks,
David

I've been eyeing this model:

http://www.giantscaleplanes.com/Lark-70.htm

It says 40 sized but the specs looks like they would fit a lightweight 60 sized engine, or maybe the 55AX would be perfect.