I am having some problems deciding on an engine for my VF 66" Extra. I have a Saito 100 but that will most likely go on a different plane. Seeing that I am not going to use this for 3D, I would prefer a 2 stroke since that is what I am most comfortable with. I really like Irvine 2 strokes, but the problem is that they go from a 72 (I want something larger), to a 1.50. Now I am assuming the 1.50 is to much - or is it? I searched here, but only found a couple posts about more than a 1.00 in these planes. Is this 1.50 to much? Any other suggestions (other than OS)?

1.50 is too heavy for the VF 66" Extra. Adequate power would be a .91 2-stroke, like the OS91FX (some love 'em, some hate 'em) or the Magnum .91 XLS (mine has great power with Jett Engineering in-cowl muffler, shimmed head and 25-30% nitro). A little extra power for good vertical authority would be a 1.20 2-stroke (Magnum again, or GMS, and there are others).

Funny you mention Jett. They have a 90 and 1.05. You mentioned their in cowl muffler. How does that fit?

Jett in-cowl muffler is basically cylinder shaped, ~3" diameter, 2" height, one exhaust outlet extends another 1" straight out the face opposite the engine. Attachment is by the normal two screws, and the adapter is on the perimeter of the flat face of the cylinder. The opposite face is rounded at the perimeter, sorta bowl-shaped. If you side-mount the engine, the muffler hangs down below, exhaust outlet points out the bottom. There's just about enough clearance beween engine and muffler to run the pushrod up to the throttle arm. Very compact arrangement. There is a baffle inside there, whose arrangement is mysterious to me. Weight is 7.0 oz, a couple oz heavier than a BCM Pitts. Never got around to taching Jett vs standard muffler, but the power boost is significant.

I've always considered their engines too pricey for my taste. I usually think YS when I want high performance.

I looked at the Hobby People website and see the Magnum .91 XLS has been discounted from what I paid. This engine deserves more notice than it gets.

Check out the ST 90 it is a great engine and other posters in the VF thread have had good luck with them in the extra. I fly mine with a TT 91 4 stroke in it and it is a great flying plane. I have also used an ASP/Magnum 91 4 stroke in it also. Both engines flew the plane fine but I like the TT engine because it has a little more power.

Rick

I just ordered a Saito 100 for mine, my first four stroke. I thought about a 90-ish two stroke but didn't want the muffler hanging out and the 4S sound is just too cool. A smoke system may be a future addition and the 4S is a better choice for that. Looking forward to flying it. Its a great plane for the $$$.

Thanks everyone. I just heard back from VF customer service who said a 100 2 stroke was way to much and would put unnecessary stresses on the airframe. Looks like I will go with the Jett 90.

I think a Jett 90 will provide somewhat more stress on the airframe than the average 100 2S engine!!!

Ross

Yeah. After more thought, I will most likely end up with a Saito 100.

I have an MVVS .91 on mine (naturally). Works very will with a 15x8 and a BCM Pitts.