OS 40VF Info
10-05-2009, 09:28 PM
#2
RE: OS 40VF Info
They're wonderful engines and the only OS I'll ever use but my application has nothing to do with speed even though I use a pipe with them. Their port timings are actually very mild which is exactly what I want, lots of low down torque. I've never seen any HP figures for them but judging by their port timings I'd suspect they get peak HP at around 15,000 revs.
10-05-2009, 10:07 PM
#3
RE: OS 40VF Info
ORIGINAL: downunder
They're wonderful engines and the only OS I'll ever use but my application has nothing to do with speed even though I use a pipe with them. Their port timings are actually very mild which is exactly what I want, lots of low down torque. I've never seen any HP figures for them but judging by their port timings I'd suspect they get peak HP at around 15,000 revs.
They're wonderful engines and the only OS I'll ever use but my application has nothing to do with speed even though I use a pipe with them. Their port timings are actually very mild which is exactly what I want, lots of low down torque. I've never seen any HP figures for them but judging by their port timings I'd suspect they get peak HP at around 15,000 revs.
10-05-2009, 10:40 PM
#4
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RE: OS 40VF Info
In an old thread I dug up the futaba support guy called it essentially a rear exhaust .40 FSR, and recommended settting it for about 13k on the ground with a pipe, which I guess would put it in the low to mid-14's in the air..? Does this jive with what you've seen? Just curious as I am close to scoring a NIB .40 FSR.. more wheedling required.
MJD
MJD
10-06-2009, 12:20 AM
#5
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RE: OS 40VF Info
OS rated the 40VF ABC at 1.25 HP @16,000 RPM. The 40FSR ABC was rated at 1.2HP@16,000RPM and the 40FSR was rated at 1.15HP@ 16,000RPM. This is off the OS engine spec sheet.
10-06-2009, 10:37 AM
#8
RE: OS 40VF Info
ORIGINAL: Broken Wings
Brian, I have some Venturi for you......
Brian, I have some Venturi for you......
Yeah, you know what I use the VF's for 
. Quite unknowingly to them, OS happened to make an engine that was superlative as a piped CL stunt engine when they first began to be used as a way of using a loophole in the American rules for line sizes. Large (.60 size) engines were beginning to ne used but those rules (for engines larger than a .40) called for larger diameter lines which were heavier and caused more drag. Enter the piped 40VF which was not only dead easy to set up with a pipe but gave roughly the same power as the ST 60's but could still use the thinner lines. Even today, the 40VF is the standard against which all other piped 40's are judged and they're quite sought after still. Apart from the extra power from the pipe, a side benefit was that the pipe acted as a speed regulator by holding the revs constant which helped keep airspeed more constant.
10-06-2009, 06:05 PM
#10
RE: OS 40VF Info
Venturis are available from [link=http://www.clstunt.com/products.htm]SSW[/link] and there's a good post on setting up a 40VF [link=http://www.clstunt.com/htdocs/dc/dcboard.php?az=show_topic&forum=103&topic_id=200223&mesg_id=200223&listing_type=search#200235]here[/link] at post #6.
As for which model would suit, just about anything available. I'm using mine in an overweight (68 ounce) model with 680 sq inch wing and it has no problem at all.
As for which model would suit, just about anything available
. I'm using mine in an overweight (68 ounce) model with 680 sq inch wing and it has no problem at all.
