stunthanger.com
Engine basics => Engine set up tips => Topic started by: Randy Powell on April 11, 2006, 11:19:02 AM
-
To Randy or anyone with knowledge,
I picked up 2 OS 46 VFs and 2 OS 40VFs last fall (all but one NIB and that one a 40 with very low time). I had planned to power my new PA plane with the 40, but it's 5 or 6 ounces porkier than I had planned and thought instead I'd go with the 46.
Brett Buck gave me THE setup to try with the 40. Is there any significant difference in setting up the 46? Venturi size, prop, pipe length, etc.? I don't have a lot of experience running these OS engines, so any help will be appreciated.
Oh, one of the 46s was setup by Mr. Smith himself, but the running instructions that he's so good about including were apparently lost along the way. 2 new pipes also came from Mr. Smith.
-
Randy...
I would drop Randy Smith an e-mail...or call him...
Brett also has a HUGE set of notes on the VF 40/46 and I am certain that he will share....
-
Rich,
I talked to Brett. He gave me a very good setup for the 40. My question was what would be different for the 46? If anything.
-
Hi Randy
The 46 is much more power than the 40, but runs very much like it.
I built 100s of these motors for people, and we always found the 12 x 4.25 3 blade and 12 1/4 x 4 1/4 2 blades worked the best with these engines.
Bill Rich always used the 12 x 4.25 3 blade, they rub a very strong 4-2 thru the pattern
you can use a slightly larger venturie, and pipe lenghts we ran with the 3 blade was 18.5 and 18 for the 2 blade
10% 20 to 22% oil fuel is a good place to start
let me know if you need any more info or help
Regards
Randy
-
Thanks Randy. I have a couple of Bolly 12x4.25 3 blades to start with.
-
The set up Randy just gave is exactly what he told us to run on our 46VF. Pertty strong engine! we had a good bit of luck with the 40 and 46VFs until we got the PAs! Mainly the PAs are newer engines set up expressly for our event. And Randy is always around for us. ;D
-
Bill,
I decided to initially go with a VF mostly because Brett talked me into it. While not as powerful, generally, as the PA or RO-Jett engines, it has the sort of run I was looking for and I got them relatively inexpensively.
On the other hand, the new plane has a removable engine mounting system that will allow relatively easy changes in power train. I'd probably have to lay up a new cowl for the RO-Jett 65 I have. I wouldn't have to for PA 65 I have. Just a new engine mount.
So I figured I'd start off with the OS VF. First the 46 then if I don't need the extra power, I may try the 40 (and .015 lines). If I'm not happy with either, I can go to one of the truck engines.
-
Hi Randy
The PA 61 or 65 will drop in where the OS came out without making any new mounts. The bolt pattern and nose lenght is exactly the same
as an OS 40 46 VF
Randy
-
Randy,
Cool. That will make it easier if I need to do that. But I have high hopes for the 46VF.