Looking for info on pipe length for an os 140rx with an os pipe and header. going to start with a 17-12 prop. does header need to be cut any? can anyone suggest a length?

it depends on a lot of factors.

head shims, nitro content , altitude etc. are you using the suggested os tuned pipe?

at sea level we actually lengthed the pipe by about 20-40 mm with an apc 17-12 and ran 20%nitro fuel with a straight 20% cool power oil mix. i think from memory we also ran one extra thin head shim as well.

it really is sometimes quite frustrating []experience to set one of these up properly but in the end if it works, the results are definately worth it.


aerowiz

Hello 426miller
A friend of mine has an OS140RX with pipe and reso OS.
Because he had no place in his fuse , he cut the pipe OS about 60 mm.
OS runs very fast with 25 % nitro and APC 17x12 on pattern which weight is 5000 g.
With that he did P07 and F07 easily.
Claude

Check www.nsrca.org In the links section there is a web page with a lot of information in setting up engines. You won't go wrong using that information.

Vicente "Vince" Bortone

426miller,

Just to give you my setup, it works very well, at least for me I'm using the Greve pipe and a dual plug head. A5 as center plug and OS-F as rear plug. The total length og my pipe setup is, measured from the middle plug and to the end chamber of the Greve pipe: 87 cm. I have added 2 extra head shims (total of 3). I use a APC 18x10 propeller and 15/15 nitro/oil fuel. The 18x10 propeller accelereates my plane very well with this setup, and I have to be quite restrictive on using full throttle when flying the Nordic sceadule.

Regards,
Dag Ragnar