advanceandy

My Feedback: (116)

this past weekend we flew a bit of ssc combat, our la's were turning 17800 - 18800 on 10 % omega
over the summer we peaked about 17400 with 15%
are the engines running better bacause of the cooler weather or what ?
it was in the upper 50'S

Sessholvlaru

Cold air is more dense than hot, which means better combustion. At least that is my understanding, hence cold air intakes on automobiles, etc.

MetallicaJunkie

How are you getting that many RPM's out of an LA engine? What size prop are you using? My Rossi 45 or YS 45 wont even do that

advanceandy

My Feedback: (116)

size prop using is MAS 8x3 the standard ssc prop on the 15 LA with 10% omega fuel

MetallicaJunkie

wow, no wonder........jus curious, have you ever blown an engine?

MartyH

My Feedback: (16)

This is the standard prop that EVERYONE flying legal SSC has to use MetalllicaJunkie. One has to be 17,500 or below to fight. I'm not sure I believe a stock OS15 la really got to 18,800rpm though. They might want to try a different tachometer before they start making changes to the setup.

Lou Melancon

AdvanceAndy,
The cooler air especially in lower humidity will allow the engines to run faster. Lower humidity allows the engine to take in more oxygen which aids the combustion process. We have often seen SSC engines jump 1,500 rpm in lower temps on dry days. Conversely hot humid days generally lower rpms. Check out this explanation by Don Nix founder of PowerMaster fuels..... http://georgiacombat.com/DonNixOnFuel.htm

TxCombatGuy

I have run LAs on 30% consistently up to 18.5 on a pressure bladder on a twin 2548 P-70 and Me-110 after being broken in properly. It is important to remove the baffle, balance the props, and potentially drilling out the stinger on the muffler. On SSC, where the target is 17.5, you don't have to mod the stinger and may not have to run high test fuel. That being said, you can wear out the engines quickly running that high, so run a little rich to improve cooling. I have shifted to the Magnum 15XLS engines as they don't have to be forced to rev at 17.5

Ed

Ken Kehlet

My Feedback: (89)

I too have run the Magnum 15 XLS engines, SUPER STRONG running and not near the price of the Europe imports.[]

Regards,
Ken