SSC Engine mods
Moderator: hbartel
SSC Engine mods
Since we can now do engine mods in SSC, What are the best ones to get my engines up to 17,500?
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Mike,
On the OS LA .15:
<ul><li>Remove muffler baffle </li>
<li>Replace head bolts with hex bolts (2.6mm X 10 mm) </li>
<li>Replace plastic backplate with aluminum FP backplate, not for performance, but for reliability </li></ul>
Then break it in properly, run no more than 18% oil, preferably 1/3rd castor, 2/3rds synthetic, and go fly.
There is a lengthier explanation at www.georgiacombat.com
On the OS LA .15:
<ul><li>Remove muffler baffle </li>
<li>Replace head bolts with hex bolts (2.6mm X 10 mm) </li>
<li>Replace plastic backplate with aluminum FP backplate, not for performance, but for reliability </li></ul>
Then break it in properly, run no more than 18% oil, preferably 1/3rd castor, 2/3rds synthetic, and go fly.
There is a lengthier explanation at www.georgiacombat.com
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Mike the best two combo things i've found is the spray bar in throught of carb and the opening of the exhaust a little when u open the carb it messes with the adjustment being religable but those are my thoughts the plastic inlet you can remove and trim off so it doesn't go into carb . which allows better flow of air into carb..
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Although mods are now legal I think the LA will easily make the rpm max on the right fuel with the right fuel delivery set up.
We routinely have to adjust the ATV down to make rpm limit with no mods done to the engines. If the leaks are sealed, you have a good pistion to liner fit, and the right fuel it should make the power without further mods.
We routinely have to adjust the ATV down to make rpm limit with no mods done to the engines. If the leaks are sealed, you have a good pistion to liner fit, and the right fuel it should make the power without further mods.
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lou mabe where you guys fly humidity and stuff temp but here they just don't make it when i first started ssc whith the tucson crew i didn't understand why they would always eat my lunch there planes were so much faster then i found out they were running 30% heli fuel drilling the baffle out and then they would turn the 17500 other wise it was around if remember 15000 so you can see they were doing circles around me. i think mods are great but if your already pulling it why do mods but if your low on rrrs its great..
Mike, I hate to say this but Lou apparently knows what he's talking about (JUST KIDDING, LOU!!!). I used Sig and Ritch's brew 20% oil fuel for two years in my FPs (same fuel i use in my B engines) and only on the most perfect days did i ever see near 17.5K. Tried some 15% Powermaster (18% oil) and the engine picked up several hundred rpm and needled better too. The contest I tried it at was nearly perfect for atmospheric conditions, but a couple of my engines were actually a hair over 17.5k, and my Magnum Xl which normally turns around 17k at best was hitting around 17.2-3. I've still never seen 18k or higher as many say they get regularly. To my knowledge, Jay Lawless has the only SSC engine (an LA) in our whole area that seems able to get over 18k consistently. Brian's Webra likes the Powermaster too.
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Mike & John,
I did a lot of fuel testing before settling on max oil content of 18%. Besides the rpm difference from running the lower oil content the cylinder head temperature was 25-50 degrees lower.
Oil content above 18%increases cylinder pressure,and the oil does not burn, or it least it shouldn't. The higher cylinder pressures make the piston, rod, crank work harder to turn the engine over and the increased percentage of non-combutstible material in the cylinder limits the power.
I use PowerMaster 5% nitro, but other fuels will work as well. I use 1/3rd castor and 2/3rds synthetic so if I get a lean run the castor will protect the engine. There is a good article about why your fuel should contain some castor on www.georgiacombat.com
I did a lot of fuel testing before settling on max oil content of 18%. Besides the rpm difference from running the lower oil content the cylinder head temperature was 25-50 degrees lower.
Oil content above 18%increases cylinder pressure,and the oil does not burn, or it least it shouldn't. The higher cylinder pressures make the piston, rod, crank work harder to turn the engine over and the increased percentage of non-combutstible material in the cylinder limits the power.
I use PowerMaster 5% nitro, but other fuels will work as well. I use 1/3rd castor and 2/3rds synthetic so if I get a lean run the castor will protect the engine. There is a good article about why your fuel should contain some castor on www.georgiacombat.com
I don't like to screw around with engine mods anymore, especially with cheap engines. So I just carry 10% and 30% fuel, preferably Powermaster to meets and one or the other or a half and half blend will get me in the 17.2 range which I consider just right. We did have one morning at Paris when 5% was almost too hot to stay under 17.5.
I've heard all of the digs about having to carry too many fuels to meets, but I don't have a problem with carrying 2 half gallons of fuel. It's much easier than some of these mods. I have never had a stock engine that would not turn 17.5 and I run both La and Magnums.
I've heard all of the digs about having to carry too many fuels to meets, but I don't have a problem with carrying 2 half gallons of fuel. It's much easier than some of these mods. I have never had a stock engine that would not turn 17.5 and I run both La and Magnums.