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Super unleaded in 160hp O-320

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tn3639(at)hotmail.com
Guest

Posted: Tue Jun 06, 2006 1:51 pm Post subject: Super unleaded in 160hp O-320

Converting to 160 hp (8.5 to 1) does not preclude your use of Auto fuel. It

simply means that you will have to use 91 -93 octane super, rather than 87

octane regular.



Is this true? This is the first I have heard of it.... if so, I sure could 

save some $$$$$ if so



Scott

RV6-A

!60hp O-320

jmsears(at)adelphia.net
Guest

Posted: Tue Jun 06, 2006 3:28 pm Post subject: Super unleaded in 160hp O-320

 	  Quote: 	
		  > Converting to 160 hp (8.5 to 1) does not preclude your use of Auto fuel. 

> It simply means that you will have to use 91 -93 octane super, rather 

> than 87 octane regular.<<


	


 	  Quote: 	
		   Is this true? This is the first I have heard of it.... if so, I sure could 

 save some $$$$$ if so




	


According to some old documentation I got from Petersen Aviation, owner of 

one of the auto gas STCs, the 150hp/160hp O320 and the 180hp O360 engines 

were approved by the FAA for auto gas.  Oh, yeah.  Let's not forget the 

normally aspirated O540s, either.  I think those are the 235 hp versions for 

you -10 builders?  H2ADs and fuel injected O360s were not approved.  I think 

it applies to any fuel injected engine, actually.  Of course, he noted that 

fuel line sizes, routing, and other variables, could impact the use of auto 

gas due to vapor lock.  He also mentioned that some materials in our tanks 

may not hold up to the rigors of auto gas.   The engines were OK, though. 

To run the higher compression engines on auto gas, just bump up to 91-93 

antiknock gas.



I invested in my first auto gas STC in 1986 and have saved money on gas for 

my airplanes, since.  My RV-6A has a 150hp O320 that runs well on 87 

antiknock.  The tanks and fuel system have shown no adverse effects of 

having auto fuel in them, other than the minor vapor locking that can happen 

during fast turnarounds.  The plugs are clean, except for some carbon build 

up.  Oil, not fuel.  No lead to foul plugs.  Per Petersen's STC, I do put in 

some 100LL a couple of times a year.  I can always tell the difference. 

Within an hour, or so, the lead deposits start building up and fouling 

plugs.



Vapor locking is a minor problem, as was the case in my other two airplanes. 

If in doubt, I add some 100LL to the mix to change the vapor pressure so 

that the fuel is less apt to vapor lock.  About the only time I chose to do 

this is if I'm going to take up a lot of kids during a Young Eagles day.  If 

it's cold outside, I don't bother.



If I ever get around to finishing my -7A, it will have an O320 160hp engine 

or an O360 180hp engine.  Since I already have some pieces and parts for the 

O320, that will probably be my choice.  I plan on using premium unleaded in 

it.  I can't afford to own an airplane and keep it filled with 100LL.  I'm 

just getting used to putting premium in my new Miata!  (It does get good gas 

milage, though.    )



Jim Sears in KY

RV-6A N198JS (Scooter)

RV-7A #70317  (Started on fuse)

EAA Tech Counselor

gptyler(at)metrocast.net
Guest

Posted: Tue Jun 06, 2006 4:21 pm Post subject: Super unleaded in 160hp O-320

My understanding is that the engine will work on the mogas but the STC

doesn't cover it. So, it would seem the decision is if you want to keep your

engine certificated.

---

Bruce(at)glasair.org
Guest

Posted: Tue Jun 06, 2006 4:41 pm Post subject: Super unleaded in 160hp O-320

Once an engine is installed on an experimental aircraft, it looses its

certified status and cannot thereafter be reinstalled on a certified

airframe without a complete disassembly/OH to determine it's status.



Bruce

www.glasair.org

 



--

klwerner(at)comcast.net
Guest

Posted: Tue Jun 06, 2006 5:05 pm Post subject: Super unleaded in 160hp O-320

Bruce,  

 I did not know this!

  

 I always thought that if you take a  dataplate of the engine (or modify it!) it would loose its certified  status, ...but not by simply bolting a fully certified engine into a  non-certified airframe? 

  

 do not archive

 [quote]   ---

sbuc(at)hiwaay.net
Guest

Posted: Tue Jun 06, 2006 6:29 pm Post subject: Super unleaded in 160hp O-320

Bruce Gray wrote:

 	  Quote: 	
		   

 

 Once an engine is installed on an experimental aircraft, it looses its

 certified status and cannot thereafter be reinstalled on a certified

 airframe without a complete disassembly/OH to determine it's status.


	




As I understand the situation (and I am certainly willing to be 

corrected!) the mere act of bolting a certificated engine to an 

experimental airframe does not cause the engine to lose its certificated 

status.



However, if the engine was to be returned to service on a certificated 

airframe, the installation would have to be signed off by an AI. 

And.....how many AI's are going to put their career on the line by 

signing off on an engine that they are not *absolutely certain* meets 

all certification requirements.



The AI covering his backside is why the engine will most likely be torn 

down to insure compliance, not just the fact that it was bolted to an 

experimental airframe. If you can find an AI that is willing to sign off 

the engine installation without a teardown, it will be legal. This 

*might* actually happen if the AI owned or had detailed knowledge of the 

experimental aircraft the engine was on.



Sam Buchanan

Bruce(at)glasair.org
Guest

Posted: Tue Jun 06, 2006 7:13 pm Post subject: Super unleaded in 160hp O-320

That's my understanding of the situation also. The engine would have to be

examined to be sure all parts were in compliance and all AD's were up to

snuff. In essence an overhaul.



Bruce

www.glasair.org

 



--

sbuc(at)hiwaay.net
Guest

Posted: Tue Jun 06, 2006 7:47 pm Post subject: Super unleaded in 160hp O-320

Bruce Gray wrote:

 	  Quote: 	
		   

 

 That's my understanding of the situation also. The engine would have to be

 examined to be sure all parts were in compliance and all AD's were up to

 snuff. In essence an overhaul.


	


Only if the AI insisted on the inspection/overhaul, but not because the 

FARs require it. If the AI has extensive knowledge of the engine and its 

compliance with AD's, he *might* forgo the inspection.



The A&P/AI that helped me with the yellow-tagged and updated logbook 

overhaul of the O-320 in my RV-6 might have returned that engine to 

certificated service without further inspection since he was familiar 

with the overhaul and all major service following the overhaul. But a 

different AI who didn't know the engine most likely would have required 

an internal look at the engine and logs before he signed off the new 

installation.



Sam Buchanan

Bruce(at)glasair.org
Guest

Posted: Tue Jun 06, 2006 8:11 pm Post subject: Super unleaded in 160hp O-320

Sam,



I believe the FAR's exempt our engines from AD's even if we don't remove the

data plate. I recall emails from our friendly FAA guy that stated that the

FAA considered all appliances when attached to an experimental airframe to

be experimental. If your engine logs state that your engine was installed on

an RV, Glasair, or any other experimental airframe followed by your

signature, I don't know of any AP/IA that would sign if off for a reinstall

on a certified aircraft. The local FSDO would be sure to frown on it. It's a

real grey area. This might be a good question to kick up to the EAA experts.



Bruce

www.glasair.org

 



--

jmsears(at)adelphia.net
Guest

Posted: Wed Jun 07, 2006 2:08 am Post subject: Super unleaded in 160hp O-320

 	  Quote: 	
		   My understanding is that the engine will work on the mogas but the > STC 

 doesn't cover it. So, it would seem the decision is if you want > to keep 

 your engine certificated.


	


One has to look at the STCs.  The EAA STC may not cover high compression 

engines; but, the Petersen seems to cover them.  Do keep in mind that STCs, 

ADs, etc. do not apply to experimentals; but, one is foolish to not comply, 

in many cases.  If the testing was done for the Petersen STC for high 

compression approval, I'd think it would be OK to use 91-93 antiknock fuels 

in them.  If not, I wouldn't.  Fortunately, his STC does seem to cover them; 

so, I'm going to use autogas in my next RV, as well.  



As for the certification, Pat Patterson learned in AB-DAR school that a 

certifiied engine is indeed decertified when it is attached to an 

experimental.  It is true, even if one does not remove the data plate, which 

I refuse to do.  Just as Sam said, all one has to do is have an IA approve 

the engine's use on a certified airplane for it to be put back to use as 

such.  I'm sure mine could be put back to service with a couple of changes 

like removing the starter and alternator.  I kept mine in certified 

condition, I thought, by having an A&P sign off the engine at inspection 

time.  I quit that when Pat told me what he'd learned.  I still have Pat, 

the A&P, help me with the inspection; but, I do the sign off, now.



Actually, I don't know why we worry so much about keeping our engines 

certified, anyway.  How often do you think an engine from an experimental is 

going to be put back into a certified airplane?  Most likely, it will be 

snapped up by another experimental builder before the certified status comes 

into play.



Jim Sears in KY

RV-6A N198JS (Scooter)

RV-7A #70317

EAA Tech Counselor

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