Bravo Engine G100UL

[Fritz1]

Bravo Owners,

I have 2000 with a 650h factory reman engine, all numbers look good, feels good, runs well. I am 62 years old and probably do not need another airplane with more engines and more switches. A couple of weeks ago I thought about putting a cylinder on the shelf just in case I need one since they are readily available again. Then the G100UL came to my mind and I figured better see what happens. I remember the transition to unleaded premium car fuel in Europe around 88/89. Some engines needed valve seats, some did not, some engines had detonation problems, some did not. So I have a hunch the Bravo engine might need something. In Oshkosh I talked to Lycoming. The said they were working on "detonation mitigating measures" which sounded encouraging. Therefore:

1.) Anybody any idea how the Bravo engine might perform with 100UL, what are the chances of detonation at takeoff power, at cruise power 2300 rpm 30" 100df rich on 1st cyl to peak?

2.) What are the chances that the Bravo engine will need cylinders or valve seats, if cylinders what would they look like, what performance is to be expected?

3.) How much additive might the Bravo engine need in the G100UL in case things do not work out with the existing cylinders, to my best understanding TEL and scavenger come in at about 10 oz for a 100 gal tank 100LL, maybe use half of that in the G100UL to calm the Bravo engine down? How well does that stuff mix?

This may all be 3 years down the road but it is coming, so better prepare for it.

Fritz

 

 

[Fly Boomer]

50 minutes ago, Fritz1 said:

This may all be 3 years down the road but it is coming, so better prepare for it.

Not a Bravo engine guy, but GAMI said it can be used without consequences in any aircraft engine, and the FAA agreed.  Only time will tell.

[Boilermonkey]

Slightly on/off topic.  When you run "cruise power 2300 rpm 30" 100df rich" do you get the EGTs to peak first or the TIT.  What are you typical temps for TIT, EGT, CHT?    We just got a reman and now have 55hrs on her and she seems to run hotter than our old engine.

[Fritz1]

TIT comes in around 1580 dF, probes can burn up at higher temps, check contacts of probe for corrosion in a first step if TIT does not look right

[Fritz1]

EGT around 1480, CHT up to 390

[N201MKTurbo]

1 hour ago, Boilermonkey said:

Slightly on/off topic.  When you run "cruise power 2300 rpm 30" 100df rich" do you get the EGTs to peak first or the TIT.  What are you typical temps for TIT, EGT, CHT?    We just got a reman and now have 55hrs on her and she seems to run hotter than our old engine.

I have about 100 hours on my rebuilt engine and the temperatures have just started to settle down. Just wait a few more hours before you get concerned. 

I know there are others that say this isn't a thing, but of the 4 engines I have had since I started flying two have done this. The last one turned out to be one of the best.

[slowflyin]

15 hours ago, Boilermonkey said:

Slightly on/off topic.  When you run "cruise power 2300 rpm 30" 100df rich" do you get the EGTs to peak first or the TIT.  What are you typical temps for TIT, EGT, CHT?    We just got a reman and now have 55hrs on her and she seems to run hotter than our old engine.

Same boat here.  My Bravo is about 40 hours out of overhaul, and she definitely runs hotter.  Particularly number 6.  My prior to OH: 17.5-18.5 GPH, 29/24, TIT 1600-1625, Hottest CHT 375-380, Cowl Flaps Closed.   Now:  18.5-19.5, 29/24, 1525, 385, Cowl Flaps 1/4.   I'm hoping she's just tight and patience will return low oil consumption.  I OHd an IO360 in my F and had a similar experience.  Engine ended up running fantastic with CHTs in line and very low oil consumption.  Fingers crossed.   Also, I run GBs baffling.  It's new and in great shape.  I've installed it on three AC and it's dropped the CHTs by 25 degrees or more all three times.  

[Pinecone]

There is no concerns over detonation with GL100UL.  It has been tested to meet the requirements of engines requiring 100LL.   And running rich, it outperforms the 100LL spec, with a rating around 145.

The warbird guys are chomping at the bit for it, as they will be able to run full rated power with it, since 115/145 is not available.

[philiplane]

Removing the lead from the fuel will make the engine last longer. Lead is incredibly harmful to the insides of any engine. Lead's only purpose is to ward off detonation, more cheaply than refining the fuel to the next higher octane level. Lead, in combination with combustion byproducts, corrodes valve seats and anything else it touches. Lead sticks to the valve stems, causing stuck valves (morning sickness). Lead forms sludge in the oil passages, and clogs up the piston ring lands and oil scraper ring drain ports, leading to high oil consumption.

Your engine will thank you for switching to 100 UL.

Edited October 14, 2022 by philiplane

[kortopates]

On 10/11/2022 at 12:13 PM, Fritz1 said:

This may all be 3 years down the road but it is coming, so better prepare for it.

Who knows how long it will take, but I am sure hoping we see it sooner than 3 years since its been finally approved!

Preparing for it though won't be much more than putting new fuel placards that include G100UL by the fuel caps; as required now with fuel capacity.  

Edited October 14, 2022 by kortopates

[carusoam]

Fritz,

Have you seen the general discussion on G100UL?

Looks like we are all in the same boat…

Just the Bravo engine is a bit more expensive than some of the other Mooney engines…

Lots of good news coming from the development…

Lots of waiting to see how it works… in real Mooneys.

 

If you haven’t seen that other thread… get a big cup of coffee first!

Best regards,

-a-

[Fritz1]

got it, so detonation is most likely not an issue, valve seats in Bravo engine most likely not different than in other Lycomings so shock absorption through lead coating not more an issue than anywhere else, overall things look promising, massive logistical undertaking worldwide

[kortopates]

2 hours ago, Fritz1 said:

valve seats in Bravo engine most likely not different than in other Lycomings so shock absorption through lead coating not more an issue than anywhere else,

Fritz, yes the new G00UL fuel has greater detonation margins that 100LL. But you apparently have some mis-conceptions of the role lead plays in avgas. Its one and only plus is  to raise octane, its cons or negatives is that it deposits are harmful, not helpful, everywhere; especially if it gets on a valve seat where it will disturb valve rotation (not help it) leading to greater chances of a burnt valve. Getting the lead out will improve your engines chances for longevity - not put it as risk - as so many post above have correctly made the case for it.   

[carusoam]

Kind of a digital fuel… 0 and 1…

it’s either going to work as promised…

or be disastrous with unforeseen issues…

 

one thing that is different…. The aviation world learned a ton watching oil go synthetic… briefly…

Some errors need not be repeated…

The only thing that could improve this project…. More time and more money….  Which aren’t being offered…

The highest risk is the plane with the most people on board…

loss of an engine is expensive…

loss of people is 10X worse…

 

No room for error on this one….

Best regards,

,

-a-