Swift 94 fuel fails trial at UND

[Mcstealth]

2 hours ago, A64Pilot said:

You raced Clubman too?

We called it SuperStock

GPZ 550's 

GS 550's

Seca's

Etc. 

We could not do anything to the engine other than aftermarket air filters and tires.  Curiously,  you could use high octane fuel.

[Shadrach]

22 minutes ago, Mcstealth said:

We called it SuperStock

GPZ 550's 

GS 550's

Seca's

Etc. 

We could not do anything to the engine other than aftermarket air filters and tires.  Curiously,  you could use high octane fuel.

We’re they checking the timing specs of the entrants? Just race gas and timing advance will increase power a bit. Weren’t some of the GPZ’s turbocharged?

[Mcstealth]

21 hours ago, Shadrach said:

We’re they checking the timing specs of the entrants? Just race gas and timing advance will increase power a bit. Weren’t some of the GPZ’s turbocharged?

Only some of the  GPZ 750's were turbos and they were excluded. At the time, anything above 550 was a different class. I raced them all.

[A64Pilot]

On 1/15/2024 at 3:58 PM, Shadrach said:

We’re they checking the timing specs of the entrants? Just race gas and timing advance will increase power a bit. Weren’t some of the GPZ’s turbocharged?

If it were WERA then they didn’t have the assets to really check anything. Most non professional motorcycle road racing isn’t well funded.

Back when I was drag racing fuel was often checked but the engine was only checked if you set a World record.

Specific gravity of fuel was what was checked and that’s easy, just a turkey baster looking tester.

Wera Clubman excepting engine displacement you could do pretty anything. The Suzukis handled better, but the Kawasakis with liquid cooling and four valves that allows made better power, so some put Kawasaki motors in the baby Suzukis. That was 25 years ago, the drag racing was 40 years ago. There was some kind of BMW motor that made much power, easily pulled everyone on the straights. It may have been a single? I think singles could be 650’s.

So I’m out of touch with todays reality.

You can get quite a lot of power from ditching the air box, properly rejetting the carbs and running high enough Octane so you can put the timing at max HP. I pulled my timing pick up plate slotted the mounting holes and put the bike on a Dyno jet Dyno and advanced timing until HP peaked at 1000 RPM below redline.

I got at least a 10% increase in power, Back in the day you could get lots of power from exhausts, but modern bikes exhausts are so good often you lose power now. Now you run race pipes to lose weight, gain ground clearance not for power. Stock pipes if they have a Cat can be really heavy.

My pig, a KLR-650’s pipe is stupid heavy. But as an old man I doubt I’ll pop for an aftermarket one, the KLR is a pig and your not changing that, even with money.

[A64Pilot]

On 1/16/2024 at 1:41 PM, Mcstealth said:

Only some of the  GPZ 750's were turbos and they were excluded. At the time, anything above 550 was a different class. I raced them all.

That was a long time ago, early 80’s?

Honda had an interesting turbo. Took the liquid cooled 500cc twin CX500 I think?

Anyway for one year they bored it to a 650 and turbocharged it. Conventional wisdom at the time was you couldn’t turbo a twin, but Honda did and it worked. The turbo pulled about 20 lbs of boost and pretty much doubled the power, the bike was a touring bike but I’ve seen the motor on a race track, Roebling Road.

The Japanese turbos didn’t last long at all before they were discontinued. Great for drag racing, I built and raced Z1 turbos, but not so much for road racing.

[Shadrach]

The only modern BMW single that I know of had a water cooled Rotax 650. Not what I would call powerful at -50hp but likely made better torque numbers over a wider range than its competitors.

 

[A64Pilot]

Well this was around 2000 or so and I really didn’t pay a lot of attention although I was racing against it.

The little Zuki was only about 45 stock, the BMW was I’m sure built and it was in a custom frame etc. All I remember was it was a BMW, I’m not sure it was a 650 but I think it was. The rules allowed larger displacements for different motor designs in an attempt to even out the playing fields. Many years ago for the Pros you were limited to 750 for a four cylinder but 1,000 cc for a twin, so with 25% larger motor the manufacturers made more power of course and the thinner twin was better for racing anyway, so twins took over. Plus a 90 degree twin is very smooth, very much unlike a Harley.

Most Clubman bikes were cheap, built on a shoestring budget and built by the racer, most that had money didn’t race Clubman, many were Frankenstein bikes, but every now and again you would see one that the owner had $$ and was professionally built, this BMW was one.

[Pinecone]

I race SCCA in spec class.  They started, at the big events, where you would have to pull some part and bring it to registration.

Once they collected from everyone, they randomly handed them back out.  So if you did some super trick prep work, it could end up one someone else's car.

They also started checking timing, as some people wear moving the timing gear on or two teeth and running super race gas.

[A64Pilot]

Many years ago I ran a Renault R5 in SCCA SSC class, it was R5’s against Chevy Vega’s. Just one year though, it was the year I crewed for a Formula Super Vee, 87 maybe?

Renault sent out one heat range cooler plugs to every racer, just plain plugs but one heat range cooler. Anyway AFTER the race the cars were inspected, everybody except the local guy was running the out of spec plugs Renault sent us, so everyone except the local guy was disqualified.

Believe it or not but the Vega’s were slightly more powerful, but the Renaults handled better, that is until they rolled over. They were prone to that.

[Mcstealth]

3 hours ago, A64Pilot said:

That was a long time ago, early 80’s?

Honda had an interesting turbo. Took the liquid cooled 500cc twin CX500 I think?

Anyway for one year they bored it to a 650 and turbocharged it. Conventional wisdom at the time was you couldn’t turbo a twin, but Honda did and it worked. The turbo pulled about 20 lbs of boost and pretty much doubled the power, the bike was a touring bike but I’ve seen the motor on a race track, Roebling Road.

The Japanese turbos didn’t last long at all before they were discontinued. Great for drag racing, I built and raced Z1 turbos, but not so much for road racing.

 

3 hours ago, A64Pilot said:

That was a long time ago, early 80’s?

Honda had an interesting turbo. Took the liquid cooled 500cc twin CX500 I think?

Anyway for one year they bored it to a 650 and turbocharged it. Conventional wisdom at the time was you couldn’t turbo a twin, but Honda did and it worked. The turbo pulled about 20 lbs of boost and pretty much doubled the power, the bike was a touring bike but I’ve seen the motor on a race track, Roebling Road.

The Japanese turbos didn’t last long at all before they were discontinued. Great for drag racing, I built and raced Z1 turbos, but not so much for road racing.

The Honda turbo was unique, that's for sure. It was not something you could race. Top heavy and not sport oriented. 

The Suzuki was the best looking, IMHO, of the turbos and handled very well. It was a 650cc four cylinder that was underpowered unfortunately. You could race it. Not many were made, or raced for that matter. 

The GPZ's were by far the most powerful, quickest, and fastest of the turbos. It was a full 750cc and the turbo worked. Had to be careful when cranked over in a corner with the GPZ. Too much right wrist and you could spin up the tire and spit yourself off if the turbo kicked in at the wrong time. 

[A64Pilot]

The Honda I saw raced wasn’t in the original frame. I’m not sure of the class, I think it slipped in because no one thought to write turbo out of the class.

The Zuki turbo was very poorly thought out, it didn’t make good power and broke often.

Suzukis have always been the best handling, Kawasaki often made more power. There was an expression back then road racing “if you weren’t racing a Suzuki, you were chasing someone who was”

The Kawasaki was the best designed turbo.

Thing I loved about Turbos was even the ones we drag raced had no muffler of course but the turbo worked really well to reduce the exhaust noise so they were very quiet, I loved the whistle and with the low compression they were easy to start and we made best power with stock cams degreed to 110 lobe centers so they idled like a stock bike, very street drivable.

We ran Titanium valves with aluminum retainers and the light weight allowed for stock valve springs.

[EricJ]

I attended our airport pilot's association pancake breakfast this morning, which is usually fun and always interesting because our ATC peeps, the airport manager, and some of our local vendors often speak and share the latest relevant info.

Our self-serve fuel vendor usually shows up and today he provided some insight on his perspective on the current state of the unleaded fuel situation.   One very interesting tidbit is that he's sensitive to the liability concerns, e.g., if somebody has an issue because the new blend weakened a gasket and a leak caused an accident, he could be affected.   He said his insurance covers the first $1M of a claim, which doesn't go very far in an aviation accident, and the distributor adds $50M of coverage on top of that.   GAMI does not have a distribution system which adds any coverage, so that is a serious issue.

He also indicated that Swift is actually pretty far along and may have distribution rolling soon.   The expectation is that once their 100 octane is being produced that they'll drop their 94UL and sites currently selling 94UL will instead sell the 100 octane.   He also said that the Switft blend is very different from GAMI's, in that while GAMI uses aromatic solvents (xylene) which may affect finishes (paint) and gasket/seal integrity, Swift uses oxegenates.   I took this to mean that the potential issues with finishes and seals, etc., would be expected to be less.

Anyway, just passing it along.   Don't shoot the messenger, and I don't really know any more than I'm passing on.

[Brent]

I came across this thread on G100UL today and thought I would pass along one conversation I had with a former colleague of mine who is a sealant expert. The chemistry is not my field, but what caught my attention is that, as mentioned previously in this thread, there remains uncertainty about the durability of existing elastomeric materials such as seals, gaskets and, especially, polysulfide fuel tank sealants, once in contact with the higher aromatic chemistry of the G100UL fuel. Until recently, I had focused on the engine performance and reliability and thought little about the fuel system impact outside the cylinders. That has changed - I'm keen to learn more about any long-term durability testing required or performed for the STC route and the FAA's broader fuel certification protocol. 

I figure my day is coming, but my 1985 M20J has yet to leak or weep fuel. Hoping we can get to unleaded fuel without accelerating other issues. 

[Pinecone]

FYI, it is more looking like the UND issues might be the lower octane combined with a different carb that runs a bit lean at full power.

[Fly Boomer]

1 hour ago, Pinecone said:

FYI, it is more looking like the UND issues might be the lower octane combined with a different carb that runs a bit lean at full power.

Also, I think the UND fuel is a completely different chemistry compared to G100UL.

[Pinecone]

Yes.  94UL is 100LL without the lead.

G100UL is a totally different fuel bland.

But again, it starting to seem that the UND issues are the 94 octane combined with a different carb that is running leaner.

[Shadrach]

24 minutes ago, Pinecone said:

Yes.  94UL is 100LL without the lead.

G100UL is a totally different fuel bland.

But again, it starting to seem that the UND issues are the 94 octane combined with a different carb that is running leaner.

Do you have a link?  I read that the problem was valve recession and I am curious how the leaner mixture would have that effect.  I think a lot of the high compression, carbureted, parallel valve engines could use a bit more fuel in take off and climb, but that is the only time it would really be useful.  

[Pinecone]

Check BT for the story.

The thought is two fold. One, the carb runs a bit leaner at take off power, so getting into the detonation range on 94 octane and also overheating the valves, leading to microwelding.

Second, UND used lean to peak EGT for cruise, which at 75% power can put the slightly richer cylinders in the danger zone, meaning some detonation with 94, then see above

Interestingly Swift is not saying do not run at peak EGT.   They are also saying to not run LOP, but I will not reopen that can

 

[Shadrach]

4 hours ago, Pinecone said:

Check BT for the story.

The thought is two fold. One, the carb runs a bit leaner at take off power, so getting into the detonation range on 94 octane and also overheating the valves, leading to microwelding.

Second, UND used lean to peak EGT for cruise, which at 75% power can put the slightly richer cylinders in the danger zone, meaning some detonation with 94, then see above

Interestingly Swift is not saying do not run at peak EGT.   They are also saying to not run LOP, but I will not reopen that can

 

Swift is actually saying that both peak and LOP are a no no.  I read nothing compelling in that BT thread, though there is some reasoned speculation.   Lycoming once again seems to be proving that their default position is to make general statements without providing supporting data. There may be a carb issue, but parallel valve Lycomings have always had somewhat more challenging cooling characteristics (flame suit on but Lycoming's cooling charts prove it).  If the operators are adhering to the manufacturers CHT limits and  recommendations, "mircowelding" should not be an issue.  I am also dubious on the idea that detonation sufficient to cause valve recession (not something I've ever heard of) would fail to produce any of the other common issues associated with detonation (cracked spark plug insulators, deformed electrodes, ring and land damage, piston pitting, scuffing etc). 

Lycoming is suggesting that the recession is caused by aromatics, but 94 UL does not have high concentrations of aromatics (relatively speaking), not to mention that many, many Archers have been running on Mogas (much higher levels of aromatics) for years.

The situation is as clear as mud. Hard data would be nice, but I have yet to see any analysis. UND and their propulsion engineering dept. should have been an impartial analyst collecting and analyzing data, but I have not seen evidence that they've done much of that. Maybe this will happen in the future as all aircraft were equipped with Garmin G1000, so they should have the raw data.

To do this correctly, they should have had a control group and an exclusively 94UL group of the same aircraft running the same missions and then analyzed each group post trial.  Instead they ran 94UL in the whole fleet of eligible aircraft and also mixed 100LL in with 94 UL during the trial (any offsite fueling was 100LL).   I have seen no synopsis of engine telemetry from the trial but it looks like they are working on that.  Lycoming and Swift are both "interested parties" and both should be sidelined when it comes to analyzing this less than ideal trial.

[DXB]

39 minutes ago, Shadrach said:

Swift is actually saying that both peak and LOP are a no no.  I read nothing compelling in that BT thread, though there is some reasoned speculation.   Lycoming once again seems to be proving that their default position is to make general statements without providing supporting data. There may be a carb issue, but parallel valve Lycomings have always had somewhat more challenging cooling characteristics (flame suit on but Lycoming's cooling charts prove it).  If the operators are adhering to the manufacturers CHT limits and  recommendations, "mircowelding" should not be an issue.  I am also dubious on the idea that detonation sufficient to cause valve recession (not something I've ever heard of) would fail to produce any of the other common issues associated with detonation (cracked spark plug insulators, deformed electrodes, ring and land damage, piston pitting, scuffing etc). 

Lycoming is suggesting this on the recession is caused by aromatics, but 94 UL does not have have concentrations of aromatics (relatively speaking) not to mention that many, many Archers have been running on Mogas (much higher levels of aromatics) for years.

The situation is as clear as mud. Hard data would be nice, but I have not seen yet to see an analysis. UND and their propulsion engineering dept. should have been an impartial analyst collecting and analyzing data, but I have not seen evidence that they've done much of that. Maybe this will happen in the future as all aircraft were equipped with Garmin G1000, so they should have the raw data.

  To do this correctly, they should have had a control group and an exclusively 94UL group of the same aircraft running the same missions and then analyzed each group post trial.  Instead they ran 94UL in the whole fleet of eligible aircraft and also mixed 100LL in with 94 UL during the trial (any offsite fueling was 100LL).   I have seen no synopsis of engine telemetry from the trial but it looks like they are working on that.  Lycoming and Swift are both "interested parties" and both should be sidelined when it comes to analyzing this less than ideal trial.

Great analysis - this is exactly the kind of fleet that is suited to do well-controlled trials for all kinds of things in aviation; the problem is who's gonna fund it.  

I can attest to the significant cooling issues with parallel valve lycomings BTW -  will take the heat on that.  

[Hank]

1 hour ago, DXB said:

I can attest to the significant cooling issues with parallel valve lycomings BTW -  will take the heat on that.  

Sounds like you already are!  

Mine's not too bad . . . .

[Shadrach]

1 hour ago, DXB said:

Great analysis - this is exactly the kind of fleet that is suited to do well-controlled trials for all kinds of things in aviation; the problem is who's gonna fund it.  

I can attest to the significant cooling issues with parallel valve lycomings BTW -  will take the heat on that.  

Glad you got through all the typos...sheesh! I know you have been trying to mitigate cooling challenges for nearly a decade.  I think you've done all that you can.  O360s don't seem to be consuming cylinders at a rate higher than their angle valved brethren so at some point, one has to call it good enough and let go.  I thought about you the other day when I came across a thread on the Van's forum that summarized Lycoming's cooling charts for each engine as follows:

Required mass flow for equal CHT at 60F OAT  

320 1.45 lbs/sec
360 1.8 lbs/sec
IO360 1.4 lbs/sec
IO390 1.45 lbs/sec

Note- I believe these numbers are at max power.

Mass flow required per horsepower looks like this:

O320  =  .0096 lbs per second per horsepower
O360  =  .010 lbs per second per horsepower
IO360 = .0070 lbs per second per horsepower
IO390 = .0069 lbs per second per horsepower

That's roughly 40% more cooling air required for equal temps per horsepower produced.

There is no getting around the extra fin area and the oil cooled pistons on the angle valve.  The portly angle valve with its 40lb weight penalty seems a bit more reasonable to me now.  

[DXB]

1 hour ago, Shadrach said:

Glad you got through all the typos...sheesh! I know you have been trying to mitigate cooling challenges for nearly a decade.  I think you've done all that you can.  O360s don't seem to be consuming cylinders at a rate higher than their angle valved brethren so at some point, one has to call it good enough and let go.  I thought about you the other day when I came across a thread on the Van's forum that summarized Lycoming's cooling charts for each engine as follows:

Required mass flow for equal CHT at 60F OAT  

320 1.45 lbs/sec
360 1.8 lbs/sec
IO360 1.4 lbs/sec
IO390 1.45 lbs/sec

Note- I believe these numbers are at max power.

Mass flow required per horsepower looks like this:

O320  =  .0096 lbs per second per horsepower
O360  =  .010 lbs per second per horsepower
IO360 = .0070 lbs per second per horsepower
IO390 = .0069 lbs per second per horsepower

That's roughly 40% more cooling air required for equal temps per horsepower produced.

There is no getting around the extra fin area and the oil cooled pistons on the angle valve.  The portly angle valve with its 40lb weight penalty seems a bit more reasonable to me now.  

Kinda sad data, and I have IO390 envy now.   I probably wouldn't have put on that Powerflow exhaust if I'd known this innate limitation of the O-360 a few years back, and I ought to get around to setting my Surefly to fixed timing mode, despite this setup approaching stock E model performance.  As a Mooney pilot, I have a hard time pulling the power back and just enjoying the efficiency dividend.

[Shadrach]

1 minute ago, DXB said:

Kinda sad data, and I have IO390 envy now.   I probably wouldn't have put on that Powerflow exhaust if I'd known this innate limitation of the O-360 a few years back, and I ought to get around to setting my Surefly to fixed timing mode, despite this setup approaching stock E model performance.  As a Mooney pilot, I have a hard time pulling the power back and just enjoying the efficiency dividend.

I would not sweat CHTs in the low 400s.  I don't think Mike Busch would make the statements he made in this article if he did not have a fair amount of cylinder data.

I’m inclined to set CHT targets of about 380 degrees F for Continentals and 400 degrees F for Lycomings. These aren’t not-to-exceed values, they’re just comfortable targets. A good way to think of them is to imagine a CHT gauge with a green arc that tops out at these targets, followed by a yellow arc that extends 20 degrees F higher and terminates with a redline. This is different from the actual markings on your CHT gauge, which probably has a green arc extending all the way up to the manufacturer’s redline of 460 or 500 degrees F, but it’s good mental image to use to ensure maximum engine and cylinder longevity.

 

[Pinecone]

22 hours ago, Shadrach said:

Swift is actually saying that both peak and LOP are a no no.  I read nothing compelling in that BT thread, though there is some reasoned speculation.   Lycoming once again seems to be proving that their default position is to make general statements without providing supporting data. There may be a carb issue, but parallel valve Lycomings have always had somewhat more challenging cooling characteristics (flame suit on but Lycoming's cooling charts prove it).  If the operators are adhering to the manufacturers CHT limits and  recommendations, "mircowelding" should not be an issue.  I am also dubious on the idea that detonation sufficient to cause valve recession (not something I've ever heard of) would fail to produce any of the other common issues associated with detonation (cracked spark plug insulators, deformed electrodes, ring and land damage, piston pitting, scuffing etc). 

There was a post in one of the threads, or maybe AVWEB from somebody at another school that had similar problems, even with 100LL (IIRC), and they traced it to the change in carbs.

I see the no LOP as a shotgun recommendation.  But there have been issues with people trying to run LOP, but not understanding things, so they richen slightly putting them into the red fin area.

George Braly stated he can duplicate the issues that UND had, and did so on his test stand with exactly the same issues.  There is some stuff going on behind the scenes before details will be released.