What can I do with my 582?

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Armilite

Well-Known Member
Joined
Sep 5, 2011
Messages
3,281
Location
AMES, IA USA
Hey guys, I have a 582 gray head, I am looking to :
1) make it as reliable and efficient as possible
2) get as much power out of it as possible while keeping it as reliable and efficient as possible.
Any ideas on my options here?
=================================

Reliability has more to do with WHO builds the Engine, WHO maintains the Engine, and WHO Flys behind the Engine. Understanding your Engine and it's pitfalls is Important. Your Gray Head is fine for Normal Flying but has a problem with Steep Dives, Shock Cooling. The Blue Head was the Upgrade to Solve that. There was a Ceramic Water Pump Seal Upgrade, if yours doesn't have it can still be upgraded.

All Rotax 2 Strokes #1 problem is Detonation. To solve that burn 100LL or 93 Pump Gas. On CPS Website under 582UL they say:
FUEL:
min. MON 83 RON 91*
min. AKI 87*
* leaded, unleaded, AVGAS 100LL or Ethanol 10

#2 Failure is using Poor 2 Stroke Oil with low Flash Points. Bottled 2 Stroke Oil unopened has a 5 Year Shelf Life. Once opened drops to 2 year, once mixed with Gas 30 Days!

A few guys like Rotax Rick is always looking for better Parts to make his Engines more Reliable. He has rebuilt over 1000 Rotax Engines so he has seen all the different Failures. Rotax's Oil Injection is one of them, so he recommends Premixing at 40:1 for his 92hp 670's which has a 450 hr TBO last I knew. Could the problem with Rotax's Oil Injection be Fixed, probably, but nobody has offered a fix yet that I know of. It's set at 50:1. He upgrades to a Rod with Double Oiling Holes on top and Dual Oiling Slots on the bottom. He uses a Ceramic Top Coated Piston in his 670 Engines with a Moly Sidewall Coating. I'm sure he does what most Racers do an enlarge and Polish Oiling Holes in the Case to get more Oil to the Bearings. He likes Amsoil Interceptor Oil. There are a few other Oils he recommends on his website.

No, his 670 Tuned Pipe will not work on your 582UL. Tuned Pipes are Designed for a Specific CC, Port Duration, and Exhaust Port Specs. R&D Aero once made Tuned pipes for many Rotaxs, some Good, some Bad. Their website is down now, but their Good 582UL Tuned Pipe with No Dead Spots made around 80hp@6500rpm. When using 11.5cr with 6500rpm and if Carbed right it takes on Avg 7cc to make 1hp. Your 582UL is 580cc/7cc= 82.8+hp is possible.

Porting of the Cylinder & Case can add 10-15% more hp. Lowell is the guy to talk to.

Using a Big Bore at the same rpm as Stock doesn't decrease the engine's life. The only Big Bore for the 582UL and 618UL was maybe 20+ years ago, where they went from 76mm to 79.4mm. The 670 78mm has been Big Bored to 82.5mm.

Many of these Older Engines weren't Prop right or used wrong Pitch or Reduction ratio. Take your Planes MTOW and use the 1kw for each 10 kg to figure what HP you really need. Example: Say your MTOW is 650 lbs = 294.835 kg / 10 kg = 29.4835‬ kw needed = 39.53802 (40hp) needed.

Figure your Prop Static Thrust you use now with your Reduction Ratio. Can it be improved upon?

Rotax Joe says using Ceramic Coated/Moly Coated Pistons in his 582's with Amsoil Saber at 100:1 his Customers are seeing 700+hrs without a De-carbon. Hirth has a Blue Max Oil that can also be used at 100:1 and Hirth's have a 1000 hr TBO.

Today, there is some Hybrid Crank Bearings that use Steel races with Ceramic Balls that run Cooler, need less Oil, and they say last 3x of Standard bearings, but cost 3x the price.

Using EFI should give you a better GPH use, Smoother running, better Starting Engine, and Solve any Carb Icing issues.
 
Joined
Apr 19, 2020
Messages
16
If you want to do he work, blueprint it to the nth decimal place or find someone who will. Although some will have hot rod advice, I say keep it stock but make it perfect. Unless you are already an expert, more chance to mess it up than help.
Not an expert by no means, I do have engine knowledge, I build
Engines for a living. Large engines. I believe in stock if that is the best reliability I can get. Just looking at all options from experience. Thank you for the reply.
 
Joined
Apr 19, 2020
Messages
16
=================================

Reliability has more to do with WHO builds the Engine, WHO maintains the Engine, and WHO Flys behind the Engine. Understanding your Engine and it's pitfalls is Important. Your Gray Head is fine for Normal Flying but has a problem with Steep Dives, Shock Cooling. The Blue Head was the Upgrade to Solve that. There was a Ceramic Water Pump Seal Upgrade, if yours doesn't have it can still be upgraded.

All Rotax 2 Strokes #1 problem is Detonation. To solve that burn 100LL or 93 Pump Gas. On CPS Website under 582UL they say:
FUEL:
min. MON 83 RON 91*
min. AKI 87*
* leaded, unleaded, AVGAS 100LL or Ethanol 10

#2 Failure is using Poor 2 Stroke Oil with low Flash Points. Bottled 2 Stroke Oil unopened has a 5 Year Shelf Life. Once opened drops to 2 year, once mixed with Gas 30 Days!

A few guys like Rotax Rick is always looking for better Parts to make his Engines more Reliable. He has rebuilt over 1000 Rotax Engines so he has seen all the different Failures. Rotax's Oil Injection is one of them, so he recommends Premixing at 40:1 for his 92hp 670's which has a 450 hr TBO last I knew. Could the problem with Rotax's Oil Injection be Fixed, probably, but nobody has offered a fix yet that I know of. It's set at 50:1. He upgrades to a Rod with Double Oiling Holes on top and Dual Oiling Slots on the bottom. He uses a Ceramic Top Coated Piston in his 670 Engines with a Moly Sidewall Coating. I'm sure he does what most Racers do an enlarge and Polish Oiling Holes in the Case to get more Oil to the Bearings. He likes Amsoil Interceptor Oil. There are a few other Oils he recommends on his website.

No, his 670 Tuned Pipe will not work on your 582UL. Tuned Pipes are Designed for a Specific CC, Port Duration, and Exhaust Port Specs. R&D Aero once made Tuned pipes for many Rotaxs, some Good, some Bad. Their website is down now, but their Good 582UL Tuned Pipe with No Dead Spots made around 80hp@6500rpm. When using 11.5cr with 6500rpm and if Carbed right it takes on Avg 7cc to make 1hp. Your 582UL is 580cc/7cc= 82.8+hp is possible.

Porting of the Cylinder & Case can add 10-15% more hp. Lowell is the guy to talk to.

Using a Big Bore at the same rpm as Stock doesn't decrease the engine's life. The only Big Bore for the 582UL and 618UL was maybe 20+ years ago, where they went from 76mm to 79.4mm. The 670 78mm has been Big Bored to 82.5mm.

Many of these Older Engines weren't Prop right or used wrong Pitch or Reduction ratio. Take your Planes MTOW and use the 1kw for each 10 kg to figure what HP you really need. Example: Say your MTOW is 650 lbs = 294.835 kg / 10 kg = 29.4835‬ kw needed = 39.53802 (40hp) needed.

Figure your Prop Static Thrust you use now with your Reduction Ratio. Can it be improved upon?

Rotax Joe says using Ceramic Coated/Moly Coated Pistons in his 582's with Amsoil Saber at 100:1 his Customers are seeing 700+hrs without a De-carbon. Hirth has a Blue Max Oil that can also be used at 100:1 and Hirth's have a 1000 hr TBO.

Today, there is some Hybrid Crank Bearings that use Steel races with Ceramic Balls that run Cooler, need less Oil, and they say last 3x of Standard bearings, but cost 3x the price.

Using EFI should give you a better GPH use, Smoother running, better Starting Engine, and Solve any Carb Icing issues.
Is there a best oil?
is the interceptor the best?
or is any high flashpoint oil good?
like Klotz in the dirt bike world.
 
Joined
Apr 19, 2020
Messages
16
I believe unless you know what you are doing stock is the best compromise.....get the manuals and set it up by the book. Your question says to me ....that for you that might be the safest way to go.
I agree the safe reliable way is the best. I’m not into hotrodding anything, that is for a short life engine. I want reliability first.
 
Joined
Apr 19, 2020
Messages
16
If you want to do he work, blueprint it to the nth decimal place or find someone who will. Although some will have hot rod advice, I say keep it stock but make it perfect. Unless you are already an expert, more chance to mess it up than help.
My dial gauges that I sue on my lathe only go to the 4th decimal, for precision work. But I get the concept.
 
Joined
Apr 19, 2020
Messages
16
I trimmed the quite above to the parts that I am going to specifically answer.

It is true that there were very few engine choices during that time that were a good option for the Mini 500. But it cones down to one set of problems: Rotax specifically setup the 582 to drive a propeller, the choice of carburetors. rotary valve, and exhaust are specific for the flat torque curve of the task. The exhaust is a critical part of this, and Rotax considers the exhaust a critical engine part, to the point that changing it voids the warranty.
Driving a rotor by nature leaves the engine at a given RPM with the load changing all over the place from full load to almost no load at all during a descent. The stock exhaust is not setup to handle this much range, and neither are the Bing carburetors. Just as you said, the result is excessive EGTs and related problems at differing flight phases, and I just can't imagine a way to fix this with the stock setup. This is a situation where it seems that modifications are mandatory, and Rotax will not go along with any user modifications, so you will never get the support of the factory, and you are now literally flying off into the unknown. So with a good voiding warranty, aftermarket pipes and other modifications were made to cope with varying degrees of success. It seems possible to me that with the right modifications, it could work, but again, nobody has ever published good info on this that I have seen. Until this happens, you are just a test pilot with an unknown engine that may or may not blow up at any time and no way to know... So as you said, the failures are even more likely to be pilot induced as there are no known and properly documented procedures or limits.
There is even a more subtle issue with piston loading as the 582 was designed to have a range of load inertia and a rotor is WAY out of the designed load arm moment of the engine, and this can lead to lubrication failure from excessive piston to cylinder pressures. I explained this in another thread some time ago.

Back to coatings, I am not sure if they change the thermal expansion of the parts that much. Generally, metals do what they will and if they are confined in one direction, they will expand in another direction instead. The coatings will only change this if they manage to alloy deeply into the metal (change the metallic properties) which is the case sometimes.
The Rotax pistons are hyper eutectic. This is to slow their rate of thermal expansion to more closely match the cylinder, but there is only so much you can do. If you open the throttle of a cold engine, it does not matter what the piston is made of or coated with, it will not be the same temperature as the cylinder. I have seen bad operators cold seize a cast iron engine with cast iron pistons.
The bottom line here is that all metals change size with temperatures. Even if the piston and cylinder are the exact same metal, improper operation will cause the dimensions between them to change, there is no getting around this.
Due to the very nature of piston and cylinder design you have a thermal conflict until things are at operating temperature. Sure, you can change the alloy to move the expansion curves around, and you could build an engine that you must full throttle from cold so it does not seize, or you could build one you have to warm up before full throttle, but as of yet, nobody has figured out how to combine both conflicting needs into one.
So from the standpoint of coatings helping with cold seizures, I am not seeing that unless the coating would allow a greater piston cylinder distance. The GPI pistons are coated, and they are set at 0.006", much looser (double) than the stock pistons. What I see is that they are more prone to piston overheating and detonation than the stock pistons due to reduced thermal transfer. But with careful operation, I have seen that they last as long as the stock pistons, so with this actual case, I have not seen any loss or benefit.

It just keeps coming back to the 582 seems to be good enough without fancy coatings, and adding coatings would just drive up the price and make it harder to repair for not much gain.

While this is not an exact answer for the question of expansion related to coatings, it will have to do until the question is more specific, maybe what types (I know you specified ceramic, but you did not specify which method, thickness or other properties) of the coatings and where.
This answer is very informative and thank you for the detail, I do better understand the concept of the Rotax design and why. You have helped more than you realize.
 

sigrana

Active Member
Joined
Oct 19, 2010
Messages
30
Location
Australia
I am answering your original question: I have had several Rotax two stroke engines, including a 582. If you put a good, well designed tuned and silenced exhaust system on them, they will perform brilliantly, avoiding any detonation, overheating etc. and giving far more power and torque through the whole r.p.m. range. They will also run at lower head and exhaust temperatures and ,of course, use much less fuel.
If you wish to know more about it, you may contact me at msmprod@optusnet.com.au.

Cheers


Hey guys, I have a 582 gray head, I am looking to :
1) make it as reliable and efficient as possible
2) get as much power out of it as possible while keeping it as reliable and efficient as possible.
Any ideas on my options here?
 
Joined
Apr 19, 2020
Messages
16
I am answering your original question: I have had several Rotax two stroke engines, including a 582. If you put a good, well designed tuned and silenced exhaust system on them, they will perform brilliantly, avoiding any detonation, overheating etc. and giving far more power and torque through the whole r.p.m. range. They will also run at lower head and exhaust temperatures and ,of course, use much less fuel.
If you wish to know more about it, you may contact me at msmprod@optusnet.com.au.

Cheers


Hey guys, I have a 582 gray head, I am looking to :
1) make it as reliable and efficient as possible
2) get as much power out of it as possible while keeping it as reliable and efficient as possible.
Any ideas on my options here?
Do you have pictures or videos of the pipe ?
ho is it shaped? Tuned?
 

sigrana

Active Member
Joined
Oct 19, 2010
Messages
30
Location
Australia
Do you have pictures or videos of the pipe ?
ho is it shaped? Tuned?
What I can tell you is that our exhaust system are (as already mentioned, have you read above?) fully tuned and silenced. It is the result of 42 years of knowledge and experience. We exclusively custom design them and build them. The silencer is part of the exhaust, not an added item, which makes the system more effective.
 

Armilite

Well-Known Member
Joined
Sep 5, 2011
Messages
3,281
Location
AMES, IA USA
I am looking to possibly use the ceramic top coated pistons, where can I find them? And which one to use ?
==================================

You can buy some pistons with the Moly Sidewall Coating. You have to send your Pistons to someone who does the different Ceramic/Moly/Heat Dispercent Coatings or get a Free Electric House Stove off Craigslist, a cheap Harbor Freight Glass Bead Cabinet or Hand Held Blaster, one of there cheap Touch Up Spray Guns and do it yourself. Techline makes the Best Coatings.
 

Armilite

Well-Known Member
Joined
Sep 5, 2011
Messages
3,281
Location
AMES, IA USA
Is there a best oil?
is the interceptor the best?
or is any high flashpoint oil good?
like Klotz in the dirt bike world.
=========================================

A Good 2 Stroke Oil is one with a High Flash Point, doesn't leave a lot of Carbon Buildup that makes Rings Stick, is Cheap, and really available. You have to decide if you want to use Oil Injection or Premix.
OIL FLASH POINTS - 1.jpg
 

n3puppy

Well-Known Member
Joined
Jun 25, 2019
Messages
138
Is there a best oil?
is the interceptor the best?
or is any high flashpoint oil good?
like Klotz in the dirt bike world.
In the latest 582 manual posted on Fly-Rotax (2018) they still specify oils meeting API-TC standards
That standard specifies characteristics for oil for used in high performance engines and considers things like ring-sticking, pre-ignition and cylinder scuffing as well as combustion by-products like ash

You didn't mention which version of Klotz - But if its API-TC rated (meets or exceeds) should be ok

Rotax doesn't Spec Flash point temp - but they do specify pour point 10 degrees C below ambient temp if you are using the oil injection system.
https://rotax-docs.secure.force.com/DocumentsSearch/sfc/servlet.shepherd/version/download/0681H000003MUpxQAG?asPdf=false


F090E6E4-7997-4216-BE04-1CF43CEE4551.jpeg
 

n3puppy

Well-Known Member
Joined
Jun 25, 2019
Messages
138
Is this chart the flashpoint of each oil? Higher temp burns cleaner?
Right Rudder
There are varying opinions on whether flashpoint of oil is really of a concern.
What IS important is what is left behind as ash and carbon deposits.
Four stroke oil can have high flash points but should not be used in two strokes because its not designed for them.

Here is a good article on oils by a distributor for Amsoil.
Does The Flash Point Of 2-Stroke Snowmobile Oil Matter? - Oil Depot - AMSOIL Dealer Serving Canada & US

Flash point is not where oil burns - its where it could burn if there is an ignition source
ALL oils burn in the combustion chamber, 1100+ degrees

Gasoline flash point is MINUS 45F. If flash point was where gas burns - everybody's cars would be exploding in summer.
If the Gas in a two stroke isn't burning, the oil isn't either.

Rotax Rick suggests two , Amsoil interceptor at 216F, and Quicksilver PWC at only 149F

Rotax recommends oils that meet or exceed API- TC ratings. Not flash point temp.
There are some oils that are still good - But not API-TC rated - WHY?
Because it costs a lot of money to get API -rated.
There are other ratings - ISO EGD (Euro) and JASO FD (Japan) that are similar to API-TC
Hirth Blue Max is ISO -EGD+ and works well - even at its comparatively low flash point of 230F

Look for the duty rating before ever worrying about the flashpoint.
 
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Armilite

Well-Known Member
Joined
Sep 5, 2011
Messages
3,281
Location
AMES, IA USA
Is this chart the flashpoint of each oil? Higher temp burns cleaner?
=====================

HIGHER FLASHPOINTS mean they Lubricate Better! Your Bearings, your Cylinder Walls. But Yes, they usually also Burn Cleaner. All 2 Stroke Oil's Burn, just some don't burn as Clean, usually the Older Conventional Oils, then your Rings can Stick and you have to do a Decarbon. With these newer Full Synthetics and Oil like Hirths Blue Max you can run them at 80:1 to 100:1 for even less Carbon Buildup. Rotax has made Millions off People Selling, rebuilding their Engines from Detonation and Oil issues. Rotax Rick does like the Amsoil Interceptor account it burns clean for the RAVE Valves his 670 uses, he also uses it at 40:1 Ratio. He's Old School where he has to see OIL dripping off every part.

Snowmobiles, Speed up, Slow Down, Speed up, Stop, Speed up, Slow Down, they aren't run at a CONTINUOUS HIGH RPM like on Planes. Snowmobiles even in RACING are usually used in COLD Weather that Helps with the HEAT Buildup, but then only for X amount of Laps, and even then many don't finish a RACE!

Amsoil doesn't even recommend their own Oil for Plane use!

FLASHPOINT is where the Oil Burns and turns to Carbon Ash! LOOK at the bottom of your PISTONS, that's Burnt OIL from the Piston getting too HOT. That Carbon flakes off into your Bearings.
 
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n3puppy

Well-Known Member
Joined
Jun 25, 2019
Messages
138
Right rudder
Looks like some definitions are in order -
FLASHPOINT is NOT where the Oil Burns and turns to Carbon Ash

From Wiki
Flash point - Wikipedia
The flash point of a volatile material is the lowest temperature at which its vapours ignite if given an ignition source.
The flash point is sometimes confused with the autoignition temperature, the temperature that causes spontaneous ignition. The fire point is the lowest temperature at which the vapors keep burning after the ignition source is removed. It is higher than the flash point, because at the flash point more vapor may not be produced fast enough to sustain combustion.[1] Neither flash point nor fire point depends directly on the ignition source temperature,
but ignition source temperature is far higher than either the flash or fire point.

In a two stroke - the ignition source required is the spark plug.
The electrical spark temp is high enough to ignite. Doesn't burn until then.
The chart below shows the Flash point AND auto ignition point of various liquids

What you see on the bottom of a piston is NOT carbon ash from the oil burning, but simple "cooking" leaving behind deposits. Just like a frying pan - no flames but gets black over time. Common sense will tell you if the oil was burning under the piston - the entire crankcase would be full of fire because the gas would be burning too

Here is another article describing important oil characteristics for aircraft use.
Choosing an Oil for Two-cycle Engines
It explains why LOW ash oil can be better than ash-less oil (counter intuitive more deposits)

Also explains why oils with High flash points can actually be bad for two stroke engines based on how the engine is used.
Because High Flash Point oils don't evaporate as quickly, MORE deposits can form when they cook in the engine, and when they eventually burn (Fire Point temp). The oil blend/additives have a big effect on what deposits are left over.

Rotax Rick has a lot of experience - He recommends an oil with so low a flash point it never even makes the charts Quicksilver PWC oil with flash point of 149 degrees
But it is designed for engines that are just like your 582 (and his 670's). That formulation burns clean and protects the engine even with the lowest flash point around.

D56C2574-371C-4E77-9520-107D60FFB2E5.jpeg
 
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Armilite

Well-Known Member
Joined
Sep 5, 2011
Messages
3,281
Location
AMES, IA USA
Right rudder
Looks like some definitions are in order -
FLASHPOINT is NOT where the Oil Burns and turns to Carbon Ash

From Wiki
Flash point - Wikipedia
The flash point of a volatile material is the lowest temperature at which its vapours ignite if given an ignition source.
The flash point is sometimes confused with the autoignition temperature, the temperature that causes spontaneous ignition. The fire point is the lowest temperature at which the vapors keep burning after the ignition source is removed. It is higher than the flash point, because at the flash point more vapor may not be produced fast enough to sustain combustion.[1] Neither flash point nor fire point depends directly on the ignition source temperature,
but ignition source temperature is far higher than either the flash or fire point.

In a two stroke - the ignition source required is the spark plug.
The electrical spark temp is high enough to ignite. Doesn't burn until then.
The chart below shows the Flash point AND auto ignition point of various liquids

What you see on the bottom of a piston is NOT carbon ash from the oil burning, but simple "cooking" leaving behind deposits. Just like a frying pan - no flames but gets black over time. Common sense will tell you if the oil was burning under the piston - the entire crankcase would be full of fire because the gas would be burning too

Here is another article describing important oil characteristics for aircraft use.
Choosing an Oil for Two-cycle Engines
It explains why LOW ash oil can be better than ash-less oil (counter intuitive more deposits)

Also explains why oils with High flash points can actually be bad for two stroke engines based on how the engine is used.
Because High Flash Point oils don't evaporate as quickly, MORE deposits can form when they cook in the engine, and when they eventually burn (Fire Point temp). The oil blend/additives have a big effect on what deposits are left over.

Rotax Rick has a lot of experience - He recommends an oil with so low a flash point it never even makes the charts Quicksilver PWC oil with flash point of 149 degrees
But it is designed for engines that are just like your 582 (and his 670's). That formulation burns clean and protects the engine even with the lowest flash point around.

View attachment 98996
=============================

Were not talking about Gasoline Flashpoints or Car Oils conventional or Synthetics 300F-495F, were talking 2 Stroke Oils! Ask Rotax Rick if he gets 450 hrs without a Decarbon using that "Quicksilver PWC Oil with a flashpoint of 149F degrees or the Amsoil Interceptor Oil Flashpoint of 183F". The bottom end of your 2 Stroke engine normally shouldn't see 200F per the Rotax Engine Head Manager I talked too at Oshkosh. So I asked him then Why are many of these Rotax's have Bearing Problems? His comment was the Oil used and Octane Gas used. I will guarantee you the bottom of that Piston Dome is Hotter than 200F. Those Pistons that are Seizing Melting on your Cylinder Walls is way Higher than 200F. Aluminum melts at 1220F. I have seen PTO Bearings with the Black Plastic Retainers Melt which takes 375F to melt that Black Plastic usually caused by people over-tightening their Belt Drives. Nylon Bearing Retainers are good till 500F and don't rust (what Rotax Rick uses). Rotax Rick is Old School, a great guy, he has to see Oil dripping off all the parts when he takes an Engine apart.

You need to Read up on 2 Stroke Oil Flash Point Testing. I'm sure Wikipedia has built a lot of 2 Stroke Engines. What was once recommended years ago, today is a different matter. Hirth recommends today their Blue Max Oil at 100:1, Skidoo/Rotax recommends their XPS BRP/Castrol = 350F, Yamaha recommends using their Yamalube = 255°F.

These Top (6) Oils are High-End Racing Oils usually expensive. I don't know anything about them, never tried any of them. Most Sled Racers I have talked to like Klotz Oils. I was using the #7 XPS BRP/Castrol = 350F in my 670 in a Sled with No Problems. I have been using Amsoil Saber Pro at 100:1 in my 1972 292 TNT Skidoo Single, so far with no problems.


1. Klotz R50 = 550F
2. Klotz Benol = 550F
3. Motul 800 = 485F
4. Castor Oil 2 Stroke = 445F
5. Bel Ray H1R = 435F
6. Maxima Castor 927 = 420F

Post off a Chainsaw Group. It also depends on how the flashpoint was obtained, open cup vs closed cup. Often times the flashpoint simply indicates the volume of solvents, as they off-gas and ignite long before the oil ever will. Oils like Yamalube, Amsoil Dominator have low flashpoints, but they offer good protection. Application of the oil plays into it as well, chainsaws has a very low output for the displacement that they have, which is why the thin low film strength oils work well enough in saws and other O P E. That said flashpoint does have some relevance "especially when obtained in the open cup method" and often goes hand in hand with higher film strength oils like R50 and Motul-800. The two best oils that I have used in chainsaws thus far are K2 and Honda HP2. Motul 710 is promising, but I haven't used it much. For Racing, most use Klotz Original Techniplate, or Maxima 927 which has Castor in it. For milling I like the thicker oils like Motul-800 and Klotz-R50, but really K2 or HP2 would be fine in this application too.

To my knowledge, these are all Open Cup Flashpoints.
 
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