gbigs Posted March 17, 2015 Report Share Posted March 17, 2015 The breaking point for maintenance intervals is at over 30% 100LL use. In other words you can use up to 30 gallons of 100LL per every 100 gallons total fuel used without changing maintenance intervals. If using Avgas the Oil Tank is also supposed to be cleaned of lead deposits at each oil change. That is also avoided by using Mogas. The Flight Design POH has a pretty strict warning about the use of Avgas Link to comment Share on other sites More sharing options...
GlennM Posted March 17, 2015 Report Share Posted March 17, 2015 Decalin Runup is a TCP based chemical that scavenges lead from 100LL. Once applied, 100LL is now 96, no lead. http://decalinchemicals.com/products/decalin-runup-fuel-additive/ NO! TCP does not take lead out of the fuel. As it says in your link, it only changes the lead by-products during combustion. Link to comment Share on other sites More sharing options...
FlyingMonkey Posted March 17, 2015 Report Share Posted March 17, 2015 NO! TCP does not take lead out of the fuel. As it says in your link, it only changes the lead by-products during combustion. It really just moves the lead from building up on valve seats and gears to building up in exhaust. That's better, but still not ideal. I read some folks have had exhaust cracks attributed to use of Decalin. I would not use 100LL as a primary fuel for a 912ULS, even if Decalin is used religiously. Link to comment Share on other sites More sharing options...
Doug Hereford Posted March 17, 2015 Report Share Posted March 17, 2015 Tom Baker, I agree with your last post. Whenever someone asks me what to include on an aircraft maintenance status report, my reply always starts with what is legally required. In my opinion, these items must be included. After that, my recommendation is for the owner to include discretionary items which are usually centered around preventive maintenance and recurring service information type maintenance. Third on my list would be things like recommended TBO's and time change items. In the case of the SLSA CT, this should include Condition inspection (to include required placards), Safety Directives, Airworthiness Directives, and Airworthiness Limitations as a minimum. While not a part of the condition inspection FAR 91.207 (ELT), 91.411, and 9.413 requirements should also be tracked as appropriate to the operation. Doug Hereford Link to comment Share on other sites More sharing options...
gbigs Posted March 17, 2015 Report Share Posted March 17, 2015 NO! TCP does not take lead out of the fuel. As it says in your link, it only changes the lead by-products during combustion. TCP is a lead scavenger. It prevents the lead from depositing on valves and fouling them by converting the lead into a less conductive phosphate. Here is a PDF title "Get The Lead Out" http://www.alcorinc.com/wp-content/uploads/2012/06/TCP_FAQ_06_12_no_bleeds.pdf If you use Decalin or the product named in the PDF, ALCOR you can avoid lead build-up in the engine, thus achieving the same outcome as using 91E10 premium auto gas exclusively. The phrase 'get the lead out' is a general way of describing the process of neutralizing the ill-effects of the lead. An entire chemistry lesson was never the intent. Link to comment Share on other sites More sharing options...
2FlyAgain Posted March 18, 2015 Report Share Posted March 18, 2015 www.flyunleaded.com Also, you can carry 6-ish hours of fuel so if you go less than 3 hrs away, you have enough to get back. Winds etc notwithstanding. I believe that it has been mentioned before in other threads...but it bears repeating that one should check the octane rating when planning an important fuel stop using airports found on the www.flyunleaded.com site. Many of the airports on this site (...at least in my neck of the woods) do NOT have 91 octane. Link to comment Share on other sites More sharing options...
FlyingMonkey Posted March 18, 2015 Report Share Posted March 18, 2015 TCP is a lead scavenger. It prevents the lead from depositing on valves and fouling them by converting the lead into a less conductive phosphate. Here is a PDF title "Get The Lead Out" http://www.alcorinc.com/wp-content/uploads/2012/06/TCP_FAQ_06_12_no_bleeds.pdf If you use Decalin or the product named in the PDF, ALCOR you can avoid lead build-up in the engine, thus achieving the same outcome as using 91E10 premium auto gas exclusively. The phrase 'get the lead out' is a general way of describing the process of neutralizing the ill-effects of the lead. An entire chemistry lesson was never the intent. Though lots of people use it, Decalin is not approved by either Rotax or Flight Design, AFAIK. Link to comment Share on other sites More sharing options...
Roger Lee Posted March 18, 2015 Report Share Posted March 18, 2015 Rotax doesn't list Decalin as an approved fluid because they never took the time to test it. They don't approve or dis-approve Decalin. This is the same reason it took them so long to put 10% ethanol was okay. Link to comment Share on other sites More sharing options...
Ian Posted March 18, 2015 Report Share Posted March 18, 2015 Rotax doesn't list Decalin as an approved fluid because they never took the time to test it. They don't approve or dis-approve Decalin. This is the same reason it took them so long to put 10% ethanol was okay. But to say they "don't disapprove" is a far cry from saying they "approve"! I'll bet they don't disapprove many fuel additives and snake oils!! Link to comment Share on other sites More sharing options...
Roger Lee Posted March 18, 2015 Report Share Posted March 18, 2015 It isn't approved in writing. I classes and verbally they say okay. It's the Austrian's that would have to take it to task and run hundreds if not a thousand hours of test before they would pout it in writing. It isn't a priority for them. In the US and other parts of the world real life experience has shown and proved Decalin isn't an issue and works to help scavenge lead deposits. Decalin like TCP is absolutely not a cure all for lead deposits. It only reduces the lead build up. Without these scavengers lead would build up worse than with their use. Anyone that has torn into a Rotax engine using leaded fuel can see the deposits instantly. If it cured all the lead problems then many GA aircraft using these products wouldn't have lead issues and owners like us wouldn't have to have 25 hr. oil changes because the scavengers would have completely removed the lead, but we all know that isn't the case. Decalin and TCP only reduce lead build up and by changing the lead additive TEL from an oxide to a phosphate. Cut and paste: "What is TCP Fuel Treatment and what does it do? TCP stands for tricresyl phosphate which is an effective tetraethyl lead (TEL) scavenger. During the combustion process, TCP chemically converts the TEL to lead phosphate, which is less conductive, thereby reducing spark plug fouling. TCP use does not impact the power provided by leaded fuel." Link to comment Share on other sites More sharing options...
FlyingMonkey Posted March 18, 2015 Report Share Posted March 18, 2015 Rotax doesn't list Decalin as an approved fluid because they never took the time to test it. They don't approve or dis-approve Decalin. This is the same reason it took them so long to put 10% ethanol was okay. I thought any oil or fuel additives were "not approved" unless specifically listed...? Link to comment Share on other sites More sharing options...
Roger Lee Posted March 18, 2015 Report Share Posted March 18, 2015 Hi Andy, Rotax knows these are out their and are being used worldwide. They have not taken the time to test them so they will not be listed as an approved additive. In real life we teach these additives are okay and have been in use for many years and as far as some of the claims from additive companies there are all sorts of articles that claim they are wonderful and ones that claim they are a sham. I would absolutely stay away from oil additives. As far as Decalin, TEP, Seafoam and Sta-bil and I haven't heard or read of any negative issues and Rotax doesn't have an issue with them. (verbally) Rotax has a couple of dis-claimers saying they haven't tested these, but see no issues using them. There is a group of followers out there that believe you need to add Marvel Mystery oil to all their fuel. (must be one of those cults that used to hang with Jim Jones ) Note* The fluids listed by Rotax are only some they have tested. Remember these engine are world wide and no company on earth could test every possible oil fuel, coolant, ect... that might go in their planes. You would need to dedicate 1K-2K hours per fluid to test it's compatibility in the engine. Rotax has tested a few in key areas and a few common to certain world regions. These are for people so they have some basis of fluids to use and not leave customers worldwide in a lurch. There is been a couple of fluids that were used in a Rotax that did cause a problem and those have a specific do not use in a bulletin. Bottom line you can use several products that meet certain use specs. For instance oil. You are supposed to use a motorcycle oil and not a car oil. Never use a straight weight oil or kiss your engine good-bye. Link to comment Share on other sites More sharing options...
FastEddieB Posted March 18, 2015 Report Share Posted March 18, 2015 Don't know if this has been posted, from SL 912-016: 5.2) AVGAS fuel additives Additives, which aid the scavenging of lead deposits under the names of Decalin® and Alcor TCP®, have not been tested by BRP-Powertrain . Field experience gained shows that these products have no detrimental effect on the engine, when used in the recommended manner. Always follow the additive manufacturers instructions especially with regard to health and safety precautions. BRP-Powertrain only has field experience with Decalin RunupTMand Alcor TCP® brands. Other similar additives are not advised as BRP-Powertrain cannot comment on their suitability for the 912/914 engine types. Link to comment Share on other sites More sharing options...
Roger Lee Posted March 18, 2015 Report Share Posted March 18, 2015 exactly Link to comment Share on other sites More sharing options...
Anticept Posted March 19, 2015 Report Share Posted March 19, 2015 Now see, that's a perfectly reasonable way to say "look, we haven't tested it, so don't hold us to it, but it seems that people in the field aren't having any problems". It annoys the hell out of me when a company jumps straight to the "We don't recommend this product as we haven't done any testing" defense. Link to comment Share on other sites More sharing options...
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