pudestcon Posted April 11, 2012 Author Share Posted April 11, 2012 Do the carbys belong this 582 and what is the fule mixture setting.I have a 582 in a Lightwing:- with the sparkplugs set at .5 of a mill and the exhaust leaks at the elbows sealed, on the climb out the EGT is cooler and the torque is noticeable i.e., less throttle needed, just a tad nothing great, but noticeable. Both carbies came with the brand new engine from Bert Floods, so the settings are factory settings and have not been adjusted. This engine has had these characteristics since the very first time it was fired up. Pud Link to comment Share on other sites More sharing options...
pudestcon Posted April 16, 2012 Author Share Posted April 16, 2012 I did some testing over the weekend.... Water temp gauge reads correct, so engine is definitely overheating. Checked operation of thermostat and it opens, as it should at 55-60*. Tacho reads correct when read against an optical rev counter on the propeller, so engine is not developing full revs. Changed out sparkplugs and all 4 are a nice tan colour - very consistent across all plugs. Also, at the suggestion of Poll, I changed the oil in the reduction box to a lighter grade - no change unfortunately. So Riley, expect a call chasing those radiators so I can check if they will solve the overheating problem! Get the coffee ready! Spoke with Gary Flood today - he has suggested I check the main jet size is 165 which he says is what it should be. He also suggested checking to ensure the needle jet assembly is located beneath the white plastic guide at the top of the carburetor. All of these will be tried next time I'm at the hangar - not for a few weeks now probably:bad_mood: Any other suggestions you have will be tried if at all possible, or at least thought about:dizzy: Pud Link to comment Share on other sites More sharing options...
terryc Posted April 17, 2012 Share Posted April 17, 2012 Hi Pud, Did you think to check the reduction of your gearbox. On some it is stamped on the body under the propeller. only some. I don't think it is a 2.58-1 but a 2.24-1. I think that would account for the 12 degree pitch blocks. I'm no expert but enjoying chasing info on propellers, blade pitch and gearboxs for you. Terry. Link to comment Share on other sites More sharing options...
Riley Posted April 17, 2012 Share Posted April 17, 2012 Right Pud Have rigged down & boxed the tall radiators and placed them by the back door as discussed. Didn't include any of the plumbing as it doesn't suit an R582 installation. Take as much time as you need as I'll be up to my a.s in alligators with other projects for some time to come. Hopefully I'll be home when you call thru but if not, the 'lations' have been advised of your visit and the dog doesn't bite (the wife does but she's overseas!). Best of luck with your over-heating identification & resolution. Cheers Riley Link to comment Share on other sites More sharing options...
pudestcon Posted April 17, 2012 Author Share Posted April 17, 2012 Hi Pud, Did you think to check the reduction of your gearbox. On some it is stamped on the body under the propeller. only some. I don't think it is a 2.58-1 but a 2.24-1. I think that would account for the 12 degree pitch blocks. I'm no expert but enjoying chasing info on propellers, blade pitch and gearboxs for you.Terry. Certainly did Terry. It's a 2.58 reduction box as stamped on the little flat plate top centre front of the housing. I also recall counting the teeth on the drive cog and the gear in the reduction box which also checked out as a 2.58 gearing. Thanks for your interest here - many heads working a problem are much better than my beat up ol' skull!! Because of the prop pitch/reduction box configuration I'm leaning(no pun intended) towards a fuel supply issue, maybe the main jets are not correct. If I apply the formula for calculating the correct jet size for my conditions (35 degrees max and 4500 feet ASL) I should use a 155 size jet. I'm going to check but Gary Flood says there should be 165 jets in the carbies supplied by Floods. Substituting 155 jets won't solve the problem though cause I probably need more fuel to get the required revs - not less. Pud Link to comment Share on other sites More sharing options...
pudestcon Posted April 17, 2012 Author Share Posted April 17, 2012 Right PudHave rigged down & boxed the tall radiators and placed them by the back door as discussed. Didn't include any of the plumbing as it doesn't suit an R582 installation. Take as much time as you need as I'll be up to my a.s in alligators with other projects for some time to come. Hopefully I'll be home when you call thru but if not, the 'lations' have been advised of your visit and the dog doesn't bite (the wife does but she's overseas!). Best of luck with your over-heating identification & resolution. Cheers Riley Thanks for that Riley. I might see if I can visit you at Bindoon in the next week or 2 - I need to inspect that pile of aluminium tube you refer to as your "Gemini Project" Pud Link to comment Share on other sites More sharing options...
billwoodmason Posted April 17, 2012 Share Posted April 17, 2012 Pud, Your problem could be as simple as stale fuel. Many years ago I owned a Drifter and used to run it on ordinary ULP - ran great!!. I decided I would give it a treat and start running it on higher octane "Ultra" ULP. The first fill with the new fuel was shandied as there was still old fuel in the tank and the initial difference in RPM was only a couple of hundred RPM - but the situation worsened on subsequent refills. It took a while for the penny to drop (only after a flying mate had considered the situation after witnessing my frustration and offered me some of his fuel.) What we concluded was the "Ultra" was stale when purchased because it had gotten old in the bowser (underground tank) because the consumption rate was very low. (Mostly only used by the owners of high performance expensive cars.) It may not be your problem but it's worth a thought. P S. I used the remaider of the "Ultra" in my Yami 4 wheeler - it seemed to run well on it. Cheers, Billwoodmason Link to comment Share on other sites More sharing options...
pudestcon Posted April 17, 2012 Author Share Posted April 17, 2012 Pud,Your problem could be as simple as stale fuel. Many years ago I owned a Drifter and used to run it on ordinary ULP - ran great!!. I decided I would give it a treat and start running it on higher octane "Ultra" ULP. The first fill with the new fuel was shandied as there was still old fuel in the tank and the initial difference in RPM was only a couple of hundred RPM - but the situation worsened on subsequent refills. It took a while for the penny to drop (only after a flying mate had considered the situation after witnessing my frustration and offered me some of his fuel.) What we concluded was the "Ultra" was stale when purchased because it had gotten old in the bowser (underground tank) because the consumption rate was very low. (Mostly only used by the owners of high performance expensive cars.) It may not be your problem but it's worth a thought. P S. I used the remaider of the "Ultra" in my Yami 4 wheeler - it seemed to run well on it. Cheers, Billwoodmason Another potential cause of a problem to put in the memory bank, thanks Bill. Not the case here though as the engine has demonstrated low RPM at full throttle and overheating from day 1 with fresh fuel. I am very careful with the fuel I use, generally buying it in 20 litre lots to avoid the issue you have raised, and mixing it just before pouring into the aircraft. Pud Link to comment Share on other sites More sharing options...
Tex Posted April 17, 2012 Share Posted April 17, 2012 Hey Pud, how did this engine get run in if it never made full noise? Link to comment Share on other sites More sharing options...
pudestcon Posted April 17, 2012 Author Share Posted April 17, 2012 Hey Pud, how did this engine get run in if it never made full noise? The run in procedure chart from Rotax does not indicate what maximum revs should be. For all other levels in the run in chart it does specify what level. I took this to mean that maximum revs as shown in the operators manual might not be reached during run in due to a 'tight' engine. Indeed, the maximum of 6800 on the 582, coupled with the correct propeller configuration, would not be reached when stationary on the ground. So maximum revs with this engine during the run in procedure was 6100 or so. Pud Link to comment Share on other sites More sharing options...
facthunter Posted April 17, 2012 Share Posted April 17, 2012 The revs you achieve are dependant on the engines ability to produce power and the propellers ability to absorbe it The propeller "loads " the engine. The one thing we haven't examined yet is the ignition timing. IF it is retarded, we have the answer. It will heat the engine and reduce the revs available. Nev Link to comment Share on other sites More sharing options...
pudestcon Posted April 17, 2012 Author Share Posted April 17, 2012 The revs you achieve are dependant on the engines ability to produce power and the propellers ability to absorbe it The propeller "loads " the engine. The one thing we haven't examined yet is the ignition timing. IF it is retarded, we have the answer. It will heat the engine and reduce the revs available. Nev What other symptoms would I see with retarded (or advanced for that matter) ignition facthunter? There is no indication of backfiring at all. All people who have heard the engine running say how sweet it sounds. No one has said the engine sounds 'off'. I'm interested in exploring this a bit further though. I'm heading for my manuals!! Pud Link to comment Share on other sites More sharing options...
robinsm Posted April 17, 2012 Share Posted April 17, 2012 Silly question but you havent got a Farenheit gauge instead of a centigrade one ? (sorry pud but just asking.?) I have not reached 6800 rpm on a rotax 582 yet. I have never managed to get more than 6300 on a good day but the motors run real well. The pitch blocks on a 3.1 c box tend to be best at 16 degrees for a 3 blade 68 inch brolga. (not sure what yours should run at but 12 degreesa sounds a bit sus. What cruise speed are you getting in the thruster? Link to comment Share on other sites More sharing options...
facthunter Posted April 17, 2012 Share Posted April 17, 2012 A retarded ignition timing will not cause backfiring. All it does is reduce the power and the max revs and make it run hotter. With a new engine I would have thought this unlikely but since we have exhausted all other possibilities we have to go back to square one . Nev Link to comment Share on other sites More sharing options...
pudestcon Posted April 17, 2012 Author Share Posted April 17, 2012 Silly question but you havent got a Farenheit gauge instead of a centigrade one ? (sorry pud but just asking.?)I have not reached 6800 rpm on a rotax 582 yet. I have never managed to get more than 6300 on a good day but the motors run real well. The pitch blocks on a 3.1 c box tend to be best at 16 degrees for a 3 blade 68 inch brolga. (not sure what yours should run at but 12 degreesa sounds a bit sus. What cruise speed are you getting in the thruster? Hehehe, yes definitely a centigrade gauge, checked against a second centigrade gauge last weekend. I have put aside the prop pitch question for now as I believe 12* pitch is not the culprit in lack of max. revs. Cruise is 55kts indicated at 5200 RPM pilot only, and the climb out performance seems ok to me - certainly comparable to the T500 I did my training in. Pud Link to comment Share on other sites More sharing options...
pudestcon Posted April 17, 2012 Author Share Posted April 17, 2012 A retarded ignition timing will not cause backfiring. All it does is reduce the power and the max revs and make it run hotter. With a new engine I would have thought this unlikely but since we have exhausted all other possibilities we have to go back to square one . Nev On looking in my Rotax repair manual it seems a bit too technical for me to attempt addressing the ignition timing - gap checks would be ok to do but it seems some specialist equipment is required. Strobe lights and a gauge by the look of it. Pud Link to comment Share on other sites More sharing options...
Tex Posted April 17, 2012 Share Posted April 17, 2012 The run in procedure chart from Rotax does not indicate what maximum revs should be. For all other levels in the run in chart it does specify what level. I took this to mean that maximum revs as shown in the operators manual might not be reached during run in due to a 'tight' engine. Indeed, the maximum of 6800 on the 582, coupled with the correct propeller configuration, would not be reached when stationary on the ground. So maximum revs with this engine during the run in procedure was 6100 or so.Pud Installation manual says Max RPM 'refer to OM'... meaning refer to Op Manual for your models max RPM, not what you can 'get'... "The break in procedure must be performed with .... properly loaded with matched propeller for max RPM." Rotax Installation Manual Section 21. Anyway don't know if this is relevant... just wondering... Link to comment Share on other sites More sharing options...
pudestcon Posted April 17, 2012 Author Share Posted April 17, 2012 Installation manual says Max RPM 'refer to OM'... meaning refer to Op Manual for your models max RPM, not what you can 'get'... "The break in procedure must be performed with .... properly loaded with matched propeller for max RPM." Rotax Installation Manual Section 21.Anyway don't know if this is relevant... just wondering... On that basis the run in procedure was not done as per the book. However, at the time I was thinking the tightness of the engine was causing the reduced RPM, and if I'd known the pitch was 12*, it would have just reinforced the 'tight engine' premise. It is obvious from a previous post that other people can't get max revs either. With the help here from you forumites though Tex, I reckon the problem will be solved...... eventually:coffee: Pud Link to comment Share on other sites More sharing options...
Tex Posted April 17, 2012 Share Posted April 17, 2012 Yeh not my place to say for sure... but the L2/RTO with me when we did my install made sure we left the old Brolga on it for run in to get 6800 before we fitted the new Bolly which we then pitched for 6500 max Link to comment Share on other sites More sharing options...
pudestcon Posted April 17, 2012 Author Share Posted April 17, 2012 What I would like is a table of prop, pitch, reduction ratios, rpm for a number of combinations. For instance - 68" brolga 3 blade composite, 12* pitch, 2.58 reduction box on a 582, ? rpm. What about if it was a 3:1 reduction drive, or a 62", or 15* pitch? I think you get my drift, but I can't seem to find one anywhere - just drawing blanks at the moment. Cheers, Pud Link to comment Share on other sites More sharing options...
Riley Posted April 17, 2012 Share Posted April 17, 2012 What I would like is a table of prop, pitch, reduction ratios, rpm for a number of combinations.For instance - 68" brolga 3 blade composite, 12* pitch, 2.58 reduction box on a 582, ? rpm. What about if it was a 3:1 reduction drive, or a 62", or 15* pitch? I think you get my drift, but I can't seem to find one anywhere - just drawing blanks at the moment. Cheers, Pud I'll leave a propellor book the radiators. It may not have all of your deired info but there are plenty of nomographs that will either ameliorate your lack of understanding or further enhance your state of confusion. cheers Link to comment Share on other sites More sharing options...
pudestcon Posted April 17, 2012 Author Share Posted April 17, 2012 I'll leave a propellor book the radiators. It may not have all of your deired info but there are plenty of nomographs that will either ameliorate your lack of understanding or further enhance your state of confusion. cheers Thanks Riley... Probably do both, enhance my understanding and increase my state of confusion:dizzy: Pud Link to comment Share on other sites More sharing options...
Methusala Posted April 20, 2012 Share Posted April 20, 2012 Well, today I washed a ton of junk from the inlet air filter expecting a great increase in performance from what I had imagined to be my air starved 582... disappointingly, no change! I also checked to make sure that both slides were acting in concert and to the fullest extent at WOT. Still no change. I still have the option of changing main jets for a size smaller. Have to order from Bert Flood. Other than that I'm running out of ideas. I really am surprised that you have 12deg pitch blocks and only get 6,200 Pud. Interesting thread and very timely for me. Don Link to comment Share on other sites More sharing options...
facthunter Posted April 20, 2012 Share Posted April 20, 2012 I'm not in favour of going leaner, without dual EGT's fitted and proven. Your carbs are new and correctly jetted ( By the book). Just check they are going wide open at the rear of the slide at full throttle. The propeller should be tried on another similar motor that is doing the right revs. Variations to a propeller can have a big impact. ( Finish, blade width, angle etc) You could also check the inlet timing. The disc is driven from the centre of the crankshaft by a skew gear. It's a long shot, but at this stage you are getting where you have to check everything. A run on a dyno would prove it but where would you get one that is calibrated so to compare it with other engines of the same model Link to comment Share on other sites More sharing options...
nong Posted April 20, 2012 Share Posted April 20, 2012 I don't suppose Rotax have quietly changed the port timing or areas? Could they have restricted the muffler to meet some whacky european noise standard? If the muffler bleed-off rate through the stinger has been reduced, it's a fair bet your pistons are too hot. Might they have tried to compensate by upping the compression? ...another sure way to increase temps. Yes, a long shot but we're getting desperate here! Aw, heck. Give 'er a port job and knock up a set of 'spannies. That'll get er crackin' ! Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now