fly_tornado Posted March 17, 2015 Posted March 17, 2015 Jim are you building a 2/3 scale DH Mosquito?
JimG Posted March 17, 2015 Posted March 17, 2015 Jim are you building a 2/3 scale DH Mosquito? Don't temp me ........ I'd be crazy enough to try....! I was very involved with the 80% DH Mosquito the Terry Kronk had underway when he died. He and Bryce were doing a brilliant job and I was deep into the overhaul of the 770 ranger engine he had planned to use. JimG 1
Russ Posted March 17, 2015 Posted March 17, 2015 Interesting Russ; what is Moreys? Upper cyl lube......another brand is Lucas. ( I think the Lucas is more popular tho ) .??? Recently told to use Castrol activ2, ...2 stroke oil. ( chap that told me should know, so I'm going to change over as soon as I exhaust my current stock ) About 100+ hrs ago, my pull throughs were "ordinary", so I had a topend rebuild done, properly done. ( read earlier post for details ) Anyway after 30....40hrs I noticed cyl variations, small, but apparent. Up till then I ran on nothing but avgas, ol mate told me to get onto upper cyl lube and run with that, within a fairly short time my pull throughs evened out, all were really good, so now I've accumulated 100+ hrs and everything is perfect. Must add.....I've recently changed fuel to a cocktail...40% avgas, 60% premium 95, Am considering going full on 98, am hearing good reports, I'll continue with the oil as well. 1
jetjr Posted March 17, 2015 Posted March 17, 2015 What rates are you using lube or active 2T I have used in disels with great results but thats fighting low sulpher fuels
Oscar Posted March 17, 2015 Posted March 17, 2015 For what it's worth... my engine was recently on a test stand, running standard plugs and 95 ULP. Following a series of runs, it was idle for several weeks. At the end of that time, we went to fire it up for a demo run - it simply wouldn't start. By that time, the petrol in the test stand tank was around six weeks old (from the service station, no way of telling how long from the refinery!). A couple of weeks later, Ian Bent was there, checked it over, carby settings correct. Changed to Iridium plugs - it started perfectly, and Ian's comment was that it sounded 'very healthy'. Still running the same batch of fuel... 1
fly_tornado Posted March 17, 2015 Posted March 17, 2015 just not quite up to the standard of an "aircraft engine"
Oscar Posted March 17, 2015 Posted March 17, 2015 just not quite up to the standard of an "aircraft engine" Yep, give me a Le Rhone Rotary with a max. 4 hours between majors anytime... or a Merlin, which was stretched to achieve 400 hours. 1
fly_tornado Posted March 17, 2015 Posted March 17, 2015 Oscar, you old scoundrel, falling back on comparing your trusty Jabiru to the mighty Merlin. If Jabiru went back to 1000 hour TBO most of their problems with CASA would probably disappear 1
Old Koreelah Posted March 17, 2015 Posted March 17, 2015 Upper cyl lube......another brand is Lucas. ( I think the Lucas is more popular tho ) .???Recently told to use Castrol activ2, ...2 stroke oil. ( chap that told me should know, so I'm going to change over as soon as I exhaust my current stock ) About 100+ hrs ago, my pull throughs were "ordinary", so I had a topend rebuild done, properly done. ( read earlier post for details ) Anyway after 30....40hrs I noticed cyl variations, small, but apparent. Up till then I ran on nothing but avgas, ol mate told me to get onto upper cyl lube and run with that, within a fairly short time my pull throughs evened out, all were really good, so now I've accumulated 100+ hrs and everything is perfect. Must add.....I've recently changed fuel to a cocktail...40% avgas, 60% premium 95, Am considering going full on 98, am hearing good reports, I'll continue with the oil as well. Very interesting Russ; can you suggest why the UC lube is improving pull-throughs? (Lube can't repair wear). I used a 1:200 mix of 2-stroke oil for a couple of years, but was advised against it. Lots of conflicting advice.
Russ Posted March 17, 2015 Posted March 17, 2015 What rates are you using lube or active 2TI have used in disels with great results but thats fighting low sulpher fuels Mixing 30ml oil.......20l petrol
Russ Posted March 17, 2015 Posted March 17, 2015 Very interesting Russ; can you suggest why the UC lube is improving pull-throughs? (Lube can't repair wear).I used a 1:200 mix of 2-stroke oil for a couple of years, but was advised against it. Lots of conflicting advice. My take.......as i said earlier 30....40hrs after a top end, variations were apparent, ( I'm fussy ) changed to adding UCL, things improved, and after 100+hrs.....still great. The oil must be controlling lead deposits, must be oiling valve guides, must be lubricating cyl walls, must be controlling carbon buildup in ring grooves. Just my take on it........bottom line, me jabs just purring. April we are heading off ( again ) this time up into the gulf, here n there, NT, WA, gone for weeks, I'm now quite comfortable with my jab doing these tiger runs. 1 1 1
Old Koreelah Posted March 17, 2015 Posted March 17, 2015 I used 2-T because I presumed it survived the combustion temps. Would the standard engine oil do the same? To keep things compatible, is there any reason why I shouldn't use Shell 100 Plus? Would it leave any residue?
facthunter Posted March 17, 2015 Posted March 17, 2015 Two stroke is the preferred additive to fuel Some reasons include. It is non plug fouling. Some engine oils have anti friction additives that foul plugs. Outboard oils have corrosion inhihiting additives. They don't cause carbon deposits as much in ring grooves. They mix with fuels better. They don't reduce the octane rating of the fuel. Piston rings need some oil present to seal well. If an engine is operating "dry" there will be more blow by. Blow by itself tends to push the oil where it doesn't do anything for the top of things. We are not suggesting adding much oil 20 mls to a tank....Nev 1
jetjr Posted March 17, 2015 Posted March 17, 2015 I have heard of sucess using flashlube too Still confused on rates 200:1 20 ml to 70 l 30 ml to 20 l.
Old Koreelah Posted March 17, 2015 Posted March 17, 2015 Two stroke is the preferred additive to fuel...Nev I presume there is no reason adding 2T to AvGas could cause problems?
Russ Posted March 17, 2015 Posted March 17, 2015 Both moreys and Lucas recommend 30ml to 20l fuel, that's what I've been doing. When I change to 2 stroke oil, then I may reduce the oil by 50% , and compare performance! plug colour, etc. I know of gyro guys adding Lucas to their Rotax machines, several guys have been doing it for 8....10yrs, they swear by it. This Castrol 2 stroke, I'm told is low ash, and quality anti oxidants, the chap that recommended this oil has a petro background, that'll do me. 1
facthunter Posted March 17, 2015 Posted March 17, 2015 OK, two strokes used to race on it at the more conventional ratios. Avgas is pretty pure and simple. Mogas has anything that will burn in it, and goes OFF quicker when mixed. Nev
planedriver Posted March 17, 2015 Posted March 17, 2015 I'm a firm believer in a good upper cylinder lubricant (possibly because I'm an on old fart that's used it for half a century) Not studied the compounds in recent times, but Redex used to soften carbon deposits preventing valve seat burning and loss of compression, kept the rings doing what they were supposed to do by not sticking in their grooves, reduced carbon build-up on plug points and also left a slight trace on the bores which reduced wear on start-up' I believe it also had a slight trace of detergent and wax in it which helped protect the bores. Reducing friction heat, plus allowing the compression to be maintained would surely help to overcome many of the engine problems that i've read about on here for the past few years Just my simple opinion, make of it what you will. Rgds Planey 1 1
jetjr Posted March 17, 2015 Posted March 17, 2015 When debating use of 2T in older diesel vehicles @ 200:1 there was some issue with using water sports products OR semi synthetics Feeling was Castrol Active 2T was one of the very few which mixed and did what was supposed to. Semi synthetics didnt mix properly and some settled out........ which would ruin your day. Re cost and rate - tell me if Im incorrect Moreys 1L treats 650L fuel 2-3 cpl Lucas 1L treats 380L fuel 8-9 cpl Flashlube 1l treats 1000l 1-2 cpl Castrol Active 2T 1L treats 200L 6-7 cpl marine is similar - rate discussed here seem way less 1
dmech Posted March 28, 2015 Posted March 28, 2015 Hi dmech, how is your research coming along, I'm very keen to hear what you have discovered as I have 2-2200's that I want to rebuild for my own projects.Anything you would like to share will be appreciated. cheers JimG Hi Jim , you would have to ring me 0437511002
Russ Posted March 29, 2015 Posted March 29, 2015 Hearing that jab are now installing a weaker oil pressure spring to all engines, the idea is less pressure to hydraulic lifters, eliminating a possible poor seating scinareo on the valves. Confirmation to come. 1
Russ Posted March 29, 2015 Posted March 29, 2015 Update.....pressure over 4.5 at cruise is now too high, hence weaker spring.
dmech Posted March 30, 2015 Posted March 30, 2015 Update.....pressure over 4.5 at cruise is now too high, hence weaker spring. went to a seminar years ago, presented by two manufacturing engineers from usa , one from GM the other from sealed power corp [ well known hyd. lifter maker] . they talked on ,so called pump up with lifters , they stated that in normal auto engine set up it would require 300/ 400 psi to act like a hydraulic ram to over come valve spring pressure , also taking into account rocker arm ratio. I don't know lifter piston area , or installed valve spring pressure used in the jab, to do the maths . in high rpm race engines 7-8 k rpm. its common to use anti pump up lifters in these engines , the lifters only pump up as a result of valve float, which leaves a gap in the valve train and the lifter does exactly what it is designed to do , fills the gap , which results in the valve not closing fully until the lifter returns to its normal position .[ rev limiter] by carefully dimensioning the components of the valve train we have been able build engines with better than 8k rpm ... with std off the shelf lifters. However since the jab only runs 3000rpm there abouts , I cant see the above causing the problem . The problem I see with the jab engine ,is more likely due to valve stem to guide interference [ sticking open momentarily ] causing the gap I mentioned earlier and then the lifter adjusting to compensate, and then ???. The valve stem or the valve guide can easily be modified to eliminate this , as was done up until lead was phased out in truck and auto engines , but still exist's in diesel engines because of soot build up on lower valve stems. Also I might mention , the solid lifter engine had issues with valve guide /stem interference , causing burnt valves /missing etc . I sent some photos of how the stems should be modified to jab , over a month ago , hav'nt heard any thing from them , but hope they are investigating it . our club jabs only run unleaded mo gas , in the 5 years i'v been a member and I have over 60 hrs flying them my self , although I know there is still a small amount of carbon build up on the v/ stems, I have not heard of a single problem regarding valve issues. Update.....pressure over 4.5 at cruise is now too high, hence weaker spring. 1 1
Jaba-who Posted March 30, 2015 Posted March 30, 2015 A couple of us were discussing engine fuel and oil additives the other day. Initially we thought it a good idea to use some morreys or Lucas upper engine lubricant but then we recalled that there had been some warnings about the effect of these additives on the fuel tank. So while it may be good for the engine I would need a guarantee its compatible with an epoxy fuel tank first.
jetjr Posted March 30, 2015 Posted March 30, 2015 Yes that occurred to me, I did have an issue with additive previously Some success being had using Moreys OIL additive Also using Shell Sports plus oil
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