posted
Rody i need some advise mate. Due to the huge debate we are mixing our own fuels now and running 25% nitro, 10% synthetic and 5 castor.We just curious as to the oil content that u guys run or can suggest thanks. Is 10,5 to much?
Regards
Mark
-------------------- Lst2 Rb928,werks clutch,carbon kit,new era,rd logics,dual hitec 645mg,40 series cheyenne wheels. Posts: 27 | From: Australia | Registered: Dec 2006
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posted
If you want to mix your own fuel then I would suggest that you always use more castor then synthetic oils.
We in general use 7-8% castor + 3% synthetic oil in our fuels. For the % of synthetic oil used this all depends on the quality of this oil, sometimes you need a little more but in general this should be enough.
posted
Rody, are the numbers you named just related to your monster fuel or also for concept fuel? I'm just asking because the fuel I'm using contains 25% nitro, 7% synthetic oil and 2% castor oil. It's basically made for .21 competition but I also don't have any troubles caused by this fuel during last season. I'm just interested. F.e., a well known mineral oil manufacturer got the "Aerosynth 3" fully synthetic oil which can handle temps up to 570°C. Is the main reason for "still" using castor based oils the one that the viscosity of the actual fully synthetic model oils becomes too low at highest working temps and maybe causes oil film tears / cuts?
[ 27. December 2006, 11:32: Message edited by: Stefan ]
posted
This is what we use when we mix ourselves sometimes, in our RB Concept Fuel we use 6% castor and 2% synthetic.
For me the best oil has always been castor, however there is more carbon built-up with this oil, but if you mix it with sythetic oils then sometimes the carbon-builtup is less depending on the sythetic oil of course.
The oil film breaks when the temps become too high and the speed of the moving part also. There are lots of oils available nowadays but not all mix well with nitro or methanol. For me the good old castrol is still not out of its use, of course there are sythetic oils wich are very good on paper but if the viscosity becomes too low then the engine looses low-end power once the temps go up while then the castor is not doing this.
posted
thanks rody much appreciated i jus dont want to damage this engine,we use cool power oil an elf fuels so 10% oil an 5% castor is a bit much? I run 7 or 8 Plug cause its really hot over here.
Cheers Mate
Mark
-------------------- Lst2 Rb928,werks clutch,carbon kit,new era,rd logics,dual hitec 645mg,40 series cheyenne wheels. Posts: 27 | From: Australia | Registered: Dec 2006
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posted
If your engine is working fine with your actual mixture and you are happy with the performances then I suggest you leave the things as they are and just enjoy.
All I can tell you is that for me castor is a sure value for the model engines, the other synthetic oils is more harder to say if they are O.K. or not.
posted
Thanks for the info! It seems that it's really up to the several ingredients used to fit best together. Best to see this at the following genial fuel producers:
posted
Rody mate there is still alot of confusion with oil content.My LHS reckons hes been in rc for 20 years,we come up with a safe mix of 20%nitro 7%castor and 5%synthetic,havent tried it yet cause the guys says that running this mix will cause the engine to run lean and is only recommended for pro's??
Thanks Mate
Mark
p.s sorry to be a pain rody but there is so many opinions, but u built the engines so i stick with what u say
-------------------- Lst2 Rb928,werks clutch,carbon kit,new era,rd logics,dual hitec 645mg,40 series cheyenne wheels. Posts: 27 | From: Australia | Registered: Dec 2006
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posted
If the engine is running too lean then the main-needle is too much closed... and need to be opened, this has nothing to do with the oil content.
Of course if you use more oil then this is indeed safer and you can run the engine leaner, however due to the more oil content the performances will be a little lower.
Anyway, I am making this example only if you want to reach maximum performances during high competition events. I think in your case this is not what you are looking for.
So if your LHS has very good experiences with his mixture then you should be able to believe him. The mixture 7/5 seems indeed a safe mixture to me.
posted
rody mate quick question ive been running 20% nitro 7%castor an 5synthetic from tha so called experienced local hobby shop,What ive noticed though is that there is a lot of carbon build up.When i pull the glow plug out the top of the piston is black,is this normal?cause its got me worried,its not getting to hot.When tha fuel is in the tank its blue but when it gets low it turns green then eventually goes like a clear yellow,ive contacted the guy that makes it and he says thats perfectly normal cause when the uv light hits it it changes the pigment or something? im not happy at all cause i havent got it to run right since i bought it.If u could shed any light on the subject it would be greatly appreciated
Thanks mate
Mark
-------------------- Lst2 Rb928,werks clutch,carbon kit,new era,rd logics,dual hitec 645mg,40 series cheyenne wheels. Posts: 27 | From: Australia | Registered: Dec 2006
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posted
The carbon built-up is normal, do not worry about this, and yes it can happen that sometimes the color of the fuel changes after some time in the tank or due to UV.
If however you have not been able to run the engine correctly, I suggest you ask your LHS from whom you have purchased the fuel to give you some assistance in setting the engine for you.
posted
thanks rody also mate yesterday when it was running rich it back fired and blew the ehaust gasket apart ive never seen that happen before,what causes this?ive had a few rc car engines now it jus seems the best 1 is givin me the most problems
[ 24. January 2007, 22:47: Message edited by: lst2mark ]
-------------------- Lst2 Rb928,werks clutch,carbon kit,new era,rd logics,dual hitec 645mg,40 series cheyenne wheels. Posts: 27 | From: Australia | Registered: Dec 2006
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posted
rody i need help mate.this engine is driving me insane i am not a novice i can tune a nitro engine but this thing has got issues,I have the hsn dialled with good power an smoke but when i tryin tune the lsn it doesnt matter how far i lean it if i sit it an let it idle for even 5 seconds then accellerate hard it bogs real bad and starts back firing ive changed plugs,fuel,fuel line u name it ive tried it?i will contact my lhs were i puchased it but i know as much about tuning these things as they do.any ideas mate cause im startin to loose faith.
-------------------- Lst2 Rb928,werks clutch,carbon kit,new era,rd logics,dual hitec 645mg,40 series cheyenne wheels. Posts: 27 | From: Australia | Registered: Dec 2006
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posted
LST2Mark...I went through the same thing...runs good wide open...then after letting it idle for a couple of seconds to check the temps...it would stall about 30feet away from me when I took off....it drove me crazy too...had me screaming obscenities in my front yard...etc...etc....
but believe it or not....you're too rich on the LSN...lean that sucker up...and lower your idle...you may need to richen the HSN afterwards...but probably not if you're getting smoke at full throttle...
I've tuned on alot of engines...and thought I knew what I was doing....but after learning to tune this RB...I realize that I never REALLY knew how to tune...and my tunes were just "in the ballpark" tunes....trust me...there is probably nothing wrong with your engine...just be patient with it, and I'm sure you'll find that "on switch"
also...if you haven't yet...look into getting the RB2045 pipe...it's a remarkable pipe...that has good torque...yet doesn't hurt the top end....it'll help you with learning to tune it..once you see what it wants...then you can move on to other pipes...
just for the heck of it...here's a video of me goofing off...my main LST2 race truck was undergoing some maintenance...so I stuck the RB in my LST1 race truck just for grins...I even installed a RDLogics dual stinger pipe...which usually makes engines run hot...but I managed to get a "in the ballpark" tune on it...hitting around 260F at the end of the tank....the power from this engine is insane...as I couldn't egt traction on the grass...
it took me awhile to learn to tune my 928...and I was scared to touch the needles after I found the tune it needed....but in reality...once you learn it...there ain't nothing to it...and unless you change something(plug...pipe)you won't really need to touch the needles after getting your tune...
Posts: 67 | From: Covington, La. | Registered: May 2006
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posted
thanks dawgbone it jus frustrates me mate.Ive tuned quite a few engines now but never had this much of a problem,the rb is so sensitive to needle adjustment,my mates got it at his house cause im over it at the moment.He tried tuning it yesterday with a 6 plug in it,an couldnt get a half decent tune but put a 7 in it and seems to be a bit better but still bogs bad down low after idle.we have leaned up the low speed needle heaps but still does it.jus outta curiosity whats your needle settings at?what plug do u run?
Thanks 4 your reply
Mark
-------------------- Lst2 Rb928,werks clutch,carbon kit,new era,rd logics,dual hitec 645mg,40 series cheyenne wheels. Posts: 27 | From: Australia | Registered: Dec 2006
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posted
I run 20% with a #7 plug and the RB 2045 pipe...
I don't know what my needle settings are off hand...I can get those for you tomorrow...like you mentioned...the needles are sensitive to adjustment...so I never get too lost in my tune...and never really paid attention to how many turns out...
but these pics may help...when I took these pics, I only had about 4 gallons on the engine...I noticed dirt sitting in the carb...so I broke the engine down to clean her up...as well as some mild porting...but this is very close to what I'm still running(close to 10 gallons)
posted
yeah...mine can idle for a good bit of time...as with nearly every engine...you have to be easy when getting back on the throttle after idling for some time...
but that you're saying it's loading up would mean that you're still rich on the LSN...remember...that you are still tuning for fuel/air mixture even at idle...so if you lean out the LSN...then close the idle to balance the mixture... i.e when you let off from a high speed run..the engine should not race...but instead go right back to a smooth low idle..
it sounds like you're getting close...just might need to lean up the LSN some more...the HSN adjustments are super easy on these engines...it's the LSN/Idle adjustments that are somewhat of a balancing act...
posted
well its at a point now where it will idle 4 up to 10 seconds and still take off clean its running a 6 plug on 25%nitro and is getting better with every tank.Temps around the 205 210 mark. Thanks heaps 4 all your help Dawgbone much aprreciated mate.
Cheers Mark
-------------------- Lst2 Rb928,werks clutch,carbon kit,new era,rd logics,dual hitec 645mg,40 series cheyenne wheels. Posts: 27 | From: Australia | Registered: Dec 2006
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posted
yeah well thought i had this engine sorted.I thought wrong spent 3 hours yesterday trying to get a good tune.when i can get it to warm up from back firing and spluttering i can get a pretty good tune,but once that fuel runs out and it cools down im back 2 square 1,i cant understand it any1 had this problem cause ive tried just about everything.contacted my lhs an they put me on to the australian distributer(who is off racing for a week),and sounds like im goin to have problems with,ive only heard good things about RB's im startin to think i got a lemon
-------------------- Lst2 Rb928,werks clutch,carbon kit,new era,rd logics,dual hitec 645mg,40 series cheyenne wheels. Posts: 27 | From: Australia | Registered: Dec 2006
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posted
hmmm...I was going to mention that 205-210F is very cold....but you sounded like you were on track with the tune...so I didn't say anything....at the end of my tanks...my 928 runs easily in the 260 range...I have found that the engine doesn't seem to mind hot temps...but you should tune with a half tank and run it till empty(don't tune on a full tank)....
I also wanted to point out that you should blast as much fuel through it as you can...as it takes a good gallon until the engine breaks free and comes into it's own...funny thing is....it seems to get even stronger after a gallon+....
if there is any way to get some video of it running or acting up...please post it...not that I'm an expert tuner...but it is a learning curve...and we can see what you're up against...
I actually think it could also be the LST header that makes it so hard to tune....as of right now...I have mine in my Muggy...and it seems alot easier to tune....RB Products(Rody) may be able to say if it's true or not....but I will say that I have managed to get a really good results with the engine in a LST...so much...that I have another untouched in an unopened box....
Posts: 67 | From: Covington, La. | Registered: May 2006
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posted
sorry it took so long to write back mate ive had ia bit of time off work,the engine has gone back to the australian distributer and im now waiting for there reply,il keep ya posted on there verdict. cheers Mark
-------------------- Lst2 Rb928,werks clutch,carbon kit,new era,rd logics,dual hitec 645mg,40 series cheyenne wheels. Posts: 27 | From: Australia | Registered: Dec 2006
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posted
I have never used the LST so cannot tell you what our engines or doing with the original header, however I have heard lots of good things about our engines in and LST so I think it should be working O.K., all depends of course what you are looking for.
posted
I think the stock pipe is high torque but it shouldnt effect the tune that much. Surely my mates got a nova528 and our cars are identical hopup wise,it had know problems with header/pipe.I tuned it from run in so?il see what the rb guy comes back with and will post the result.
-------------------- Lst2 Rb928,werks clutch,carbon kit,new era,rd logics,dual hitec 645mg,40 series cheyenne wheels. Posts: 27 | From: Australia | Registered: Dec 2006
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posted
I was pointing out the header....I wouldn't try to run the RB or Nova with the stock LST2 pipe...but because of the lack of aftermarket and the LST's design...the only headers/manifolds that can be used is the stock LST or RDLogics(which are identical)...you could also use an Aftershock header matched to a two piece pipe..
I would advise either the RB2045(good all-arounder with fuel efficiency) or a good quality 086 in which is brutal...I prefer the 2045 as it gives the engine a smoother torque curve...as well as fuel efficiency...
the Nova528 and RB928 are really completely different engines...the heatsink and bearings are about the only engine parts that are identical...everything else is pretty much different...
Posts: 67 | From: Covington, La. | Registered: May 2006
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posted
well dawgbone i think u were right mate.got the engine back from the rb guys they had tuned it but i still wasnt happy with it. It had funny characteristics revving up an stuff,put the 928 in my schumacher havoc and it came to life?idled perfect unbelievable power,borderline overkill and perfect temperatures i cant fault it,its like a totally different engine and so easy to tune its not funny.The standard lst2 pipe must choke it? Anyway thanks heaps dawgbone for all ya help mate greatly appreciated,i think i will order a 2045 pipe.
Rody thanks for your help 2 mate an sorry for being a pain in the a** its jus so frustrating...
-------------------- Lst2 Rb928,werks clutch,carbon kit,new era,rd logics,dual hitec 645mg,40 series cheyenne wheels. Posts: 27 | From: Australia | Registered: Dec 2006
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if the LST header is in fact the cause of the tuning problems with the 928, then maybe it's something that RBProducts can look into...maybe even manufacture a specific header for the 928/LST...as the LSt2 has come to be a very worthy truck...
just for S&G's...here's some of my recent testing vids..
this is my latest 928 in a LST2 with a Novarossi 086 pipe...I was being easy on it and not holding maxx revs for too long as I was at the end of breakin...the OWB slipped on me a bit.. http://flemdawg.com/Movies2/RBTM928.wmv
this is my oldest 928 with 2045 in my latest RC the Losi 8T...it requires a bumpstart engine...but I shimmed the engine up about 3mm to make room for the rotostart..Losi is releasing a specific starter box for the truck and I'll install the original backplate...the tune isn't quite there, and I was trying to adjust my brake epa while driving and I let it stall at the end... http://flemdawg.com/Movies2/8TTesting.wmv
posted
hey dawgbone quick question mate u reckon the 2045 pipe is the go for the lst2?and also what clutch setup do u run? I had a werks racing clutch in mine but the inside of the clutch bell chewed the front plate of the clutch out and forced the spring through the clutch plate,which caused total failure
-------------------- Lst2 Rb928,werks clutch,carbon kit,new era,rd logics,dual hitec 645mg,40 series cheyenne wheels. Posts: 27 | From: Australia | Registered: Dec 2006
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posted
I gave up on the Werks setup....it's far more complicated than need-be...plus with the RB...I couldn't get it to stop slipping...I tried red/black shoe combinations...along with different adjustmens...but it always seemed to slip on me...but the reason why your clutch failed...is because the LST has an oversized clutchbell..causing the Werks clutch to extend too far...there are people that are making CB with added material in the middle to decrease the CB's ID...head over to www.lstforums.com for all the info about LST's....
I personlly have found that the stock alloy shoe and springs are the best...with maintenance..you can get them to last well over a gallon...but I change mine just over a gallon just to be safe...
as for the pipe...it's really good on fuel consumption...it may kill a little eof the top end...but not much....it really is a great pipe across the board...the 086 is also a great pipe...OFNA's version is a bit stronger than anything else I've tried...but it's a good pipe as well...although I think it might deliver a little better top end...but I also think it may burn a little more fuel....to be completely honest...I can barely tell the differene between the two...but there are different factors between my two 928's....the old one...I have no carb restritors...and I have done mild port work..(I'm no engine modder...but like to tinker)
the newest one with the 086 is bone stock wth the restrictor that came with the engine...
so really...it's hard for me to give an accurate comparison....I still believe that the 2045 has a smoother power delivery and good bottom end for the LST....and the 086 is a little more radical...and less fuel economy...
posted
going to order a 2045 asap but i have to order from over there cause no1 stocks it here,so it will cost like a $150aus il let ya know how it goes,thanks again for ya help mate.hey dawgbone check this out mate.cousin playin around makin a vid of us,mines the black lst2 and the blue little havoc.right click an save as.
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