im sure there are a lot of these, but i have an hpi hellfire ss and im trying to decide between the os 28 truggy engine, or the os 21 v-spec. i currently have the k4.6ho and it about needs replacement. please tell me which of those engines you think i should get and why.

Well to start you'll have to wait tell the middle of sept. and thats a hopeful on the 28 ZX....and I seen some SS's run the V-spec and it pull that trug good and the fuel run time is great....your fuel run is going to be way longer then any 28 will be...I run a 28 in my 8-T but I have a good pit man...[8D]

well, if you had a hellfire, which would you chose: os 21 or os 28?

Are you going to race or bash or do you want to just whoop up on your friends???...."L"...[8D]

well, ill be mostly racing, however i will be doing some driving around home.

I would say if you don't mind pitting more and you get a good pitman go 28....if you want the fuel time go 21.....I would go LRP Z28R.spec3 Truggy...it will make your SS run like a rocket.....and fast is always a good thing....[8D]

yea the only thing is on regular weekends, the b main (which im usually in) is 15 min. if i had a 21 i would only need to pit once.

I have heard good things about the Go-Tech .28, my LHS has started stocking them and they are raving about them...it will probably be my next engine, especially now that Im working there on a casual basis...[:-]

I was wondering if maybe I could get a little help. New to Nitro and breaking in my engine. I fired it up and the idle was crazy fast. Clutch was engaged and the truck was moving forward. I adjusted the needles 4 1/2 high, 3 1/2 low but the idle stop screw in the manual said "1 mm" from the body. From the factory it was at about 1/4 inch. I screwed it TIGHT and it came about 1/8th from the body. Still the same idle speed. Is it busted or what? Any advice is appreciated.

Are you talking about the idle screw itself or are you looking down the barrel of the carb and adjusting it (which is how it should be done)?

Dont necessarily worry about the factory needle settings and trying to get them there, they are very general. If you can get it to fire your in good shape. Get it to start and warm up a little, make sure the throttle trim on your radio is zeroed out before starting it. Once you get it warmed up, then try lowering the idle screw and see where the idle goes from there. If you cant get it to lower than you'll need to richen the low speed needle some. When you get it running, you really dont want the engine racing and clearing out, you want to see oil coming from the exhaust pipe and sluggish performance, but you also want to see temps in the 200 degree range.

Your low speed needle directly effects the engines idle, if you richen it, it will get lower (and load up eventually), if you lean it, the idle will get higher and take longer before it loads up and stalls.


As far as the topic, think about how much you want to spend and then consider your options. Theres a lot of good engines out there right now in the price range of the Vspec .21 and .28. I just bought a ninja .28 myself and hope to break it in tomorrow, but I have heard from a few people that own them and 10 minute+ runtimes are possible with this engine.

Where do you race in CT? I usually run at wolcott or madness, at wolcott a .28 can be utilized for sure with all the bigger jumps and stuff, madness is a little tight but a lot of guys still run .28's there.

Yea Brian, def start you own thread and try not to "HIJACK" someone elses (which you have just done) [X(]
As for you problem, it sounds like you have scewed the idle screw itself all the way in...which will make you idle higher as you have to unscrew the idle screw so the carb closes until it stops at about 1mm open (looking from the top into the carb opening, without air filter on).
So in the beginning you want to have your LSN flush, and dont touch it until your about 10 tanks and finished the breakin, and then it will need only a slight lean (probably) if anything.
Your new to Nitro so I would just do the brakin like the book say, dont get too hung up on keeping the temp up to 200...later on with other engines you can maybe try the Heat Cycle method, but the manual method will do fine, I have run in my first two engines like this and they have lasted well, infact my K4.6 is still going strong (touch wood [X(])

I would...idle the first tank, with the wheels up on blocks (cause they will spin as the idle may have to be higher to keep it running, you can easily adjust this on your trim tab instead of mucking with the idle yet), then after that do a couple of tanks on the ground, concrete is best because it is smooth, you truck should be running really rich and should run like a pig, bog down etc and dont worry about full throttle, about half max.
After each subsequent tank lean it out slightly on the HSN (clockwise) about 1 hour each time (mentally divide your HSN into 12 hours like a clock! example: a 1/4 turn would be 3 hrs) after the next couple of tanks dont be afraid to give the truck full noise, but keep it to short bursts, after 10 tanks you should be nearly there, but COMPLETE breakin will take longer than this so continue to take it a little bit easy and you will continue to get more power out of the engine.

you race at rc madness? i might know you. the only thing about the os 28 is it might be too much power to handle. what do you think?

hello?

You won't have to wait that long on the .28ZX. My local hobby shop has them in stock so they must be available now. It is awful tempting but I can't justify spending 300 to 350 bucks right now.