Z00M

iTrader: (15)

I use the legal Skyline pipe(5.2mm tip) on my Mongoose-G4 and it seems to be an excellent match for the TZ. Once tuned right, my TZ has massive bottom end and doesn't run out of revs on our 60 metre main straight.

nitrodude

iTrader: (8)

You want to mark where your flywheel is at BDC(Bottom Dead Center). If you leave your piston at TDC(top Dead Center) and let the engine cool there, it will expand the sleeve just a little, and rob your engine of life.

You want to mark BDC, amd make sure to turn the flywheel to it when you're done running the engine.

HarKonnenD

iTrader: (23)

NO I mean mark it so you KNOW when it is at TDC or near there so you turn the flywheel to get it BDC. Ofcourse leaving it at TDC isn't any good.

BigDogRacing

iTrader: (12)

Well if you had read back in this thread you would've found that Ron Atomic TQ'd the RD Logics race with an FW05RR, 12tz and a Skyline pipe- whichever one is ROAR legal. I'm not that familiar with them...

Also, if you had read just ONE page back you would've found a complete guide to primary break in.

msgsr- if you're going to rich idle it for one tank you may as well do the whole 3 tanks stuff. The whole point of not doing the so-rich-it-washes-down-the-cylinder-walls at idle method is because it causes an improper sleve to piston matching. I explained the long drawn out version in some other break in thread, but basically to make it short, as the RPM's increase, the conrod stretches and other things make the piston go higher in the bore. If you break in the motor at idle the piston never reaches full stretch and you're wear pattern on the sleve only goes so high. Then when you begin to run the motor at higher RPM's the piston starts to go higher in the bore past the first wear pattern and simply causes more wear than it would have if you had simply heat cycled the motor at 80% max HP (meaning it's running just rich enough to reach 80% max RPM).

Here's something else for you to consider- in the past racers are used to hearing the old addage about breaking in race motors at 2000 RPM blah, blah, blah. Well, race motors have valves and a rotating camshaft which can basically eat itself with full spring pressure. Also, we don't even break race motors in anymore because the solid and hydraulic roller lifters won't eat the cam. Plus the cams are mosly billet in a race motor anyway. The tolerances are now far better because of technology and every machinist I know of uses torque plates to final bore and hone the cylinders which means the cylinders are as close to perfect as humanly possible, so all that is needed is... basic heat cycling to create a good seal while making sure the lubricating system is working properly and everything is aligned correctly in the motor. Our 2 cycle race motors have 3 moving parts not counting the carb slide- we know if everything is working right before it's ever put in the car or started, so all that is needed is a few heat cycles, check it for cleanliness and begin final tuning.

And for those who say they break rods in less than 2 gallons, give me a break. You are obvioulsy doing something wrong. For one, and the most common mistake I see is unloaded free-revving. You don't honestly think these motors are supposed to be run wide open with no load for more than a second or two do you? I mean, the red line on your Mitsubishi Galant is like 6000 RPM so why would you think it's OK to free-rev your r/c race motor at 45,000 RPM?

wyl03

iTrader: (44)

how many minutes from you get from each tank of fuel?
(I'm assuming that you are using the 75cc tank?)

Z00M

iTrader: (15)

Yes, we do use 75cc tanks.

Haven't tried how many minutes from a tank, but after 5 min heats, there is somewhere between 20 - 25 cc's left in the tank.

caggers

OS engines generally run quite hot, whats the temp range of the TZ once warmed up. I say this because my TR runs very hot even while rich.

jt6

iTrader: (3)

I have not had this problem with the 2 TRs I have. I do have one that runs a little warmer than the other when tuned right but not too hot. One runs around the 215 range and the other likes to run around 245 or so.

Z00M

iTrader: (15)

It took me a little while to understand how to tune the TZ, but once I got on top of it, it doesn't run hot at all. Usually somewhere around the 200 - 220F range.

Darth Vader

Hi Zoom,

Care to share your needle settings?

Z00M

iTrader: (15)

I don't really have the turns in or out but I can share how I have tuned it if you like.

The mixture(midrange if you want to call it that) has been left alone.

The low end needle is set almost flush with the ball cup holder for the throttle slider. The low end is what I struggled with the most. I had it set rich thinking I was looking after the motor, but when I set it really rich, the motor would flame out after our long straight and would not idle well. The reason for this seems to be that it was loading up so much with fuel off throttle that when I went to get back on the throttle it flamed out from too much fuel. I also noticed that after a run if it didn't flame out, it would be idling higher than when it went out. This was because the temp took so long to come up that it would then idle higher once warmed up.

So the low end is now set so that it will idle for at least 20 seconds on the box and then pull with just the slightest hesitation about being rich. If it hesitates too much then it is too rich and will seem like it's playing up. Also make sure the motor returns to a constant idle and doesn't idle up or down while waiting the 20 seconds.

The top end needle I then worked with the get the temps at about 200 after the 3 min warmup and no more than 220 after the 5 min race. The motor is still blowing good smoke all the way down the straight (60 metres). I think after a bit more running, I will go leaner on the top end to see just how much power this thing really makes.

I know it would be easier if I just said this many turns out or in, but at the end of the day, all conditions are different so the tuning will be different.

I am running a Novarossi gold #6 hot plug and this is working well along with the Skyline Racing Developments pipe.

Cheers,

Mike.

Darth Vader

Thanks Mike,

Very informative. Actaully it's better than you telling me how many turns in and out because that would vary with the pipe, clutch, car, etc.

I'll try your method once I complete the running in.

Cheers...

ntc3freak

fooh.u bought it already vader???tell me how it performs ok.also thinking to buy this engine to go with the 710 .what pipe u use???tell me how it performs thanks

Darth Vader

just got it early this week.

Plan to run it in after work today, but looking at the sky now, seems unlikely. Well hope it rains in the morning and dries up by 6.

Wanna see it run, come to Tomato's this Sunday...

ntc3freak

ok.i might come but will not be long lah.i have an exam going on u knoe