Broke in and raced the engine today. Had some problems, but the engine was very fast and had no run time issues.
It was a hot day. By noon, track temp was 125F. By 1:00pm, it was 135F . Used the turbo 6 plug that came with the engine and Mugen Seiki 20% fuel. V-ONE RRR clutch setting was .8mm. Lightweight flywheel, clutchbell and steel gears. Kit defaults for pinon and spur gear.
Factory settings were used when starting the engine. It would not draw fuel from the tank without holding the stinger (Thanks Justin). Once fuel was drawn, it would start but not hold an idle. I gave it some throttle and it idled just fine - so I figured I would open up the high-end up to 1/2 turn (didn't work, put it back) and then the low-end up to 1/2 turn (also didn't work, put it back). Finally, my buddy (Thanks JD) suggested that I turn-in the idle screw (slide valve stop screw). I ended up turning it in two full turns before the engine would idle.
So now that I got the engine started, I took it for a nice leisurely drive around the track. Nothing too fast. After 3-4 laps I brought it in and guess what? First read was 320, a few seconds later 300. Oh oh. Now what? I let the engine cool to 107F before starting it up again. Opened the high-end 1/4 turn and took it out again. JD would check the temp and open the high-end. This happened a few times. Engine finally settled down to about 260. Still had some low-end issues, so opened that as well. The engine bogging was the weirdest thing ever. The engine would really slow down, but not actually die. You would hear a deep "Waugh! Waugh! Waugh!" sound when I pulled the throttle. Flywheel would not engage (i.e not reving very high). I had to pump the throttle to clear the engine. This became a problem any time I was off throttle for too long. Even holding the throttle at WTO would not clear the engine. I had to pump it. After the two tanks and all the troubleshooting, it was qualifying time. Unlike last time we raced, we didn't have as much open practice.
When I was on throttle, engine was good. Lots of power. V12 Plus pipe worked great. If I got off throttle and tried to accelerate, there would a delay before the throttle would kick in. This happened for both the two qualifiers and all three mains. Luckily, the engine didn't actually die on on any of the starts, but I did have to keep blipping the throttle to make sure the engine would not go into bog mode. Engine behaved at about 260F. Just before the third main, I leaned out the top end and the engine finished at about 220F. Engine would flame out if the car landed on it's back, even if I blipped the throttle. In case you haven't drawn the conclusion yourself, engine was running way too rich. What a mess! If you know what I mean.
After racing was done, I checked the settings. 6.5 turns on the high-speed, 5 on the low-speed. Two turn-ins on the idle screw. Went back to 5.5 on the high-end, 4 on the low-end and the engine was almost running right. Opened the idle 2 turns and the engine seemed to be running a lot better. No more bogging. Couldn't actually run on the track, because they started to take it down. But these results were much more encouraging.
This is clearly an example of how
not to do things and any advice (especially from from Nano, Josh or mxwrench) would be very benifical to all, I'm sure. If at all possible, you should not break-in and race the engine on the same day. I didn't have much choice.
- Turbo 7 plug would have been good to try. I'm sorry, but I'm only going to use the CRF plugs.
- Running different % nitro would have been good. I've only been running 20%.
- Make sure you have a very small, long screwdriver if you've got a RRR. It's hard to adust the low-speed because the fuel tank is in the way. The head is small, which also makes things difficult.
- I ended up overstretching both of my Skyline V12 Plus tuned pipe springs, so make sure you get some longer ones. Unfortunately, I only had tighter ones on hand (RD Logics) and those are much more resilient than the Skyline springs.
Although I had some problems today, I'm really looking forward to the next opportunity to run and tune the engine. I like it much better than the OS TZ.
I'm really tired. Worked on the car till 3:30am and then got up about 6:20am. I'm ready to hit the shower and catch some Zzzzzz's. As indicated above, let's help the next guy do a better job at breaking in and adjusting the engine.
Josh - I was hoping that I could just lean out the engine like you indicated, instead of opening it up. I knew I was in trouble, when I had to turn things in the other direction way more than you had said, but, ah, well, ah, um...
