break in question
 

Do new engines run hotter than normal until they are fully broken in? I havea Sportwerks .26 that is about halfway broken in. I'm at the point where I am running it full throttle, but still very rich. I see lots of smoke come out when I open up the throttle, but the temperatures seem higher than they should be. I don't have a temp gun, but a drop of water boiled off pretty quickly after some full throttle runs. It seems like the friction of an unworn engine would cause higher than normal temps, and this is why people run easy and very rich. Does this make sense?

RE: break in question
 

You want the temps to get way up there! After a certain amount of time let the engine completely cool off. Do this for about the first 35 minutes. It is commonly called heat-cycling.

I wouldn't run the engine at such a rich setting and on my first break in tank I was already giving plenty of WOT.

Ryan

RE: break in question
 

Let me tell you this about Sportwerks .26 engines: the settings from the factory seemed pretty lean to me (at 3 out for hi and 2.5 out for the low) for a break in from scratch. But I like only running a touch rich during break-in to spare the con rod, and I read about this from O.S., too, so it seemed ok to me: Only slightly rich...modest and light running from the jump.

I saw alot of good smoke, too, but after getting thru some trouble shooting, changing the plug etc and getting some real run minutes, I discovered the low speed needle seemed to be lean after I kept the engine running and could hear it would not settle down off throttle. Check it out: if you turn the low speed screw, it sort of wants to return to its original position, so that if you start out from the bottom and turn it out 2.5...it slowly springs closed....as much as a 1/4 turn. This was more than enough to go from 'ok' to lean (dang!).

Here I am, fresh on tank 1.5 of break in getting my first real continuous minutes in, when I backed off the throttle, the engine revs were way to high. I did a pinch of the fuel line and the motor shut down in a milisecond.!!! And I used factory settings on the low end!

It was way too lean on the low end: The engine should have rev-ed up a little, then died; that would meant the low speed was set 'ok'. I checked the temps: 296 (spit on the head to double-check and instant sizzle/boil)!!!!!!!!!!!! And yet the high speed was fine. But the low speed had closed 1/5 to 1/4 of a turn! I had to do a double look. But it really was about 2 1/4 from bottom, causing lean running.

So, I used a smaller screw driver (for better feel) and turned it down to the bottom carefully and then back out 2.5. With the smaller screw driver, and better light, I could see/feel the screw wanted to close a bit. It was sort of springy I went all the way back to about 2 3/4 out from bottom on the low and it closed itself a little bit and settled right around 2.5.

For safe measure, I backed the hi speed out about 1/8.

I fired the engine up and got thru 5 solid tanks of break in at 190-230 degrees. Most checks were right around 220. My pinch test saw the engine rev a little and die. Perfect.

I'm glad you checked in. I was very pissed to see more than one high temp reading during break in. It was hard to tell intially that it was the low speed for me, because during break in, the idle is often high and it masks low speed lean issues. Further, most facotry settings are plenty rich, so one never expects to be lean on factory settings during break in.

That being said, my 2-5 tanks were smooth as silk, with it about 80% in tune (leaving high a little rich for now). The low speed is good and the idle doesn't engage the clutch. I can tweak the high speed any time I like and she'll rip now.

RE: break in question
 

Thanks for the feedback. I'm pretty sure my low speed is ok because when I do a pinch test, the engine revs higher and then finally drops and dies. It takes about 5 seconds for it to die. Maybe I am running the top end too lean, but I guess I was expecting the car to run faster if tuned right. Also, the glow plug still looks shiny which normally means you are running rich right? And then there is the fact that I see plenty of smoke at WOT.

RE: break in question
 

Did you take out the carb restrictor? You should, if you feel performance isn't good enough. Other than that...

What other cars do you have or did you own? My Mayhem seems very fast to me, and I had a Savage, a Losi LST (hated it) and my Inferno GT is a rocket -- still, the Mayhem keeps my need for speed satisfied.

On some other boards, others noted high temps during break in on this engine and the Mach .26 (which is its clone I believe).

Mayhem is as fast as Ofna CRT and most RTR buggies. Faster than the Hellfire, as fast as a Maxx...Losi....faster than Savage....

RE: break in question
 

I replaced the medium sized carb restrictor with the larger one, but I guess taking it out entirely is an option. I'll wait until break in is finished. My car is a no-name brand that my brother bought for me off the internet. It is made by Sinyih, and had a .21 Sinyih engine before I replaced it with the Sportwerks .26. It's am 1:8 scale rally car meant for on road or light off road (mostly dirt tracks). It has 4WD, but also has a two speed transmission. The only thing I have to compare it to was the old Sinyih engine which I'm assuming was a piece of crap, but maybe not. I'm also just comparing what the top speed looks like, I don't have a radar gun or anything, so the Sportwerks engine may indeed be faster. I only use it for messing around in big parking lots, not racing.

Another possibility is that the 2-speed transmission is not switching gears. Sometimes I think I can hear the engine revs change, but I'm not totally sure. Is there a good way to check this? Maybe rev slowly instead of flooring it right off the line?

Thanks again for your help.

RE: break in question
 

Well, for starters, dropping in a stronger engine doesn't equate to a different top speed.

Let's assume the SW .26 is a big power upgrade over what you had, and produces a similar redline to the old motor (with 7-ports, it probably matches or betters the old red line):

>Acceleration should be noticably improved.

>Top speed, which is a product of the ability of the engine to hit redline and of the gear ratios, probably would look and feel identical.

To harness the new power (the SW .26 HAS to be a good upgrade) you need to consider two things right off the bat:

1. You probably need different gearing. Bigger pinion (cluthc bell) gears...or smaller spur gears...or some combo of both. Imagine pedalling a multispeed bike in first gear. Would getting The Hulk to do it make it any faster? No, the gear would waste all the power, especially a very short gear.

2. The SW .26 might blow through first gear so fast (in two feet!) that it spends it's time pulling through second, making it seem sluggish. Find out if you can adjust the tranny to shift later (often accomplished by tightening a specific grub screw internal to the tranny. Check the manual for the right one, if it exists).

Check out current set up: Start out with very very light throttle and then see if you can notice it shift when you build revs. Sometimes when the gears are very close in ratio, it is very difficult to hear any appreciable/audible drop in engine RPM (the 'shift' sound is the engine dropping RPM as the next gear engages).

RE: break in question
 

I understand what you are saying now about the top speed being identical because the redlines are probably pretty close. Acceleration and low end torque are vastly improved with this engine, and like you said, it makes sense that top speed would be about the same. Looks like I will need a new clutch bell. I have been considering this anyways because the low end torque is insane now.

RE: break in question
 

What are your engine settings for a Sportwerks engine that is fully broken in and tuned?

RE: break in question
 

WHAT AIR CLEANER ARE YOU GUYS USING? I WAS USING AN OFNA ASSEMBLY AND I KEPT GETTING SMALL AMOUNTS OF DIRT IN THE CARB!

RE: break in question
 

High speed: between 2 3/4 and 3 out from bottom

Low speed: between 2 1/4 and 2 1/2 out from bottom