what is *your* break-in procedure? Im not intrested in manufacterers recomendations, I want to know if there are any "trade secrets" some of you could share. car guys say if you monitor crankcase presure you can tell when the rings/bores are fully broke-in. I havent tried it but it sounds logical, not sure exactly how either but it can that difficult. I understand that pulling a vacum in the crankcase is good for some extra HP, can you do this on a bike? I know it helps prevent minor oil leaks too but instead of a leaking oil out it pulls air in causing the oil to foam which cant be good. would type of cooling make any difference in break-in procedure? (air vs liquid cooling) or ring/bore compositions? should I alter ignition timing specifiacally for break-in? Im mainly intrested what works for air-cooled bikes (specifically thumpers) but I would like to learn how/if cooling system or number of cylinders would make any difference. also, would it be better to wait until the engine is broke-in to put a new clutch in or would that matter at all? any tips on what the best "first ride" would be? certain rpms, on/off throttle reps, from what I gather so far I should use the non-synth lt wt oil, start and ride imediately, accelerate/deccelerate a few times with low revs then let it rip! while still deccelerating often so the engine can breath (lubricate the rings) its been suggested that I should even redline it a few times. after the ride,drain the oil and change the filter and thats it. less than 10 miles should do it. does this sound about right? thx /////
I think it was Muzzy that said he just does a couple runs on the dyno to break in his motors. He will rebuild his engines a few extra than most. What the hell, (oops sorry Tex...I meant heck) give it shot and let us know the outcome. David
Raceworx broke my R6 in on the dyno. I don't know how many heat cycles. I took it easy for a 6 lap practice session and let her rip. I haven't ridden it in 5 months since. I just did some engine work on the SV and we are going to the dyno on Sat. My bud says you need to put a load on the engine to seat the rings. I'm running the recommended oil and after the 1st race weekend I'll change it and the filter. I'll run the recommended oil for 2 more oil changes and then switch to synthetic. Both bikes are on dinosaur liquids for the time being.
Not a "pro" by any stretch of the imagination but: I've broken in all my engines with heat / loading cycles with good success. One SV has a full season on it and shows less that 4% leak down. Start the engine and let it completely heat up at idle and then let it cool down completely. Run the engine at 1/3 max rpms with light loading but being carefull to not "chug" the motor. Run it like this for 20 min. And then let it cool completely. Goto 2/3 rpm's with moderate to light loading (keep it in the lower gears)... 20 min then let it cool completely. I usually change the oil / filter at this point to get the ring and cylinder wall dust out of the engine. Now keep it around 2/3's with heavily loadings and a few runs up to the higest RPMs for another 20 min. Last is normal "spirited" riding for 20 and another cool down. This was orginally published in Motorcycle I think but I can't find the link.
My .2 cents, i've been taught to break em in how your going to ride them. I usually let them sit and idle for like 45 mins. enough time to seat the rings, ie no smoke from the exhaust, I immediately drain the oil, and refill with fresh oil, letting it run until the oil is hot and Lettter RIp! I'f it's not right on assembly it wont be right after you let it heat up and cool down for upteen times! HAvent had on grenade Yet!
dyno it out of the box. get it up to temp and do a few 50% runs leting it decell on its own no brake let it cool then 70% then 85-90% then drop the hammer. todays engines are so well machained the break in is just for the rings that only "seat in" under load and decell baby it to long and your rings will never get a good gas seal. I have heard this from several higher than me type the factory test runs every motor before it is installed at the rev limiter briefly to start the rings to seat.
I got my sv in the crate 2 weeks before race practice day last season and did pretty much what Huey said. Practice got rained out so I broke it in at a track day the next morning as first race was the following weekend. My understanding is it also helps to vary the revs, avoid holding it at constant throttle openings. But I am no expert. I did the partial throttle and heat cycling but by midafternoon I was getting tired of being passed so I started pushing it. In August it was dynoed at 68hp. The class limit here is 70. So far it seems just fine. Maybe breaking it in on the street (much the same way) taking a little more time.. would make a motor last a bit more?
RUN IT HARD!!! This is break in advice from Pat McGiven...@ http://www.mototune.com What's the Best Way to Break in a New Engine ?? The Short Answer: Run it Hard ! Why ?? The piston ring seal is really what the break in process is all about. Contrary to popular belief, piston rings don't seal the combustion pressure by spring tension. Ring tension is necessary only to "scrape" the oil to prevent it from entering the combustion chamber. If you think about it, the ring exerts maybe 5-10 lbs of spring tension against the cylinder wall.... How can that small amount of spring tension seal against thousands of pounds of combustion pressure on the way down ?? Of course it can't. How Do Rings Seal Against Massive Combustion Pressure ?? From the actual gas pressure itself !! The pressure takes the path of least resistance, which means it passes over the top of the ring, and gets behind it to force it outward against the cylinder wall. The problem is that new rings are far from perfect and they must be worn in quite a bit in order to completely seal all the way around the bore. If the gas pressure is strong enough (open that throttle man !!!), then the entire ring will make contact with the cylinder surface, and it will wear perfectly into the right shape. The Problem With "Easy Break In" ... The rough crosshatch pattern in the cylinder bore acts like a file to allow the rings to wear. The rings quickly "use up" the roughness, regardless of how hard the engine is run. There's a very small window of opportunity to get the rings to seal really well ... only about 20 miles !! If the rings aren't forced against the walls, they'll use up the roughness before they fully seat. Once that happens there is no solution but to re hone the cylinders, install new rings and start over again. Fortunately, most new sportbike owners can't resist the urge to "open it up" once or twice, which is why more engines don't have this problem !! An additional factor that you may not have realized, is that the person at the dealership who set up your bike probably blasted your brand new bike pretty hard on the "test run". So, without realizing it, that adrenaline crazed set - up mechanic actually did you a huge favor !! -------------------------------------------------------------------------------- Here's How To Do It: There are 3 ways you can break in an engine: 1) on a dyno 2) on the street, or off road (Motocross or Snowmobile.) 3) on the racetrack -------------------------------------------------------------------------------- On a Dyno: Warm the engine up completely !! Then, using 4th gear: Do Three 1/2 Throttle dyno runs from 40% - 60% of your engine's max rpm Let it Cool Down For About 15 Minutes Do Three 3/4 Throttle dyno runs from 40% - 80% of your engine's max rpm Let it Cool Down For About 15 Minutes Do Three Full Throttle dyno runs from 30% - 100% of your engine's max rpm Let it Cool Down For About 15 Minutes Go For It !! Frequently asked Question: What's a dyno ?? A dyno is a machine in which the bike is strapped on and power is measured. It can also be used to break in an engine. NOTE: If you use a dyno with a brake, it's critical during break - in that you allow the bike to decelerate fully on it's own. (Don't use the brake.) The engine vacuum created during deceleration sucks the excess oil and metal off the cylinder walls to keep the rings from wearing too much. That's why a new engine "smokes" on decel. When you're doing it right, you'll notice the smoke goes away after about 7-8 runs.
More Break-In Tips... From Pat McGiven @ Mototune http://www.mototuneusa.com/break_in_secrets.htm On the Street: Warm the engine up completely: Because of the wind resistance, you don't need to use higher gears like you would on a dyno machine. The main thing is to load the engine by opening the throttle hard in 2nd, 3rd and 4th gear. Realistically, you won't be able to do full throttle runs even in 2nd gear on most bikes without exceeding 65 mph / 104 kph. The best method is to alternate between short bursts of acceleration and deceleration. You don't have to go over 65 mph / 104 kph to break in your engine. Also, make sure that you're not being followed closely by another bike or car when you decelerate ! The biggest problem with breaking your engine in on the street (besides police) is if you ride the bike on the freeway (too little throttle = not enough pressure on the rings) or if you get stuck in slow city traffic. For the first 200 miles or so, get out into the country where you can vary the speed more and run it through the gears ! Be Safe On The Street ! Watch your speed ! When you're not used to the handling of a new bike, you should accelerate only on the straightaways, then slow down extra early for the turns. Remember that both hard acceleration and hard engine braking (deceleration) are equally important during the break in process. On the Racetrack: Warm the engine up completely: Do one easy lap to warm up your tires. Pit, turn off the bike & check for leaks or any safety problems. Take a normal 15 minute practice session and check the water temperature occasionally. The racetrack is the perfect environment to break in an engine !! The combination of acceleration and deceleration is just the ticket for sealing the rings. Go For It !!
Of the pro builders I've worked with and heard about, they all break them in on the dyno's in similar to what HFD1' described. These were all superbike engine builders. They varied some but not to much. They all used cheap oil for the breakin(some even used mineral oil).
thanks many thanks for that info. Ive read pats recomendations as well as many other sites including aviation related stuff ton the subject. most say a gradual break-in period is best. alot of talk about non-detergent oils, it suposed to fully seat the rings quicker but also increases the risk of "glazing" extended heavy loads prematurely will also glaze the bores. new plan: go with pats recomendations and add to that a compression test and oil change between each run. when the compression tests stabilize I should be good to go! /////
