Breaking in a Stroker Motor
Originally Posted by Knightracer
Tom don't worry about it. Dave will break it in on the dyno for you. I had all of 50 miles on mine when I trucked it up there to get it tuned to break it in. I asked Dave his thoughts and he said he breaks in all their motors on the Dyno. I said well if thats what you do have at it, and that was the end of my break in. I figure if the guy has been doing it for that long he knows what hes doin.
Originally Posted by Soon2BEVO
I know the manual said to do it a certain way but I just broke my car in by beating the living sh*t out of it for the first 1000 miles. Now at 42k, it doesnt burn a drop of oil, it's problem free, and its made great power thus far.
Evolving Member
Joined: Nov 2005
Posts: 139
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From: Manchester, CT
sorry guys this is kinda newb, i kno wut a stroker kit does but im having a hard time understand HOW it works. i kno it increases displacement. do you physically make it bigger, or is the stroke longer? anyone care to clear it up for me...thanks
Originally Posted by mikejam1688
sorry guys this is kinda newb, i kno wut a stroker kit does but im having a hard time understand HOW it works. i kno it increases displacement. do you physically make it bigger, or is the stroke longer? anyone care to clear it up for me...thanks
I know when I bring my car up to Buschur, David will do what he does and Im sure everything will run great. I was just wondering about how most people are breaking in a stroker and when I did a search for it couldnt find anything.
I will be running the 35R with some alchy and a few other things...
So, it seems the best way is to break it in with conventional low detergent oil, change the oil frequently, and stay low on boost for the first 200 miles, moderate boost for the next 500, then drive it hard.
I'll add my thoughts, since I put something like 8 motors in my 2G and broke them all in differently. Wish I could bring myself to put a stroker in the EVO...
Breaking the motor in easy, with "typical" WG spring pressure for example, was the worst. It took forever to get full compression in all cylinders, as much as 10k miles in one case. One cylinder was only ~20 psi low for most of those 10k miles, but for the money you pay for a fully built motor you'd like to have full compression
It eventually came up to match the others.
I feel that the motor should be run with your target boost as soon as it's been running long enough to prove it doesn't leak. That's roughly the time it takes to open the thermostat and turn on the radiator fans in my book. I was running a 20 psi spring, so that's the boost I used to break the motors in. I do keep RPM down at first, but get into the boost for short bursts to drive the rings into the cylinder walls while the crosshatch is still there. I work up to full redline RPM by ~100 miles. Doing it this way on the last few motors provided full compression in all cylinders at that 100 miles. Does't matter what type of motor this is either, stock or stroker or built 2 liter. The "grit" of the final hone can affect things however. A stock motor is going to have a pretty coarse crosshatch from the factory, which tends to make it break in fully regardless of what the owner does, and is why you can get away with an easier break in process. A built motor will typically have a much finer crosshatch honed into it and makes it much more necessary to get the rings seated quickly!
Changing oil frequently is just as important or more important than getting the rings seated. The break in is an extension of the maching process. A lot of debris is created. I change the oil after it initially runs and warms up on the jack stands (~10-20 minutes of idle-low rpm). Run it with boost gradually working up the rpm, and change oil again at ~50 miles. Again around 100. Then 500, and 1000. From there the usual intervals. This prbably changes slightly every time I do it/write it, but you get the idea. I've looked at the bearings on motors that were changed in this fashion and motors that the oil was left in for 1 to 3 thousand miles before the first change. The difference is unbelievable. Motors that were changed frequently in the beginning had perfect bearings after up to 20k miles, while one that went to 3k had very deep grooves cut into the center of the bearings all the way around. Oil is cheap There is plenty of discussion about what type of oil to use, I always just used regular 10w-whatever.
So breaking a motor in on the dyno sounds good to me. A couple other things to watch for. Make sure you are not overly rich while breaking the motor in. It's good to avoid knock, but make sure the engine management is set up for a decent AFR with whatever injectors you are using. Also, avoid running the motor for hours on end trying to troubleshoot simple idle problems or similar, you can easily miss your chance to get the rings seated.
Breaking the motor in easy, with "typical" WG spring pressure for example, was the worst. It took forever to get full compression in all cylinders, as much as 10k miles in one case. One cylinder was only ~20 psi low for most of those 10k miles, but for the money you pay for a fully built motor you'd like to have full compression
It eventually came up to match the others. I feel that the motor should be run with your target boost as soon as it's been running long enough to prove it doesn't leak. That's roughly the time it takes to open the thermostat and turn on the radiator fans in my book. I was running a 20 psi spring, so that's the boost I used to break the motors in. I do keep RPM down at first, but get into the boost for short bursts to drive the rings into the cylinder walls while the crosshatch is still there. I work up to full redline RPM by ~100 miles. Doing it this way on the last few motors provided full compression in all cylinders at that 100 miles. Does't matter what type of motor this is either, stock or stroker or built 2 liter. The "grit" of the final hone can affect things however. A stock motor is going to have a pretty coarse crosshatch from the factory, which tends to make it break in fully regardless of what the owner does, and is why you can get away with an easier break in process. A built motor will typically have a much finer crosshatch honed into it and makes it much more necessary to get the rings seated quickly!
Changing oil frequently is just as important or more important than getting the rings seated. The break in is an extension of the maching process. A lot of debris is created. I change the oil after it initially runs and warms up on the jack stands (~10-20 minutes of idle-low rpm). Run it with boost gradually working up the rpm, and change oil again at ~50 miles. Again around 100. Then 500, and 1000. From there the usual intervals. This prbably changes slightly every time I do it/write it, but you get the idea. I've looked at the bearings on motors that were changed in this fashion and motors that the oil was left in for 1 to 3 thousand miles before the first change. The difference is unbelievable. Motors that were changed frequently in the beginning had perfect bearings after up to 20k miles, while one that went to 3k had very deep grooves cut into the center of the bearings all the way around. Oil is cheap
There is plenty of discussion about what type of oil to use, I always just used regular 10w-whatever. So breaking a motor in on the dyno sounds good to me. A couple other things to watch for. Make sure you are not overly rich while breaking the motor in. It's good to avoid knock, but make sure the engine management is set up for a decent AFR with whatever injectors you are using. Also, avoid running the motor for hours on end trying to troubleshoot simple idle problems or similar, you can easily miss your chance to get the rings seated.
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