Dropping in a new motor ? Seating rings
10-14-2004, 10:57 AM
#1
Race Director
Thread Starter
Dropping in a new motor ? Seating rings
Thought I would post this for you guys that are planning on dropping in a new bullet. A new motor should not burn a drop of oil after it is broken in. If you want find out how the rings seat then read the whole thing or you can skip to the bottom paragraph after you are convinced it is critical to seat the rings and readhow I do it, not neccessarily the way everyone does it.
The first few hundred miles of a new engine's life have a major impact on how strongly that engine will perform, how much oil it will consume and how long it will last. The main purpose of break-in is to seat the compression rings to the cylinder walls. We are talking about the physical mating of the engine's piston rings to it's corresponding cylinder wall. That is, we want to physically wear the new piston rings into the cylinder wall until a compatible seal between the two is achieved.
Proper engine break in will produce an engine that achieves maximum power output with the least amount of oil consumption due to the fact that the piston rings have seated properly to the cylinder wall. When the piston rings are broken in or seated, they do not allow combustion gases to escape the combustion chamber past the piston rings into the crankcase section of the engine. This lack of "blow-by" keeps your engine running cleaner and cooler by preventing hot combustion gases and by-products from entering the crankcase section of the engine. Excessive "blow-by" will cause the crankcase section of the engine to become pressurized and contaminated with combustion gases, which in turn will force normal oil vapors out of the engine's breather, causing the engine to consume excessive amounts of oil.
In addition to sealing combustion gases in the combustion chamber, piston rings must also manage the amount of oil present on the cylinder walls for lubrication. If the rings do not seat properly, they cannot perform this function and will allow excessive amounts of oil to accumulate on the cylinder wall surfaces. This oil is burned each and every time the cylinder fires. The burning of this oil, coupled with "blow-by" induced engine breathing, are reasons that an engine that hasn't been broken in will consume more than its share of oil.
When a cylinder is new or overhauled the surface of it's walls are honed with abrasive stones to produce a rough surface that will help wear the piston rings in. This roughing up of the surface is known as "cross-hatching". A cylinder wall that has been properly "cross hatched" has a series of minute peaks and valleys cut into its surface. The face or portion of the piston ring that interfaces with the cross hatched cylinder wall is tapered to allow only a small portion of the ring to contact the honed cylinder wall. When the engine is operated, the tapered portion of the face of the piston ring rubs against the coarse surface of the cylinder wall causing wear on both objects.
Each tiny groove acts as the oil reservoir holding oil up to the top level of the groove where it then spreads over the peak surface. The piston ring must travel up and down over this grooved surface, and must "hydroplane" on the oil film retained by the grooves. Otherwise, the ring would make metal-to-metal contact with the cylinder wall and the cylinder would quickly wear out.
However the ring will only ride on this film of oil if there is sufficient surface area to support the ring on the oil. When the cylinders are freshly honed the peaks are sharp with little surface area. Our goal when seating the rings on new steel cylinders is to flatten out these peaks to give more surface area to support the rings, while leaving the bottom of the groove intact to hold enough oil to keep the surface of the cylinder wet with oil. See illustration. At the point where the top of the peaks produced by the honing operation become smooth and the tapered portion of the piston ring wears flat break in has occurred.
When the engine is operating, a force known as Break Mean Effective Pressure or B.M.E.P is generated within the combustion chamber. B.M.E.P. is the resultant force produced from the controlled burning of the fuel air mixture that the engine runs on. The higher the power setting the engine is running at, the higher the B.M.E.P. is and conversely as the power setting is lowered the B.M.E.P. becomes less.
B.M.E.P is an important part of the break in process. When the engine is running, B.M.E.P. is present in the cylinder behind the piston rings and it's force pushes the piston ring outward against the coarse honed cylinder wall. Piston rings are designed to take advantage of the pressure and us it to push the rings out against the cylinder wall. Therefore, as pressure builds during the compression stroke, the rings are pushed harder against the cylinder wall which aids in seating the rings.
The higher the B.M.E.P, the harder the piston ring is pushed against the wall. The surface temperature at the piston ring face and cylinder wall interface will be greater with high B.M.E.P. than with low B.M.E.P. This is because we are pushing the ring harder against the rough cylinder wall surface causing high amounts of friction and thus heat. The primary deterrent of break in is this heat. Allowing to much heat to build up at the ring to cylinder wall interface will cause the lubricating oil that is present to break down and glaze the cylinder wall surface. This glaze will prevent any further seating of the piston rings. If glazing is allowed to happen break in will never occur. Also, if too little pressure (throttle) is used during the break-in period glazing will also occur.
Most people seem to operate on the philosophy that they can best get their money's worth from any mechanical device by treating it with great care. This is probably true, but in many cases it is necessary to interpret what great care really means. This is particularly applicable when considering the break-in of a modern, reciprocating engine.
For those who still think that running the engine hard during break-in falls into the category of cruel and unusual punishment, there is one more argument for using high power loading for short periods (to avoid excessive heat) during the break-in. The use of low power settings does not expand the piston rings enough, and a film of oil is left on the cylinder walls. The high temperatures in the combustion chamber will oxidize this oil film so that it creates glazing of the cylinder walls. When this happens, the ring break-in process stops, and excessive oil consumption frequently occurs. The bad news is that extensive glazing can only be corrected by removing the cylinders and rehoning the walls. This is expensive, and it is an expense that can be avoided by proper break in procedures.
We must achieve a happy medium where we are pushing on the ring hard enough to wear it in but not hard enough to generate enough heat to cause glazing. Once again, if glazing should occur, the only remedy is to take the motor apart and re-hone the cylinderst and replace the piston rings and start the whole process over again.
Now here is what I do ( this procedure is not written in stone but more of a guide) after the initial breakin of cam
take the warmed up car out onto backroad and take it up to 3000RPM in second gear (auto or stick) and let your foot off the gas and let the motor slow the car down. Do this 4 or 5 times and take it home. Let it cool down completly and then take it out again and this time take it up to 4500 - 5000 RPM 3 or 4 times letting the motor brake the car each time, and your done. I change the oil afer cam breakin ( that's right 30 min. running time) and then after about 500 miles and then at around 1000 miles.
One added benefit of following this procedure is you won't have to wait for weeks to find out you didn't tighten that pesky #6 rod cap enough
The first few hundred miles of a new engine's life have a major impact on how strongly that engine will perform, how much oil it will consume and how long it will last. The main purpose of break-in is to seat the compression rings to the cylinder walls. We are talking about the physical mating of the engine's piston rings to it's corresponding cylinder wall. That is, we want to physically wear the new piston rings into the cylinder wall until a compatible seal between the two is achieved.
Proper engine break in will produce an engine that achieves maximum power output with the least amount of oil consumption due to the fact that the piston rings have seated properly to the cylinder wall. When the piston rings are broken in or seated, they do not allow combustion gases to escape the combustion chamber past the piston rings into the crankcase section of the engine. This lack of "blow-by" keeps your engine running cleaner and cooler by preventing hot combustion gases and by-products from entering the crankcase section of the engine. Excessive "blow-by" will cause the crankcase section of the engine to become pressurized and contaminated with combustion gases, which in turn will force normal oil vapors out of the engine's breather, causing the engine to consume excessive amounts of oil.
In addition to sealing combustion gases in the combustion chamber, piston rings must also manage the amount of oil present on the cylinder walls for lubrication. If the rings do not seat properly, they cannot perform this function and will allow excessive amounts of oil to accumulate on the cylinder wall surfaces. This oil is burned each and every time the cylinder fires. The burning of this oil, coupled with "blow-by" induced engine breathing, are reasons that an engine that hasn't been broken in will consume more than its share of oil.
When a cylinder is new or overhauled the surface of it's walls are honed with abrasive stones to produce a rough surface that will help wear the piston rings in. This roughing up of the surface is known as "cross-hatching". A cylinder wall that has been properly "cross hatched" has a series of minute peaks and valleys cut into its surface. The face or portion of the piston ring that interfaces with the cross hatched cylinder wall is tapered to allow only a small portion of the ring to contact the honed cylinder wall. When the engine is operated, the tapered portion of the face of the piston ring rubs against the coarse surface of the cylinder wall causing wear on both objects.
Each tiny groove acts as the oil reservoir holding oil up to the top level of the groove where it then spreads over the peak surface. The piston ring must travel up and down over this grooved surface, and must "hydroplane" on the oil film retained by the grooves. Otherwise, the ring would make metal-to-metal contact with the cylinder wall and the cylinder would quickly wear out.
However the ring will only ride on this film of oil if there is sufficient surface area to support the ring on the oil. When the cylinders are freshly honed the peaks are sharp with little surface area. Our goal when seating the rings on new steel cylinders is to flatten out these peaks to give more surface area to support the rings, while leaving the bottom of the groove intact to hold enough oil to keep the surface of the cylinder wet with oil. See illustration. At the point where the top of the peaks produced by the honing operation become smooth and the tapered portion of the piston ring wears flat break in has occurred.
When the engine is operating, a force known as Break Mean Effective Pressure or B.M.E.P is generated within the combustion chamber. B.M.E.P. is the resultant force produced from the controlled burning of the fuel air mixture that the engine runs on. The higher the power setting the engine is running at, the higher the B.M.E.P. is and conversely as the power setting is lowered the B.M.E.P. becomes less.
B.M.E.P is an important part of the break in process. When the engine is running, B.M.E.P. is present in the cylinder behind the piston rings and it's force pushes the piston ring outward against the coarse honed cylinder wall. Piston rings are designed to take advantage of the pressure and us it to push the rings out against the cylinder wall. Therefore, as pressure builds during the compression stroke, the rings are pushed harder against the cylinder wall which aids in seating the rings.
The higher the B.M.E.P, the harder the piston ring is pushed against the wall. The surface temperature at the piston ring face and cylinder wall interface will be greater with high B.M.E.P. than with low B.M.E.P. This is because we are pushing the ring harder against the rough cylinder wall surface causing high amounts of friction and thus heat. The primary deterrent of break in is this heat. Allowing to much heat to build up at the ring to cylinder wall interface will cause the lubricating oil that is present to break down and glaze the cylinder wall surface. This glaze will prevent any further seating of the piston rings. If glazing is allowed to happen break in will never occur. Also, if too little pressure (throttle) is used during the break-in period glazing will also occur.
Most people seem to operate on the philosophy that they can best get their money's worth from any mechanical device by treating it with great care. This is probably true, but in many cases it is necessary to interpret what great care really means. This is particularly applicable when considering the break-in of a modern, reciprocating engine.
For those who still think that running the engine hard during break-in falls into the category of cruel and unusual punishment, there is one more argument for using high power loading for short periods (to avoid excessive heat) during the break-in. The use of low power settings does not expand the piston rings enough, and a film of oil is left on the cylinder walls. The high temperatures in the combustion chamber will oxidize this oil film so that it creates glazing of the cylinder walls. When this happens, the ring break-in process stops, and excessive oil consumption frequently occurs. The bad news is that extensive glazing can only be corrected by removing the cylinders and rehoning the walls. This is expensive, and it is an expense that can be avoided by proper break in procedures.
We must achieve a happy medium where we are pushing on the ring hard enough to wear it in but not hard enough to generate enough heat to cause glazing. Once again, if glazing should occur, the only remedy is to take the motor apart and re-hone the cylinderst and replace the piston rings and start the whole process over again.
Now here is what I do ( this procedure is not written in stone but more of a guide) after the initial breakin of cam
take the warmed up car out onto backroad and take it up to 3000RPM in second gear (auto or stick) and let your foot off the gas and let the motor slow the car down. Do this 4 or 5 times and take it home. Let it cool down completly and then take it out again and this time take it up to 4500 - 5000 RPM 3 or 4 times letting the motor brake the car each time, and your done. I change the oil afer cam breakin ( that's right 30 min. running time) and then after about 500 miles and then at around 1000 miles.
One added benefit of following this procedure is you won't have to wait for weeks to find out you didn't tighten that pesky #6 rod cap enough
Last edited by MotorHead; 10-14-2004 at 06:08 PM.
10-14-2004, 11:10 AM
#2
Burning Brakes
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St. Jude Donor '05
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Thats definitely sound advice right there. I think it IS quite important to show an enginee what it WILL be doing right in the begining. Taking it up to 5 grand a couple times after a gradual, slow build up with time to cool down in between makes perfectly good sense to me. You want to make sure everything is copasetic and you dont have any lips in the cylinder walls. Ive followed a similar mantra with v8's and 4 bangers that Ive built, and have always had hella good performing, 0 oil buring engines. 
10-14-2004, 11:14 AM
#3
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Nice write up, the procedure is pretty much the same as the break in instructions that comes with GM crate eng's. Gotta get the cyl pressure up after cam break in to seat those rings.
10-14-2004, 11:23 AM
#5
Burning Brakes
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St. Jude Donor '05
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Heres a question...If Im getting an engine built, and its going to be dyno tested and tuned, does that also mean they'll break it in the same way BEFORE they dyno test it? YOu wouldnt think theyd run an enging to 7 grand without it going through a break in period would you?
10-14-2004, 11:28 AM
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Originally Posted by 81 Vette
Heres a question...If Im getting an engine built, and its going to be dyno tested and tuned, does that also mean they'll break it in the same way BEFORE they dyno test it? YOu wouldnt think theyd run an enging to 7 grand without it going through a break in period would you?
Believe the crate eng companies have you take it easy for 500 miles just make sure nothing comes loose at high rpm's/speed. Seems I have read some write ups when doing dynos, they break in the cam and seat the rings, change the oil and then do the dyno's.
10-14-2004, 11:37 AM
#7
Le Mans Master
I am afraid this is my problem since I ran it too retarded and got hot during the initial break-in. Plus, I get smoke out of the valve covers at idle which I am afraid is due to the blow-by. Oh well, one more problem.
Last edited by SteveG75; 10-14-2004 at 12:41 PM.
10-14-2004, 11:55 AM
#8
Race Director
Thread Starter
Originally Posted by 81 Vette
Heres a question...If Im getting an engine built, and its going to be dyno tested and tuned, does that also mean they'll break it in the same way BEFORE they dyno test it? YOu wouldnt think theyd run an enging to 7 grand without it going through a break in period would you?
I have a roller cam and I did not have to wait 30 minutes. I had it up to 5 grand 5 minutes after I fired it up and got it on the road. It does not burn any oil at all and I have 3000 miles on it
10-14-2004, 12:00 PM
#9
Race Director
Thread Starter
Originally Posted by Fevre
There is not break in period for race eng's. Believe the crate eng companies have you take it easy for 500 miles just make sur e nothing comes loose at high rpm's/speed. Seems I have read some write ups when doing dynos, they break in the cam and seat the rings, change the oil and then do the dyno's.
Believe the crate eng companies have you take it easy for 500 miles just make sur e nothing comes loose at high rpm's/speed. Seems I have read some write ups when doing dynos, they break in the cam and seat the rings, change the oil and then do the dyno's.
10-14-2004, 12:04 PM
#10
Burning Brakes
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St. Jude Donor '05
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hahaha thanks guys, just checking. Hell, Im pretty stoked on this one custom combo Im looking at right now...24k mile warranty on a custom harcore small block ulta street engine isnt too shabby. (Only 615 horses might be why 
)
)
10-14-2004, 12:07 PM
#11
Race Director
I have a solid flat tappet so I had to break in the cam. Once that was done and the oil changed I took it out for a short drive to make sure there were no leaks. Once that was done it went to 6000 rpm a couple of times and brought it back in to cool down. A few more runs like this and it was on its way. I did notice that after about 1000 miles it did seem to rev a little easier but I have never burnt a drop of oil and after 7K on the motor it is still running great. The machine shop I deal with said the same thing. On roller cammed engines they are on the strip almost immediatly. If it was put together right it will stay together.
10-14-2004, 02:29 PM
#12
Race Director
Thread Starter
Originally Posted by SteveG75
I am afraid this is my problem since I ran it too retarded and got hot during the initial break-in. Plus, I get smoke out of the valve covers at idle which I am afraid is due to the blow-by. Oh well, one more problem.
10-14-2004, 02:39 PM
#13
Tech Contributor
Interesting points, one thing I didn't think of was sealing the screw in studs. If there isn't any sealant on them what would you expect oil usage to be? 1qt in 200,500,1000 miles? I have to check a recent top end job that's using oil about 500 miles with no signs of a leak or fouled plugs?
Thanks,
Gary
Thanks,
Gary
10-14-2004, 02:51 PM
#14
Le Mans Master
Originally Posted by MotorHead
I would not jump to that conclusion just yet. Just breaking in your cam will seat the rings to some extent. I had new motor that was OK on oil consumption years ago and I don't even remember breaking in the cam. I would look at other things first such as badly sealed intake gasket, valve seals leaking and screw in studs not sealed properly. While seating the rings as desribed above is very important and I would definatly do it on every new engine it probably doesn't mean you are automatically doomed if you didn't.
10-14-2004, 04:02 PM
#16
Race Director
Thread Starter
Originally Posted by gtr1999
Interesting points, one thing I didn't think of was sealing the screw in studs. If there isn't any sealant on them what would you expect oil usage to be? 1qt in 200,500,1000 miles? I have to check a recent top end job that's using oil about 500 miles with no signs of a leak or fouled plugs?
Thanks,
Gary
Thanks,
Gary
I would think you could get 1 qt in every 1000 miles ( or less ) from oil leaking through (all) the intake head stud(s) and directly into the intake port runner if no sealer was applied to the stud on assembly
10-14-2004, 04:30 PM
#17
Tech Contributor
Well I'm going to go through the paces with it;compression check leak down test. The heads are new WP sportsmans using umbrella seals, I hate to think they're the problem.
Gary
Gary
10-14-2004, 04:38 PM
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Originally Posted by gtr1999
Interesting points, one thing I didn't think of was sealing the screw in studs. If there isn't any sealant on them what would you expect oil usage to be? 1qt in 200,500,1000 miles? I have to check a recent top end job that's using oil about 500 miles with no signs of a leak or fouled plugs?
Thanks,
Gary
Thanks,
Gary
10-14-2004, 05:40 PM
#20
Race Director
Thread Starter
Not sure about other heads but on my Vic. Jr. heads they go clear thru to the intake runner you can see the end of the stud up there