[Z06] blueprinted?
08-25-2005, 11:09 AM
#2
Get Some!
Originally Posted by vipervetteguy
What does it mean when they say an engine is "blueprinted"?
How desirable is this?
How desirable is this?
08-25-2005, 12:46 PM
#3
Le Mans Master
Member Since: Apr 2004
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St. Jude Donor '05-'08-'09
A number of people are confused by the terms “balanced” and “blueprinted” when referring to engine rebuilding. What does it mean when someone says they have a balanced and blueprinted engine?
All parts are made to certain tolerances, meaning that there are variations on size and weight. In addition, parts that rotate will not rotate truly if one side of that part is slightly heavier than the other. It will produce runout, which is a machinist’s term for wobble. Even in an item, such as the crankshaft, which is supported by bearings along portions of its length, the rotating part will try to wobble and cause excessive bearing wear. So, in an engine, we have two separate balance requirements—those of rotating parts and those of reciprocating parts—the pistons and connecting rods. Both of those classifications are balanced differently.
Reciprocating parts are balanced on a spring scale—similar to a bathroom or postal scale. The pistons are all weighed and the weight marked on them. Then, the three heavier will be lightened so they weight the same as the lightest. The idea being to produce four pistons (in a four cylinder engine) of exactly the same weight. The connecting rods have two ends—the small end where the piston connects and the big end where the rod connects to the crankshaft. Each end is weighted and the three heaviest small ends are matched in weight to the lightest small end. Then, the same process is repeated with the big ends.
With the reciprocating parts—crankshaft, harmonic balancer (crankshaft pulley) and the flywheel, the process is different. The previous parts have been balanced statically (they do not move) while the rotating parts are balanced dynamically (they are spun). The first step is to assemble the harmonic balancer to the crankshaft using the crankshaft pulley nut. Then, the crankshaft is installed in the balance machine and the flywheel is installed in it, using the flywheel bolts. The assembly is spun on a machine that works like the dynamic balancer used for tires. It will show where either metal needs to be added to the crankshaft or removed to balance all of the rotating mass as an assembly. Peter Burgess, well known MGB engine specialist, recommends the reciprocating parts be balanced in all engines and that the rotating parts be balanced on high performance engines. Even a road engine, however, will benefit from being dynamically balanced, providing smoother operation and longer life. Since the cost of having the reciprocating and rotating parts balanced was about $100, I decided to have both done on the 79 engine I am rebuilding. Actual cost was influenced by the fact that I had already had the pistons installed at another machine shop and they had to be removed, balanced and re-installed. I took the balance work to Bailey’s Machine Shop in Mesa because the machine shop which did the majority of the work did not have a balance capability.
Blueprinting an engine simply means to build it to some specification. This could be a factory specification (for cars which must run “stock” engines), the specifications of someone’s racing engine or one of the ones listed in Peter Burgess’ “How to Power Tune MGB Four Cylinder Engines”. In other words, it is an engine built to some plan rather than one taken in with the directions, “see how much you need to clean up the cylinders and tell me what size pistons to order”. In its most basis sense, a blueprinted engine is any engine built to a plan. Ideally, this should be an integrated plan with all the factors of performance and use built in. You can build a fully balanced and blueprinted race engine, but it will be of little use as a daily driver. A more modest engine specification, such as .040” over pistons, crankshaft rod and main journals turned no more than .010” and a chrome bumper cam and duplex timing gear, is also a blueprinted engine, offering street driving capablility and, probably, meeting all emissions requirements (have not put the engine together yet, so do not know).
So, the next time someone says, “I have a balanced and blueprinted engine”, smile and say, “So do I. From the factory.”.
All parts are made to certain tolerances, meaning that there are variations on size and weight. In addition, parts that rotate will not rotate truly if one side of that part is slightly heavier than the other. It will produce runout, which is a machinist’s term for wobble. Even in an item, such as the crankshaft, which is supported by bearings along portions of its length, the rotating part will try to wobble and cause excessive bearing wear. So, in an engine, we have two separate balance requirements—those of rotating parts and those of reciprocating parts—the pistons and connecting rods. Both of those classifications are balanced differently.
Reciprocating parts are balanced on a spring scale—similar to a bathroom or postal scale. The pistons are all weighed and the weight marked on them. Then, the three heavier will be lightened so they weight the same as the lightest. The idea being to produce four pistons (in a four cylinder engine) of exactly the same weight. The connecting rods have two ends—the small end where the piston connects and the big end where the rod connects to the crankshaft. Each end is weighted and the three heaviest small ends are matched in weight to the lightest small end. Then, the same process is repeated with the big ends.
With the reciprocating parts—crankshaft, harmonic balancer (crankshaft pulley) and the flywheel, the process is different. The previous parts have been balanced statically (they do not move) while the rotating parts are balanced dynamically (they are spun). The first step is to assemble the harmonic balancer to the crankshaft using the crankshaft pulley nut. Then, the crankshaft is installed in the balance machine and the flywheel is installed in it, using the flywheel bolts. The assembly is spun on a machine that works like the dynamic balancer used for tires. It will show where either metal needs to be added to the crankshaft or removed to balance all of the rotating mass as an assembly. Peter Burgess, well known MGB engine specialist, recommends the reciprocating parts be balanced in all engines and that the rotating parts be balanced on high performance engines. Even a road engine, however, will benefit from being dynamically balanced, providing smoother operation and longer life. Since the cost of having the reciprocating and rotating parts balanced was about $100, I decided to have both done on the 79 engine I am rebuilding. Actual cost was influenced by the fact that I had already had the pistons installed at another machine shop and they had to be removed, balanced and re-installed. I took the balance work to Bailey’s Machine Shop in Mesa because the machine shop which did the majority of the work did not have a balance capability.
Blueprinting an engine simply means to build it to some specification. This could be a factory specification (for cars which must run “stock” engines), the specifications of someone’s racing engine or one of the ones listed in Peter Burgess’ “How to Power Tune MGB Four Cylinder Engines”. In other words, it is an engine built to some plan rather than one taken in with the directions, “see how much you need to clean up the cylinders and tell me what size pistons to order”. In its most basis sense, a blueprinted engine is any engine built to a plan. Ideally, this should be an integrated plan with all the factors of performance and use built in. You can build a fully balanced and blueprinted race engine, but it will be of little use as a daily driver. A more modest engine specification, such as .040” over pistons, crankshaft rod and main journals turned no more than .010” and a chrome bumper cam and duplex timing gear, is also a blueprinted engine, offering street driving capablility and, probably, meeting all emissions requirements (have not put the engine together yet, so do not know).
So, the next time someone says, “I have a balanced and blueprinted engine”, smile and say, “So do I. From the factory.”.
08-25-2005, 01:05 PM
#5
Get Some!
Originally Posted by ironarms
So, the next time someone says, “I have a balanced and blueprinted engine”, smile and say, “So do I. From the factory.”.
http://www.custompistols.com/cars/articles/balanced.htm
08-25-2005, 01:23 PM
#6
Drifting
Originally Posted by ironarms
A number of people are confused by the terms “balanced” and “blueprinted” when referring to engine rebuilding. What does it mean when someone says they have a balanced and blueprinted engine?
All parts are made to certain tolerances, meaning that there are variations on size and weight. In addition, parts that rotate will not rotate truly if one side of that part is slightly heavier than the other. It will produce runout, which is a machinist’s term for wobble. Even in an item, such as the crankshaft, which is supported by bearings along portions of its length, the rotating part will try to wobble and cause excessive bearing wear. So, in an engine, we have two separate balance requirements—those of rotating parts and those of reciprocating parts—the pistons and connecting rods. Both of those classifications are balanced differently.
Reciprocating parts are balanced on a spring scale—similar to a bathroom or postal scale. The pistons are all weighed and the weight marked on them. Then, the three heavier will be lightened so they weight the same as the lightest. The idea being to produce four pistons (in a four cylinder engine) of exactly the same weight. The connecting rods have two ends—the small end where the piston connects and the big end where the rod connects to the crankshaft. Each end is weighted and the three heaviest small ends are matched in weight to the lightest small end. Then, the same process is repeated with the big ends.
With the reciprocating parts—crankshaft, harmonic balancer (crankshaft pulley) and the flywheel, the process is different. The previous parts have been balanced statically (they do not move) while the rotating parts are balanced dynamically (they are spun). The first step is to assemble the harmonic balancer to the crankshaft using the crankshaft pulley nut. Then, the crankshaft is installed in the balance machine and the flywheel is installed in it, using the flywheel bolts. The assembly is spun on a machine that works like the dynamic balancer used for tires. It will show where either metal needs to be added to the crankshaft or removed to balance all of the rotating mass as an assembly. Peter Burgess, well known MGB engine specialist, recommends the reciprocating parts be balanced in all engines and that the rotating parts be balanced on high performance engines. Even a road engine, however, will benefit from being dynamically balanced, providing smoother operation and longer life. Since the cost of having the reciprocating and rotating parts balanced was about $100, I decided to have both done on the 79 engine I am rebuilding. Actual cost was influenced by the fact that I had already had the pistons installed at another machine shop and they had to be removed, balanced and re-installed. I took the balance work to Bailey’s Machine Shop in Mesa because the machine shop which did the majority of the work did not have a balance capability.
Blueprinting an engine simply means to build it to some specification. This could be a factory specification (for cars which must run “stock” engines), the specifications of someone’s racing engine or one of the ones listed in Peter Burgess’ “How to Power Tune MGB Four Cylinder Engines”. In other words, it is an engine built to some plan rather than one taken in with the directions, “see how much you need to clean up the cylinders and tell me what size pistons to order”. In its most basis sense, a blueprinted engine is any engine built to a plan. Ideally, this should be an integrated plan with all the factors of performance and use built in. You can build a fully balanced and blueprinted race engine, but it will be of little use as a daily driver. A more modest engine specification, such as .040” over pistons, crankshaft rod and main journals turned no more than .010” and a chrome bumper cam and duplex timing gear, is also a blueprinted engine, offering street driving capablility and, probably, meeting all emissions requirements (have not put the engine together yet, so do not know).
So, the next time someone says, “I have a balanced and blueprinted engine”, smile and say, “So do I. From the factory.”.
All parts are made to certain tolerances, meaning that there are variations on size and weight. In addition, parts that rotate will not rotate truly if one side of that part is slightly heavier than the other. It will produce runout, which is a machinist’s term for wobble. Even in an item, such as the crankshaft, which is supported by bearings along portions of its length, the rotating part will try to wobble and cause excessive bearing wear. So, in an engine, we have two separate balance requirements—those of rotating parts and those of reciprocating parts—the pistons and connecting rods. Both of those classifications are balanced differently.
Reciprocating parts are balanced on a spring scale—similar to a bathroom or postal scale. The pistons are all weighed and the weight marked on them. Then, the three heavier will be lightened so they weight the same as the lightest. The idea being to produce four pistons (in a four cylinder engine) of exactly the same weight. The connecting rods have two ends—the small end where the piston connects and the big end where the rod connects to the crankshaft. Each end is weighted and the three heaviest small ends are matched in weight to the lightest small end. Then, the same process is repeated with the big ends.
With the reciprocating parts—crankshaft, harmonic balancer (crankshaft pulley) and the flywheel, the process is different. The previous parts have been balanced statically (they do not move) while the rotating parts are balanced dynamically (they are spun). The first step is to assemble the harmonic balancer to the crankshaft using the crankshaft pulley nut. Then, the crankshaft is installed in the balance machine and the flywheel is installed in it, using the flywheel bolts. The assembly is spun on a machine that works like the dynamic balancer used for tires. It will show where either metal needs to be added to the crankshaft or removed to balance all of the rotating mass as an assembly. Peter Burgess, well known MGB engine specialist, recommends the reciprocating parts be balanced in all engines and that the rotating parts be balanced on high performance engines. Even a road engine, however, will benefit from being dynamically balanced, providing smoother operation and longer life. Since the cost of having the reciprocating and rotating parts balanced was about $100, I decided to have both done on the 79 engine I am rebuilding. Actual cost was influenced by the fact that I had already had the pistons installed at another machine shop and they had to be removed, balanced and re-installed. I took the balance work to Bailey’s Machine Shop in Mesa because the machine shop which did the majority of the work did not have a balance capability.
Blueprinting an engine simply means to build it to some specification. This could be a factory specification (for cars which must run “stock” engines), the specifications of someone’s racing engine or one of the ones listed in Peter Burgess’ “How to Power Tune MGB Four Cylinder Engines”. In other words, it is an engine built to some plan rather than one taken in with the directions, “see how much you need to clean up the cylinders and tell me what size pistons to order”. In its most basis sense, a blueprinted engine is any engine built to a plan. Ideally, this should be an integrated plan with all the factors of performance and use built in. You can build a fully balanced and blueprinted race engine, but it will be of little use as a daily driver. A more modest engine specification, such as .040” over pistons, crankshaft rod and main journals turned no more than .010” and a chrome bumper cam and duplex timing gear, is also a blueprinted engine, offering street driving capablility and, probably, meeting all emissions requirements (have not put the engine together yet, so do not know).
So, the next time someone says, “I have a balanced and blueprinted engine”, smile and say, “So do I. From the factory.”.
Balance has to do with balancing the reciprocating components rods piston assemblies and crank
The better the in process Q.C. the less benifit you will see......It made big differences 10-20 years ago ...Less now
I think you answered everything!!
08-25-2005, 03:46 PM
#8
Le Mans Master
Originally Posted by ironarms
Blueprinting an engine simply means to build it to some specification. This could be a factory specification (for cars which must run “stock” engines), the specifications of someone’s racing engine or one of the ones listed in Peter Burgess’ “How to Power Tune MGB Four Cylinder Engines”. In other words, it is an engine built to some plan rather than one taken in with the directions, “see how much you need to clean up the cylinders and tell me what size pistons to order”. In its most basis sense, a blueprinted engine is any engine built to a plan.
Blueprinted basically means that the engine was built to tight tolerances according to the manufacturer's specifications. In other words, there is supposed to be less margin for error in a blueprinted engine. It is carefully measured as it is assembled and as a result should be more consistent and reliable. It is primarily a reliability issue, performance gains for blueprinting are probably very small.
Ideally, this should be an integrated plan with all the factors of performance and use built in. You can build a fully balanced and blueprinted race engine, but it will be of little use as a daily driver.
A more modest engine specification, such as .040” over pistons, crankshaft rod and main journals turned no more than .010” and a chrome bumper cam and duplex timing gear, is also a blueprinted engine, offering street driving capablility and, probably, meeting all emissions requirements (have not put the engine together yet, so do not know).
The above engine may, or may not be a blueprinted engine. The author of this article has taken the position that blueprinting means "you had a plan for the engine." That's a load of crap. Blueprinting is the act of carefully making sure the engine is built exactly according to the plan. They all have plans.
So, the next time someone says, “I have a balanced and blueprinted engine”, smile and say, “So do I. From the factory.”.
they encounter and just nod their head and try to get away as fast as possible.
08-25-2005, 04:13 PM
#9
Get Some!
Tom while I was jogging I was thinking of a response to this article. I agree with you, this guy is trying to be a wise guy, and does it poorly.
"Blueprinting is the act of carefully making sure the engine is built exactly according to the plan. They all have plans."
That was my point, but I'm just not a wordy guy. Blueprinting is more that just a plan, and machine shops that make engines for us hotrodders do a lot more than the factory does.
"Blueprinting is the act of carefully making sure the engine is built exactly according to the plan. They all have plans."
That was my point, but I'm just not a wordy guy. Blueprinting is more that just a plan, and machine shops that make engines for us hotrodders do a lot more than the factory does.
08-25-2005, 11:54 PM
#10
Le Mans Master
What blueprinting to me is, is making sure that every component is built and fits as the "original blueprint" called for. For example, I remember basically building each engine twice. You first of all measure each piston diameter and bore each cylinder so that each piston has the same piston-to-wall clearance. All pistons are not created equal. Then you assemble all the rods and rod bearings and torque them to the crankshaft with plastiguage to measure the bearing clearance on each journal. Remove, adjust so that they are all equal to what the blueprint called for and reassemble. Same with crank journals, align bore, valve seats, ports, combustion chamber volumes etc. etc. etc. Balancing of course is as others have stated where all pistons, rods and assemblies are matched for weight as well. The blueprinted engine will definitely exhibit improved horsepower and smoother, therefore more reliable performance. The object is to have each and every cylinder performing exactly the same for maximum effect of all working together.
08-26-2005, 09:33 AM
#12
Le Mans Master
Originally Posted by Shylor
Every engine is balanced and blueprinted to certain specifications. So I think the term really means its done with tighter specs.
A piston that comes from the factory spec'd as 4.000 inches in diameter may actually be 4.002, and the next may be 3.999 and the cylinders they go into may be spec'd at 4.005 but will actually be 4.007 and 4.003. Which piston goes into which hole is anybody's guess and as you can see, if the small piston goes into the larger hole, there's a huge difference in wall clearance. The accumulation of these tolerances on each and every part, which are all within the original spec, can make a big difference. Hand built and checking clearances for every part makes every cylinder perform identically. THAT'S blueprinting.
Last edited by robvuk; 08-26-2005 at 09:39 AM.
08-26-2005, 11:07 AM
#13
Melting Slicks
Member Since: Sep 2004
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Originally Posted by robvuk
A piston that comes from the factory spec'd as 4.000 inches in diameter may actually be 4.002, and the next may be 3.999 and the cylinders they go into may be spec'd at 4.005 but will actually be 4.007 and 4.003. Which piston goes into which hole is anybody's guess and as you can see, if the small piston goes into the larger hole, there's a huge difference in wall clearance.
Actually... for many years US manufacturers have been measuring pistons individually and separating them by size. The bores are also measured and then pistons are selected from the appropriate size bin for each bore. This DOES NOT equal blueprinting, but improves the piston fit in the bores.
In fact, with modern machining techniques, including feedback controls in the lathe (for pistons) or bore honing machine, the spread of tolerances from one part (or bore) to another has been substantially decreased in the last 10 years or so. Engines produced today, including the LS1/2/6/7 family -- as delivered -- are very close to design intent.
I used to work for a company that manufactured the measuring and feedback control machines and was astounded at the progress that has been made in high-volume machining during the last decade.
Frank Gonzalez
08-26-2005, 12:18 PM
#14
Le Mans Master
Originally Posted by gonzalezfj
Actually... for many years US manufacturers have been measuring pistons individually and separating them by size. The bores are also measured and then pistons are selected from the appropriate size bin for each bore. This DOES NOT equal blueprinting, but improves the piston fit in the bores.
In fact, with modern machining techniques, including feedback controls in the lathe (for pistons) or bore honing machine, the spread of tolerances from one part (or bore) to another has been substantially decreased in the last 10 years or so. Engines produced today, including the LS1/2/6/7 family -- as delivered -- are very close to design intent.
I used to work for a company that manufactured the measuring and feedback control machines and was astounded at the progress that has been made in high-volume machining during the last decade.
Frank Gonzalez
In fact, with modern machining techniques, including feedback controls in the lathe (for pistons) or bore honing machine, the spread of tolerances from one part (or bore) to another has been substantially decreased in the last 10 years or so. Engines produced today, including the LS1/2/6/7 family -- as delivered -- are very close to design intent.
I used to work for a company that manufactured the measuring and feedback control machines and was astounded at the progress that has been made in high-volume machining during the last decade.
Frank Gonzalez
I've been out of it for decades. I would hope that things have improved over that time. I'm sure that blueprinting an engine means less today than it did back then. Now its probably more about "changing" the spec rather than meeting it.
Thanks, good info.