I've heard this term a couple times, "blueprinting" but I'm not completely sure what it means. Anybody know the answer?
nkh
Blueprinting
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Nathan K. Hammond
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Blueprinting
7AC-5691
Super 85-12F @ DVK
Super 85-12F @ DVK
Just about what you did with your engine. You take the specs of the engine and put it together very carefully, sticking to the limits and such put out by Continental.
Lots of people sometimes think that when you build a race engine you make it "tight" so everything fits well together. Well, its the opposite and race engines (at least car engines) are built a bit on the loose side. You want them to rev up fast and they are overhauled ever few races so their clearances (except the piston ring gap, for max compression) usually on the loose side.
When they are building an engine in this mannaer, most people will also weigh each component (pistons, rods etc) and match their weights. Heavier components are shaved or filed down to match the lighter part of the set, then the entire rotating unit can be balanced together as well. One piston that is 10-15 grams heavier than the opposite piston can make for a very vibration prone engine. Make them all the same weight makes it smoother.
Also some people will "cc" the combustion chambers, and make them the same size and port and polish the chamber and intake and exhaust ports to make things flow better. If you really want to get into it have known people to smooth out the oil galleys to improve oil flow and pressure, as well as smooth the inside of the block (case in our situation) to make the oil not cling to the inside of the engine.
Its an endless battle for smoothness and horsepower. You can almost go on forever depending on the money you want to throw at any engine.
JoeA
Lots of people sometimes think that when you build a race engine you make it "tight" so everything fits well together. Well, its the opposite and race engines (at least car engines) are built a bit on the loose side. You want them to rev up fast and they are overhauled ever few races so their clearances (except the piston ring gap, for max compression) usually on the loose side.
When they are building an engine in this mannaer, most people will also weigh each component (pistons, rods etc) and match their weights. Heavier components are shaved or filed down to match the lighter part of the set, then the entire rotating unit can be balanced together as well. One piston that is 10-15 grams heavier than the opposite piston can make for a very vibration prone engine. Make them all the same weight makes it smoother.
Also some people will "cc" the combustion chambers, and make them the same size and port and polish the chamber and intake and exhaust ports to make things flow better. If you really want to get into it have known people to smooth out the oil galleys to improve oil flow and pressure, as well as smooth the inside of the block (case in our situation) to make the oil not cling to the inside of the engine.
Its an endless battle for smoothness and horsepower. You can almost go on forever depending on the money you want to throw at any engine.
JoeA
blueprinting
Nathan: Pretty much like Joea says and it depends on the engine . I did my 65 and it drove me insane. Things like Continental put two lobes on the cam in the wrong place, not allowing the lifter to be aligned properly to rotate as they should. Had to close my eyes on that one. They still make it to tbo anyway.
Pistons are all over the place in weights from Continental, however the Brazilian made jobs for Superior did not deviate more than 2/10 ths of a gram for all four
The other weird thing on mine was that I sent the crank away for dynamic ballancing and they did not touch it. It was that close. Cost me 35 bucks to find out some-one did it at some previous time.
Ron
Pistons are all over the place in weights from Continental, however the Brazilian made jobs for Superior did not deviate more than 2/10 ths of a gram for all four
The other weird thing on mine was that I sent the crank away for dynamic ballancing and they did not touch it. It was that close. Cost me 35 bucks to find out some-one did it at some previous time.Ron
Before you believe anything I say, check with two more people. If they agree, I must be right.
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zero.one.victor
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Nathan, I think blueprinting can probably mean whatever someone wants it to mean. Kinda like a rebuild--whereas an overhaul is defined in the FAR's. Most of what people have just described as blueprinting sounds to me like they balanced the engine and flowed (or ported and polished) the intake and exhaust systems. I would think that blueprinting means to take the blueprint dimensions for each part, like the cam, and making sure the parts all actually "measure up" (pun intended).
I also think that some of this stuff is not approved on a certified engine. Balancing pistons by picking out 4 that weigh the same is OK, changing the weight of a piston by drilling,grinding, etc to match the others is not. Same with grinding/polishing/etc on the cylinder heads, etc. Just because it makes more power and is smoother and may in fact actually make for a better engine, doesn't mean it's approved. Kinda like C-85 pistons and a C-90 cam in an O-200-- good stuff, just don't get caught.
Of course, for an experimental, anything goes.
Eric
I also think that some of this stuff is not approved on a certified engine. Balancing pistons by picking out 4 that weigh the same is OK, changing the weight of a piston by drilling,grinding, etc to match the others is not. Same with grinding/polishing/etc on the cylinder heads, etc. Just because it makes more power and is smoother and may in fact actually make for a better engine, doesn't mean it's approved. Kinda like C-85 pistons and a C-90 cam in an O-200-- good stuff, just don't get caught.
Of course, for an experimental, anything goes.
Eric
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jim pacquin
balance
in the 80's I flew a mooney that had had a VICTOR overhaul 150 hours before. I THINK....I dont know for sure, that they balance EVERYTHING! Valves, Pistons, you name it. In any event it started immed. it ran like a honda , VERY smooooth, and performned very nicely. When I (who am not a mechanic) look at the inside of an 85 continental and see its simple design,and sloppy tolerances, its amazing that it can cost 10-12 thousand to overhaul these ancient lawnmower engines! Then on top of this, people put them together doing sloppy work, sometimes not even knowing what their doing,use "yellow ticketed" parts that are or are not legit (yellow ticketed by WHO?) and we pay thousands for lousy engines. And...some of the worst work is done by supposed "PROFESSIONAL " shops.
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Paul Agaliotis
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Blueprinting is an old hotrodders term for checking the engine components size and installation is correct. The size is easy to measure but the installation can be harder to get correct.
With the small Continentals when #1 is on TDC the next cylinder to fire should be at TDC exactly 90 degrees later. If it is not, the crankshaft would require to be index ground. This is an example of a blueprinting process. I have found some V8 engines to be as much as 5 degrees off.
Paul
With the small Continentals when #1 is on TDC the next cylinder to fire should be at TDC exactly 90 degrees later. If it is not, the crankshaft would require to be index ground. This is an example of a blueprinting process. I have found some V8 engines to be as much as 5 degrees off.
Paul
Mailing Adress : Paul Agaliotis 2060 E. San Martin, San Martin,Calif. 95046
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Nathan K. Hammond
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Jim,
Know what you mean. I believe that it was Mike Berg who had a engine that was just not running right. He pulled one cylinder and found that it was something like .015 over with standard pistons and rings in it, so my feeling is that I would rather personally build an engine and know for sure that its right inside than trust a shop that I did not know.
Regarding Eric's comments. I may not be legal to remove weight while balancing but do not believe that anyone would have a problem with it if its done correctly and within limits. Matching piston and rod weights goes a long way, then getting them to a gram of each other works wonders as Jim mentioned on the engine he flew with.
JoeA
Know what you mean. I believe that it was Mike Berg who had a engine that was just not running right. He pulled one cylinder and found that it was something like .015 over with standard pistons and rings in it, so my feeling is that I would rather personally build an engine and know for sure that its right inside than trust a shop that I did not know.
Regarding Eric's comments. I may not be legal to remove weight while balancing but do not believe that anyone would have a problem with it if its done correctly and within limits. Matching piston and rod weights goes a long way, then getting them to a gram of each other works wonders as Jim mentioned on the engine he flew with.
JoeA
In my case, the guy put standard rings on a .015 over piston. Having said that, anyone can make a mistake and I wouldn't have thought too much about it, if the piston hadn't been marked .015 right on top and the ovehaul log stated: "All engine parts measured new standard". At this point everything seems to be running pretty well, so hopefully everything else is right. I'm gathering A65 parts though, anyway and will build the next engine myself (with my AI looking over my shoulder).
By the way, no report back from Wag Aero on engine mount rubbers other than what I posted before. So I don't know if that means we're out of business on decent mounts or .........?????? I'm going to try a set of those Continental mounts, though and see if they're any better. Right now it's less than 20 degrees so it will have to wait until next spring unless I find a heated hanger.
By the way, no report back from Wag Aero on engine mount rubbers other than what I posted before. So I don't know if that means we're out of business on decent mounts or .........?????? I'm going to try a set of those Continental mounts, though and see if they're any better. Right now it's less than 20 degrees so it will have to wait until next spring unless I find a heated hanger.
"If God had intended man to fly He would have given us more money"
blueprinting
Jim: Yup that yellow tag crap should be taken with a grain of salt. Two examples that I have run into. Camshafts with lousey grinds for equal lift and duration. Lifter bodies that have the barrels cleaned to the point that they are beyond the sloppy Continental wear limit in the case. Can you say (low oil pressure)? Not all yellow tagging is bad, but not all of it is good.
Ron
Ron
Before you believe anything I say, check with two more people. If they agree, I must be right.
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jim pacquin
balancing,etc.
I joined the assoc. in august when I bought my 85 champ. I really appreciate the help Ive gotten from all of you concerning various engine problems, etc. I live in Baltimore in the winter, near mayville,n.y. in the summer (dart airport) where my aeronca is hangared. Its a great airport and I hope some of you stop in when it warms up in the spring. IF my 85 gets funny noises, I really feel good knowing I can get on here and hear from you who know engines! I know where the exhaust comes out and where the prop is and thats about it. (Im a member, not a "guest")