dc2 man
Posts: 2074
Score: 118
Joined: 2/8/2009
Last Login: 3/15/2010
From: limerick, IRELAND
Status: offline
|
Engine Blueprinting...IN DETAIL FOR WAQR... 
Blueprinting
Blueprinting is the remachining of components to tighter tolerances to achieve better balance.
Ideally, blueprinting is performed on components removed from the production line before normal balancing and finishing. If finished components are blueprinted, there is the risk that the further removal of material will weaken the component. However, lightening components is generally an advantage in itself provided balance and adequate strength are both maintained, and more precise machining will in general strengthen a part by removing stress points, so in many cases performance tuners are able to work with finished components and go the quest for maxmium from this engine in every aspect.
Engine blueprinting is a standard procedure utilized at a machine shop. Blueprinting your engine is completely nessassary to obtain maximum power and to insure the longest possible engine life and reliability. It also adds discipline to the process which decreases any chance of engine failure due to improper clearances.
When people set out to build the ULTIMATE ENGINE they blueprint it which means hand building an engine with perfectly fit components using maximum and minimum recommended clearances. These specifications are determined using this cad engine 35 years of engine building experience.
The Engine Blueprint Process
First, one needs to make sure all parts are one hundred percent clean. This is done by boiling the block, making certain water jackets are perfectly clean.you would also inspect and analyze the block (especially if it's used) bolt holes would be re-tapped, cleaned and oiled, as well as their mating bolts. Any surfaces refinish will have all holes chamfered, and any casting burrs or irregularities will be ground away.
this would be how a car engine would be blueprinted so same technique and painstaking effort would apply to my zenoah cad engine.
on a car or anything with The V type block it will be align bored to maintain perfectly equal deck heights and keeping the crankshaft parallel to the decks. Any variation in these areas will result in irregularities in combustion chamber volume. This is critical in the accurate and precision blueprinting process.
After align boring, cylinders are bored with the main bearing caps still torqued in place. then finish hone the cylinders to their proper size using a 220-280 grit stone and taking care to obtain a good cross hatch pattern. After honing the block it must be boiled again, taking care to remove all honing grit from the bores and also from the lower end of the block.
The crankshaft must have correct angularity of the rod throws as well as be perfectly straight. If your block is used it will be checked for cracks and have the journals ground to perfect angular index. Oil holes get chamfered and bearing surfaces polished. The oil passages are then cleaned thoroughly with a good brush.they would use fully grooved main bearings or groove or cross drill the crankshaft main bearing journals. These procedures are also helpful in insuring longer engine life.
If used the connecting rods will be carefully checked for imperfections and Magnafluxed. All rods are reworked so they are EXACTLY the same length from crankshaft centerline to wrist pin centerline. Generally the length of the rods will be controlled by working to the minimum manufacturer's clearance for piston to deck. Any burrs and irregularities will be removed from the rods, and always use new rod bolts and nuts. The rod alignment and side clearance are also critical.
The pistons should be individually and carefully fit to the respective pins. Chamfering any sharp edges on the piston reduces possibility of localized hot spots which cause pre-ignition and/or detonation. Each piston is carefully matched for clearance with each bore. Too little clearance will result in scuffing and too much clearance reduces the effectiveness of the rings.
The compression rings should each be placed in the bore and straightened with the top of a piston to square the ring in the bore. Gaps can then be checked, with .0035 per inch of bore the minimum allowable gap. also sure to check ring side clearance in piston groove. The maximum is .006 but .003-.004 is most desirable.
Now that the main reciprocating components are selected and fit, the engine roatating assemblies be balanced. they would continue balancing with rings, pistons, rods, bearings, crankshaft, flywheel, crankshaft dampner and pulley.(remember this would be a four cylinder four stroke procedure) but you are seeing the meaning and detail involved in the "blueprinting process... Some engines recommend an allowance for oil weight in the crankshaft when balancing. Additional weight is added to the bob weights in these cases to compensate for oil weight. Balancing will provide insurance for engine durability, and will also help obtain maximum horse-power.
The cylinder head is disassembled, cleaned and carefully inspected for cracks. If the surface is in questionable condition they would go ahead and resurface it. All holes and sharp edges should be carefully chamferred and deburred. Bolt and spark plug holes get retapped and cleaned. The valve guides are checked and replaced or repaired as necessary.
would also check valve stems and replace those valves not acceptable. This is also the time we machine the valve guides if necessary for the installation of seals. The valve job should be done according to recommendations for the engine.
All burrs and irregularities should be polished out of the combustion chamber. After this the chambers should be checked for volume in cubic centimeters. The chambers are then enlarged by grinding to the volume of the largest chamber. When all chambers are equalized the desired minimum CC's you can mill the heads carefully until the correct volume is reached.
In order to check the CC volume of the chamber a Plexiglas plate, light oil, and a chemical burette are needed. With the spark plug and valves installed the plate is placed over the combustion chamber and sealed with a light coat of lubricant. Using the burette it is then a simple matter to measure the amount of liquid needed to fill the combustion chamber.
Valve springs are checked for tension and installed height, and replaced or shimmed as needed. If the head has individual rocker arms on studs the stud should be threaded or pinned in its boss.
The next step is to torque main bearing and rod bolts slowly and in progressive steps to the proper tension. they would use protectors on the rod bolts to prevent crankshaft scars, and keep rotating the engine as each step in the installation of the crankshaft and pistons is taken. This will enable spotting the exact location of any misfit or mismatched parts.The use of Plastigage here will serve as a double check on clearances.
then install the timing gears and chain the use of a camshaft degree wheel will insure perfect crankshaft to camshaft timing.
Offset keys or cam gear bushings are available to allow accurate adjustment of possible timing discrepancies.
After installing the heads, one would make sure they are torqued to the proper specifications, the valve train will then be completed and checked. In cases where higher lift camshafts have been installed it is possible to have the valve spring bottom out, or the canoe type rocker be interfered with by its mounting stud. Where this happens the spring must be changed, and the rocker arm relieved to provide the necessary clearance.
The complete engine build they would go through must be performed as painstakingly and accurately as possible. The blueprinted engine is the utmost in performance, horsepower and durability possible.
When your engine was mass produced by the manufacturer, the various parts were made to an ideal size, give or take a bit. Unfortunately with all the parts giving or taking a bit you end up with an engine that is not all that ideal. On the other hand, if you have an engine made up from all ideal parts, you have a real beauty and don't let it out of your sight.
Blueprinting is just a method of adjusting or machining parts to bring them back to the specified tolerance without giving or taking. This is a highly specialised job, and should be done by experts in conjunction with the latest rule book.
over time waqr i have done a lot of research and i hope this helps you.this info is based on a 1/1 scale machine but you can see the detail that goes in to a BLUEPRINTED engine,so this will give you some idea of the work and detail that will be in this cad zenoah 27cc....
dc
< Message edited by dc2 man -- 5/14/2009 10:32 PM >
_____________________________
MAXED ELCON BEETLE|FG-EVO|GT5-R|CARSON|NUTECH|SOLO|CAD|JETPRO|MF|
http://www.rcuniverse.com/forum/m_9126147/tm.htm
Hide Signatures
|
Search This Thread
Printable Version
All Forums >> RC Cars, Buggies, Trucks, Tanks and more >> RC Giant Scale Cars >> RE: FG BEETLE PRO REBUILD THREAD(my style) 
RE: FG BEETLE PRO REBUILD THREAD(my style) - 
One stupid question: What does blueprinted means 
? 
