BlownChevy

iTrader: (20)

I plan on B&B with the new motor....the de burring goes without question! I agree with the above post, you can never be to careful when it comes to the money some of our toys cost.

hog

Balance and blueprint is perhaps the most overused phrase that people dont know the meaning for.

Balancing-making sure that each part of the rotating assembly isthe same or near the same weight, being out of ballance will create destructive harmonics
the total weight of each rod is equalized with the other rod and both ends of the rod are equalled, then teh weight of each rod and piston assembly are spun on the crank for fial balancing, I have seen some balanced kits advertise "balanced to withing 1/2 a gram". You usually pay more money for a more specific balance job. Some rotating assemblies come balanced some dont. If a part is to light, it get "heavy metal" to add mass, if its too heavy, it gets drilled, look at any flexplate or flywheel and you will see the drill bores.

Blueprinting-the method of building an engine from a list of pre-picked specs.
A house is built froma blueprint, these plans back in the day were actually drawn with blue ink, hence the name, blueprint.
Lets say you were building and engine, if it is a gasioline street engine, its bluprint might include a certain ring gap, comp ratio and bearig clearances.
If the engine is a nitrous race engine, its blueprint would include a looser top ring gap probably and maybe a different specs throughout the engine.

To blueprint an engine means to build from a blueprint of predetermined engine specs, if something is built from a blueprint, usually someone with some sort of expertise has put their building specs. Back in the day an engineer would put a blueprint of specs in front of a tech to follow.

A blueprinted engine would contrast an engine that was just put together without the actual tolerances of teh various parts being known.
If teh engine is blueprinted, you should be able to disassemble the engine and measure every different part of teh engine with a mic. and have that measurement be within a certain tolerance of what the blueprint said it should be.
A blueprint is really like a recipe of all the clearances and measurements of teh various components of an engine.

What seperates a good engine shop from an allright engine shop, is their repeatability or their ability to build Nitrous racing engine #1 EXACTLY the same as Nitrous Racing engine #2. Anyone can throw an engine together, its how the engine FITS together which determines success.

The whole purpose of blueprinting engines is soi that if you were trying a new ring endgap for instance, maybe you had a series of ring failures, you would be able to go back to those blueprints and see exctly what changes were made that might have contributed to those failures. If it wasnt for blueprinting, builders would be shooting in the dark with their combinations.

If someone has an engine that has been ballanced and blueprinted, if the blueprinting and the balancing is of sound quality, that engine should also be of sound quality.

peace
Hog

dewmanshu

iTrader: (4)

I had my stock 5.3 pulled on my new radix installed and had the machine shop build a blueprint as so in the future I could always return to the "print" (a software file nowadays) For spec checks and so forth. Bore .020 over JE SC pistons, but I kept the stock bottom. I figured the balancing and "smoothing would help with longevity (plus $ was a factor). I remember looking at the stock rods when I got it back and you could see where they "ground" spots on particualr areas of them to make them all balance.

3 months later I lost the thrust bearing. (After two transmissions did I figure I finally figure that out.) That machine shop is out of business today and more importantly...once the thrust went. You couldn't be more right with the difference between a great shop and a good shop is the ability to keep #1 and #2 the same. I didn't do my research well enough cuz I found out later the shop I used was notorious for inconsistency.

"Blueprinting" is a great idea if you are building a motor ground up, it would be nice to have references for future work and changes. Balancing should just be a give me.

IDISAPR

Any motor you are willing to spend the time to put together yourself is worth the extra cost. I don't think the cost factor is that much in the overall picture, and the piece of mind is worth while, I always felt like it's the little things that payoff down the road.

That being said, if I were just doing a R&R, I don't think I'd go through the process. I think overall factory tolerances are close enough for a street motor that isn't seeing all that much RPM anyhow.

moregrip

iTrader: (8)

LPE has a nice description of all the procedures they perform in thier balance and blueprint, very nice