Balancing and blueprinting...what are they doing?

[cremmenga]

follow the link provided earlier in the thread and your question will be answered

OK, here it is again. http://www.hastingsmfg.com/Service%2...ueprinting.htm

its a dead link for me man.

[montoya_fan01]

try it now

[TomoHawk]

Spot on about balancing. But the important thing about balancing is to have it done While the engine is being rebuilt, as it has to come totally apart any way. No reason to disassemble it again after it was reassembled.

[Zrush]

Spot on about balancing. But the important thing about balancing is to have it done While the engine is being rebuilt, as it has to come totally apart any way. No reason to disassemble it again after it was reassembled.

Tomo that's the only way to truly balance an engine is when it's apart. It's MOST inportant when your putting in hi-po parts that didn't come in a stock motor. Zrush is balanced due to all internals are preformance parts. Scott actually went to the shop and watched the process. Matter of fact every rotating part (drive shaft, half shafts) and such were balanced. Costs extra but everything on that particular Z cost extra so what the hell.:paranoid:

Do it right the first time on any rebuild.

Vicky

[Sundowner]

balancing is an essential part of an engine rebuild if you plan on revving the hell out of the motor, since rotational imbalance increases with the cube of the rpm, IIRC. I just built a toyota 22rte and I did not rebalance it. that motor has a pitiful 5000 rpm redline, and I'll never hit that in my truck, anyway.

balancing in a very old motor makes all the difference in the world. they did not have the balancing technology in the 70's that they do today. remember the old muscle car shaker hoods? why do you think they shook? look at a 69 Mach 1 mustang next to a 2004 Mach 1 mustang. they have the same shaker hood, but the 04 is dead still while the 69 bops around in the hood.

blueprinting is a little different. when the factory assembles a motor, they allow for certain tolerances due to cost reasons. for instance, oil clearance for the main journals on the aforementioned toyota crank are about .020" from the factory. the min oil clcearance is .015 and the max (fresh assembly) is 0.25. when the builder blueprints that crank and bearigs, every tolerance is dead-nuts 0.020. what does this mean for you? maybe 15-20 hp that will last about 20k miles until the tolerances wear-in and even out to whatever odd number they're happy at. what does this mean to a stock-class SCCA race driver? it's the difference between winning and losing on an engine that will get torn down again after the racing season is over.

[bpilati]

balancing is an essential part of an engine rebuild if you plan on revving the hell out of the motor, since rotational imbalance increases with the cube of the rpm, IIRC. I just built a toyota 22rte and I did not rebalance it. that motor has a pitiful 5000 rpm redline, and I'll never hit that in my truck, anyway.

balancing in a very old motor makes all the difference in the world. they did not have the balancing technology in the 70's that they do today. remember the old muscle car shaker hoods? why do you think they shook? look at a 69 Mach 1 mustang next to a 2004 Mach 1 mustang. they have the same shaker hood, but the 04 is dead still while the 69 bops around in the hood.

blueprinting is a little different. when the factory assembles a motor, they allow for certain tolerances due to cost reasons. for instance, oil clearance for the main journals on the aforementioned toyota crank are about .020" from the factory. the min oil clcearance is .015 and the max (fresh assembly) is 0.25. when the builder blueprints that crank and bearigs, every tolerance is dead-nuts 0.020. what does this mean for you? maybe 15-20 hp that will last about 20k miles until the tolerances wear-in and even out to whatever odd number they're happy at. what does this mean to a stock-class SCCA race driver? it's the difference between winning and losing on an engine that will get torn down again after the racing season is over.

So how much does Balancing and Blueprinting add to the total engine rebuild?

[TomoHawk]

That's why the blueprinting is where the big money goes. You can't have just any rebuilder do it. Because the bolts wear & stretch slightly every time you tighten them to check the tolerances, you need to find a guy that can do the job right basically on the first try.

I always thought the muscle car engines shook because they had high-compression engines with a low idle and strange spark timing. Same reason why they don't start easy and wear out starters.

[Sundowner]

That's why the blueprinting is where the big money goes. You can't have just any rebuilder do it. Because the bolts wear & stretch slightly every time you tighten them to check the tolerances, you need to find a guy that can do the job right basically on the first try.

I always thought the muscle car engines shook because they had high-compression engines with a low idle and strange spark timing. Same reason why they don't start easy and wear out starters.

compression on a new muscle car is as high if not higher than that old 351 Cleveland I had in my Mach 1. the starters wear out becuase they're sucky starters. Ever see one of those fancy gear driven starters for high-zoot race motors? it's a $75 off-the-shelf Denso starter with a machined adapter on it. I have the exact same starter in my 84 4runner, stock

[John Coffey]

They explained to me that blueprinting was getting all of the measurements back to "factory" or original specs. but they also all said that it is kinda obsolete because, most of the parts now adays are made so well and to exacte specs so it is not needed in most cases!

Blueprinting is much more then just getting parts back to the factory specs. In racing classes where the car has to run stock internals (crank, rods, pistons, cam, etc.) blueprinting is the meticulous measurement, machining, and fitting of OEM parts to make absolutely the most horsepower. For example:

A stock L24 engine makes about 150hp. A L24 engine prepared by Sunbelt to meet SCCA's ITS rules makes a bit over 200hp using stock internals and a header. That's a 33% increase in power with a stock cam, unported head, stock pistons, rods, crank, etc.

Blueprinting to that level is very expensive because it is almost pure labor.