Numbers Matching? Why should I care?
06-19-2023, 08:16 PM
#81
Safety Car
Carl- Please allow me to pose a completely different hypothetical situation to you... and then, ask your thoughts.
Letz suppose that in 196X, a set of twins were gifted the EXACT same set of C2 Corvettes, for a high school graduation present.
EXACT same body style, colors, options... they saved all the original paperwork, and pampered them during their ownership.
The twins are now selling these TWIN Corvettes... they both have the EXACT same mileage, and cosmetically appear EXACTLY the same.
There is no way you can 'easily' tell the two cars apart... they drive EXACTLY the same, and are priced EXACTLY the same.
Now the 'slight' deviation... one of the Corvettes has a CE replacement block, but it 'appears' EXACTLY like the other.
In my opinion, at least 90% of people would take home the Corvette with the ORIGINAL engine.
Additionally, most people would see the increased 'value' of having the ORIGINAL engine, over a replacement block.
If you disagree, I'm sorry... I can explain it to you, but I can't understand it for you.
Please note, I have nothing against a replacement engine, as either Corvette will provide the EXACT same driving pleasure/experience.
So if you would have opted for, and paid the EXACT same price for the Corvette with the CE engine... kindly educate us on your decision.
Letz suppose that in 196X, a set of twins were gifted the EXACT same set of C2 Corvettes, for a high school graduation present.
EXACT same body style, colors, options... they saved all the original paperwork, and pampered them during their ownership.
The twins are now selling these TWIN Corvettes... they both have the EXACT same mileage, and cosmetically appear EXACTLY the same.
There is no way you can 'easily' tell the two cars apart... they drive EXACTLY the same, and are priced EXACTLY the same.
Now the 'slight' deviation... one of the Corvettes has a CE replacement block, but it 'appears' EXACTLY like the other.
In my opinion, at least 90% of people would take home the Corvette with the ORIGINAL engine.
Additionally, most people would see the increased 'value' of having the ORIGINAL engine, over a replacement block.
If you disagree, I'm sorry... I can explain it to you, but I can't understand it for you.
Please note, I have nothing against a replacement engine, as either Corvette will provide the EXACT same driving pleasure/experience.
So if you would have opted for, and paid the EXACT same price for the Corvette with the CE engine... kindly educate us on your decision.
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carl3989 (06-20-2023)
06-19-2023, 09:39 PM
#82
I fully understand your theoretical. I have 2 C2’s with original, born with block / stamps. The 3rd is a new from GM CE. In your theoretical assume both have 100k miles, which is reasonable. The original engine will be well worn unless rebuilt. If rebuilt, something always gets lost. Tuftride on the crank, cam profile or metallurgy, close but not quite valve springs, lower compression from valve recession and/or piston replacement………you get the picture. Now the CE engine may be near new, low miles with original tolerances and metallurgical properties and compression. No rust in the water jackets. I’ll take condition with the CE. There is a market for both.
So pretend both engines were the same age, had the same internals, and similar mileage (apples to apples)... would you still take the CE block, when EVERYTHING was equal?
Now I'll play your game... in answer to the initial question of why the OP should care: The original engine wouldn't matter, if they intended to use the vehicle in a demolition derby.
(I see your ludicrous answer, and raise you one - LOL)
Have phun with your reindeer games... this has turned into a total train wreck... Chugga-Chugga-Choo-Choo
Last edited by 427 Sidepipes; 06-19-2023 at 10:17 PM.
06-20-2023, 04:25 AM
#83
Le Mans Master
Concerning the rebuilt original engine. Was it rebuilt by a fully equipped automotive machine shop with the latest equipment by trained machinists, and rebuilders, and assembled to high standards by a knowledgeable experienced engine assembler similar to what all NASCAR teams employ? Or was the engine rebuilt by a convenient local engine rebuilder with equipment of various types, clocked hours, maintence, and calibration. Does the engine have NOS factory replacement pistons with GM part numbers, or a set of cast replacements made in China, Does it have its original crankshaft which was inspected, magnafluxed, and measured with only polished rod and main journals to preserve their standard dimensions? This is important to experienced engine builders who always measure all five main bearing bore sizes in the block with caps torqued in place and all eight new or reconditioned connecting rods which are pre-assembled and torqued to measure their inside diameters.
This is important because there are factory specs for sizes of torqued bearing bores which control the amount of crush (interference fit) on bearing inserts because only standard size replacement rod and main bearings are available in .001 undersize, standard, and .001 oversize. This makes it possible for the assemblers to adjust oil clearance values of assembled parts to preferred specs by selecting different combinations of the three during engine pre-assembly mock-up checks in order to record his numbers in the build sheet records.
You don't have this option when you are installing crankshafts with rod and main journals reconditioned to various undersizes. Replacement bearings in .010, .020, and .030 undersize are only available in the standard size, no option to choose + or - is made available. This is critical to any experienced engine builder. This means shop employees charged with honing the rods and regrinding the crankshaft must be experienced enough to hit target sizes every time, any miscalculation here means it's possible the engine could get reassembled with incorrect oil clearances. If your rebuilt engine did not come with records which show these measured and recorded values you might have some unknowns inside.
This is important because there are factory specs for sizes of torqued bearing bores which control the amount of crush (interference fit) on bearing inserts because only standard size replacement rod and main bearings are available in .001 undersize, standard, and .001 oversize. This makes it possible for the assemblers to adjust oil clearance values of assembled parts to preferred specs by selecting different combinations of the three during engine pre-assembly mock-up checks in order to record his numbers in the build sheet records.
You don't have this option when you are installing crankshafts with rod and main journals reconditioned to various undersizes. Replacement bearings in .010, .020, and .030 undersize are only available in the standard size, no option to choose + or - is made available. This is critical to any experienced engine builder. This means shop employees charged with honing the rods and regrinding the crankshaft must be experienced enough to hit target sizes every time, any miscalculation here means it's possible the engine could get reassembled with incorrect oil clearances. If your rebuilt engine did not come with records which show these measured and recorded values you might have some unknowns inside.
Last edited by Greg Gore; 06-20-2023 at 04:58 AM.
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BAD-L88 (06-22-2023)
06-20-2023, 05:51 AM
#84
Pro
Wow
Concerning the rebuilt original engine. Was it rebuilt by a fully equipped automotive machine shop with the latest equipment by trained machinists, and rebuilders, and assembled to high standards by a knowledgeable experienced engine assembler similar to what all NASCAR teams employ? Or was the engine rebuilt by a convenient local engine rebuilder with equipment of various types, clocked hours, maintence, and calibration. Does the engine have NOS factory replacement pistons with GM part numbers, or a set of cast replacements made in China, Does it have its original crankshaft which was inspected, magnafluxed, and measured with only polished rod and main journals to preserve their standard dimensions? This is important to experienced engine builders who always measure all five main bearing bore sizes in the block with caps torqued in place and all eight new or reconditioned connecting rods which are pre-assembled and torqued to measure their inside diameters.
This is important because there are factory specs for sizes of torqued bearing bores which control the amount of crush (interference fit) on bearing inserts because only standard size replacement rod and main bearings are available in .001 undersize, standard, and .001 oversize. This makes it possible for the assemblers to adjust oil clearance values of assembled parts to preferred specs by selecting different combinations of the three during engine pre-assembly mock-up checks in order to record his numbers in the build sheet records.
You don't have this option when you are installing crankshafts with rod and main journals reconditioned to various undersizes. Replacement bearings in .010, .020, and .030 undersize are only available in the standard size, no option to choose + or - is made available. This is critical to any experienced engine builder. This means shop employees charged with honing the rods and regrinding the crankshaft must be experienced enough to hit target sizes every time, any miscalculation here means it's possible the engine could get reassembled with incorrect oil clearances. If your rebuilt engine did not come with records which show these measured and recorded values you might have some unknowns inside.
This is important because there are factory specs for sizes of torqued bearing bores which control the amount of crush (interference fit) on bearing inserts because only standard size replacement rod and main bearings are available in .001 undersize, standard, and .001 oversize. This makes it possible for the assemblers to adjust oil clearance values of assembled parts to preferred specs by selecting different combinations of the three during engine pre-assembly mock-up checks in order to record his numbers in the build sheet records.
You don't have this option when you are installing crankshafts with rod and main journals reconditioned to various undersizes. Replacement bearings in .010, .020, and .030 undersize are only available in the standard size, no option to choose + or - is made available. This is critical to any experienced engine builder. This means shop employees charged with honing the rods and regrinding the crankshaft must be experienced enough to hit target sizes every time, any miscalculation here means it's possible the engine could get reassembled with incorrect oil clearances. If your rebuilt engine did not come with records which show these measured and recorded values you might have some unknowns inside.
06-20-2023, 07:34 AM
#85
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Member Since: Apr 2005
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Well this has certainly gone off the rails.
Back to Carl. You questioned why should you care? Answer is you either do or you don’t and the why is up to you to decide.
To me the only why would be if I wanted a matching #s car and was willing to pay a premium for it. Then question then would be how much of a premium would I pay. And that is they question nobody can answer for another person.
My 67 BBC Coupe is a NOM car. If it was matching #s engine I would have be willing to pay $8-$10k more. Not because I wanted a #s car but because it’s probably worth it to somebody down the road.
That said the down side is that many people with #s engine are afraid of blowing them up so they don’t drive them much and when they do they baby them. That’s not for me.
Back to Carl. You questioned why should you care? Answer is you either do or you don’t and the why is up to you to decide.
To me the only why would be if I wanted a matching #s car and was willing to pay a premium for it. Then question then would be how much of a premium would I pay. And that is they question nobody can answer for another person.
My 67 BBC Coupe is a NOM car. If it was matching #s engine I would have be willing to pay $8-$10k more. Not because I wanted a #s car but because it’s probably worth it to somebody down the road.
That said the down side is that many people with #s engine are afraid of blowing them up so they don’t drive them much and when they do they baby them. That’s not for me.
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427 Sidepipes (06-20-2023),
Helix9595 (06-20-2023)
06-20-2023, 07:50 AM
#86
Pro
Yep
Well this has certainly gone off the rails.
Back to Carl. You questioned why should you care? Answer is you either do or you don’t and the why is up to you to decide.
To me the only why would be if I wanted a matching #s car and was willing to pay a premium for it. Then question then would be how much of a premium would I pay. And that is they question nobody can answer for another person.
My 67 BBC Coupe is a NOM car. If it was matching #s engine I would have be willing to pay $8-$10k more. Not because I wanted a #s car but because it’s probably worth it to somebody down the road.
That said the down side is that many people with #s engine are afraid of blowing them up so they don’t drive them much and when they do they baby them. That’s not for me.
Back to Carl. You questioned why should you care? Answer is you either do or you don’t and the why is up to you to decide.
To me the only why would be if I wanted a matching #s car and was willing to pay a premium for it. Then question then would be how much of a premium would I pay. And that is they question nobody can answer for another person.
My 67 BBC Coupe is a NOM car. If it was matching #s engine I would have be willing to pay $8-$10k more. Not because I wanted a #s car but because it’s probably worth it to somebody down the road.
That said the down side is that many people with #s engine are afraid of blowing them up so they don’t drive them much and when they do they baby them. That’s not for me.
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427 Sidepipes (06-20-2023)
06-20-2023, 10:27 AM
#87
Back to Carl. You questioned why should you care? Answer is you either do or you don’t and the why is up to you to decide. To me the only why would be if I wanted a matching #s car and was willing to pay a premium for it. Then question then would be how much of a premium would I pay. And that is they question nobody can answer for another person..
As long as the purchase price was 'reasonable', caring is no longer a factor. Drive it and have fun... absolutely NOTHING wrong with a replacement engine.
06-20-2023, 10:59 AM
#88
Safety Car
Here we go again... another person adjusting the conditions/circumstances, to favor one side (thatz not fair, but you aren't the first to try).
So pretend both engines were the same age, had the same internals, and similar mileage (apples to apples)... would you still take the CE block, when EVERYTHING was equal?
Now I'll play your game... in answer to the initial question of why the OP should care: The original engine wouldn't matter, if they intended to use the vehicle in a demolition derby.
(I see your ludicrous answer, and raise you one - LOL)
Have phun with your reindeer games... this has turned into a total train wreck... Chugga-Chugga-Choo-Choo
So pretend both engines were the same age, had the same internals, and similar mileage (apples to apples)... would you still take the CE block, when EVERYTHING was equal?
Now I'll play your game... in answer to the initial question of why the OP should care: The original engine wouldn't matter, if they intended to use the vehicle in a demolition derby.
(I see your ludicrous answer, and raise you one - LOL)
Have phun with your reindeer games... this has turned into a total train wreck... Chugga-Chugga-Choo-Choo
.
06-20-2023, 11:25 AM
#89
Just an exercise to point out an original engine will not have the same history/mileage of the CE unless it came from St. Louis with a CE, which we know didn’t happen. So the premise they are equal cannot be. But you be happy and drive yours, I’ll be happy and drive mine .
.Some folkz find that too hard to comprehend, and prefer to argue a totally different scenario.
Bon voyage...
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Vega$Vette (06-20-2023)
Maybe you missed the OPs post was theoretical?
06-20-2023, 12:04 PM
#91
06-20-2023, 12:39 PM
#92
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Oh just stop.....