Team Camaro Tech banner
1 - 20 of 22 Posts

·
Registered
Joined
·
28 Posts
Discussion Starter · #1 ·
Hey guys, brand new here, but I've been reading forum notes for a year now (and since they go back to 1998, there are a LOT,.... you guys have been busy for a LOOONG time!! ;-) :hurray:

2 Questions: 1) I am considering purchase of a BBC block, and noticed that the pad stamp (with suffix code) uses a different "1" for the two ones that are in "T0118MW". The first "one" in the sequence looks exactly like a "Times New Roman" numeral 1. But the second one in the sequence is missing the top leftside extension off the top of the vertical line. It is clear that a different punch tool was used. The rest of the block looks very virgin, and although I am not a expert on Broach marks, the seller says they are there. Did GM sometimes use a different punch tool when two "ones" were next to one another?

2) Since I do not know what to look for in Broach Marks, I was hoping you could explain what they are, and how to identify them.

Thanks guys!!
=Steve
 

·
Registered
Joined
·
7,608 Posts
When the deck was milled, the factory used a broach, which is kind of like reel type lawn mower. The shaft of the tool was parallel with the deck, and ran the length of the block. The markings left are long straight lines running down the length of the deck.

When most machine shops deck a block they use a fly cut tool. Sort of like a rotary lawn mower. The shaft of the tool is perpendicular to the deck, so the markings are more like swirl marks.
 

·
Registered
Joined
·
28 Posts
Discussion Starter · #4 ·
Thank you both. This is VERY helpful. Never knew how the milling was done at the factory, nor that the machinists were typical to switch punch tools in the middle of marking pads (lots of lunch breaks i guess).
 

·
Registered
Joined
·
5,771 Posts
JohnZ has pics of the factory broaching machinery.

An "I" was commonly used in place of "1" due to broken or worn-out dies. Was a replacement for when there wasnt enough.
 

·
Premium Member
Joined
·
7,728 Posts
The "I" character was almost always used in place of the "1" numeric character. The factory deck broaching process was a lot like using a wood plane on a piece of wood, except the blade was stationary and the block was pushed through it, leaving longitudinal marks parallel to the block centerline.

Photo below is a classic example of well-defined factory broach marks still apparent after 45 years; many blocks had very light broach marks originally, which essentially disappear as the exposed surface ages and oxidizes. There's a lot more to analyzing a pad than seeing whether or not it has broach marks - many don't have their original marks at all any more. :thumbsup:
 

·
Registered
Joined
·
29 Posts
What's the VIN number on the block? You should send it to the Camaro Research Group (CRG) to put into their database. The car might be out there. I'm looking for the original MW block for my car and that date is a possibility. Martin
 

·
Registered
Joined
·
28 Posts
Discussion Starter · #8 ·
Hey Martin.
I mis-typed. It was a MT motor. It was on eBay & did not meet the reserve. I'm not in need of a L89, so not going any further with that one. He may put it back up. I didn't record the VIN. But I'm also interested in a MW, or even a MQ.... so still looking. Good luck,... it's not easy.
And Thanks to John, Dave & UnReal for the notes on dye's & broach marks. cools stuff.
=Steve
 

·
Moderator
Joined
·
3,662 Posts
Could you guys explain something to me ....... unless the block is the exact "numbers matching" block for the car it is in, what the heck does it matter what the numbers are ? I guess I have never understood the value of a "correct date" or "correct engine code" if it is no the actual block that came in the car. A block is a block otherwise. Does it really add that much to the value of a car if its not the actual block it came off the assembly line with ???????

Just curious,
 

·
Registered
Joined
·
7,608 Posts
There is value in the "correct" motor. How much?......depends. But if I'm looking at two identical Camaros, one with an Impala motor, and one with a non-numbers match, but correct Camaro motor, I'll take the latter. I would even pay more, but how much more depends on the motor. If it's an I6, probably no more; if it's a 350 2bbl, probably a little more; but if it's an L78, I'd probably pay quite a bit more for the "correct" motor.
 

·
Premium Member
Joined
·
11,170 Posts
Although I am not really into the "numbers" game, if I was shopping for a car I would not pay a penny more for it unless is was the engine that came with it.
But if the numbers were decked off, then you could not prove its the motor that the car was born with, unless you have vin on the side of the block. Right? Only thing other than that would the the castings #'s and date casting, Right? Or do we need the CSI group too?
 

·
Registered
Joined
·
1,657 Posts
Could you guys explain something to me ....... unless the block is the exact "numbers matching" block for the car it is in, what the heck does it matter what the numbers are ? I guess I have never understood the value of a "correct date" or "correct engine code" if it is no the actual block that came in the car. A block is a block otherwise. Does it really add that much to the value of a car if its not the actual block it came off the assembly line with ???????

Just curious,
Bill,

For me if a fairly original car had a replacement block that was date code and casting "correct", it would add some value to the car.

My car didn't have the original water pump on it so I found one that had the correct date and casting number and installed it. No it's not "original" to the car but it is the "correct" water pump for the car.

Same for some with a block or any other part, original, no, correct casting number and date code, yes.

Some of us like to see how close we can get our cars to exactly how they rolled off the assembly line, with original parts.

You don't have the "numbers" disease so it will be a little hard to convince you. o)

Hope that helps a little,

Doug
 

·
Premium Member
Joined
·
3,320 Posts
Car was for sale for a loooong time in San Jose California
 
1 - 20 of 22 Posts
Top