Does this make sense?
Thread Starter
Pro
Joined: Sep 2006
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From: Raymore, i.e., Kansas City MO
Does this make sense?
Here's part of an item description on ebay. The seller claims all numbers totally match. Then I read this part....
"All cast numbers are unaltered original and a perfect match to the car. The pad was resurfaced, broached and stamped with the correct numbers."
What does that mean?
And what are factory broach marks anyway?
Thanks for helping reduce my ignorance.
"All cast numbers are unaltered original and a perfect match to the car. The pad was resurfaced, broached and stamped with the correct numbers."
What does that mean?
And what are factory broach marks anyway?
Thanks for helping reduce my ignorance.
Le Mans Master
Joined: Jul 2000
Posts: 8,506
Likes: 3
From: Calhoun, GA_______ Let It Rock
Blocks were put through a machine that would cut/shave/level where the cyl. head bolts to it. If the cutting blades on the machine started to get dull. It would leave cut marks (looks like swirls) on the exposed pad. The head or blades would rotate. Making it look like swirls on the exposed pad.
Smaller machine shops do not have such a machine. They can do the same thing. But, it leaves it without those marks. Some people look for the marks as another indication of an original engine. Rebuilding an engine, it is fairly common practice to deck the block. To provide a perfectly flat mating surface for the cyl. head.
Now....it sounds a little weird (to me) for someone to go to the trouble to try and replicate broach marks. But, the seller was upfront about the effort to put them back.
Instead of "matching numbers" and "correct to the car" stuff. Ask if, the engine is the one that was in it. When it left the factory.
Smaller machine shops do not have such a machine. They can do the same thing. But, it leaves it without those marks. Some people look for the marks as another indication of an original engine. Rebuilding an engine, it is fairly common practice to deck the block. To provide a perfectly flat mating surface for the cyl. head.
Now....it sounds a little weird (to me) for someone to go to the trouble to try and replicate broach marks. But, the seller was upfront about the effort to put them back.
Instead of "matching numbers" and "correct to the car" stuff. Ask if, the engine is the one that was in it. When it left the factory.
Le Mans Master
Joined: Feb 2006
Posts: 6,048
Likes: 5
From: "cutesy" TN
Originally Posted by Grey Ghost
Blocks were put through a machine that would cut/shave/level where the cyl. head bolts to it. If the cutting blades on the machine started to get dull. It would leave cut marks (looks like swirls) on the exposed pad. The head or blades would rotate. Making it look like swirls on the exposed pad.
Smaller machine shops do not have such a machine. They can do the same thing. But, it leaves it without those marks. Some people look for the marks as another indication of an original engine. Rebuilding an engine, it is fairly common practice to deck the block. To provide a perfectly flat mating surface for the cyl. head.
Now....it sounds a little weird (to me) for someone to go to the trouble to try and replicate broach marks. But, the seller was upfront about the effort to put them back.
Instead of "matching numbers" and "correct to the car" stuff. Ask if, the engine is the one that was in it. When it left the factory.
Smaller machine shops do not have such a machine. They can do the same thing. But, it leaves it without those marks. Some people look for the marks as another indication of an original engine. Rebuilding an engine, it is fairly common practice to deck the block. To provide a perfectly flat mating surface for the cyl. head.
Now....it sounds a little weird (to me) for someone to go to the trouble to try and replicate broach marks. But, the seller was upfront about the effort to put them back.
Instead of "matching numbers" and "correct to the car" stuff. Ask if, the engine is the one that was in it. When it left the factory.
Close; don't take this the wrong way Grey Ghost (Jerry).
"Broach marks" are left by the machine that cut the raw casting. It was a big machine (I heard it described as the size of a locomotive) that cut the block in one stroke. It made the block "true". If the block hasn't been decked it will have straight line left from this procedure. Machine shops can not afford a machine like this. They use a smaller machine to deck the block it uses a rotary cutting tool that leaves "swirls". If you see "swirls" it has been decked. Straight lines are the "broach" marks.
Hope this helps.
Le Mans Master
Joined: Jul 2003
Posts: 6,808
Likes: 24
From: Westport CT
well, that's not all of the current truth either.
Folks have gotten pretty good at recreating "broach marks" too these days. Just ask the good folks up at Engines Limited (sorry to freak out those of you who have engaged them for their broaching-restamping services). Folks have certainly gone beyond the "grind off the old pad with a rotary grinder days".
Sounds like this ebay seller is indicating that the pad has been correctly recreated - either on the original engine that "had to be decked" (the likely story you will hear) or using a cast-date-correct replacement engine.
Folks have gotten pretty good at recreating "broach marks" too these days. Just ask the good folks up at Engines Limited (sorry to freak out those of you who have engaged them for their broaching-restamping services). Folks have certainly gone beyond the "grind off the old pad with a rotary grinder days".
Sounds like this ebay seller is indicating that the pad has been correctly recreated - either on the original engine that "had to be decked" (the likely story you will hear) or using a cast-date-correct replacement engine.
Le Mans Master
Joined: Jul 2000
Posts: 8,506
Likes: 3
From: Calhoun, GA_______ Let It Rock
Mr. knight37128; I call pistols at 30 paces.
j/k
j/k
Originally Posted by knight37128
Close; don't take this the wrong way Grey Ghost (Jerry).
Last edited by Grey Ghost; Oct 17, 2006 at 10:58 AM.
Team Owner
Joined: Oct 2000
Posts: 38,897
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From: Washington Michigan
Originally Posted by mbroadway
And what are factory broach marks anyway?
Thanks for helping reduce my ignorance.
Thanks for helping reduce my ignorance.
