Duplicating C2 engine BROACH marks...

[magstar67]

I picked up my engine from the machine shop this week, in the process of the rebuild they had to deck the block, unfortunately they milled over part of the stamp pad. The numbers are still easily readable but about half of the broach marks are now gone and that part of the pad has the 'rotary' style of machined surface commonly seen today.

I know folks are recreating the broach marks on restamped blocks, this may be a taboo subject here but I need to know if I can fix my pad so it looks correct...any suggestions for recreating the GM broach marks?

Thanks, magstar67@yahoo.com

[Wayne W.]

Re: Duplicating C2 engine BROACH marks...

It will be much better just to leave it like it is. You can explain that situation, but if you try to hide it it will cast more doubt than good.

[Dave Suesz]

I'll ask one question...

(rhetorically) The original numbers are still visible. Are you ashamed you had your engine rebuilt? No? Then why would you try to cover up the fact? (OK, three questions)

[Ken K.]

Re: Broach Marks.

Being that we are talking about "Broach Marks", Does anyone have a have nice photo a motor stamp pad with these Broach marks? I what to make sure the my 1967 motor wasn't re-stamped. Can these marks be seen by a naked eye? Is there anyway to help bring these marking out better? The stamp pad should not be painted, correct? Should the two different stamping, (vin numbers, assembly plant code) be the same size, or is one bigger that the other? Thanks

[Joe C.]

Re: Broach Marks.

Ken:

Pad should not be painted, or coated with anything other than a film of motor oil as a protectant.
Broach marks can be seen with the naked eye, but originality will become apparent under magnification.
VIN derivative is 3/16". Alphanumeric date/engine code is 1/4".

[Tracy C.]

See pg 12 of Volume 30 #2 Fall 2003 issue of the

Corvette Restorer.

There is a couple of good clear pictures of 66 big blocks in the article written by Everett Ogilvie. (Great article Everett!)

I don't know if font size or character order changed for 67, but you can see the verticle broach marks in these pictures. Albeit, the lower pad has some rust pitting, the marks are still visible.

tc

[Dick W.]

Re: Broach Marks.

One of the best ways to view correct broach marks and stamps is to go find an Impala or pickup of that era that still has the stampings on it (not milled off with a rotary mill). remember that VIN characters changed in "68?. No one will spend the effort to stamp a motor in a lowly pickup unless it might be a 402, or 427. When I was doing restorations I would use cars and trucks for references on pads. Yer mind can get fuzzy looking at too many Vettes. All of the sudden what is real and what is restamped?

[Terry M.]

Saa also V20 #4, spring 1994, cover

It is a small block, but the pad stretches over both front and back covers, and is larger than life size.

[Patrick T.]

Re: Broach Marks.

Here is my '67 small block pad with the Al Grenning seal of approval. The lines are faint, but they are there. PT

[Tracy C.]

Re: Broach Marks.

Very Nice Patrick...

I've seen many references to Al Grenning on this board. Does he evaluate and/or provide pictures of period (+/- 30 days) examples upon request?

Are quality digital pics like this availible from him?

tc

[Patrick T.]

Re: Broach Marks.

I think Al has a message in the NCRS Driveline under "information wanted". You may want to check there. PT

[Bill Stephenson]

Re: Broach Marks.

Patrick,

-----How do you figure that 6 got there under the 1? Not being judgemental at all,just wondering........Bill S