Broaching

[Morris R.]

Saw a 327/350 block this weekend without any broach marks from what I saw, is it possible that a block could leave the factory without any and if so, why would/could that happen ? I ask the ower if he knew, he said that's the way he bought it 15 years ago. Looking for some opinions. Thank you

[Joe L.]

Re: Broaching

Saw a 327/350 block this weekend without any broach marks from what I saw, is it possible that a block could leave the factory without any and if so, why would/could that happen ? I ask the ower if he knew, he said that's the way he bought it 15 years ago. Looking for some opinions. Thank you

Morris-------


It could not happen. The surface of the block had to be machined (broached) and I know of no way to do that without leaving any broach marks, whatsoever. They might be subtle, but they have to be there.

[Frank D.]

Re: Broaching

Engine was probably decked at some point in its past...

[Joe R.]

Re: Broaching

Morris,

Yes, a block could be smooth and I have seen several. Due to rusting the broach marks can disappear as they are not very deep into the surface of the block.
But as Joe L. says they were there when the block left the factory.
You didn't mention but was there any stamped marks on the block? A factory replacement block should have had the letters CE.

JR

[Ray G.]

Re: Broaching

Hello;
Al Grennings books and seminars are worth the time and $s.
Ray

[Joe L.]

Re: Broaching

Engine was probably decked at some point in its past...

Frank-------


Even if it were decked, there would still be broach marks. They would be circular, but there nevertheless.

[Morris R.]

Re: Broaching

Thank you everyone question answered!

[Bruce M.]

Re: Broaching

You may have encountered a case similar to my 66 L36. It has vertical broach marks rather than the normal horizontal ones, and they are very faint, yet the pad is perfectly clean. Al Grenning judged it to be original at BG, so there must be some exceptions out there.

[Michael W.]

Re: Broaching

'Broach' marks are only produced by a 'broaching machine' and not by any other tool- including rotary mills or grinders as used in engine overhaul shops.

The appearance of the marks varies tremendously, usually as a result of tool wear. One block might look almost mirror smooth while another might stop just short of appearing like the Grand Canyon. To think that there is one and only one type of broach mark is incorrect.

If a pad surface was almost mirror smooth 40-50-60 years ago, there's a good chance that any residual machining marks are even less visible now.

[David H.]

Re: Broaching

Hello;
Al Grennings books and seminars are worth the time and $s.
Ray

+1 If you have the opportunity, attend.

[Larry E.]

Re: Broaching

FWIW: Having taken many seminairs with Al Grenning he indicated that it is not unusual to find a original pad w/o broach marks. This is
due to age/moisture and etc.. Of course it had them when new. Larry

[Edward J.]

Re: Broaching

I have a 72 small block that has a pad with little or no broaching and the pad is not a weathered pad, so as Mike W. says tooling bits have something to do with the broach marks.I have to agree with this as I have seen many stamps here on the TDB and while judging (In my short time).

[Roy S.]

Re: Broaching

FWIW: Having taken many seminairs with Al Grenning he indicated that it is not unusual to find a original pad w/o broach marks. This is
due to age/moisture and etc.. Of course it had them when new. Larry

In fact Larry the following comment will cause some stir but it is very true. Absence of Broach marks has never bothered me, what I don't like is the presence of other machine marks. It is safe to say that old cars age, block surfaces age and if the broach marks were barely visible when new the chances of them being visible now are very slim. However the presence of new created surface finishes of any type, or even rust pits in a area that is typically oily/greasy/dirty should raise a flag.

[Gary B.]

Re: Broaching

In fact Larry the following comment will cause some stir but it is very true. Absence of Broach marks has never bothered me, what I don't like is the presence of other machine marks. It is safe to say that old cars age, block surfaces age and if the broach marks were barely visible when new the chances of them being visible now are very slim. However the presence of new created surface finishes of any type, or even rust pits in a area that is typically oily/greasy/dirty should raise a flag.

Roy,

Well said. And much appreciated if it encourages others to think the same way.

Gary