Shot blast block cleaning & stamp pad....

[Jim V.]

Does today's machine shop method of cleaning engine blocks which involves baking and subsequent shot blasting effect the appearance of original stamp pads? Seems with the advent of environmental concerns today's machine shops' cleaning process has replaced caustic cleaning tanks with a baking and shot blast procedure. I recall having read that the shot blast (very fine powder) tends to eliminate the stamp pad broach marks and leaves a non original looking surface. Any experience out there to confirm or dispell this notion?

Thanks!

[Mike M.]

Re: Shot blast block cleaning & stamp pad....

tell the machine shop to avoid blasting the pad.its unnecessary and could do away with factory broach marks. mike

[Clem Z.]

they would have to mask it off somehow

because this done in a closed chamber automatically. changes in procedure is not easy

[Clem Z.]

i do not under stand all this fuss about

broach marks when NCRS give top awards to corvettes like the 12 mile L-88 which i understand does not have the orignal engine. am i wrong????

[Harmon C.]

It,s no fuss if you don't mind -38 points

Clem
You have 145 points to lose with the bonus 10 to get a Duntov. If you start out with 107 left after the block the road is steeper.

Lyle

[Alan Drake]

Re: i do not under stand all this fuss about

Beside the rebuilding and saving broach marks etc.
Get Al Grenning book on engine numbers or better still try to attend one of his Technical Presentations. You will be surprised at what real blocks look like.
The ones that look original are not and the ones that look restamped are not, some with and others without broach marks.

[Clem Z.]

NCRS will have to learn this is not 1957

and the way engine shop equiptment works these days is not in line with their ideas. if you can do your own engine work it is not a problem but if you must have a shop do it they are not going to change because the govt outlawed caustic which was used in the old hot tanks and it is not coming back.

[Tracy C.]

Al has a book on engine stamps availible? *NM*

[Alan Drake]

Re: Authentication Library only

I was at a Technical Presentation by Al on "Pads, Tags & Documentation" where we were using his Authentication Library as a reference. I don't have on yet.

Just assumed that the section of Engine Pads was part of the Library, however due to the huge amount of info Al had - I now realize that would be impossible. He probably has over 124 pages just on 67 pads.

Sorry for the mis direction.

So only option is -- attend one of his presentations

[Tracy C.]

Re: Authentication Library only

I attended his session at Park City last year.. I wish I could have retained 1/10 th of what I saw there.

tc

[Harmon C.]

Re: Authentication Library only

Al's class is good but you always want to keep in mind that his libray was not made at the end of the assemby line but years later.I have been to it many times. As far as broach marks go it is not rocket science they were on the original block and if they are gone NCRS could care less why as our rules are they need to be their. As far as the stampings go that is where the libary helps.
Lyle

[lyndon sharpton]

Re: i do not under stand all this fuss about

yeah,

how does that work? did they restamp the pad on that? are just leave it blank?

[Noel K.]

Re: i do not under stand all this fuss about

if the casting number is correct and the casting date is correct, but the pad stamp is deemed incorrect and the broach marks aren't apparent, how many points do you lose ?

[Michael S.]

Re: NCRS will have to learn this is not 1957

What about baking the block? The large rebuilder here "bakes" the blocks to a high temp thereby burning/incinerating any grease/dirt/paint. The blocks/heads/intake come out perfectly clean with no dirt or paint. They have won numerous awards for this supposed "environmentally friendly" process for cleaning engine parts.

This would seem to me to be the best alternative for NCRS folks worried about numbers. This process only involves the cleaning of the block. As far as machine work, your on you own.

[Clem Z.]

i was under the impression after baking

they shot blast to remove left on material. the pad could be protected with a rubber tape like the people who do tomestone lettering with sand blasting use.