Removing ID when decking block?

[Steve L.]

Why is it that when decking an engine block, the block ID is removed. When milling this surface, can't this area be avoided? It shouldn't bother anything if there is a small step where the number is stamped???

Just curious.
Steve L
73 coupe since new

[Joe L.]

Re: Removing ID when decking block?

Steve----

The milling machines used in machine shops are a ROTARY machine. In other words, the cutting is done in a circular pattern on about a 12" radius. There is no way that such a machine can surface the deck of the block essential to cylinder head sealing without surfacing the engine stamp pad.

Horizontal milling machines, which THEORETICALLY might be able to mill the block surface and "stop short" of the stamp pad, are usually not found outside of engine manufacturing plants.

[Craig S.]

Re: Removing ID when decking block?

Steve - this can be done with the proper surfacing machine. While I haven' had it done personally, there was a high end shop I visited in Phoenix several years ago that used Serdi surface grinder instead of the typical Storm-Vulcan rotary surface mill used for decking. The owner touted this process as more controlled with the ability to stop short of the pad. I have also read somewhere the the rotary type Storm-Vulcan mill can be set up to avoid the pad, but I am not sure how or what the process is...Craig

[George D.]

Re: Removing ID when decking block?

I had my block milled with the circular style cutter that Joe L. mentioned and the machinist was able to leave the numbers on the pad untouched. However, you can see the where the cutter left a radius mark on the pad.

[Jack H.]

I remember....

seeing a car that was on the judging field where the owner had decked the lid and was proud of the work the machinest had done, stopping short of the stamp pad. Yep, you couldn't see where the milling process had stopped because the valve cover & gasket hid it.

Looked simply GREAT, until it came time for the Operations Check and oil came 'puking' out the front of the valve cover is tiny dribbles! It's tough to mill & stop short leaving a ridge line that CAN be absorbed by the el cheapo cork valve cover gaskets the factory used....

[Clem Z.]

Re: Removing ID when decking block?

if you can find a machine shop with a large milling machine it can be done because they have a X-Y axis to work with while a block decking machine can only move in one axis.

[Craig S.]

Re: I remember....

Jack - I a confused, what does the cork valve cover gasket have to do with the head gasket sealing area? I could see if you don't surface to clear the head on the cylinder case deck, there would be a problem, but the valve cover are seems unrelated to any of this....Craig

[Duke W.]

Re: I remember....

I'm missing something here. If you milled the deck and left the number pad untouched I can see the potential for a water/compression leak at the head gasket, but how would this affect valve cover sealing.

Duke

[Craig S.]

Re: Removing ID when decking block?

Clem - the Serdi surface grinder I saw in Phoenix was like that, had total control, I remember the guy was really pround of that unit as well as his Serdi valve cutting machine, seems like they were over $100K each. I was very impressed...

[Al Corelli]

Re: I remember....

Yeah, That one got me too.

What does a VCgasket have to do with a head gasket?

How could a VC and gasket cover up the stamp pad? Were the heads milled down to 1/4" thick???

I'd be amazed that it started at all!



AC

[Jack H.]

Re: I remember....

You're all right.... This car had a NUMBER of problems!

It puffed steam AND puked gobblets of oil.... The 'stop short' milling of the deck lid resulted in head gasket integrity problem plus the owner did an amazing job of media blasting and repainting the steel valve covers but FAILED to re-true the outer edges of the valve covers prior to final install.

Apologies for not making full disclosure that there was more than a single issue involved in this particular 'restoration'. I was chuckling as I typed remembering how everyone on this judging team stared biting their cheeks during the Ops Check trying to be 'politically correct' while the owner talked on about the 'heroics' he'd surmounted....