Head casting numbers

[BONERACIN]

I recently recieved some heads that the casting numbers look different from all the others that i have seen.  The casting number is 17090-06 and 17096-06. I would post pics but the site keeps giving me an error saying the file is to big. Anyone ever seen any differrent casting numbers?

[Jeffd]

yes that is normal.

[springer-]

Those are the later 06-current style Mercury Marine castings.  The prior foundry used a symbol with a "P" in it.  If you look between the holes for the pushrods, on the rocker cover side, you should see the Mercury Marine logo.  The earlier heads have the casting numbers 17192-06 and 17193-06.

The logo should look like this ....

[Don D]

+1 on that
Agreed.

[BONERACIN]

I seen the Mercury symbol on them, and that is what had me confused. Thanks for the help.

[66SHOVELHD]

Any pros and cons to these heads, other then just being 06?

[Don D]

No not for an end user in a performance application. They are tougher to grind I can tell you that.

I suspect the change, guessing because I have no insider information, was made due to a bid specification for a new tougher alloy (Mercalloy possibly B391 in this case) that the former foundry could not satisfy and or cost reduction. It's all about heat tolerance, and cost. Mercury uses lost foam VS sand casting which also offers better resistance to core shift and higher precision, if that is the process they are employing, once again only speculating.