I am pretty sure that they could get the sand out through the water pump hole if they really wanted too. Also if they have trouble getting the sand out I reckon there would be a couple of plugs hiding away in the back of the block.

They used to get the sand out of pretty intricate castings in the foundry I did my trade in. And they were as rough as guts with new castings on the shaking machines..

I've always believed the cracking bit myself.

I guess if the block didn't crack, it might blow the heater tap off, or crack the water pump..

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SooperDooperMiniCooperExpertEngineering

All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.

Only time and constant engine time moves the block casting sand.

A couple of weeks ago I helped our local mechanic replace an alloy radiator on a very low milage falcon. The mechanic didn't need the help actually, I was just there chatting. Anyway, the radiator was damaged because of an impact with a indigneous macropod.

Once the radiator was out and empty and we compared it with the new replacement radiator. The damaged one was close to double the weight of the new one and it was nearly all casting sand which has been flushed out of the block and collected in the radiator. I dont know if this is the current norm but somewhere quantity is more important than quality.

Mike

I work at Ford's Alluminium casting facility and we used three methods of casting - high pressure, low pressure and gravity. Low pressure casting is now done in Mexico which is where the cylinder heads come from.

Prior to this though, we made heads at the Geelong plant - the casting sand is mixed with silicone so that it melts and binds the sand together in a hot die. These pre-formed shapes are put into a bigger die and molten alluminium is pumped into the die cavity and it forms around the sand.

When the alluminium cools, the sand is then knocked out of the various 'overflows' or 'gates' using mechanical hammers or as Mick says, throwing the castings around the place - some stays in the casting and only comes out after heat treating the casting. Even then not all of it comes out - however it comes out as the vehicle is being driven......and settles in the radiator, just as Mike says.

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Rod
http://smg.photobucket.com/albums/v607/Rodney/