I was thinking the same thing!

This is why serious auto race engines stay plugged into an oil heater before going onto the track. Cold coolant temp is not so bad, cold oil is REALLY bad!

Very good point/question, I have wondered the same thing. I can tell you from my own experience that dart big m blocks are very stable and mine was honed on a steel tq plate but my machinist said the same thing that was mentioned earlier, these particular blocks are so thick and rugged that the measurements don't change much from having the plate on to having it off, as far as how much it changes at temp I don't know. I also have kept my cylinder bores at 4.500 instead of trying to gain a few cubic inches at the exspense of wall thickness, I believe that the amount of side load/cylinder load when making 140 hp per cylinder is extreme and having as thick of a cylinder as possible helps to hold it somewhat stable when running hard, just my opinion though, Smitty
My cylinders varied by .002-.003 max when checking them with a dial bore gauge after all machine work was done and block was back at my own shop with no tq plate on it, Smitty

Here is a really good thread on Speedtalk. Speedtalk is a great site for engine building. Not much flaming over there either, its pretty cool.:
http://speedtalk.com/forum/viewtopic.php?f=1&t=24533

Smitty,

Are you sure they were .002"-.003" and not .0002" - .0003" ??? If they really did vary 2 to 3 thousanths, you need to find a new machine shop Clearance on some pistons is only .003" ..... if the bores varied that much the engine will never be right.

Just my opinion,

Bill Koustenis
Advanced Automotive Machine
Waldorf Md

That was with out plate torqued on it.