I thought some would be interested to see this graph. I recreated the graph from an old engine textbook so it isn't perfect but it's very close. The only details I have about the test is that it was run for 60hrs and done by Continental Motors. The book is copyrighted 1986 so the test is at least 20 years old. Could be 40 who knows.
I ASSUME that the experiment was run using a small block V8 of the late 70's or early 80's vintage. So this info probably only loosly applies to todays iron V8s and not much at all to the small 4 cyl AL engines in todays small cars. I guessing the test was run at 3/4 to WOT throttle for 60hrs while the coolant was artifically kept at the desired temp. I think the test had to be run near full throttle because your average engine probably spends 60hr at less than 60F in its life and doesn't have 0.004in cylinder wear. But then again most engines are not run WOT at cold temps. The engine would have to be pulled down to measure cylinder wear compared to starting specs. Must have been an expensive test. I wonder if the wear measured was cylinder diameter or radius? I guessing diameter.
This data may or may not mean anything IMO but it's still interesting. It mostly tells me how hard it is on a engine to drive it hard while it's still cold. Also those of you running 160 T-stats in your motor (so you can run more timing) might want to rethink it.
Happy discussing and thanks to Razl for hosting the image for me.
[ December 17, 2004, 05:06 PM: Message edited by: OffOrWFO ]
