Tommy Cookers wrote:I watched this when broadcast, and have just looked at the thread from about 2 years ago
I still have a question ....... PISTONS ?
This programme (or another similar one by RH) seemed to clearly say that the piston had to be a push fit (tight) at room temperature, and the engine (Renault) would not run unless pre-heated to something like normal running temperature.
What piston (and/or liner) material would have needed this fit ? (presumably not now permitted with engine freeze rules ?)
Lurk wrote:Renault recently reveals some F1 engine particularity on a public web note (maybe it was only in french?). They said that F1 engine cannot do cold start physically. Piston is slightly oval while cylinder is round and so the piston is stucked in the cylinder. When heated up & due to thermal dilatation, piston & cylinder get their "working" shapes and engine can be started. If I remember well, minimum temperature was 50°C.
A shame the website I saw it do not keep a lot of archives, I cannot retrieve it
747heavy wrote:F1 engines, as most high level race engines, are preheated before fireing up.
This means, there is a external heater and pump connected to them and hot water/antifreeze is circulated through the system.
After this procedure (which takes ~20 min for a DTM engine) the water and oil is close(r) to operation temperature, and the parts in the engine are warmed up, and are closer to there designed tolerances.
Chances are, that due to the very tight tolerances in a F1/race engine, you would not be able to turn a engine over at 20°C, or if, wear and friction would be extremly high.
I will try to find a photo later.
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