Ok, we all know why F1 tolerances have to be tight.
BUT
Why are the clearances between moving parts so tiny?
Even as close as requiring the engine fluids to be warmed up before the engine can be started!
needing the piston tight when cold implies that the block expands more than the piston when hotspacer wrote:Because of the unequal thermal expansion coefficients between materials used in the engine (i.e. pistons vs engine block).
Or uneven geometric thermal expansion inside components (i.e. pistons being oval when cold, but round when hot).
All of this to achieve "optimum" clearance in running conditions.
Could certainly conceivably be true. If the clearances are what they should be when the engine is hot and running, who cares what they are at ambient? (A temperature at which the engine will never be operating).n smikle wrote:Let me throw a cruve ball....
In the video where they were preparing the Leighton house car for start up, the narrator said that when cold, the engine is so tight it cannot be turned by hand tools. How true is this?
Imagine the engine builder has just assembled an engine and it won't turn! wouldn't that be just wrong?
the same was said of the Renault on a lightweight BBC programme with Richard Hammond (someone tell him that the 60s Mustang was not a muscle car !), which caught my attentionn smikle wrote: In the video where they were preparing the Leighton house car for start up, the narrator said that when cold, the engine is so tight it cannot be turned by hand tools. How true is this?
I wasn't aware that they carried oil in any other place other than the tank on the front of the engine> Where else are they carrying?strad wrote:It does seem odd when you consider they have to carry extra oil in a separate tank because it goes thru so much.
This is nonsense. Since most of the materials in the engine, where there are sliding/rotating interfaces, have a similar CTE rate, there would be little change in clearance with temperature. The clearance between a steel or Ti conrod bearing bore and a steel crank pin would not change appreciably from RT to operating temperature. Nor would the clearance between an aluminum piston skirt and an aluminum cylinder bore change significantly from RT to operating temp.n smikle wrote:.....In the video where they were preparing the Leighton house car for start up, the narrator said that when cold, the engine is so tight it cannot be turned by hand tools. How true is this? .....
True,,that's what blueprinting is all about.It's not small clearances that matter, it's the precise control of operating clearances that matter.