[HyperMOA]

Originally Posted by CaberTosser

OK, so the pistons are a bit misshapen when cold, do they machine them at room temp or do they heat both the pistons and the block to the engines operating temp for the piston turning and cylinder boring procedures?

They are machined at room temp knowing the amount of expansion for the component at its rated operating temp.

I’d like to point out that the engines idling in a persons driveway where a neighbor might get PO’d are worlds apart from heavy equipment in remote northern locations. I know those machines need to keep running, but in a densely populated city the temperatures are neither as extreme nor are the everyday driver pickup truck engines nearly as large as the big machinery being referenced. That’s two entirely different discussions. Of course a larger piston with greater mass will have more dimensional changes from thermal expansion but in reference to the original discussion I was talking specifically about a truck the size that one would see in a typical neighbourhood driveway, that being a 3/4 or 1 ton HD pickup. I was not referring to a Cat 797 nor a seismic tundra buggy. Different mechanical animals and different circumstances. Note though that even remote work camps don’t allow parking idling trucks next to the buildings HVAC air intake; people in their own driveway should extend that same courtesy to their neighbors, simply warm the vehicle up further away from the neighboring structures or park in a heated garage. Being thoughtful is not rocket science.

Whether it is a 3524/C127 or a 4 HP Briggs and Stratton the same effect takes place proportionately. The mass difference does not change. Your piston in your Briggs and Stratton has more mass on the head than the skirt thus they will expand at different rates until the temp has stabilized. I am speaking of diesel engines in general, and proper warm-up procedures. Do you think that a 6.7 Ford, N14 Cummins or a CAT 3406 behave differently? No they don't. I'm not telling people to straight-pipe anything or to idle all night. I am telling people about realities of proper warm-up procedures. As there is so much wrong info being passed off. Do I have to argue about water heaters with you?

Some people don't have the option of a heated garage or garage at all. What is the solution then? I should hope that your HVAC system isn't drawing air from my driveway, or the street. If it is, blame your builder not me.

You are right about being thoughtful though. I would never straight pipe a vehicle that I have to warm-up for 15 minutes. I also won't point the exhaust towards my neighbours house either. When I am riding my obnoxious Harley I roll it down the driveway hit the starter and idle out of my neighbourhood. When I come home late on it, I try to have enough speed to kill it as I coast through my neighbourhood and up my driveway. Because the noise is obnoxious, that's why I do it. However, being thoughtful has nothing to do with proper warm-up of an engine. Why does idling your truck for 7 minutes not annoy your neighbours, but 15 minutes does?

To me the main point is courtesy, don’t go stinking up peoples homes or making the neighbourhood sound like a drag strip with obnoxiously loud exhaust systems. I like the rumble of a V8 as much as the next red blooded gearhead but many people feel the need to go overboard with their choice of exhaust systems/ white sunglasses / flat brimmed hats/ thick chain necklaces/ neck tattoos and other status symbols among the Summers Eve Army.

No argument there at all. Quit lumping my stock, emission compliant diesel in with them. It will warm-up (not idle) for 10-20 minutes every cold-start. If that is unacceptable to you, too bad. That is not unacceptable in our climate. If you choose not to do so that is fine by me. Don't complain that others do.

On a side note I have to look out my window to see if my truck starts in a 2x6 walled house with triple pane windows. I can't even hear it, neither should my neighbours.