Mr. Fairdeal are you still in the testing business?

[99yam40]

I am thinking it has to do with wearing in the rings and cross hatch in cylinder walls.
nice and slow, no high temps or loads( the more fuel you burn the more heat is generated)

I have several friends that bought new Suzuki's in the past and they took a day or two to go through the break in like this.
just slowly easing along for hours

My 2014 F150 Ford PU when new said to not pull a heavy load with it until you drove it for so many miles(I cannot remember what the # was)

Once I hit that number of miles I hooked up to a trailer with a 5500lb tractor on it and hit the high way doing 70 -75 MPH and had no problems with it.
Sure wish I had one of these newer 5L ford motors in anyone of the cars I had back in the day.
65 Mustang 2+2,
65 Tbird,
Or the 67 Cougar

[zenoahphobic]

Never heard of "cold seizure" where the piston expands greater than the liner because that liner was water cooled. Firstly these cooling systems have thermostats that would prevent significant water to move so they actually heat up quicker than an equivalent air cooled cylinder.
Secondly the piston imparts its heat to the cylinder wall, so their temperature changes occur in unison, if you like.
Thirdly, the importance of running in is to control the expansion from heat that is caused by friction not so much from the heat of combustion. Piston ring heat increases as revolutions increase, pretty much independent of engine load. Hence the most important reason to keep revolutions low at first. (Although racing guys might tell you to run flat out on a set of new rings!)
Running in equates to lapping in surfaces. As machining gets to extremely accurate measures, the need for running in lessens.

[TownsendsFJR1300]

Running, (a new engine), only at low RPM's for a long time is the worst thing you can do for ring seating.

Various RPMSs, creating higher pressures inside the combustion chamber, help seat the piston rings-which is the main purpose (besides, other parts seating in to each other).

I'm not an engineer however I don't buy half of what Wiesco recommends.

It's a water cooled engine, with a thermostat.. Tolerance' are MUCH tighter, again much tighter, than an air cooled engine.



*I did a semi "Moto-Man" break in with my old FJR 1300 MC. Red line was 9,000 RPM's.

Out the showroom floor, it was run at various RPM's (recommended by Yamaha) however it was taken up to 8,000 RPM's on the way home several times...
Oil and filter was changed at 50 miles, again at 200, then at 500-recomended). Bike / engine ALWAYS ran great, no making oil (water cooled and FI'ed) 4 cylinder in-line

[99yam40]

Never heard of "cold seizure" where the piston expands greater than the liner because that liner was water cooled. Firstly these cooling systems have thermostats that would prevent significant water to move so they actually heat up quicker than an equivalent air cooled cylinder.
Secondly the piston imparts its heat to the cylinder wall, so their temperature changes occur in unison, if you like.
Thirdly, the importance of running in is to control the expansion from heat that is caused by friction not so much from the heat of combustion. Piston ring heat increases as revolutions increase, pretty much independent of engine load. Hence the most important reason to keep revolutions low at first. (Although racing guys might tell you to run flat out on a set of new rings!)
Running in equates to lapping in surfaces. As machining gets to extremely accurate measures, the need for running in lessens.

From what I have read, the heat from combustion on the pistons is not transferred directly to the cylinder walls,it has to go through the rings to get there as they are the only thing in direct contact with the walls.
Did Boscoe post up something about that not long ago?

All motors need to warm up properly before hammering them. at least that is what is recommended to make sure they do not get damaged

From what I have seen the stats on outboards control water flow to the heads mainly, there is always flow around the cylinder walls.
now automobiles and other things with radiators that the stat controls the flow into the radiator are a different story
at least that is the way it looks to me.

I believe you are way off base on the friction thing causing most of the heat

[pstephens46]

From what I have read, the heat from combustion on the pistons is not transferred directly to the cylinder walls,it has to go through the rings to get there as they are the only thing in direct contact with the walls.
Did Boscoe post up something about that not long ago?

All motors need to warm up properly before hammering them. at least that is what is recommended to make sure they do not get damaged

From what I have seen the stats on outboards control water flow to the heads mainly, there is always flow around the cylinder walls.
now automobiles and other things with radiators that the stat controls the flow into the radiator are a different story
at least that is the way it looks to me.

I believe you are way off base on the friction thing causing most of the heat

Interesting. Engine heat in general. What creates the majority of the heat? Friction or combustion?