Engine Breakin

[rw7810]

Has anyone seen this felows thread on breakin? He deals in motorcycles engines, but the theory has some merit:

http://www.mototuneusa.com/break_in_secrets.htm

[fintstone]

Pretty much how I broke my 3.0 in.

[Jim Sims]

Reads to me like a recipe for premature engine wear. I really like that "warm the engine up" first step.. Not very relevant for new engines that are now coming with plateau finished, laser honed cylinder bores. Jim

[Jay Auskin]

I work for an engine manufacturer. We basically build it, warm it up, and then nail it on a dyno.

1 million+ V8 diesels can't be wrong.

[Wayne 962]

Some good info there...

-Wayne

[Porsche_monkey]

It's been here before. I (still) agree with him 100%.

[Doug Zielke]

That article has been batted around here several times.
Essentially, it tells you not to "baby" a new motor and suffer the consequences of poorly seated rings. Good advice.

[Porsche_monkey]

I like Doug's summary. Three words, "Don't Baby It".

[Jim Sims]

"Warming the engine up" before going to higher rpms will not provide sufficient oil to the the bearings and valve train during the first few minutes of engine operation; one should go to 2000 to 3000 rpm right away. Going to higher rpm's (5K plus) before parts are run in can lead to higher stresses, scuffing and accelerated wear. Breaking an engine in this way may seat the rings "faster" (but probably not better) and at the expense of engine life. It is very common for modern "run of the mill" production engines to last 150,000 miles; the manufacturer's break in instructions are one of the reasons this is possible. Jim

[mtelliott]

Jim,
Then what do you suggest? I know Wayne talks about 20 minutes at 2000. It seems like you are saying 5 minutes at 2 - 3000, then run it to not exceed 5000. I don't want to speak for you but that's what I read in your comments.

Wayne,
Your comment is in sort of counter to what you write in the book. "Some good info there ..." Thoughts?

All,
Is it that there's too much information and no single right answer? And if that's the case, then maybe we just need to know what are the wrong answers!

Michael

[Jim Sims]

No; I'm saying one should go to 2000 rpm immediately and run there for 20 minutes to get plenty of oil to the valve train and bearings. Then follow the other guidelines in Wayne's engine rebuild book. What I feel is wrong with the website's advice is "warming up the engine"; people could interpret this incorrectly and idle their newly built or rebuilt engine to warm it when instead they should be running fast enough to pump plenty of oil. The 2nd issue is running a newly built or rebuilt engine to high rpms before it is broken in; I feel doing this is analogous to taking a cold engine to redline before it is warmed up and parts are at the correct clearances. Doing this, denies the pistons, rings and other moving parts optimum mechanical support at the higher loads encountered at high rpms. There are many new developments going on with engine piston, ring and cylinder bore technology (such as special laser honing cylinder wall patterns at a limited width band at the bottom and top of the stroke) and the website appears to be basing its reasoning on obsolescent engine technology. Jim

[5axis]

I have to agree with moto man... There is a saying for race bike engines.. Break it in slow and it will always be slow. I got super deal on a GSXR 1100 that was a slug because of this very issue. A top end do over on a almost new bike made it into a rocket again.
BTW
The old GSXR's are air/oil cooled just like our beloved flat 6's.

[rw7810]

Jim - When I read moto-man's article again, he doesn't just say to run it at high rpms as you say, he says a couple of times you need to "load it up" in all gears over and over again to get the high pressure gases to push the rings out. This apparently excellerates the breaking in/ seating.

So if I put this in contexts to Wayne's book, then run up to 2000 immediately for 20 minutes to "warm up" them run it up and down through the gears loading up the engine for about 20 miles, followed by an oil change.

[Jay Auskin]

whoops, I didn't mean "warm up" at idle

[Wayne 962]

Right - I essentially agree with this guy's statements. However, there's a very small sentence in his stuff that says "completely warm up the engine first." - That's your 20 minutes at elevated RPMs...

-Wayne

[Doug Zielke]

Right....no one ("Motoman" included) is saying to take a new motor to the redline. Just don't lolly around like it's a Sunday drive.
(Actually, my Sundays are spent worshiping at the Church Of The Wide Open Throttle.)

[Jim Sims]

"Right....no one ("Motoman" included) is saying to take a new motor to the redline." ???


I quote from Mr. Motoman:

" On a Dyno:
Warm the engine up
completely !!

Then, using 4th gear:

Do Three 1/2 Throttle dyno runs from
40% - 60% of your engine's max rpm
Let it Cool Down For About 15 Minutes

Do Three 3/4 Throttle dyno runs from
40% - 80% of your engine's max rpm
Let it Cool Down For About 15 Minutes

Do Three Full Throttle dyno runs from
30% - 100% of your engine's max rpm
Let it Cool Down For About 15 Minutes
Go For It !! "


Now unless this guy is proposing that one buy hours of dyno time to do these runs (how many hours does it take to get to the equivalent of 500 to 1000 miles?), 80% to 100% of a 911's engine's max rpm is going above 5000 rpm to redline right away.

I'm not a biker myself but I am aware that in the bike world there are two different versions of pistons and rings available with different clearances. One version has smaller clearances and is meant to produce longer lasting engines but requires a longer careful break in be done. The version with larger clearances is meant for racers and those who want to get on the throttle right away but doing this comes at the cost of reduced engine life.

Cheers, Jim

[Doug Zielke]

Originally posted by Jim Sims
[BI'm not a biker myself but I am aware that in the bike world there are two different versions of pistons and rings available with different clearances. One version has smaller clearances and is meant to produce longer lasting engines but requires a longer careful break in be done. The version with larger clearances is meant for racers and those who want to get on the throttle right away but doing this comes at the cost of reduced engine life.

[/B]

Well, m/c engines *are* my background as hobbyist and racer for over 35 years. Don't know about these "different versions" of pistons and rings. Parts is parts.

I do know that the break-in procedures for modern engines are vastly different than for older ones. This is due to a combination of better materials and lubricants.

Long break-ins don't accomplish a thing (in modern motors) except glaze the cylinder walls, and inhibit optimum piston ring sealing.

[Jim Sims]

Do whatever you believe is to be true, it's your machine and your money. Different MC piston and rings sets exist with different clearances. See:

http://www.steelthundercc.com/enginebreakin.htm

Cheers, Jim

[350HP930]

Originally posted by Doug Zielke
(Actually, my Sundays are spent worshiping at the Church Of The Wide Open Throttle.)

I see you and I practice the same religion.