Mototune break in article

[mpg99999]

Have any of you read the mototune articles on engine break in? I am curious to see what you guys think on the matter. The articles on intake porting is interesting as well. Here are linkes for the break in article:

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

and

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

here is an index of all the articles:

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

 

[Chumley]

It's interesting reading, . . . but:

There are hundreds of different combinations of pistons, piston ring materials/cylinder wall alloys. Also, there are hundreds of different types of piston ring designs, ring tensions etc. based on each different engine design. (engine designs change substantially based on the intended use.)

It's simply not possible to extrapolate a specific break in method to all engines in general other than to say, "follow the directions in the owners manual" or, in the case of a custom design, "follow the manufacturers break in recommendations."

If your experience concerning a specific manufacturers product is more than the people who designed and built the product, that's fine too. Ignore them and blaze your own trail!

Chumley

 

[evelrod]

Agreed, Chumley. Interesting reading but---

A couple of things jumped out at me---"I have never ported a two valve head---" as example. Applications of "intuitive" aerodynamics, another. Fun to read, though.

Where does a 'moto-head' find the time to do all that is shown on the incredibly complex (to me) web site. I am in awe! It must be great to be young, I don't remember!

I have 'blazed my on trail' for fifty plus years of racing---too late to change now.

Rod

 

[76GMC1500]

He criticizes manufacturers for reccomending an easy break-in period. I think the manufacturers do so because a new engine creates a lot of heat due to friction because the surfaces haven't worn in yet. This is especially apparent on air-cooled motorcycle engines when you have to shut them down after 15-20 minutes during the inital break-in of a freshly honed cylinder. Even though water temps may be within spec, oil temps and piston temps can be very high, causing scuff damage to the cylinder wall and piston skirt.

 

[mpg99999]

In response to evelrod, he does the website full time now.

 

[MaxRaceSoftware]

Where does a 'moto-head' find the time to do all that is shown on the incredibly complex (to me) web site. I am in awe! It must be great to be young, I don't remember!

I have 'blazed my on trail' for fifty plus years of racing---too late to change now.

Rod
----------------------------------------------------
It must be great to be young, I don't remember!


he can get away with some of those cylinder heads mods because 4-valve with their low to mid lift flow and ports
that are relatively straight

but do something like to that extreme on 2-valve 23 SBC heads
and power will go away

the low to mid lift flow can make up for head that might be close to or going into sonic choke at higher lifts

the straighter the port..the more you can do something like he did

the more turn in the port....you can kill it doing something like that most of time

it would be interesting to see what port shape/mods
MotoMan would do with an old SBC 23 deg head (2-valve)


still interesting reading..




Larry Meaux (maxracesoftware@yahoo.com)
Meaux Racing Heads - MaxRace Software
ET_Analyst for DragRacers
Support Israel - Genesis 12:3

 

[enginesrus]

76GMC1500 (Mechanical) Feb 24, 2004
He criticizes manufacturers for reccomending an easy break-in period. I think the manufacturers do so because a new engine creates a lot of heat due to friction because the surfaces haven't worn in yet.
--------------------------------------
The reason he does this, is because, he has given examples of how the manufacture, fires the newly assembled engine up and with a 30 second warm up they rev it up to max rpm and load. I suppose it is to save fuel and time.

Kinda like the break in of a cam at over 2000 rpms, which is hard to do if the engine will not go over 1300 rpms.
The only part in an engine that needs break in is the rings and cylinder. Every thing else is a bearing surface, separated by an oil film. The ring - cylinder interface is the only place that is purposely machined and or coated to cause metal to metal or coating to coating contact for a period of time and yet still have some lubrication for wear in purposes.

 

[76GMC1500]

Flat tappet cams need to be broken in carfully because the increased friction of the still rough surfaces creates a lot of shear force which can knock the lobes off of the cam in short order. Most manufactuers reccomend a 2000-2500 rpm break in because that is when the cam gets the best oiling. Or so they say.

Even piston rings ride on an oil film.

An intersting fact, aircraft engine manufactuers like Continental reccomend break in be done under full power.