Justin........LMFAO.........Awesome sig pic. How symbolic

--Joe

 

From the subject I was picturing something more like "Gone in 60 Seconds"... a tutorial theft or something...

 

Way, way back in the 70's, when I had my '71 340 Demon, I read a very similar article in Hot Rod Magazine. Said to run it hard especially 2nd and 3rd gear but not to the red line. Said to up the limit in steps. So many runs at each step. That 340 never burned any oil-never smoked

 

I'm sorry, I just can't sit by and read this stuff without responding. I have built, bought, and maintained quite a few engines over the last 20 years. Some were racing engines, some for the street. I have also spoken with several professional race engine builders, and a few factory tech reps on this very subject. All of these people share my opinion on proper break-in for ANY piston engine.

The critical factor for break-in is the piston rings. Whereas it is true that the tension of the rings will not change with milage, thier abilty to seal properly is determined by the loads applied to the ring/cylinder wall interface during 'run-in', more commonly referred to as 'break-in'. When new, or freshly bored and re-ringed, the smooth edges or the rings do not adequately seal against the sides of the machined finish of the cylinders. Over time the 'high spots' in the cylinder wall finish will become worn down to the point that optimum sealing action occurs. Most poeple at this point probably conclude that this process will occur regardless of the pressures the cyliders experience. This is simply not true, even though there are many poeple that claim thier experience says otherwise.

When an engine is new/re-ringed, and excessive combustion pressure is applied, the un-burned air/fuel mixture leaks past the rings. The earlier and more often this happens, more of the mixture is leaked. This creates 'glazing' of the cylinder walls which may wear off eventually, depending on it's severity, or it may not. As the milage accumulates (if the engine is being run-in properly), it is acceptable to increase gradually the pressure applied until a conservative amount of mileage is reached. This helps create the most power from the engine and also help the oil control rings to perform thier function.

The racing engines I have built were run-in on a very accelerated schedule due to time constraints and the knowledge that they were to be torn down and inspected/freshened at regular (very short) intervals. Making maximum power reliably was the over-riding concern, not longevity. This is the opposite concern of street driven engines. I want them to make good power, but also remain in service for as long as possible with oil control or non-uniform cylinder pessures.

This is a free country and you all can do as you like. I just think you should base your decisions on sound mechanical principles, not just what someone with potentially limited experience and/or knowlege has gotten away with. Your choice.



PS - I'm not trying to whiz in anybodys Cheerios, just trying to share my humble opinion.

Eric

 

I've never ever gotten a fast motor when I've broken them in nicely, on 2 stroke jet ski's, or bikes.

My 00' was broke in nice and smothly, as you suggest, and she's not terribly fast.

Myabe TZrider can contribute. I think his knowledge would be valuable.

 

Performance two-strokes are a bit of an exception in that ring and cylinder wear are accelerated due to being under power on every down stroke and the presence of the air/fuel mixture (albeit with some oil) on BOTH sides of the piston and thus, in effect, 'washing' the cylinder walls constantly. Most two-stroke have very short recommended cylinder maintenance intervals for that very reason, plus the fact that are used in higher performance vehicles that are operated at or near maximum rpm and/or throttle settings. Additionally, marine applications suffer from the exposure to moisture and thus are more prone to the effects of corrosion (ask your local Sea-Doo tech). If the bikes you are talking about were four-strokes, there may be some coincidence in respect to carburetor tuning (factory settings are usually on the lean side), or you just were fortunate with the run-in cycle. Either way, what I stated is not a hard and fast rule, just the preferred method. What other logical explaination (no conspiracy theorists, please) could there be for the maufacturers' of Mercedes, BMW, Porcsche, Honda, Yamaha, Suzuki, the 'Big Three' U.S. companies, etc, to prescribe a similar 'break-in' period to what I have suggested? Anyone with any knowledge of written recommendations to the contrary, please send that information to me. I would LOVE to see it.

Eric

 

hahaha interesting stuff..............and here I thougth this thread was going to be about stealing L's or something.

 

Joe, Good post, I guess I broke mine in right also! Jim

 

I wish the analysis included looking at the camshaft, cam bearings, rockers, and the crank side.. not just the piston and rings....Jerry

 

Me 2 !

 

I had read this article with interest about a year ago.

This prescribed break in procedure does fly in the face of camshaft break-in procedures based on what I have read/followed from aftermarket performance camshaft manufacturers.

I believe we complicate things further with forced induction. You would want to insure excellent seating of rings prior to loads of boost on a brand new engine I would think. With turbo performance cars, it is widely accepted practice to turn the boost down under initial break-in, then crank it back up after minimum of a few days / 100+ miles of driving. Some wait as much as 1,000 miles, but that is overkill IMO.

As far as the manufacturers being the ultimate source of info, then you should wait 5000 miles for your first oil change and never change your rear end diff fluid. Also, you must replace your cabin air filter at 15,000 or who knows what will happen! (Ford Manual)

 

TURBOBO has an interesting point. It can be difficult to sift out the B.S. in some of the manufacturer recommendations. Personally, I do the first oil change at 1000 miles and then every 3000 thereafter. As far as camshafts on new engines, 30 minutes at approximately 50% of the RPM limit at NO LOAD, is usually recommended (notice the NO LOAD part). As far as the mileage for 'break-in', 1000 miles is probably overkill in most, if not all cases. There are very few people out there with the seat-of-the-pants skill necessary to determine when and how hard to operate an engine during 'break-in'. Fewer still have the time, equipment, and expertise to evealuate this process scientifically (compression/leak-down/dyno comparisons). So, we are given the conservative guidance of the 1000 mile period.

Another thing to keep in mind is, maintain your vehicle systems in accordance with how they are operated, and the conditions in which they are operated. The Factory recommendations may not be conservative enogh for cabin air filters and differential fluids, etc. Nothing is absolute, except that we will all be dead someday.

Peace and Love

Eric

 

Huh, I didn't even know I had a cabin filter. Guess it is due for a change! Does K&N make one of these?

 

Do the 5.4's have cast iron or steel cams.

When I had my 89 Shelby Dakota cam reground at Lunati it had roller lifters. When I picked it up and asked if it needed to be broken in they just chucked. They said steel roller cams don't need breakin lube and to just coat it with oil before installing.

I use to ride sportbikes from 83 until 3 years ago and I made attempts to break them in like the manual said. I had a cousin who thrashed everyone he bought from day one. His bikes were always fast and never gave him problems. Needless to say the last one I bought was WOT from the start and never gave me problems other than holding on.

I saw this senario played out numerous times as he loved to trade bikes and cars. They were all fast and problem free.