evil 944t

uh, I think ST's dyno break in might be a little different than what your thinking.

333pg333

I wouldn't compare ST's break in to anyones...maybe Corleone's...

bscpanther

owners manual... man I have always wanted to see what a 951 owners manual looks like.

333pg333

Well if you can find one you should also see what they say about oil viscosities and the temps they are best suited for. You'd be surprised to see just what visc. the factory suggests. Anyone using 0W-40 type oils would want to be spending most of the year in an igloo!

Lorax

In the winter, I use rotella 90w gear oil in my car, it's really goo for the big bearing clearances in these cars. Keeps the lifters quiet and the oil pressure high. In the summer, I just stick my grease gun into the oil fliller and let her rip.

DFASTEST951

Ok, so as much as I try to not talk about being on my fourth motor, I can honestly say I have had direct experience on this matter and it cost me about $40,000 to find out the hard way.

The motor before the one I have now I drove it like a renegade hooker from a pimp who was trying to make her choose up while being simultaneously chased by the law. Basically, I drove the car like an *******. I swear, if a granny showed up next to me on a moped, I was ready to go.
I ended up blowing the motor. #4 piston nearly shot out of my hood. I will say that I blew it running a 383 stroker motor by Lingenfelter in a Firebird...and I beat him too. It was a 3 liter 8 valve. When it got back to David, he took it apart. He examined every part to see what caused the damage. It was concluded that the heat from the motor started to melt the piston as everything was too tight to run that hard. It needed to be "broken" in first. In fact I have a picture of this piston. It's now a paperweight. A $30,000 ***** f#&*$n paperweight.

About a year and a half later, I managed to save another $30,000 for a fully built, race prepped 3 liter 16 valve motor. When it was done, there were about $10,000 worth of incidental add ons to the bill. Expected I guess. Anyway, it took three weeks to build, it came with a warranty...again...AGAINST DEFECTS OF BUILD AND/OR PARTS. NOT ABUSE.

I drove that car like it was made of crystal. For the first 1,000 miles, I never went over 3,000 rpms. Boost completely off. Actually, now that I think about it, I drove it for 25 miles or so around Scottsdale AZ before heading home. Changed the oil. 360 miles to Vegas, at 80 mph, 3,000 rpms. No more. When I got to Vegas, all city driving. Running through the gears. Different rpms. After 1,000 miles I got up to 3,500 rpms. At 2,000 miles, I got up to 4,000 rpms. At 2,500 miles, I turned the boost on, no more than 14psi and started going up to 5,000-5,500 rpms. At 3,000 miles I was back in Scottsdale with the car and it went on the dyno. Just over 500 whp without a load. Then the 480 whp loaded dyno everyone knows about. That's with APE chips and me running rich. In hindsight, Vitesse chips could give me twenty to thirty whp on a load dyno.

Bottom line, after mulitiple attempts to build the same exact motor as mine, each and every motor David built never came up to the same power level as mine. Was it the break in? We think so. He said I went way overboard to break it in easy but after the last mistake, I couldn't afford another one.

I've seen that website before. I've done that. With my own motor. It doesn't work. This is my experience. DON'T DO IT PATRICK!!!!!

Oh, here's the damn pic of the piston. Nice huh?

333pg333

Haha Joe I was worried just what piston you were about to show us with that naked torso. lol
Next time you want to show a naked torso please have a neutral party do it. Hmm let's see, who could that be?? Well if it has to be the lady in your avatar, then so be it, but make sure she covers up...............NOT!!!
Hey Joe, really, thanks for your input. Really I was throwing this to the panel and I think the guy is genuine as he really has nothing to gain unless you subscribe to his site. However my mechanic would personally kill me if I attempted this. It's not like they need to have my car in their workshop for more than the 11 months of the last year again.
Oh what fun it is to run with another broken enjun hey! (insert Jingle Bells music)

evil 944t

Lol, very true!

Duke

Seriously.... race engines are often broken in hard.
Who spends a couple of days on the engine dyno running low rpms and low load?

IMHO break in procedures are like oil discussions... everyone has their own favorite and swears by their oil brand (or break in procedure) as the only working option.

IMHO: run it at various rpm's and various throttle...including WOT and higher rpm's after a short while..

333pg333

That's the thing I was saying. Why is it ok to break it in on a dyno rapidly with plenty of WOT, and not on the road? You often hear that the racetrack is the perfect place. Now this isn't because you're going to be 'Driving Miss Daisy' around for hours on end, it's because you can go up and down the rev/load range. Again why is this good but doing it on the street is bad?

Duke

Agree! I think it's mostly due to private persons... For 99% of the persons that have put a lot of their hard earned money and time into an engine build it just feels wrong to start their newly built jewel and run it hard.

Basic human psycology... Someone with a lot of time/money invested in their engine want a similar, almost magical, break in procedure to match the investment.

Oh, that's MHO

333pg333

Yes I agree with that logic however this guy is saying that if you do that you are in fact harming or thwarting your car's potential. Makes you feel like you are in a lose / lose situation. I mean can anyone quantifiably say he's wrong?

Duke

Well all high HP engines I know of are running a various load/rpm break in including WOT after a very brief period. They sure as hell aren't low of power so guess which theory I'm using

Tms951

I did and have it confirmed by various engine biulders is:

Run it on the street for 70 miles, keep it under 4000rpm. This is basicly to make sure that the engine is all set and the tune is good enough to do hard pulls.

Do what the web site you posted says, that is the same web site I used. I did it on the street because I did not have acess to a dyno at that time. I did it on an empty highway at night.

Change the oil, still using dino oil.

Do another 400-500 miles with lots of accel and decel, trying not to cruise at at specific rpms for too long.

Change oil to Synthetic.

your engine is not completely broken in. Some people will say the last 400-500 miles is not needed and race cars don't do it, I did it for good measure.

JEC_31

Thanks for sharing, DFAST. Information is good.

Just related the tale to my chopper/hot-rod coworker who is adamant that new rings must be allowed to slowly wear into new cylinder honing, not quickly. Quickly leads to heat and bad sealing.

The compelling evidence is the 480 hp motor that lived happily after getting the "drive like a granny with a crystal motor" break-in procedure. Dammit, I wanted that car.


IMO I think we can safely set aside Motorcycle Boy's dire warnings unless we're rebuilding NA sportbikes. He makes good points... but his egotistical "I are smarter than OEMs who have many decades of experience doing R&D and building millions of motors" attitude does not convice me of his scientific prowess.

Also, there's a lot more going on inside a 4-stroke reciprocating-piston engine than simply rings on cylinder walls.