I'm breaking in my motor and everyone tells me to stay with 1.5k to 3k and not to go over 55 mph. I believe and doing just that. I was just curious...what does 55 have to do with anything if you stay under the spec. r's?

 

Just taking a guess, but I would think it has something to do with the load you are putting on your motor.

 

Its like from the movie speed...if you go over 55, the bomb is armed..as soon as your drop below, you go "BAM!"

 

You guys are killin me.... There has to be a logical reason.

 

Thats pretty much there is too it....dont want to stress out the engine before it gets settled in and broken in. Im not sure exactly why, but its pretty much a fact and needs to be followed pretty closely. Im sure you can get away with going over 55, but I wouldnt do it alot.

Plus, if you go over 55 and the bomb IS armed, just make sure you dont get on an uncomplete bridge...jumping those things is alot harder in real life.

 

The only real break in you are doing is with the rings. Ground speed really has nothing to do with it. The only real thing you want to do is vary the engine load which helps seat the rings better. The old 500mile break in routine is crap. Just bringing the engine up to operating temperature and driving it 10 or 15 miles 2 or 3 times will break it in good enough. A lot of the old break in stories you hear about or read really don't apply to later model engines.

 

Personally, I don't really believe in breaking in a motor. Ok well maybe take it easy for the first 100 miles. Think about alll those worktrucks & cars out that that fair sized companies buy. I bet they are babied, then drove the **** out of after 100 miles And how many of those vehicles do you see in the 150,000 to 200,000 mile range? Well where I work there are a few like that. And I have heard many stories. Also look at topfuel dragsters. How much does a motor like that cost? They ESTIMATE that they make around 7000hp. Do you see a break in period for a motor that uses's a blower a 440 hemi doesn't have the power to turn over stock?


I dunno, its hard to tell when you hear stuff like that. When I build a motor I'll take it easy for the first 1000 miles, but after that, I can't promise anything


*EDIT*
Ok just curious, does anyone agree with me?

 

i built my motor, started it for the first time with the blower, 50 miles later it was ***** to the wall. motor ran forever after that!

now i have a diff. car and i would do it the same way if i built this one up.

 

There are some people that even recommend a couple of 1/2 and WOT romps once the engine is up to temperature and break in is done. I agree that 55 is just an arbitrary number and if you have a stronger motor it will be under less load at 65 then someone who did a stock rebuild at 55 so whats the big deal. Unfortuneatly i don't have the money for a new bottom end so i'm not graced with the pleasure of breaking one in

-Brent

 

Putting a mph speed on break in doesnt mean anything, that's BS. what rpm you're at and what gear you're in will have more affect on engine load. you'll see more air resistance at that speed, but that's negligeble.


And that above example about top fuel engines has me lmao. Think how long those motors last... yeah, exactly. And FWIW, they do run them in the pits after each run and it's subsequent rebuild. and considering how long they have to last on the strip, they're broken in for ten times as long as they're raced

 

I think the old 55 mph limit was supposed to be applied to cars w/out overdrive trannies. At 55 mph on a car with 1:1 final ratio in the tranny, you're probably approaching 3k rpms. Personally, I usually take it easy for a week or so (500 miles) so the bearings will set properly. Then, drive it however you want (like ya stole it ).

 

i have heard allot of different stuff about breaking motors in. i personally would stick with this method:
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also, all aircraft engines are broken in that way, and they are much much more reliable than car motors. think, there is no "pulling over" in a plane.

 

Well I guess its up to me then.... I think for piece of mind I will stick with the good ole 500 mile break in period. Can't harm anything.

 

Yo

Brand new LT1? How much did that run you for? The motor itself and then installation... I wouldn't mind throwing a brand new engine if I ever get a LT1.

Chris

 

I built it myself with a friend and its a forged stroker so....you don't wanna know. I just left a post on your thread. Your the guy looking at the 94 Formula right?