Fresh Turbo engine advice

[sayed ali]

Hello,

I've recently rebuild my m20 motor with all new internals + m52 crank, my question is how long should I let the engine idle for the first start up?

I've heard some people saying that I have to start it for 3-4 days about 2 hours per day, is that true?

Thanks in advance..

[beefjurky69]

I let mine idle for 20 min than change the oil. Go out and drive it kinda hard with alot of decel to set those rings.

[sayed ali]

I let mine idle for 20 min than change the oil. Go out and drive it kinda hard with alot of decel to set those rings.

Hmmm, sounds a little hurry, anyway thank you and good luck

[whodwho]

I don't see the need for idling for break in, my opinion is only idling it long enough to make sure you have oil pressure and you don't have leaks and then driving it to load the rings when the critical part of the ring seating happens. And if you have a new cam you don't want to idle it until after the cam break in procedure.

[93supercoupe]

I don't see the need for idling for break in, my opinion is only idling it long enough to make sure you have oil pressure and you don't have leaks and then driving it to load the rings when the critical part of the ring seating happens. And if you have a new cam you don't want to idle it until after the cam break in procedure.

x2

Heres my break in......

idle it, check for leaks, get it upto operating temp, change the oil and strap it to a dyno and let it rip

[FLG]

As stated, get it running, check for leaks, change oil and go out and drive the piss out of it letting the engine do a lot of the breaking (decell). Id honestly just check for leaks and like supercoupe said go straight to dyno though.

[jules325i]

I was under the impression that idling a new engine glazes the Bores and the piston rings dont bed in properly and that you should set the rpm to around 1500, and when driving you should alter the engine speed plus avoid extended periods of high engine speeds.

[JCarp90]

Listen to FLG. Fire it up, check for leaks and then beat the shit out of it. 3rd gear pull, then decel in the same gear.

[chondamx]

Listen to FLG. Fire it up, check for leaks and then beat the shit out of it. 3rd gear pull, then decel in the same gear.

This is how I always broke in my new motocross bikes and fresh rebuilds. I ran them thirty minutes, changed oil, and rode them at race pace while being conscientious of varying RPMs. It's an age old debate, but I firmly believe light breaks-in result in glazing...I've never had a bike smoke, even those that were ran long enough to toast crank bearings without a top end build.

[Kozworth]

I dont understand this. I did the same exact thing to my previous m20. Rebuilt, oringed block, and blew the headgasket on one of the first pulls. Ive always heard things like "take er easy on the first 500 miles" or whatnot after an engine rebuild. I am disagreeing with you guys but I am just wondering how these rumors are actually fiction.

[FLG]

I dont understand this. I did the same exact thing to my previous m20. Rebuilt, oringed block, and blew the headgasket on one of the first pulls. Ive always heard things like "take er easy on the first 500 miles" or whatnot after an engine rebuild. I am disagreeing with you guys but I am just wondering how these rumors are actually fiction.

Something was not done correctly or there was some kind of defect possibly. When I broke in my 440 for my charger we brought the engine to the dyno after 20 min of varying rpm to break in the cam, changed oil and beat the shit out of it. You could tell when things were seated, no more blow by and hp/torque increased as the pulls went on until it settled.

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[Jeff Schaadt]

Bought a brand new 2007 Mini Cooper S, drove from Dallas to Houston that Friday nite....did a 2 day National Tour (AutoX)... Put 50,000 miles on her, multiple trips across the country to attend an AutoX.... Never missed a beat.

[andrewm]

So....

there's a few varaibles. That "idle and rev" period is usually for motors with new cams, because the cams need to cycle.

I'm a HUGE fan of beating in a motor with runs. The few I've built...

Start up, idle/rev 5 minutes. Change oil.
Cam break in. Change oil.
Then I beat the living hell out of it. I took it to a backroad that was 65mph in a light traffic environment and went through second and third gear pulls for an hour or so. The rings will set pretty quickly. Change oil.

Then its erally just normal heat cycles, but you NEED the heat to set those rings. If something goes wrong (HG, bearing failure, etc) - something else was wrong.