Questions About Motor Break-In Procedure

[DangoAZ]

So I just turned the key last night and fired the Supra for the first time on my 7mgte stock rebuild. No major issues on start-up... I think I have successfully turned money into noise! I primed it to get oil pressure, started it up, and then let it run for a minute to make sure I wasn't leaking/burning/destroying anything, then shut her down.

I've done the reading up on jdub's recommended break in procedure of 3/4 throttle pulls followed by high vacuum deceleration in gear to get the rings seated, and it all seems to make sense to me: http://www.supramania.com/forums/showthread.php?t=48993

What I don't know is how critical it is to get those pulls done in the first X amount of time... I still have a vacuum leak around my injector seals, so I know I need to fix that before I can drive it. It should (I hope I didn't just curse it) be as simple as wiggling the injectors until they seal. But should I worry about getting it timed now, or is "timed well enough to run" OK for the break-in? What about burping the coolant system of air?

Fixing the timing, if I do it with the motor running, will inevitably get everything up to ops temperature, even with the little time it will take because it's warm outside. And it pretty much has to get up to ops temperature to burp the coolant. So I will basically be running at idle for ~10 min if I do these things. Will I be defeating the purpose of of the "hard and fast" break-in procedure jdub describes by letting it sit and idle while I tune things in? Any recommendations?

Thanks for any advice...
Dan

Oops... Just saw I clicked this into the "GE Technical" section... Can a Mod please move to the "GTE Technical" or wherever appropriate? Sorry.

 

[Poodles]

Timing is less than 5 minutes, and the cooling system will take care of the bubbles itself if it's all working properly.

Get the rings seated ASAP, the longer you wait the more chance of them glazing...

 

[DangoAZ]

Timing is less than 5 minutes, and the cooling system will take care of the bubbles itself if it's all working properly.

Yup... New Toyota T-stat w/ jiggle valve removed. That's what I wanted to hear - I'll time it in quick.

Get the rings seated ASAP, the longer you wait the more chance of them glazing...

OK... Learned something new. Glad I asked. What do they glaze with - carbonized oil?

 

[TurboStreetCar]

the cylinder walls will wear down no matter what, the thing is that you want the rings to be pressed against them with enough force to even out the surface creating a good seal. If the force of the ring on the wall isnt that great the cylinder wall will smooth out without really wearing much of the ring resulting in not as perfect of a seal.

The engine needs to be run up to operating temprature before bieng broken in any way so start it up, set the timing and take care of the cooling system then take it out and get it broken in.

Its not that critical. its not that you only have 5 minuites to break in the rings or the motors junk, just do it on first drive and do it as soon as you can.

 

[northwestsupra]

im going to jack this due to the previous link to jdubs thing was closed how about engine break in with a full rebuild but high performance? same deal, i mean it says 3/4 throttle, but what about turbo boost on a new turbo also? what would jdub do?

 

[jdub]

Exactly the same thing I would pull the EFI fuse/spark plugs and crank the motor till oil pressure shows on the gauge.

You want to do your runs within the 1st 20 miles or so...avoid idle for long periods.

 

[northwestsupra]

So basically do the runs ASAP, run it hard to 4000rpm keep it in gear, let it drop down to idle in that gear. what speed are we going to? never mentioned this, or what gear? because from what i remember your not suppose to do any freeway speeds for a while like 1500 miles or something

 

[jdub]

I would downshift through the gears to keep vacuum high as possible during the coast down. Speed? Who cares...it's the RPM that matters. You want to shift through at least 4th to 4000 RPM.

It's not highway speed that's a problem, it's extended periods of the same RPM. You can get on the highway, just don't stay on it for an hour...you want to vary RPM as much as possible after the initial runs.

 

[NashMan]

hum mm no one runs break in oil any more ???????

that a tad bit odd

makes breaking in an engine allot more for giving if you run the stuff

you can see the diffs on the dyno from none break in oil to reg oil

at lest from what we have sean

 

[CyFi6]

I have read to break the engine in hard, but i have also read you need to drive it easy until you get 5 heat cycles and re torque the MHG... so what are you supposed to do when you have a new engine with a new MHG?

 

[NewWestSupras]

I have Ross pistons and a Titan mhg on my 7M. When I broke it in, I ran single wt. 30 dino. I took it on the highway late at night and just ran up and down through the gears to about 4k rpm. Got lots of vacuum pulls from 4th down, then back up again for about an hour, little to no boost. Then I changed the oil and it seemed to work quite well. I have approx. 40k km's on the motor now, compression and vacuum is still quite good. No oil burning. gl with yours.

 

[northwestsupra]

that is some good information there, now what about turbo break in? lol, and also differential break in?

 

[hvyman]

^ you just need to prime the turbo before first start up and put oil in the diff.

 

[boostcraver]

that is some good information there, now what about turbo break in? lol, and also differential break in?

I can't remember where I read it, but I read somewhere that running a new diff hard within the first 500 miles or so will prematurely wear the internal gears. Something about a coating on the gears that has to be worn off first or it will create excessive heat and fry the diff. I am not a certified mechanic or anything so I really don't KNOW for sure. Any one who knows better, feel free to point me in the right direction.

 

[Poodles]

Depends on what was done to the diff. If they're brand new gears, you need to heat cycle them and they need to wear into each other (they face of the teeth aren't smooth....AT ALL). If it was just a pumpkin swap like most poeple do there won't be any break-in needed.

 

[j3r3my]

not to thread jack but im also in the process of a breakin on a 7mgte and it scares the hell out of me worrying about the rings not seating i have started it a few times and let it idle as i fixed cel codes is this bad and i put only 2 miles on it so far should i spool it or just shift before?

 

[hvyman]

Dont let it idle and drive it kinda hard out of boost or as little boost as possible.

 

[CyFi6]

Dont let it idle and drive it kinda hard out of boost or as little boost as possible.

How exactly do you drive hard and stay out of boost at the same time, i go into boost driving normally, and what is the idea behind staying out of boost anyways? What exactly are you hurting by going into boost while breaking in a motor?

 

[Poodles]

I usually recommend stock boost, or if you're really anal, disconnect the wastegate arm so it stays open (of course that's not going to work with a DDP...) Engine braking is very important as well...

 

[NashMan]

I can't remember where I read it, but I read somewhere that running a new diff hard within the first 500 miles or so will prematurely wear the internal gears. Something about a coating on the gears that has to be worn off first or it will create excessive heat and fry the diff. I am not a certified mechanic or anything so I really don't KNOW for sure. Any one who knows better, feel free to point me in the right direction.

nope you do not

stock diff
drive around for like 500 drive as your Normy do drain oil done no stuiped high speeds thou

after maket lsd metal type such as kazzz

lot's of figure 8's forlike 1 half an hour then drain oil