How to break in a new engine

Supra

New Member
May 11, 2005
304
0
0
48
Rockford, IL
How do you guys recommend breaking in a new engine? For the sake of arguement, I'm thinking 7M-GTE but it may be helpful for 7M-GE as well. I've searched and read several methods but noone seems to have put together a how to thread on how to breakin a rebuilt Supra motor. So far this is my summary of what I've read:

0 miles
30W oil
drive it: no boost, <3,000RPM varied, hard as possible on the throttle

5 miles
change oil filter
drive it: low boost/no boost(?), <3,000RPM varied, hard as possible on the throttle

500 miles
10/30 or 10/40 non-synthetic
change oil filter
change oil
drive it: low boost, <3,000RPM varied, hard as possible on the throttle

1,500 or 2,000 miles
10-40W synthetic
change oil filter
change oil
drive it: like you stole it...

Add your comments and preferances please. :1zhelp:
 

DaSuprawolf

Im SICK of N/A
Dec 29, 2005
456
0
0
ChicagoLand
in the manuel it said to go from 20mph to 50 at full throtle around 12-15 times, this seats the rings to the cylinder very well, the load on the engine is good, then after that it says to drive normal for 500 miles not slow, not fast. then change oil and your set.
i dont think being hard on it all the time is a good thing, but if you dont seat the rings, it will never run right.
 

jtamulis

www.NotRice.com
Apr 9, 2005
537
0
0
Pittsboro, NC
www.NotRice.com
Wow, i took it easy on my 7M MKII and I'm thinking the next build I'll run it hard
and compare. I do in fact burn oil on my MKII even tho is has maybe 2k miles
on it.

Jeff
 
Last edited:

MKIIINA

Destroyer of Turbos
Mar 30, 2005
1,825
0
36
41
Plano, TX
break in procedure is as varied as the person. some people say you can drive it like you stole it right off the bat while some say no full throttle/boost until after 1000/500/350 miles of easy driving. alot of different ways to go about breaking in an engine but what ya have there is probibly a good start!
 

1TuffSupra

Sho' Nuff
Jul 11, 2005
500
0
0
42
Raleigh, North Carolina, United States
when I put a rebuilt motor in my old eclipse I ran it pretty hard for the first 75-100 miles, changed the oil, and then drove it pretty gingerly the rest of the time. Just make sure that when your driving it you dont keep it at a certain rpm for a long period of time. City driving is the best kind of driving when it comes to breaking a motor in. It never burned a single drop of oil from what I could tell. Plus my car ended up with a freakishly high comp ratio too reg compression was like ~180 I got #s between 215-220. So it definitely seemed to work out pretty good.
 

americanjebus

Mr. Evergreen
Mar 30, 2005
1,867
0
0
37
wa.
its pretty confusing seeing so many opinions when i see these threads the one i have been persuaded into is "drive it the way its going to be used" if your going for hp then go hard on it right away. i'd love to hear more procedures and explanations with them.
 

aljordan

LEADED FUEL ONLY
Jul 14, 2005
466
0
0
49
Indianapolis, Indiana
www.apeserver.com
Either way will work.

I went the easy way on my first motor. The current motor... I was running a bar of boost about 2 miles away from the garage.

Cold compression numbers with 3 cranks are 141-145. If i let it crank until the needle doesn't go up anymore, add another 10 psi. If I do it hot, then add another 10 psi.

I say beat the crap out of it. Run boost, go to 6k rpms, left off and keep downshifting to help pull the rings out into the bores.
 

Supra

New Member
May 11, 2005
304
0
0
48
Rockford, IL
lintlars said:
http://www.mototuneusa.com/break_in_secrets.htm

I followed this and have never burned a drop of oil after the first oil change

I've read that article. My interpretation is that that page applies to factory new engines. I assume that home rebuilds aren't built to the same tolerances and/or cleanlyness usually.

To clarify a bit:
My definition of low boost is under 10psi on 60-1 CT-26 or smaller turbo.
My definition of rebuilt included stock -> +.020" pistons & MHG since that's the typical rebuild.
 

figgie

Supramania Contributor
Mar 30, 2005
5,224
16
38
50
Twin Cities, Minnesot-ah
-Rich87Tx2 said:
I've read that article. My interpretation is that that page applies to factory new engines. I assume that home rebuilds aren't built to the same tolerances and/or cleanlyness usually.

To clarify a bit:
My definition of low boost is under 10psi on 60-1 CT-26 or smaller turbo.
My definition of rebuilt included stock -> +.020" pistons & MHG since that's the typical rebuild.

umm new engines and rebuilds are the same

cross hatch on the cylinder walls are there in both and that is what matters.

I know Ken henderson was making 900+ HP within 2 miles lmao! His motor still runing without issues. Same with Ryan Woon.

<-- I am definetly tearing it up for sure!! 1 bar of boost right from the get go.
 

Stretch

Tallest MK3 driver ever!!
Mar 30, 2005
1,275
0
36
37
Toronto, Ontario
Rock on Figgie! Tear it up and cut it out! If the engine blows up then you obviously didn't build it right!:biglaugh: I'll be doing the same hard break-in someday too.
eric
 

Yeahdoug

New Member
Jun 3, 2005
53
0
0
39
Rochester Hills, MI
When my engine build is complete (soon!) I will probably break it in using kinda what that website says. A few half throttle runs and then a few full throttle runs. Probably at only ~10 psi though.
 

Supra

New Member
May 11, 2005
304
0
0
48
Rockford, IL
figgie said:
umm new engines and rebuilds are the same

I disagree. New engines are built in much better equipped facilities, in better conditions and with better starting materials than 95% of the rebuilds that will appear on this forum. The majority of rebuilt engines on this forum are a trade-off between machinist/builder knowledge, equipment, budget and future use which is then applied to a piece of warped, abused 150,000 mile hunk of non-running metal in the hopes that it will "run right".

That said - I've rebuilt ~20 7M-GTE's and 2 7M-GE's with various breakin methods and wanted to see what the results of others is/was. The main reason I asked this was because I have babied *my* motors and they have historically had a short life - fail for one reason or another. Every motor that I've built and shipped (save for one) was throughly beaten immediately and they are running great after 10's of thousands of miles. I was looking to see if this was a trend for me personally or if this was a group wide trend. Personally, it's looking like beating the motor is the way to go. But don't hold me responsible if you grenade something. :icon_bigg
 

figgie

Supramania Contributor
Mar 30, 2005
5,224
16
38
50
Twin Cities, Minnesot-ah
-Rich87Tx2 said:
I disagree. New engines are built in much better equipped facilities, in better conditions and with better starting materials than 95% of the rebuilds that will appear on this forum. The majority of rebuilt engines on this forum are a trade-off between machinist/builder knowledge, equipment, budget and future use which is then applied to a piece of warped, abused 150,000 mile hunk of non-running metal in the hopes that it will "run right".

That said - I've rebuilt ~20 7M-GTE's and 2 7M-GE's with various breakin methods and wanted to see what the results of others is/was. The main reason I asked this was because I have babied *my* motors and they have historically had a short life - fail for one reason or another. Every motor that I've built and shipped (save for one) was throughly beaten immediately and they are running great after 10's of thousands of miles. I was looking to see if this was a trend for me personally or if this was a group wide trend. Personally, it's looking like beating the motor is the way to go. But don't hold me responsible if you grenade something. :icon_bigg

disagreee all you want

.003" equals .003". ;) no matter if that .003" is measureed in japan or the Ivory Coast. In the end it is .003". ;) So care to take a guess as to what spefics an engine is built to? starts with a T and ends in SRM. So if they follow those specs the motor can be ragged on senseless from the get go.
 

IJ.

Grumpy Old Man
Mar 30, 2005
38,728
0
0
62
I come from a land down under
My main reservation with the Hammer it school of thought is that most 7M's built by "enthusiasts" will have teething problems that need to be fully sorted before they can be driven hard and if not you risk further damage........(cooling,tune and so on it's very seldom just a rebuild and most times a LOT of new untested/tuned components)

I agree that if clearances are correct the motor shouldn't nip up but I shoot for the low side so take it a little easy during breakin to be sure everything is behaving as expected.
 

corewitz

New Member
Dec 6, 2005
53
0
0
Omaha NE
is that guy in the article reffering to turbocharged motors or would the boost from the tubo actually seat the rings even better?