How To Break In An Engine...
06-25-2003, 08:14 AM
#1
Three Wheelin'
Thread Starter
How To Break In An Engine...
<a href="http://www.mototuneusa.com/break_in_secrets.htm" target="_blank">http://www.mototuneusa.com/break_in_secrets.htm</a>
Definitely goes against everything I've heard about proper engine break-in etiquette.
However, maybe he's one of those guys who dispels 'old wives tales' regarding a favorite topic as he has lots of experience to back up his 'simply outrageous' claims.
His explanations and reasoning do make sense, so the next time I have a new engine, at the very least, I'll feel compelled to consider what he says.
Has anyone else heard similar accounts?
Definitely goes against everything I've heard about proper engine break-in etiquette.
However, maybe he's one of those guys who dispels 'old wives tales' regarding a favorite topic as he has lots of experience to back up his 'simply outrageous' claims.
His explanations and reasoning do make sense, so the next time I have a new engine, at the very least, I'll feel compelled to consider what he says.
Has anyone else heard similar accounts?
06-25-2003, 09:43 AM
#2
Rennlist Member
Join Date: Dec 2002
Location: Southern New England
Posts: 1,975
Likes: 0
Received 0 Likes
on
0 Posts
His experience is compelling, but consider that there may be some subtle differences since his expertise lies within the realm of Japanese motorcycles. I think I'd stick w/ the Stuttgart recommendations!
Perhaps the rebuilders in our group could discuss what they have found. Clean pistons or lots of blow-by?
"100% ring sealing mode", formerly known as "bwaaaaaAAAAAA"...
Perhaps the rebuilders in our group could discuss what they have found. Clean pistons or lots of blow-by?
"100% ring sealing mode", formerly known as "bwaaaaaAAAAAA"...
06-25-2003, 10:05 AM
#3
Burning Brakes
A few years ago I read an account by the chief engineer for the Corvette. The advice was to run it hard right away if you want it to be fast.
I think the article makes some valid points. Machining has come a LOOONG way in the last decade. The quality and matching of parts is much better than it once was. Many engines have a brief "run in" at the factory these days. They don't run them lightly either <img border="0" title="" alt="[Wink]" src="wink.gif" />
The other break in advice I have read about goes as follows. Once warmed up you should run it in increasing rpm sections at full throttle and then back off allowing engine compression to slow the car. So you run it from 2000-4000 a few times, then 3000-5000, then 4000-6000. One thing you are not supposed to do is run at a constant speed for extended periods. I think that is something that is reccomended by most manufacturers. the above does what the article explains but also puts pressure on the other side of the rings during engine braking.
Like the guy stated, this is controversial and we will probably see many opinions. I think he is on to something though.
I think the article makes some valid points. Machining has come a LOOONG way in the last decade. The quality and matching of parts is much better than it once was. Many engines have a brief "run in" at the factory these days. They don't run them lightly either <img border="0" title="" alt="[Wink]" src="wink.gif" />
The other break in advice I have read about goes as follows. Once warmed up you should run it in increasing rpm sections at full throttle and then back off allowing engine compression to slow the car. So you run it from 2000-4000 a few times, then 3000-5000, then 4000-6000. One thing you are not supposed to do is run at a constant speed for extended periods. I think that is something that is reccomended by most manufacturers. the above does what the article explains but also puts pressure on the other side of the rings during engine braking.
Like the guy stated, this is controversial and we will probably see many opinions. I think he is on to something though.
06-25-2003, 11:44 AM
#4
Three Wheelin'
Ask the aircraft engine manufacturers. I've heard (I talked with the head of Aeronautical Engineering at SJ State) them say that to break the cams in, the car should be run up and down in the revs for a couple of miles. Not hard enough and the rings don't seat. I think it was Cessna's site that had a good explanation. I think the majority of folks don't know, but someone does. A lot of empirical testing has been done. Finding it might take some googling.
06-25-2003, 05:37 PM
#5
Three Wheelin'
Join Date: Nov 2001
Location: Northern Kentucky
Posts: 1,446
Likes: 0
Received 0 Likes
on
0 Posts
I now have 500 miles on the Bastard. I have run it up to 5200 under full throttle, 7 lbs of boost. I did that last week with 300 miles on the rebuild. The cams are already cut in, so no issue there.
I am going to wait until I get 750 or so on it before I turn the monster loose.
A lot of new M3s spun bearings with just a few thousand on the clock....that is something to keep in mind, but that engine also turns 8,000 rpm, so 6,000 is a lot lower with the 928.
I am going to wait until I get 750 or so on it before I turn the monster loose.
A lot of new M3s spun bearings with just a few thousand on the clock....that is something to keep in mind, but that engine also turns 8,000 rpm, so 6,000 is a lot lower with the 928.
06-26-2003, 08:22 AM
#6
Three Wheelin'
Thread Starter
</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">I now have 500 miles on the Bastard. I have run it up to 5200 under full throttle, 7 lbs of boost.</font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">How did it feel; are you happy with the results so far?
</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">A lot of new M3s spun bearings with just a few thousand on the clock....that is something to keep in mind, but that engine also turns 8,000 rpm, so 6,000 is a lot lower with the 928.
</font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">That is true, but there is something fundementally wrong with those engines. So many has blown up that there is a website devoted entirely to the problem. If I had the link handy, I would've posted it.
I found it:
<a href="http://members.roadfly.org/jason/m3engines.htm" target="_blank">http://members.roadfly.org/jason/m3engines.htm</a>
It makes for interesting reading.
</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">A lot of new M3s spun bearings with just a few thousand on the clock....that is something to keep in mind, but that engine also turns 8,000 rpm, so 6,000 is a lot lower with the 928.
</font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">That is true, but there is something fundementally wrong with those engines. So many has blown up that there is a website devoted entirely to the problem. If I had the link handy, I would've posted it.
I found it:
<a href="http://members.roadfly.org/jason/m3engines.htm" target="_blank">http://members.roadfly.org/jason/m3engines.htm</a>
It makes for interesting reading.
06-26-2003, 10:50 AM
#7
Addict
Rennlist Member
Rennlist Member
Join Date: May 2001
Location: Wilbraham, MA
Posts: 2,758
Likes: 0
Received 0 Likes
on
0 Posts
I recently installed a rebuilt 5 liter shortblock in my '80 euro s. My car is not street legal, so I was concerned about how to break it in. I was advised to use non-synthetic oil and run it hard....
My first event with the motor was the PCA Club Race at Lime Rock, followed by the PCA Club Race at Watkins Glen and then a track day at Lime Rock.
I didn't do anything any different that I have in the past with my previous broken in motor, and so far haven't had any issues....
I am lower in hp than a couple of other similarly configured 928 motors, but it is presumed to be due to the difference in exhaust systems.
Stan
My first event with the motor was the PCA Club Race at Lime Rock, followed by the PCA Club Race at Watkins Glen and then a track day at Lime Rock.
I didn't do anything any different that I have in the past with my previous broken in motor, and so far haven't had any issues....
I am lower in hp than a couple of other similarly configured 928 motors, but it is presumed to be due to the difference in exhaust systems.
Stan