Topic: How to break in new rings
I'm installing new cylinders and piston and rings on my 1600 DP.Going up to 87mm.What is the correct way to break them in?Can you drive it right away?
Pilot Hill Ca.
Re: How to break in new rings
Some say to drive it like normal, some say drive it like you stole it. But I like to just break it in slowly. take a nice leisurely trip varying your speed and stopping often for cookies.
Then about 200-300 miles change the oil and adjust the valves and see how it looks.
burrhead
A wise man makes his own decisions, an ignorant man follows public opinion.
A wise man makes his own decisions, an ignorant man follows public opinion.
Re: How to break in new rings
What burrhead described is pretty much what I've always heard was the best way to break-in a new engine. One of the more important things being to vary your speed (don't drive at the same speed/load conditions for a real long time)...and vary the "load" occasionally by doing some accelerating.
Have fun,
- Nick
1979 Super Beetle Convertible
Re: How to break in new rings
Hiya Gold,
To break in the rings on the engines I have built I followed this procedure............
I got the car up to 45 mph. I made sure the tranny was in third gear. At that point I took my foot off the gas and let the car coast down to 20 mph. I then downshifted into second gear and pulled the car around and redid the run (up to third gear again). I did that 16 times. I then drove the car normally. I've not had a bit of a problem going this route.
Of course, the above does assume that you've already done the cam and bearings break-in. But you are skipping the lower end, aren't you?
Mike
1970 AS Bug
1970 Bus - The Ruptured Duck
1970 AS Bug
1970 Bus - The Ruptured Duck
Re: How to break in new rings
I'm in the "drive it hard" camp.
Before I believed that, I bought my Mexican Beetle new from the dealer. It's first 100km were varied between 80 and 90km/h on a flat road. The result is significant blowby today. Clearly, driving it with a light load doesn't work.
I recall reading about two guys who both decided to buy identical motorcycles at the same time. One kept the revs down and baby'd it around town for the first few hundred miles. The other guy ran the crap out of it right off the showroom. Later, they both decided to dyno their bikes. The guy who beat the hell out of his bike made significantly more hp than the guy who took it easy.
Here's the theory:
We all know the rings have to seat into the cylinders to make a good seal. This happens in the first few hundred miles. Then after that, nothing you do will affect that seal. So you need to get the rings to seal properly as soon as possible.
The rings have a normal spring tension forcing them outward against the cylinders. But this tension is fairly small compared to the forces created by the cylinder pressure. The greater the cylinder pressure, the greater the force pushing the rings against the cylinders, then the better the sealing.
Because of this, you should take your new engine to the nearest hill you can find and drive it up that hill at full throttle. Repeat. This maximized the cylinder pressures, making them seat in much better.
Last edited by Bruce (2010-09-04 20:33:45)
Re: How to break in new rings
I moderate during break in, which means that it will see WOT but not to redline, and varying speed. Seems to have developed a good track record over the years:
1969 Plymouth - 160,000 mile on first engine, 225,000 miles on upgraded street/strip engine. Retired due to rust.
1984 Dodge van - 51,000 miles, traded in for a car when I found a wife. The slant six was so smooth that you had to look at the gauges to see if it was running, and everyone swore it was a V8.
1984 Chrysler LeBaron - 186,000 miles. Ok for a gussied up k-car with a 4 banger. Engine outlasted body.
1991 Caravan AWD - 128,000 miles. Still ran well when it was wrecked by a Mustang.
1993 Town & Country AWD - 238,000 miles. Traded in when ABS failed and dealer refused to fix. Engine ran like silk and STILL did not need oil between changes.
1996 Caravan - 90, 000 miles when it was stolen. 3.3L V6 could smoke the tires all the way through 1st and 2nd.
2001 Town & Country - 173,000 miles and still going strong. Getting ready to tune it up for the first time.
2004 PT Cruiser - 162,000 miles and still going strong. Never been to the dealer, never left us stranded, never had a problem despite being beaten hard on the streets and the racetrack. Added a half quart of oil for the first time last week, but then the oil change was 2,000 miles overdue.
Paul