I have build several engines on my cars, and I allways baby the engine for the first 1000 to 2000 miles, But I heard when you have a build engine with forged pistons it's the oppossite. you have to drive it like your racing it from the start. any input will be helpful thanks.

 

depends on how you build the engine (cylinder wall finish, ring gap, etc)

when i broke my engine in I took it easy for the first 1000 miles (<5psi, <5000 rpms) and my engine has less than 3% leakdown on all cylinders now

 

There are so many diff ways to run a engine in, Most of the diff ways are fine, I would not run a engine in for 2000miles that is way to long,
500miles is about the max I would use to run it in and general driving not to slow but not to fast,
Some use the hard method and theres nothing wrong with that either,
When I run in on the engine dyno its 2 hours at diff loads then I start pulling some good boost, Then I go for full power mapping and never had a problem with that,
Its best to ask your engine biulder but if its you then look at what people say then do it the way you think is best.

Mark

 

Thanks for the advise guys. I guess 500 miles and the run that baby at WOT. Im bulding my 4g63 6 bolt with forged pistons stock bore.

 

I put mineral based oil in mine then ran it at 2500 rpm for about 10-15 minutes, then changed the oil and filter again with mineral based oil, then ran it for about 200 miles with little to no boost. Oil and filter again then 500 miles at moderate rpm, never over 5000rpm and little to no boost still. Change oil and filter again. at 1000 miles switch back to synthetic and go no more than 200 miles, oil and filter again and resume normal oil change intervals. It sounds like a lot of crap but I am stupid ****! LOL So far so good on my rebuild!

Josh

 

i did the mineral oil startup also, but i didnt drive the car on the mineral oil

 

I've read lots about this subject, and what I believe is as follows. A perfectly built motor doesn't require any break in. A great way to seat the rings is to bring the car to a high rpm then let off the throttle and let it decelerate on its own. Repeat a few times and you should be set.

I've noticed lots of motorcycle guys never break in motors, period. I've also seen a lot of people with high hp 4 cylinders break in their motors by immediately using a 2-step once or twice on the dyno and then tune.

 

Thats exactly what I heard. So I guess on this build I will do this break in process.thanks guys you all been pretty helpful.

 

I cant see any negative to treating it like a baby on break in.

I can see a negatve on treating it hard on brake in.

The rings aren't seated, the cylinder walls arent de-burred.

Regualr oil changes are good especially with a magnetic filter. There will be alot of tiny tiny metal shavings on the first few changes as all the internals wear a little and get seated.

Just my 2cents.

 

1000 miles under 3000rpm then get a oil change

 

Having had (and built) about 20 different kinds of engines, most of the break-in requirements depend on the build (rings, clearances, new/used cylinder walls/sleeves, etc) I would talk to your engine builder first, then the ring manufacturer next, one thing that you do is change the oil after whatever break-in you do. Use the cheap stuff mineral stuff at first.

 

Ive used the steady 2000 rpm for 30 minutes method.
Thats what we did at DPRracing

 

I have seen the same two way.... baby for 500 miles or the other way break it in on the track.... I have talked to many many motor cycle guys and almost all of them say to take a new motor and break in it in on the track... and most of them have good success with the "beat on it" break in..... I tend to start it run it easy for about a half a tank of gas to debur everything... then beat on it for the rest of the tank, change the oil, and the drive it normal. With modern day machining, and processes things seem to fit a lot better than the "old days" I donno, I guess the best advice is to talk to your engine builder... as said before... if its you, read the advise and do what you feel is right.

 

I would apply a little of both ways.

 

http://www.mototuneusa.com/break_in_secrets.htm