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Engine Break In, breaking-in, motor break-in [Merged 10-6]

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BrokeTurbo

20+ Year Contributor
49
0
Sep 4, 2002
As the following thread will illustrate, motor break-in is not the issue it was in the fifties and sixties.
For all intents and purposes, your method will not significantly matter, within reason.


Well, I am getting the laser back from the shop this weekend. Here's a List of whats new, and whats not.New Pistons, Bearings, Rods, Crankshaft, Rings, Oil pump, Belts, Pullys, Head, Valves, No balancer belt. The only real thing thats old, but freshened up is the block, and valve cover, and the FI system. (Fuel Injection)

I am going to run Mobil 1 10w-30 with a Puroilator PL101xx Filter. I have a new clutch with a resurfaced flywheel going on. I've also got new fluids in the transmission.

My question is how should I break it in? This is my first non 70's Chevy, and I was wondering if there are any tricks to it.

The way I was going to do it, was 15 min of idle, warm up. Make sure all fluids/hoses/electrical is plugged in. Then about 1 hour of normal driving. Might take out to the Highway, and cruise around 65-70 for a little bit.

This sound good? I was not going to get on it, or push it till ive got about 500 miles on the engine. Even then, I'll still be taking it easy. Anyone have any tips or help? Thanks
 
Originally posted by BrokeTurbo
The way I was going to do it, was 15 min of idle, warm up. Make sure all fluids/hoses/electrical is plugged in. Then about 1 hour of normal driving. Might take out to the Highway, and cruise around 65-70 for a little bit.

For break-ins (at least on new engines), it's usually recommended not to drive at sustained RPMs for too long at a time.... and you probably don't want to be redlining too much either. If you're driving on the highway try to vary your RPMs a little, maybe slow down a bit once in a while and drop to 4th, let it rev a bit higher for a while, etc, etc..
 
Mitsu says break in on the engine is 500 miles and you are not supposed to go over 55MPH during that time period and as stated above you will want to vary your rpm's when crusing. Personally I don't even go above 4k let alone redline until I've got at least 1000 miles on the engine/rebuild... and since you've pretty much got a new engine you should take it easy for a while. Enjoy! :thumb:

L8R :dsm:
 
Hi everyone!

I overheated my engine and warped my head. I had the head machined and rebuilt. While the head was off I cross hatched the cylinders and put some 95 pistons in with stock rings. Its about 1500 miles later and I'm not getting the power I expected. In fact the car feels like it did before the new pistons. I checked the compression and all 4 were around 150. I put some oil in and they all went to around 170. This test was performed while the engine was hot.

I only ran 4 psi up to 1000 miles and then slowly turned it up to 16 psi, which is where I am now.

Im wondering if my rings havent seated yet, or if I glazed my cylinders.

What do you guys think?

Thanks,

:confused:
 
When you break in an engine.. Usually think about this..

If you want a fast motor, break the engine in hard. Downside, the engine wont last long.

If you want your motor to last, break it in really easy. Downside, the motor wont be fast.

4 psi when breaking in the engine is a little low.
You should have ran around 13-14 psi.
 
My first 400 miles were around town, but my next 500 were highway mileage.

I read on an old DSM archive where sombody said that by 1000 miles the rings should be about 90% seated. If my compression is supposed to be 180 PSI then 90% of 180 is 162. So I'm 500 miles over 90% but I'm still short. I wish I would have measured the compression within the first couple miles to see if it was higher than where I am now. Then I guess I would have know if my compression is better or worse.

Do you think my rings will never seal, or should I just keep on it and maybe they will? If my rings aren't gonna seal and there is no hope then I guess I need to pull the pistons back out and try this again!

What do you think????
 
If you only honed the cylinders and droppped in new pistons and rings, you can't expect 100% out of the motor. The cylinders weren't bored, they are probably worn, and that will hurt compression and power. 150 psi across the board isn't horrible for a block with a lot of miles on it.
 
My block is orriginal and had about 80,000 mile on it.

So you are saying that if I want more compression then I need to bore the block.

Do you think there is still a chance that my rings could seal better if I continue driving?
 
How many miles do you recommend to go easy on a new/rebuilt engine before it's broken in? Anyone know any numbers?
 
I picked up moble 1 synthetic to break my new engine in with. Is this ok or should I get regular oil first. I plan on using moble 1 oil and filters on a regular basis.
 
Regular oil first. Synthetic is too thin for engine break in purposes. How long you should run it on regular is a matter of opinion. I ran mine on regular for the first 3000 miles. I changed the oil after 100, then 500, then 1000, then 2000, then 3000. But I am overly anal about oil changes.
 
I'm still not quote sure on what should and shouldn't do during the break in period of a built engine and head. Like what oil to use, how many miles, etc.

Can anyone give any tips and advice? Thanks in advance.
 
if you plan on using synthetic,i've heard that its better to start with a mineral based oil to break it in,then switch. don't rev over 5k for more than 15seconds till you have atleast 500miles on it,just baby it. drive like you are trying to conserve gas. after you've got 500 miles on it,in first or second gear take it to about 6500-7000,then let off the throttle slowly till you're back down to about 2k,do this a few times then drive it lightly about 200 more miles and it should be broken in pretty well.
 
I am having a new engine built for me and I am a little unsure about the break-in process also. I have always heard that you should be really gentle until it reaches a certain mileage, however a friend of mine sent me an e-mail of how to properly break in an engine and its maybe not what you would expect. If you want I can e-mail it to you. E-mail me if you are interested at [email protected]. Otherwise good luck!
 
there are a lot of theories about engine break-in most will tell you to baby it, some will tell you to drive it like it you stole it, use mineral based oil for break-in regardless. search the net for more advice on the subject, allwheeltsi's way does sound correct.
 
i always head 600-700 miles of babying then drive normal. That's from friend's mechanics after their engine swaps (mostly old v-dub cars but should be similar)
 
Currently I am helping a friend rebuild his engine. Its a 6bolt 2.0TC turbo engine out of his GSX. Heres the question:

In the owners manual it says when you first start the engine, you want to hold the rpm at 2000rpm for a short period of time(cant remember what it said). Then when you get the car on the road, you want to run the engine from 30-50mph full throttle then back down to 30mph about 12 times to seat the new piston rings. Is this correct? What should the boost settings be at? As low as the wastegate will allow without the use of a MBC?

Thanks and sorry if this has been answered before. I am at a friends house and I'll be leaving soon and he wants to know by tomorrow if the above is correct. :thumb:


Also when he was removing a balance shaft bearing (removing balance shafts) out of the block, the bearing punch was a bit too big for the block and he put about a 1/2in. crack in the block where the frost plug will go. The crack goes from the balance shaft bearing hole to the outside of the block. It doesn't look that bad or serious, so if I throw a few tack welds on the block there will it be ok still? This kind of worries me even though it isn't mine. Thanks again

Damn :dsm:'s!!! But I still love 'em
 
That is the correct way to seat the rings. Don't use any boost during the break in period, or you could damage the rings.

Jake
 
Originally posted by halvorja
That is the correct way to seat the rings. Don't use any boost during the break in period, or you could damage the rings.

Jake

Ok but how don't I use boost when I floor it?

Then when you get the car on the road, you want to run the engine from 30-50mph full throttle then back down to 30mph about 12 times to seat the new piston rings. Is this correct?

Thats what I am talking about. How can I do this without going into boost? Thanks
 
take the actuator off of the wast gate flapper arm and wire the gate in the open position. should almost elininate all boost, on my 20 g it kept it down to 2 lbs all the way threw 6k rpms
 
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