So I finally finished my project and need advice on breaking in the motor. I know this been asked before and I've done my research, only to find many different methods. So how do I go about breaking in a B18C?

 

http://www.dprracing.com/dpr-engine-break-in.html

So - you've found different methods, but you can't decide which to follow?

What can we do besides offer you more choices?

Dan's experienced with racing engines, the link above is the approach I've used and it seemed to work well. I've seen others recommend something similar.

Bottom line is - if you baby the engine the rings won't seat well in the short time you have before the cylinder hone loses it's ability to seat the rings.

Happy motoring!

Mark

 

Thanks, haven't came across that page but it seems well put together.

 

With. Saafe tune, vary the load and rpm. Be sure to do a lot of engine braking and keep up on those oil changes. You don't have to go slamming rev limiter out of the box but you do need to add some heat/load to it.

 

its too often people think a fresh engine is something brittle. If the engine breaks during break-in using any of the various break-in methods, it was going to break regardless the type of break-in procedure you follow.


use common sense and good judgement.

 

Agreed (above) - the old idea of babying the car for 500 miles almost guarantees a so-so ring seating.

As the previous poster said, redline isn't necessary - it's getting enough speed to let off the gas and brake with engine compression.

The key is to get plenty of compression braking early in the break-in process, so that the rings seat before the hone is smoothed off and you lose the ability to finish seating the rings.

That hone, properly done, is the 'file' that removes metal from the rings to conform them to the cylinder wall.

The cylinder pressure from letting off the accelerator and coasting pushes the rings against the cylinder wall to accomplish this.

Mark

 

and its typically the rings that get blamed for a failure and not the hone when the improper honing speed/stone/angle was used. But how does a beginner know the difference? To them a hone is a hone unless they actually ask questions to their machinist.

 

Proper breakin will require a vary of RPMS as well as coasting down in gear. Coasting down in gear will help build up pressure under the pistons to help expand the rings. This should be done within the first 5-10mins of the car actually having load on it.

"The Easy" break-in is a myth and has since been proven to not be the "best" way. While it does fine when varying RPMS, its not the best way to start it off. Dont be "scaried" of the throttle.

 

Thanks everyone for the replies, I guess I have my answer now.

 

I find it interesting that people suggest using vacuum and deceleration to aid break in ring sealing. This negative pressure does not put any extra ring tension against the cylinders. Positive cylinder pressure... say from acceleration on the other hand will force the rings outward.

This must be in a book somewhere, why else do people suggest this? How do they know that this is for sure what the rings want on every engine?

 

the final hone grit on honda motors are fairly fine.its not gona wear the rings much because honda rings dont really need it. if its done right the rings should seal fine wether you baby it or beat on it.older v8 motors that used cheap cast rings required a rough hone. with honda rebuilds proper assembly and clearances are gona dictate ring seal aside from runing it pig rich and washing the rings out completely

 

What about this for thought:

If we are really trying to get load and heat into the motor what about making lower rpm pulls in higher gears. According to my egt gauge that does just fine throwing some heat into the cylinders, then when u engine braake it cools down quickly

 

There's a ton more to "breaking in" than just the initial driving aspect.

Can you more knowledgeable guys share what your pre-startup routine is. This is critical. Once we get a lot of the good points, I can summarize and, maybe, 98vtec an sticky it for prosperity.

 

You'll hear many opinions on priming. I believe in it, I believe that Dry priming will help build up pressure faster. I also Leave the valvecover off when dry priming. I do this to make sure that everything is working as it should and is lubed as it should. I also believe in pouring some oil in the oil filter as well.

I usually prime a engine 3-4 times at 10-12 second intervals. I also do the first valve adjustment before starting.

Once the motor is actually started, I spend the first few mins making sure the car stays running and monitor AFRs. I'll normally have a second person with me help to make sure there's no leaks from anywhere. Once the car has warmed up and started climbing to operating temp I'll begin to tune the idle and Lock in the Dizzy and sync it with the timing map. I'll allow the car to run and reach operating temp and make sure the fans come on.

Once the fans kick on and i see that it holds temp and pressure and doesn't overheat, I'll shut the car down and change the oil and perform another valve adjustment. After I'll do a drive, Varying rpms and monitor AFRs as well as ign. After a few mild pulls and i say mild because i'm not completely banging the rev limit, i'll pull the plugs to ensure everything does look good. This is a break-in i use regular and I've honestly never had a lick of problems.

The break-ins normally consist of a First start up oil change, a first drive oil change, then i'll drive the car for around 200-300 miles before the next oil change.

When people call me to tune their car's, And its a new motor, I usually make the effort to be there on first start ups.

 

This does a couple of things. Compression rings seal because combustion pressure gets behind them and forces them outward. When you are at WOT and cylinder pressure is high, the compression rings are being forced out toward the cylinder walls and, when the rings are new, this will force the high spots against the cylinder walls and "wear" them in until the ring is concentric with the cylinder wall. When you coast in gear, the high vacuum in the cylinder will help draw oil up past the rings and flush out any metal filings that were formed when the rings were wearing in.

 

Verify engine has oil, coolant, and trans fluid.

Tow car to tuner.

Pull injector clips and disable ignition.

Crank engine in 10 second bursts until oil pressure is built up.

Fire engine up and let your tuner do his thing while the engine is held at 2,000 RPM until warm. Check for leaks during this process.

Change oil.

Put it on the dyno and tune it.

Change the oil.

Drive it.

Change the oil after the first event.

Done.

I don't tune so if you are doing that yourself there are more steps to be taken aside from the actual tune that I haven't included.

 

Good point re changing oil. There maybe a lot of internal debris and even coolant mixed in with the oil.

Also unclipping the injectors is key when cranking the motor to prime the oiling system.

Make sure the battery is fresh. Can't prime with a weak battery.

 

An engine that isn't properly stored or covered before start up will have little knicks of crap in the first idle drain. Dead bugs, etc etc.

Dont wanna fill up the cyl with gas lol.

 

when i did mine i cranked it while it was still out of the car to build up the oil pressure and make sure no leaks before its in the bay

once started i made sure to adjust the idle and timing

then drove it easy for 5 minutes and did the break in according to the page.

so far its been great. no drop in cylinder pressure
( except the one i fed up by checking my machinist work i pulled the piston out to make sure rings were set right and used the chepa autozone ring compressor )
even though it flooded first time overnight( i forgot to check)
drained the oil and got on it pretty hard within first 50-100 miles.
and oil stopped smelling like fuel

 

We used to break in our engines on a Superflow SF902 engine dyno by just varying the load and RPM. 30 minutes later, we're making pulls to validate power output.

 

So basically dont baby the car? My car should be done tuesday i also needed some of this advice.

 

use your actual brakes as little as possible. In an ideal situation, you would break the engine in on the dyno as you have no traffic, speed limit or anything else for that matter to get in the way.

Aquafina's process he posted is about what I use except I would recommend doing a pre-start up compression test and a post dyno compression test. After some time driving, I would perform another compression test to compare with the dyno test to confirm ring seal. This is more so confirmation for the tuner that the engine left with good compression.

 

Go on a road trip and just drive it. Not too hard but take it a little way up.

 

Take it on long drives, go on a road trip. Don't drive it to hard bout take it to some limit.

 

great info thus far.

When we did 3 compression test before/after
a
fter a few mins of running cr was 165-170psi
after breaking the car on the street it was 215psi.

this was on b20 with 9.9ish cr.