What's The Best Way To Break-in A New Engine ?

[fiji bob 0]

well you wouldnt use full throttle on any cold engine let alone a freshly rebuilt one so im not sure 20 mins at 2000rpm is a problem, afterall even if you did favour the hard driving approach you would still have to wait for the engine to warm up first

[OlberJ 1]

You gotta have some balls/amounts of stupidity (delete as appropriate) to run your engine hard from the word go.

 

Someone else's engine (company car) fine but not your own engine.

 

Am doing 500 miles before giving it some. I wan't the engine to last.

[Ahl 4]

Well thats your opinion Olie.

Have you read the linked website properly?

 

It doesn't ignore oil changes or warming the engine up but does advocate hard acceleration and deceleration to high revs. The same method that a lot of good engine builders will recommend.

[Dream Weaver 2]

I may go for this method when mins done, but it is slightly worrying.

[sorrentoaddict 1]

engine running in is one of the keys to good performance AND long engine life. Yes, contrary to popular belief, these two things are not mutually exclusive - you can end up with a long-lasting engine, and also with the maximum real-life cylinder pressure from your given engine spec, CR etc..

 

however, it can ONLY be achieved by separating the running-in phases of the different engine components. Here is why:

 

hard, brutal running-in from the first outing (on cheap mineral oil) is VITAL and very beneficial for the cylinder rings sealing and for the future engine's performance - if done right, of course. At the same time, this is a bloody nightmare for the following other parts of the engine, especially if they are brand new:

 

- tappets

- camshaft

- valves/seats

- crank/bearings

- various ancillaries & bearings (alternator, w.pump, cambelt tensioners etc..)

 

For bedding-in a new camshaft in particular, there is a VERY strict and dedicated running-in procedure, that is VERY different to what an excellent running-in of rings looks like.

 

Hence the key to a perfect engine build (as running-in seems as the last 10% of the complete build, but can be important as much as 50-60% from the entire result), is to RUN-IN the parts independently:

 

- run-in the liners/pistons/rings in a used engine, or an everyday "mule" engine, and give them the bully treatment from the word go (of course, it has to be done with many other precautions, and not literally destroying the engine - you have to think before you do anything, of course).

 

- then use the already run-in pistons/rings/liners (or block), paired and run-in, when building the final engine (with the proper crank set-up, head, etc..). This engine should be run-in on the "soft" side of approaches, with good quality oil, but still not fully synthetic. As well, the rules for full thermal "cool-down" cycles has to be carefully pursuited in order to enable a nice, proper bedding in of the crankshaft & bearings & rods & block. Of course, if you decide to run-in a totally new camshaft in this "go" as well, then the first couple of minutes of the running of this "final" engine have to be performed as per the camshaft running-in porcedure, which is very different and specific.

 

- only after this final engine has passed several thousand miles with a relatively mild approach with an occasional "thrash", one can think of switching to a full-synthetic oil.

 

One thing is for sure - if a new engine (or a set of new rings/pistons/liners) is pampered and "pussy-footed" from new, the performance potential (cylinder pressures) of that given engine will NEVER be fully achieved - actually you will waste many small expensive things you bought/did to the engine while it was built...

 

And there are many more engine-type specific things to take into account.

 

To simplify it - a proper running-in can wrink out surprisingly big effects of a given engine spec., making it even hard to believe (hence it is especially important in Gr.N / cup engines, where no or very little engine mods are allowed).

On the other hand, an improper running-in can easily make an average performance and/or lifespan out of an otherwise magnificiently built engine.

 

That is why I consider not serious for an engine tuner to "finish" off an engine and leave it to the customer's knowledge and feel to run it in - there is much more to building an engine than just firing it up and checking that the fans cut in..

 

 

Hope to have made it clearer. Or not.

 

 

Cheers

 

 

Alex

[Mandic 0]

So one can not run-in the engine PROPERLY if pistons/rings/liners and crank are put in at the same time?

[sorrentoaddict 1]

if piston/rings/crank/bearings/camshaft(+/-followers)/valves are ALL new, and put in the same time, the running-in will be very tricky and usually some of the components' life will suffer - and you will NEVER be able to give the rings the "vacuum treatment" i.e. the good old thrashing they need - because you will make clear damage to some of the other new components.

 

This dosen't mean that the engine will be crap - there are ways to run-in an engine even when everything is new and fitted at once (due to time/cost resons, etc..) - however, even if you conceive and plan everything properly, such an engine will NEVER have the ultimate performance/lifespan potential as a fully dedicated run-in procedure, using one "mule" engine and then assembling the final beast.

 

Of course, there will be people that will argue with this, but if cost/time is no object, the multi-phase running-in is the only way to do something really efficient.

 

And don't forget this: the more money you invest in a given engine build,

the more you will want to spend that little extra time & cash in order to finalize the "build" with a proper, planned "rodage", that will maximize the mileage and performance out of your investments.

 

So it's your money at the end of the day - I know it is expensive, but what's the point of spending 5,000 EUR on a nice MI spec., and to half-ruin its potential by "saving" some 200-300 euro and a couple of weeks hassle to make it properly run-in ?

 

 

AG

[Mandic 0]

Ok, so it's better to do all the braking-in in two engines or can one do it all in one.

 

Correct me if I'm wrong, so one can put new liners/rings/pistons and fit old crank in (in tolerances of coures) and put the old head on. Starts the engine, beds in pistons/rings/liners and after that, disassembles the engine (puts out the old crank, but keeps the old head on), puts new bearings in and fits new crank, starts the engine again (to bed in the crank). Again disassembles the engine, but this time one only swaps the head with new one and beds the cams, valves, followers, ...

 

If You can not tell me how to do it properly from any reason (business/racing secret, ...), I'll totally understand it.

 

 

 

Many thanks

 

Ziga

[sorrentoaddict 1]

Mandic,

 

there are no secrets really - the first part of your description is true,

this is the right sequence of things to do. But HOW indeed you are going to

bed the rings, and using which method (there are many), is up to your choice.

 

as for doing it like you describe it in the second part of your text, i.e doing it in 3 stages, I wouldn't say that a 3-stage breaking-in procedure would be justified for anything apart from very expensive and delicate engine project.

 

separating the ring bedding-in from the rest usually does the trick perfectly. More important, of course, is to use a breaking-in method that works for a given engine. alloy blocks and cast iron blocks, differ a lot in this context, for example.

 

 

Cheers

 

 

Alex

[Mandic 0]

separating the ring bedding-in from the rest usually does the trick perfectly. More important, of course, is to use a breaking-in method that works for a given engine. alloy blocks and cast iron blocks, differ a lot in this context, for example.

 

Can You please tell us more about this... I guess it has to do with different liners/block material?

 

Just one more thing, I »know« that cams should be bed-in by setting en engine to 3000-3500 RPM for cca 20 minutes or something, rings should be run-in hard (full throttle through the gears), so the cilinder pressure can help to fully seal the rings, but what about the crank, it runs on an oil film, so what's the theory behind running-in the crank, cos I can't see why plain bearings should require break-in, they (sholud) never make the contact with the crank. Does it have anything to do with metal bits from liners penetrating into babbit layer of the beraings.

 

Thanks

 

Ziga

[sorrentoaddict 1]

no, running in the "crank" properly has to do with thermally cycling the crank itself together with the surrounding static elements holding it in place, and the rods/piston group (klipna grupa).

 

this is done with a reason - if you succeed in making the block "get" the "shape" (this is difficult to imagine) of the crank when it rotates, the crank bearings will always be more parallel to the crank journals (at high revs), hence the engine will run faster (lower friction), run smoother and run LONGER, as even in terminally high oil temperature situations, there will be no contact between crank and bearings..

 

running-in is a science of "making friends" between various engine components.. and it is much trickier than you'd think.

 

and piston rings are not to be bed-in just by full-throttle sessions - on the contrary, it is a combination of coasting and "thrashing", so called "vacuum treatment" (don't confues this with some jokes about blond girls )

 

 

Cheers

 

 

Alex

[Mandic 0]

Is there any book or any other source where I can read more about it, cos this is getting more and more interesting, just other day I read on some page on the web, that bearings are oval not circular, not by much, but they are, to achieve high RPM.

 

Such details and better overall understanding how engines work makes me "happy". Knowledge is Power.

 

 

Cheers

[sorrentoaddict 1]

No.

Knowledge is torque.

Valve area is power.

 

 

Recommended read:

 

Modern Engine Tuning by Alexander Bell.

 

 

Cheers

 

 

Alexander (not bell)

[Mandic 0]

 

 

Cheers for info!

[Mandic 0]

Found this, very well written:

 

Before startup:

No spark plugs in, ECU fuse removed, WOT, Crank until oil light goes off for 2-4 seconds.

 

first start up:

Let Idle for ONLY 5 minutes while looking for leaks ... coolant and oil. Let it get up on temp... watching, lookin and listening to things that you may have messed up on. Turn off after or before the 5 minutes.

 

Check oil. Let cool COMPLETELY.

 

2nd startup:

Take the car out somewhere near by just incase you break down. Keep in mind that you need to be back in 5 MINUTES or less for the cool down. Drive the car around like your a Grandmah... listen, smell and look for thens that might be going wrong. Return back and turn the car off.

 

CHeck oil + Leaks.... Let cool COMPLETELY

 

3rd start up:

Same as Before, remember 5 MINUTES!! go out to a open stretch where you can act like a Ricer for a lil bit... when you get there do this... Star in 2nd gear at around 2,000 rpm's and revv it out to around 5500 at WOT, then release the gas and let the car slow down on its own w/ the engine drawing vacuum. when it gets back down to 2,000rpms again gag it again to 5500-6000. repeat this but ONLY go to about 6000 rpms max. Do this 12 times and return back to your garage or home. Turn the car off.

 

Check oil + Leaks.... Let cool COMPLETELY

 

4th start up:

Do the exact same thing as before but start at 3,000 and rev to 7000 then let it slow down to about 2,000 and repeat until you do it 12 times total. Return home.

 

Check oil + Leaks... **DO COMPRESSION CHECK**

 

while engine is still warm, pull plugs, ecu fuse and do each cylinder twice. Dont forget to do it at WOT also.

 

Just check to make sure your rings are seating correctly, make sure your compression is around what it should be for your compression ratio your running.

 

After you let the car cool down COMPLETELY ... change your oil AND oil filter.

 

Go out on short trips at around 10-15 minute each, makeing sure you let it have a COMPLETE cool down each time. When your maken these trips, dont run it at a constant RPM; exampe, interstate driving. Do town driving where you will have constant RPM changes and load changes. The differnt RPM changes and loads will help break in the bottomend bearings correctly. Load is also a great plus for breaking in the rings. Remember to keep your trips short and let the engine cool completely each trip.

 

The reason I say, keep the trips around 5 minutes at first, then around 10-15 after that first oil change is because... i said so. JK, Its because your engine is running at higher temps than normal, and like we all know (I hope) is that heat breaks down the protection of the oil but it also will cause the oil to "glaze" your cylinder walls. If your Cylinder walls become "glazed" than that means break in is "OVER"... So You need to make sure your motor is completly to spec before this happens. This will help your engine last longer, have better compression, consume less oil and all that stuff. So these "small" sessions are VERY important to a proper break in.

 

The reason I say, Floor it like your a ricer , back and forth with the RPMS is because I said so also... jk... Its because it'll be a good work out for breakin in the bearings + MAINLY for the rings. When your adding that load on the engine It'll press the rings outwards into the cylinder walls groving a seal for your rings. This is the best way to seat rings, and most manuals will back me up w/ that theory.

 

Just remember this too:

 

Oil change +oil filter after your first 20-30 total minutes of first start up

 

Oil change + oilfilter after 200-300miles easy/moderate driving... no speed racer 10,000rpms on start up

 

http://www.honda-tech.com/zerothread?id=1471867

 

I'll probably follow his advice when breaking-in mine...

 

 

Cheers

 

Ziga

[Redtop 14 2 Cars]

When im running engines in, in my race car formula ford. I go by what my engine tunner says. It depend s on how tight the engine is built [full rebuild], and it is generally on a dyno for a while as well as running it in on the track with a different viscosity of oil. I would recommend driving the vehicle for aprox 1.5 - 2k with some heavy weights in the boot. It helps the engine labour a bit more and it has been proven with my dads new vans. I would recommend to drive it on abit but not revving the s*it out of it. It may not last long if it's highly tunned.

[C_W 3 1 Cars]

Found this, very well written:

http://www.honda-tech.com/zerothread?id=1471867

 

I'll probably follow his advice when breaking-in mine...

Cheers

 

Ziga

 

If it's for a full rebuild how does it take into account the recommendation that new cams/followers should be bed in by very fast (2000rpm) idling for 20minutes on first start up?

[Rippthrough 98]

If it's for a full rebuild how does it take into account the recommendation that new cams/followers should be bed in by very fast (2000rpm) idling for 20minutes on first start up?

 

 

I'd bed in the cam before worrying about anything else.

[Ahl 4]

If it's for a full rebuild how does it take into account the recommendation that new cams/followers should be bed in by very fast (2000rpm) idling for 20minutes on first start up?

It doesn't.

 

Im rebuilding my engine with everything but the cam, getting the rings bedded in as good as possible (but without thrashing the bejesus out of the bearings), then im sticking the new cam in.

[Guest hydrair]

Going of past experience (2 new 106 gti's, 206 sh1t ti, 309 mi16 with brand new engine and 306 rallye) drive them hard for the first 1000 miles with cheep running in oil. Then buy some good quality oil and drive it the way its ment to be driven.

[TB_205GTI 1]

Remember that there is a huge difference between a full race engine and a daily driver. In a race enigne you often try to minimise the internal looses as this gives more power on the wheels. minimizing internal losses often brings higher oil consumption, but this is not a big issue as the engine is often taken apart and rebuilded. In a road car, high oil consumption is not ideal, and the last 2Bhp at the weels is not what breaks the camels back. Therefore running in a race engine should be rather different than running in a road car. I didn't do anything special when running my new engine in. (apart from the frst 30 minuttes or so). I'm using it as I normally would.