Engine break in methods after rebuild. Opinions on this method.

[nikp]

So what do people make of this?

[Adam]

is it me or is this only aimed at piston engines??

Adam

[nikp]

yeah, it is. Still, can\'t opinion be made oin this anyway!?

And besides, the theories on it can be put to a rotary too, can they not? i.e. The compression is created via the large pressure pushing the apex seals against the walls of the rotor housing. After all, the apex seals are the equivalent to piston rings.

[Fish]

The engine should be broken in as per the company that rebuilt it states. EVERYONE has different ideas on this subject.

Fish

[Adam]

no dig intended mate....  i just thought i was missing something. I was looking for a section on the site that mentioned rotaries that was all,

My personal feelings on this is i always take advice from roatry experts who have worked with rotaries for years, and every one of them has given me the smae advice on runing in a rebuilt engine.  but there are some interesting facts in there i must admit.

Adam

[nikp]

I was merely curious what peoples opinions are. I am just a curious person when it comes to technical and mechanical things.

[elford_tim]

Oh great, I haven\'t seen this page mentioned on any newsgroup or forum that I frequent for at least four weeks...  :Giggle

I\'d take the advice with a CostCo-sized bag of salt or two. As everybody else has mentioned, it is mainly targeted at piston engines anyway.

In my personal opinion his "advice" goes in the same bucket as the ssssnake oil products like Slick50. After all, you\'d expect that the manufacturers know a little bit about the product they sell and if his method was so superior it would have made an appearance in the owner\'s manuals by now.

The normal trade off is power vs longviety (sp?). You get more power if you reduce the friction inside the engine (ie, it\'s "loose") but tighter tolerances tend to be better for long-term performance. For example, mirror-like bearing surfaces may be better for power (less friction) but they are bad at oil retention, thus increasing wear.

If you tear down your engine every 10,000 miles anyway you may not notice the difference and enjoy the additional power. If you\'re trying to squeeze another 100k out of an engine that has already done 250k, you\'re likely to notice.

[Archbish]

My understand is pretty simple:

Hard run in gives a short lifespan, but more power.

Easy run in doesn\'t give quite as much power, but the lifespan is extended.

But like Fish says - if you got your engine from a rotary engine builder, follow their instructions TO THE LETTER!!

[BlitzBoy]

yeah my break in period was 25 miles, then mapped on the dyno at 1.3 BAR 450@wheels

Yes thats right you heard it "TWENTY FIVE MILES"

[mullins]

It depends on what internal parts have been replaced. If you\'ve just done the seals & springs and haven\'t done the rotor bearings, etc then an hours run-in to bed the seals should be fine in my experience.

[BlitzBoy]

yes , just the seals and springs were done, bearings were done on my first rebuild.

[oldone]

We used to build the race motors,install,go to the circuit,do 5 laps slowly,come in and see what\'s leaking.Nothing leaking,cool down,go out and do normal race speed for 5 laps,come in and check liquid levels.Change to race plugs,change oil filter and oil..........go out and lash the beast for at least race distance.
These motors were good for at least 10,000.00 road miles and the rest.............like you say,all has their own idea for engine life and break in.... :Typing

[kev-yorks]

Don\'t run in any engine myself 20 mins or so at fast idle to get all the temps up shut down and a level check. Then drive it like you intend to drive it. Use the same procedure for all my engine rebuilds petrol/ deisel rotary or piston. Not saying its the right way but it seems to work for me.
Kevin

[oldone]

Somebody say DIESEL ?................ :Hammer

[stuart wizy]

break in is most important for bearings on piston engines and rotarys, also running in rings to bores or apex seals and side seals to rotor housings to gain full compresion hence the phrase bedding in.
If an engine has had all new bearings then it should be run in properly or you could risk a bearing picking up.(ie clearence to tight with to much load)
Ive rebuilt engines with reground cranks and all new main and big end bearings that would slow right down in any gear going down hill because everything is tight for the first 100 mile or so. you can really feel the difference on a rebuilt engine for the first drive so new bearings make a big difference to run in distances.