13 replies to this topic

[TiMtImInYtImTiM]

Hello,

After having had 2 new engines built for me and seen many engine builds over the years I have heard my fair share of differences in opinions when it comes to running a new engine in.

After following a strict guide on how to do so with my very first 1380 build. Including several oil changes and varied rev and throttle increases I ended up being too gentle and created problems. I followed guidance from somebody else the second time around and had no problems for the duration of the engines life. I am currently running in a rebuilt 1293 MPI engine and am pretty confident in the method I will use to run it in.

It seems that there are many ways to skin a cat when it comes to running an engine in. I thought it would be interesting to hear everyone's opinions.

Edited by TiMtImInYtImTiM, 27 February 2013 - 12:21 PM.

[Fast Ivan]

Why don't you kick off with your method?

[mailman]

Yea, I'm interested to hear your method that worked well.

[ANON]

http://www.mototuneu..._in_secrets.htm

[Vipernoir]

20-30 min stationary run in at over 2500rpm. Change the oil & filter.
70-100 miles of gentle-ish driving including the hard pulls as specified by Hastings. Change the oil.
400 miles of normal driving including booting it, but never letting it lug or bog down. Change the oil & filter.
Drive normally.

[tiger99]

So your method involves extra oil changes. Makes a lot of sense, as the initial wear debris will be flushed out quickly. I for one would not begrudge the cost of an extra couple of gallons of oil, and a filter or two, if it was going to gain many thousands of miles of engine life.

I wonder if it would be better to use the special running-in oil for the first stationary run? I would be very reluctant to drive the car with that in, as we probably don't know what it would do to the gearbox, but maybe it would help the engine to bed in quicker?

An A series engine, especially an A+ can sometimes last up to 150k miles, more usually 80k to 100k, which is nowhere near as good as many modern engines. I think that some, maybe all, of that difference is due to the machining processes, which produce much better finishes on cylinders, cranks and cams nowadays. I wonder if it follows that having a Mini engine machined to modern tolerances and finishes would make it last as long? There is only very minimal running in on a modern engine, and to my amazement my daily driver did not need an oil change until 12500 miles from new.

Edited by tiger99, 28 February 2013 - 10:11 AM.

[Vipernoir]

I use Unipart 20w50 which has a nice amount of ZDDP, is sensibly priced and iirc OEM.

Oil change every 1500-2000 miles and oil & filter every other change.
Oil is cheaper than an engine when bought in bulk - Unipart will usually do a nice dicount for 100ltrs+.

[TiMtImInYtImTiM]

20-30 min stationary run in at over 2500rpm is interesting as I was told by several sources that you must not let the engine run at a constant speed in its early days. I.e. don't get out on the motorway and do your run in at 50 constantly. My method has been to drive around on a small amount of throttle keeping the revs below 2500 rpm until 250-300 miles. Change oil/filter and increase to slightly more throttle and 3000 rpm until 500 miles. Change oil/filter and start gradually working towards full throttle steadily increasing revs until 600-700 miles and then another oil change before driving normally. I guess it also depends on the type of engine that you are running in. So many different methods and they must all work.

http://www.mototuneu..._in_secrets.htm

I like this method and it makes for an interesting read:

Edited by TiMtImInYtImTiM, 28 February 2013 - 02:17 PM.

[mailman]

Has anyone, with experience running many engines in, got an opinion on the mototuneusa method? It seems to make a lot of sense but it goes against most popular positions or ideas.

[Spiffingly Good]

Now i know lots will disagree and by no means should anyone follow my advice, but the last engine i built, full strip and rebuild. I simpy primed the oil with ignition disconnected, fired it up tinkered to get fuelling right, the took for a drive, nothing special about 10 miles then changed the oil. Then just drove as I normally would including a 500 mile round trip to MITP at 80 mph fully loaded.

[Old Bob]

http://www.mototuneu..._in_secrets.htm

That seems to be all about piston ring/cyliner initial wear and bedding down. There is a lot more to a full rebuild than just the cylinders and I would be concerned about all the other bearing surfaces 'getting friendly'.

Bob

[Old Bob]

My own running in procedure - mostly with older engine designs because new motors aren't so stretched at normal road going speeds - is all about load and very little about speed. So, lots of gear changing to prevent the engine labouring and keep the engine speed down to about 3/4 of max for the first couple of hundred miles, gradually opening up for longer and longer periods.

Clean oil is everything so an oil and filter change after 500 miles and again at 1,000 miles.

I believe a little mechanical 'sympathy' results in a powerful and long lasting engine life, but others see it differently and seem to get away with it.

Bob

[ANON]

i queried the bearing situation with a mate, he's been rebuilding engines professionally for best part of 30 years, he pretty much said run and go with bearings.

i've ran stuff in just about the same way as the link since i rebuilt my first engine twenty odd years ago, never had an issue with any, touch wood!! i do try and run in for about 300 miles but try and do it all at once. gets a bit boring trying to stay on local country lanes in case of breakdown though!!

[crock]

If you are installing a new cam and the cam grinder gives you instructions for the initial start up, follow that. It is typical to have to keep the engine over 2000 for 10-20 minutes with the transmission in neutral. After that, let the engine cool completely and check the head torque and valve clearances. Next take the car for a drive and try to load the engine (ie, use nearly full throttle) for brief bursts of acceleration. Don't be afraid to get up to 5000 rpm. Be sure to get on and off the throttle, it is sustained steady speed you don't want.Try to drive for 20-50 miles like this. Let the car cool completely, check head torque, check valve clearances, change the oil. Now drive the car normally, except try to drive the car at at varying speeds, not steady state. Don't be afraid to use full throttle and maximum rpm, just back right off when you get there. Give the engine a full tune up, service, oil & filter change, and drive happily ever after.

The big mistake people make is trying to baby the engine the first few thousand miles. The cylinder walls glaze over and the valves fail to seal fully. This has been well documented. So why do the manufactures recommend babying the engine? Because they feel it is too difficult to explain the correct technique to customers and they don't want people to do sustained high speed driving. Sustained high speeds will damage a brand new engine. Anybody with enough mechanical skill to build their own engine is capable of understanding that sustained high speed driving is different from brief spurts of full throttle driving. Brief spurts of heavy throttle is what seats the valves and beds in the rings. The engine requires cylinder pressure to make this happen.

The above break in procedure comes direct from Honda engine engineers, off the record of course.

Now once you break in your engine, don't forget to give it that occasional Italian tune-up!

Edited by crock, 01 March 2013 - 06:45 AM.