Rebuilt Engine- How Long Do You Leave The Running Oil In For?

[cRaig 273 1 Cars]

Hello again,

 

Another question- how long does one leave the running oil in a rebuild engine, before dropping it out and putting normal stuff in? Miles rebuilt it fully, new pistons and liners etc, if that makes any difference.

 

Thanks again

Craig

[Tom Fenton 1,542]

Personally I would let it do 50 miles, then drop it, replace with cheapo (make sure NOT synthetic) oil for another 100. Drop again, cheapo again to 200. Then decent stuff after. Change filter each time. Its important to drive it normally, don't thrash it but don't baby it either.

[kyepan 291]

as above, it's also worth reading the pumaracing running in procedure, it adds some comedic context to the situation.

[Carbs4me 45]

I could do with knowing this stuff too! what running oil would you guys recommend?

 

I found this:

http://www.morrislubricantsonline.co.uk/scripts/prodView.asp?idproduct=93

 

Tom your saying, replace the oil after 50miles with more of the above? or just halfords oil for an example!

[allanallen 528 2 Cars]

Everyone's got an opinion on this do here's mine-

 

Cheapo Mineral oil or running in oil for 25 miles whilst bedding the rings in.

Change oil (+filter) for a decent branded mineral oil and drive normally slowly increasing the revs for another 150-200 miles.

Drop oil and put in your preferred brand of semi/fully synthetic oil, and a filter of course.

Job jobbed!

[kyepan 291]

I ran mine in hard (once fully warm), and it makes good power (10 more than standard). The first 20-50 miles are fairly critical to the quality cylinder sealing you achieve.

As previously stated, there are different opinions on how running in should be done.

http://www.ntnoa.org/enginebreakin.htm

http://www.mototuneusa.com/break_in_secrets.htm

http://web.archive.org/web/20100420112752/http://www.pumaracing.co.uk/runin.htm

 

these are some of the "hard" ones. but none of them state high revs or long periods of load.

 

Essentially once it's warm, just give it short stabs of wide throttle up to 4500rpm followed by coasting on no throttle to 2krpm, repeat, whilst keeping an eye on temps. if it gets too hot, stop. then carry on. gradually increase revs as it comes to life, by 50 miles we were using 5rpm for short periods, by 100miles we were doing 6krpm for short periods, by 500 miles it was business as usual. the engine certainly loosened up and got quicker as time went on.

Edited May 31, 2012 by kyepan

[Sinbad 16]

A friend of mine who has tuned lambretta bikes takes his engines to a bloke who swears by riding them hard,(not thrashing or heavy loads up hills) then turning them off to cool down,then ride same again like that for a couple of hundred miles to run in.

Obviously different engine but the same principle could apply for a car engine.

[Miles 331 1 Cars]

Never hard on these engine's, Catch 22 as the bearings pick up if you do, Run them in smoothly and the bearings bed in and last

 

Oil thou the first lot clears the build lube and bed's everything in, then after 500 miles some good quality 10/40 oil is fine

[cRaig 273 1 Cars]

Thanks everyone. Will get a few oil filters in stock and sort it soon. It started well Miles, lots of oil pressure- looks like you know what you are doing..

[Mad Scientist 106]

Never hard on these engine's, Catch 22 as the bearings pick up if you do, Run them in smoothly and the bearings bed in and last

 

Oil thou the first lot clears the build lube and bed's everything in, then after 500 miles some good quality 10/40 oil is fine

 

I've no doubt you know more about these engines than me Miles, but how can the bearings need bedding in if they are fitted with the correct clearance, and accurately reground journals etc? They aren't touching anything.

[allanallen 528 2 Cars]

Never hard on these engine's, Catch 22 as the bearings pick up if you do, Run them in smoothly and the bearings bed in and last

 

Correctly clearanced and fitted bearings don't require any bedding in, they run on a film of oil so there shouldn't be any contact. If your bearings 'pick up' when your running an engine in you've either got a clearance issue or an oil feed problem.

 

Edit, what mad said.

Edited May 31, 2012 by allanallen

[Sinbad 16]

Echoing the last 2 comments,you could change bearings then thrash the nads off it instantly,its only rings which "bed in"

[Miles 331 1 Cars]

Well from experience even of brand new engines (This is when the car's where new) running them in slowly works wonder's I've found, giving them death from the start give's (or can do) loads of problems, This is my method and it's always worked much like using the Fuch's oil and a customer running dry for 10 miles without any damage (broken pump chain as the engine was supplied from a rolled car), changed the chain and pump and the engine carried on until we upgraded it 2 years later

[petert 587]

replace with cheapo (make sure NOT synthetic) oil for another 100. Drop again, cheapo again to 200.

 

Not cheap oil at all. That would be bad. It's important that you choose a QUALITY mineral oil that contains ZINC. Most oils for cars no longer contain zinc (or very little) as it damages catalytic convertors. However, there are still mineral oils available that do eg diesel oils. Zinc is probably the most critical component as it cushions the load between the cam lobe and lifter/bucket. This is the most highly stressed part of an engine. If you can't buy oil with zinc, buy an additive such as Crane Break-In Lube. Manufacturers such as Petrite make quality running in oils which contain zinc.

Edited June 1, 2012 by petert

[Tom Fenton 1,542]

Depends on the application. If we are talking about a standard 8v XU which is more than likely using the original cam and buckets, I stand by my comment.

[petert 587]

You couldn't be further from the truth. 8V cam lobes are very soft and if not run in with the buckets properly you'll kill it in the first 20 minutes. Mi16 cams in comparison, are very hard and less susceptible to poor quality oil.

[Tom Fenton 1,542]

Why do you need to run in a cam and buckets which have already done say 80k miles?

[petert 587]

I'm talking about new or reconditioned components.

[Tom Fenton 1,542]

Depends on the application. If we are talking about a standard 8v XU which is more than likely using the original cam and buckets, I stand by my comment.

[cRaig 273 1 Cars]

It does have a 'good second hand' rather than new cam.

 

Can of worms this whole topic isnt it! Ignorance is bliss lol

[omega 82]

as you can see there are many diffrent replys but when you break it down there are only 2

 

1= you do it the hard way,give the engine lots of work from the start,some people say this makes a quicker engine

 

2= run it in slow.after a few miles change your oil/filter,do a few more miles change oil/filter, the repeat with good oil

 

i would say if you can find a magnectic sump plug as well then that a good idea.

[kingboyk 2]

Miles has done a rebuild for me too, and suggested a running in period of 500 miles followed by new good quality 10/40 semi oil and filter. I've bought Total Classic. Should be changing the oil today as I've done just over 500 now. Yes I am excited!