Running in a rebuilt engine.

[Cokes]

Another week delay before the engine builder can fix their faults.
Now booked for the 17th,
My MOT due the 23rd.
And I'm booked for a rolling road power run on the 25th.(can be cancelled)

With the weather I expect in Scotland at this time of year I'm not going to have the road time between the 17th and the 23rd to do what I'd planned for running the engine in.

I guess what I'm asking is does anyone else have any ideas how I could meet my targets ?
If I was guaranteed dry days I could book Monday 19th and Tuesday 20th off but didn't want to push the engine so much so soon.

Am I being over cautious ?
What sort of mileage should I cover ?
What's the best way to do the running in ?


HEEEEELLLLP

[Boosted LS1]

Drive the car locally and go round on a circular route so you're never far from home. Take tools with you. Give the engine spells under load and accellerate, then lift off as this will oil the bores. Find a dual carriageway or somewhere where you can build up the revs etc. Don't nurse the engine. Once you know all seems well and you have more confidence increase the load and revs. Do the mot but cancel the dyno day, it could end in tears as your not ready and neither is the engine.

[N7GTX]

Agree with the above from Boosted. Main thing is not to go on to the motorway and sit at 70 mph all day - vary the revs and load.

[roseytvr]

Depends what your actually running in - is the cam new?

[QBee]

When I was running mine in, I was told use thinner oil (20w50 say), and drive between 2000 and 4/4500 rpm, up and down the gearbox, up and down the rev range, NOT sitting at steady speed, and most definitely NOT labouring the engine, so be in a lower gear rather than driving up a hill at 2000 rpm in 5th. It's actually proper driving and quite fun. I did 1200 miles in 8 days.

Definite no-no is thrashing it at max revs, and another is poddling along at 1200 rpm. Don't be shy, use the revs and the gears well.

I do similar driving now when towing my TVR on a trailer with my petrol Saab.....I have to stay one gear lower all the time and keep the revs up higher than usual to stop the engine labouring (my instinct after so many diesel cars is always to be in the highest gear possible), and as a result the fuel economy is actually better and the Turbo Boost gauge stays lower, a sure indication that I am labouring the engine less.

[macdeb]

Start, heat into engine, turn off and cool. Then drive the car on dual carriageway and apply light throttle in 4th and work the engine [not labour] then still in 4th back off throttle and repeat many times. [to the annoyance of other drivers] This will bed the rings in as the combustion gets behind the rings and pushes them out into the bores, the off throttle helps oil and cool. First 100 miles critical, then build revs over the next 200 miles, change oil and 98% of running in is done at 300 miles. Build revs higher and for longer over next couple hundred miles. Change oil again at 1000 miles.
There is a more detailed document on this by 'Puma Racing' knocking around somewhere, I'll dig out.

Edited by macdeb on Saturday 10th October 09:19

[BeastMaster]

If its a new cam and followers on first start up its important to keep revs up +2k for the first 20 mins, if the cam is something special refer back to the cam supplier or engine builder for advise.

A new cam can be damaged on first start up sitting at idle when the forces on the lobes are greatest.

[Sardonicus]

macdeb said:

Start, heat into engine, turn off and cool. Then drive the car on dual carriageway and apply light throttle in 4th and work the engine [not labour] then still in 4th back off throttle and repeat many times. [to the annoyance of other drivers] This will bed the rings in as the combustion gets behind the rings and pushes them out into the bores, the off throttle helps oil and cool. First 100 miles critical, then build revs over the next 200 miles, change oil and 98% of running in is done at 300 miles. Build revs higher and for longer over next couple hundred miles. Change oil again at 1000 miles.
There is a more detailed document on this by 'Puma Racing' knocking around somewhere, I'll dig out.

Edited by macdeb on Saturday 10th October 09:19

^ Once you have broke the cam in then the above applies pretty much agree with the 1st 100 miles bit, there is a very small window to get those rings broken in slightly narrowed by the cam brake in time/slot unfortunately (no load) unless your using a Dyno but my motto is this short of being a complete numpty i.e racing/thrashing the motor during the 1st 100 miles for example if the motor breaks it was a wker anyway, take the time too let the motor cool after the cam break in checking for leaks making adjustments etc, the valve springs I used actually recommend a couple of hot cold heat cycles initially I used this time to adjust my valve clearances as they tend to loosen up after cam break-in and rectify a small coolant leak this is all normal in my experience this methods always worked for me give or take I even used a piton that was notoriously oil thirsty back in the day (fast Ford) even when the bores were finished with the correct hone I had no oil usage after about 400 miles which was nice I don't like oil burners but back on point its not rocket science just look at the break-in period like ..... Use it or loose it

[CHIMV8]

I have run in as documented in this thread
Changing oils to engine,gearbox and diff(all strpped and rebuilt) at 1000miles.

When woul it be sensible to take to Jools for a dunno set up?

[carsy]

CHIMV8 said:

I have run in as documented in this thread
Changing oils to engine,gearbox and diff(all strpped and rebuilt) at 1000miles.

When woul it be sensible to take to Jools for a dunno set up?

I`d get it too him now.

I took my new build to him with i suspect no more than 200 miles on it. As Simon says if its built right you are good to thrash from the start really. If it breaks it was probably always going to break.

[QBee]

Yes......agreed, but when you do break it and take it back broken after 200 miles.....and it's the rings or whatever that make it obvious how it broke. What then?
To be fair, when a friend of mine fitted a faulty (non-hardened followers) camshaft recently, it went in less than 100 miles, and he had done all he needed to do to run it in correctly.
I guess what the guys above say about "if it's going to break it will do so immediately" probably holds water, but we all try to follow instructions to the letter to keep warranties intact.

Edited by QBee on Saturday 10th October 13:39

[CHIMV8]

Covered 500 miles so far

[carsy]

I know what you are saying Anthony but when looking at the internalls, rings piston bores etc, i fail to see how the rings would be anymore likley to break on day one as against 1k miles further down the line.

For as long as i can remember there has always been the argument of running in as in this thread. ie load it up and then coast back down throttle closed. Repeat umpteen times then the jobs done OR take it easy for 1K miles.

I`ve always gone with load it up from day one, just makes sense to me. Having said that i also know people who have done the take it easy route. End result the same i suspect.

[QBee]

I did what Rob Robertson told me when he built my engine - as stated in my first post.
I did that because that was what he told me to do.
That's the limit of my knowledge, so all the other thoughts are extra info for me.
I have heard that race engine owners take much more the shorter running in view expressed above.

[Cokes]

Bit confused now
My engine was just stripped, skimmed, checked and rebuilt with new bearings, seals and rings.
No new cam as it only has 10k miles on it.

Some say fast, some say slow, some say 1000 miles, some say 100.
Can't see how everyone could be right

[ray von]

QBee said:

I did what Rob Robertson told me when he built my engine - as stated in my first post.
I did that because that was what he told me to do.
That's the limit of my knowledge, so all the other thoughts are extra info for me.
I have heard that race engine owners take much more the shorter running in view expressed above.

Surely this is the best advice on here? Do what the guy who built the engine tells you to do. With absolutely no offence to anyone on here I could imagine having the engine break, then telling the builder you ran it in the way some guys on the internet told you to

[Boosted LS1]

There is no set period to run an engine in as the process takes many many miles. An engine may not be fully bedded in until thousands of miles have past. As said above the main aim is to get the rings to bed into the bores. The initial process can be done by giving the engine a good blast of revs the instant it fires up if you have the bottle. After a couple of hundred miles you would probably have a thin wear line around the compression rings. A bit like when you lap valves in. As the engine racks up more miles the wear pattern widens until it's eventually as wide as the ring face. I'd consider that fully run in but would drive the engine normally after say 300 miles, ie full throttle bursts as and when.

ETA. I've never been able to wait 20 mins whilst a camshaft beds in. I'd do a quick check for leaks and get driving asap at over 2500 revs. Easy to do if you pick the right day.

[Sardonicus]

ray von said:

Surely this is the best advice on here? Do what the guy who built the engine tells you to do. With absolutely no offence to anyone on here I could imagine having the engine break, then telling the builder you ran it in the way some guys on the internet told you to

No ones told him to thrash it though built enough engines so stand by what I said earlier if it brakes during break in then it already had problems before it was even run but yes agree do like your builder advises if you want to keep warranties etc in place

[Boosted LS1]

Sardonicus said:

o ones told him to thrash it though built enough engines so stand by what I said earlier if it brakes during break in then it already had problems before it was even run

Which is why manufactures rev their engines to the max, test them on a rolling road before we get told to run them in again, lol. If we don't they void the warranty.

[Sardonicus]

Boosted LS1 said:

Which is why manufactures rev their engines to the max, test them on a rolling road before we get told to run them in again, lol. If we don't they void the warranty.

Seen some factory video for Honda motor cycles where they do just this then the unsuspecting new owner rides around careful not to rev it too hard for the 1st 1000 miles