Running In A New Re Built Block

[wardy18 33 1 Cars]

hi all

 

A bit of advice, I have just fitted a newly built block and was wondering if I need to run it with running in oil to start with or not to bother, my normal oil 10w40

 

Thanx

[James_R 3]

If it's got new rings and they're yet to be run in, then yers in a word. You want to use some 20-50 mineral oil to make sure they rings get a good bedding in (can't be overly well lube'd for this) and follow the procedure for running in as per 4 stroke perf tuning seems to work pretty damn well. Then swap to 10-40 once you've got the rings bedded.

[DamirGTI 342]

This might help :

 

http://guy-croft.com/viewtopic.php?t=78

 

Damir

[wardy18 33 1 Cars]

thats one hell of a guide

 

i havent got alot of time as i should have it ready to fire tonight but i have a hillclimb monday!!

 

gona get some running in oil, Mineral stuff and do as many miles as i can possibly fit in and remembering the following:

 

1) NO IDLING

2) No Severe Hills as too much engine load

3) keep revs between say 2000 and 5000

 

does this sound about right as a conclusion!????

[James_R 3]

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

 

I'km more an advocate of this method, which is pretty much repeated in G. Bells (4-stroke tuning) book, max revs are 75% your limiter.

 

Get the car at the lowest speed possible in 5th that it will pull cleanly,plant the throttle till said revs, then coast down give it 30secs-1minute and repeat about 10-12 times then continue the rest of the journey up till about 25-30miles swap out the oil and that's the rings done. then you can pretty much pop in 10-40 and drive it "normally" till about 500miles raising the revs and abuse as you go.

[Rom 0]

I done very similar to what the link James posted says.

 

Theres 2 camps really, the softly softly camp, and the harder faster camp. Both have followers, both have proven engines behind them. There is no right or wrong answer, its something you will have to decide for yourself. You can only be told what others have done.

 

Mine got ran in hard, and has run well ever since. Oil and filter change after the initial run in ( on mineral oil ), again after a few hundred miles of normal use (semi syn)

[wardy18 33 1 Cars]

Ok sound, well i have 5 litres of Castrol "Running In Oil No 2" as it says on the front so ill use this for the run in period, the car will be fired up for the first time tomorrow so i have Friday/Satde and Sunday to give it as much running time as poss

 

So the procedure is:

 

DO NOT IDLE

DO NOT EXCEED 75% MAX RPM (5500rpm ish)

 

De Accelerate to say 2000 rpm in 3rd then throttle on hard into 4th not exceeding 5500 rpm then de accelerate again

 

Do i do this repeatedly for the 30 miles or just the 12 times?!? If only 12 times how do you drive it for the rest of the journey, also would you say this running in oil is suitable?!

 

Thanx for the info guys, cant wait to get it running in the hillclimb monday

[Cameron 16]

There is a right and wrong answer, but it depends on your intended use. In a road car long term reliability is the key so engines are always run in softly to avoid shortening the bearing shell life. In a race engine however you rebuild it regularly and maximum power is key, so you don't worry about the bearing shells wearing as they can be easily replaced. Instead you focus on bedding the rings in properly. If you read up on running in hard you'll find that you only have a very short window to bed the piston rings in so that you get the best possible seal.

Basically as its a race engine I'd say run it in hard. As James said, put it in 5th at around 2.5K and floor it to around 4-5K then immediately jump off the throttle. You only need to do it a few times and each time you do you'll notice a very marked improvement in power!

[wardy18 33 1 Cars]

ah ok excellent, this is much more like what i wanted to hear rather than the slow method which i had no time to do properly in time for the hillclimb

 

so 12 times with the method in 5th from 2500rpm to 5000rpm will do the job, do i need to take it easy after that and how many miles do i need to do on the running in oil?!?!?

[Cameron 16]

Don't take it easy, just avoid high rpm and low rpm loading. Just drive normally for around 500 miles after doing the rings.

[James_R 3]

You can drive ti to the 75% mark hapily just not for held periods and don't labour the engine (e.g 5th up a hill and low revs)

 

You want the revs to be as low as possible that it will pull cleanly as if the engine's any good then it will still pull you up to speed quick enough!!

 

Change the first oil and filter at about 25-30miles then I'd swtich so semi for the remainder abotu 500miles (changing at about 250-300 again). Also don't be alarmed when the first oil you drop is pretty metalic, that's pretty normal.

[Sandy 191]

It's partly relevant to how it's been built. If high quality, carefully matched bearings, precise journal finishing, properly sized rings, precise (ideally machine) plateau honing on precise stable boring etc, then it'll be as good as it'll ever be within an hour or so of running. Obviously with less precision, more bedding in is required!

[kyepan 291]

Also the type of compression rings is a factor, chrominum plated rings take a while to bed in, moly rings bed in almost instananiously - according to 4 cylinder short block high performance by des hamill.

[wardy18 33 1 Cars]

I must say its gonna be a pain starting it up for he first time as I really should start it up and let it warm up and make sure there not leaks etc and let everything get warm but then I can't let it idle and I need to bed the rings in as discussed straight away to save glazing bores.........

 

Gonna be tricky, any advice

[Sandy 191]

Take it straight up to 2500-3000rpm and keep it there for 20 mins while you watch over it.

[Batfink 201]

and then if you see a problem stop immediately and deal with it

[wardy18 33 1 Cars]

perfect thanx guys

 

Todays judgement day

[wardy18 33 1 Cars]

ok so it should now be all run in, i took it for a drive today, about 15 miles and was constantly revving up and down between 2k and 4k and also in 4th or 5th gear hitting the throttle and building revs up to say 4k a number of times, could only do it up to 5k once as i ended up at 85mph lol

 

i first started the engine yesterday only to find i had exactly the same problem as when i started a few weeks, changed plugs and leads, still missfiring, found out in the end that the left carb wasnt refilling with fuel, the float arms were fouling against the inside of the carb and when full the float would stick at the top so when the carb was empty it would just be running of 2 cylinders!! all sorted now and running extremely well, just need to set the carbs up properly tomorrow morning before the hillclimb starts!!

 

wish me luck )