Engine Break-In?
Turbo Mini Forums

I've de-scoped my engine plans, at least to start, and am going to use most of my existing Metro Turbo kit (versus FI, MegaSquirt, etc.). Thinking about getting it running, what's the general method for break-in of a fresh motor? I'm assuming that I wouldn't want to break in under boost. So, what do folks do? Should I install a normally aspirated exhaust and intake, run it in, then switch over to the forced injection gear? Or is breaking the motor in under boost OK?

I've got my head opened up a bit from stock, so running lower than standard compression.

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1967 Cooper 's' Turbo build @ www.drjing.com

Its down to personal preference. You should always break the cam in on initial start up, but running in is done by some at limited revs whereas some of us, myself included, just go out and nail it straight away

I seriously doubt it!

As Paul says, there's a lot of personal preference. I've just taken hold of a "new" (200 miles) engine and need to decide how best to run it in.

Some discussions have already taken place on this of course; these won't give you a straight answer (you'll get the "be gentle" and the "nail it" recommendations!) but should allow you to get both opinions and decide which suits you?

Good luck!

Dave

Pedal to the metal! I would cycle it trough different revs, just be careful with temps and don't rev it for long times. But its up to you. If you run forged pistons they would need some heat cycling though :)

Audi s4 b5 - 470bhp & 486ft lbs

On 30th Apr, 2012 Brett said:
yeah stick the bit in and give it a wobble

Get the fuelling right and drive it reasonably hard.

From my personal experience.
I've had 2 brand new VW's 1.9tdi's with the same engine.

The first one I nannied it and it smoked and used oil.
The second one I drove it like normal (pretty hard) and it never smokes, uses no oil and is quicker (however this may have something to do with the car being significantly lighter )

If something is worth doing, it's worth doing half of.

^ Wot he said for the followers though.

If something is worth doing, it's worth doing half of.

Thanks, all. I've seen various opinions on breaking in an engine (I've always broken in "by the book" and taken it easy for the first 500 miles, varying RPMs, with no problems), but was not sure if there needed to be something different for a boosted engine. I'll break mine in as per my normal procedure. Cheers!

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1967 Cooper 's' Turbo build @ www.drjing.com

I was always told If you break it in fast it'll stay fast

Thats for women isn't it?

On 7th Jun, 2011 Mattlad said:
I was always told If you break it in fast it'll stay fast

i drove mine 200miles to coombe, raced it round coombe, drove it to germany, took it round the nurburgring, drove it to belgium then home 1800mile round trip and even now its smokeless runs perfect and you can still see the honeing in the bores after a good 5k miles.

I generally do 100 miles of 'normal' driving, and from then on gradually drive it harder and harder every 100 miles. After about 300miles drive it with a lead foot.

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1/4mile in 13.2sec @ 111 terminal on 15psi

With or without boost on a newly built engine though?

Exactly, carts60. I believe no boost prior to breaking it in, because the rings aren't bedded in and you'd get blow-by (which I'm assuming could prevent proper bedding due to contamination). I'm told that as long as I don't stomp on the pedal, I'll be fine and won't generate boost.

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1967 Cooper 's' Turbo build @ www.drjing.com

We ran the van in with a bit of boost, then slowly wound it up.

Smoked it's tits of, but that was slack valve guides...

A bit confused.
I'm joining the school - that you want to do a bit of lively driving to break the engine in, but lots of people are saying dont run it with much boost at all before you get it on a RR and set up because of the potential for problems like blow by etc.

Problem with that is that the RR won't take the car unless its been bedded in properly and has at least 300 miles on the clock.

Just take a stab in the dark and hope you don't screw the engine driving on boost? OR run the engine hard without and boost somehow, then RR it with boost?

Get a wideband and drive it gently. WE got 150 bhp out of the van tuning it on the wideband.

We'll be doing a basic tune for low boost (6psi ish on the actuator), running it for a couple of hundred miles, oil change and then of to the rollers