New Engine in and about to start her up, what steps to take?

shep_no_platinum · 25 Mar 2011 at 10:45

So me and a friend last week removed his mini engine and he had it rebuilt. We are refitting it this weekend and will hopefully get her running again.

However, we are both curious to what steps we take...

We have read and been told numerous methods...

The main one is we keep hearing is:

1. Take the HT leads off the plugs so no spark takes place, fill the engine with oil and turn the car over until oil pressure is seen on the gauge.

2. Once oil pressure is up put the HT leads on and turn the car over (with oil and water in) and leave her running for 15 minutes.

3. Turn the car off and leave it for 2 hours and tighten the head bolts using a torque wrench (specific newton metres - unsure of the amount).

4. Take the car for a drive and don't be too soft or too harsh.

5. Get the emissions set up so the car is fuelling correctly by a garage and then run the engine for about 500miles and then have it rolling roaded by a mini specialist - oil, plugs etc will be changed again.

Is this right or am i missing an important step etc?

Dogbreath · 25 Mar 2011 at 10:53

All fairly reasonable advice IMO.

When you say "rebuilt" has it had a new cam and followers? If so don't let it idle after starting, keep RPM up to 2000+RPM for the first 15-20 minutes, especially if this is a high lift cam with stronger valve springs.

It is a good idea to re-torque the head nuts at some stage, the A series doesn't use stretch bolts like modern cars so the clamping load can settle a bit after a few heat cycles. Doing it after just 15 minutes of running seems a bit OTT, though it won't hurt.

neil-ste · 25 Mar 2011 at 11:01

I'd remove the spark plugs entirely when trying to build oil pressure, it'll make the engine much easier to spin over on the starter. I'd not be too alarmed if there were no oil pressure after about 30 seconds or so of spinning it over, sometimes engines can't turn fast enough on the starter to make worthwhile oil pressure, it should be fine as soon as it starts.

shep_no_platinum · 25 Mar 2011 at 11:16

its just the head thats been rebuilt. Gearbox and pistons were ok. New crank and bearings.

burns · 25 Mar 2011 at 11:30

Shep_Cobain said:
its just the head thats been rebuilt. Gearbox and pistons were ok. New crank and bearings.

What about the camshaft? The pistons rings and camshaft are the main things that require special consideration on break in. Sounds like just building oil pressure will be fine.

InvaderGIR · 25 Mar 2011 at 11:45

When I do it...I just treat it as having had a service...so ensure all liquids are at the correct levels and all electrics are connected and turn the key. Worked fine when I rebuilt an engine 4 years after it was dismantled. :cool:

Matt82 · 25 Mar 2011 at 12:01

when youre priming the oil on the starter motor it works better with the plugs out. turns over faster and kills the battery less