How do you break in an engine

[Quaser]

Just fitted my rebuilt engine - how do i run it in?

Q

[JEANIE]

just try to keep the revs below 3500 and dont be tempted by the 10 year olds in there citroen saxos

[gangstabmw]

Amen to that !!!

Damn saxo drivers think they're the fastest things on the road yet I can beat VTR's in my 318iS without really worrrying (hahaha)

[E30Adam]

You need to run it with really shitty oil for the first 50 miles taking it very very easy. This is assuming that you've got new rings & rehoned bores etc.
When you've done 50 miles, while the engine's still hot, change the oil & filter and replace with more shitty oil. Run it for about 200-300 miles and change the oil again but for something a bit better this time, you still need to take it easy not exceeding 3,000 revs ideally.

When you've done about 800 - 1,000 miles, do a final oil change and filter if you want and drive it carefully (not exceeding 4,000 revs) untill 1,500 miles.

Now take it and give it a good thrashing.

[Toby_Unna]

that's half true but you must also NOT 'lug' the engine at all - by which i mean wide throttle and low rpm in a high gear. this isn't good for even a run-in engine, as it puts heavy loads on the big ends.

my understanding is that reasonably high rpms is ok as long as the engine is spinning freely - lightish throttle and low gear, and not for extended periods. wouldn't go above 5 though.

i wouldn't use full throttle at all for a few hundred miles.

[E30Adam]

I think the basis of running an engine in is just to avoid putting heavy loads onto it. Everyone seems to have a different way of doing it but the above method worked for me.

There's a controversial method about ragging the hell out of it from day 1 but I didn't have the guts to try it. I didn't exactly stick to the guidelines though and mine turned out okay.

[Jimbob]

Ah man, 1500 miles on my new engine as well

[E30Adam]

You could always try this method Jim...

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

[Jimbob]

Nah, don't think so
I'll just drive it how I do normally anyway, just make sure I don't exceed stupid revs

[E30Adam]

I'll just drive it how I do normally anyway, just make sure I don't exceed stupid revs

That's the last thing you wanna do

[Jhonno]

you should after 500/600 miles start increasing the rev limit every 100miles as well

and avoid motorways! the best type of driving to run an engine in is back roads where your constantly changing the revs

[Jimbob]

I'll just drive it how I do normally anyway, just make sure I don't exceed stupid revs

That's the last thing you wanna do

[Quaser]

Car is an auto so lagging shouldnt be a problem

Also disconnected the kickdown switch to be on the safe side!

Q

[SCOTT325SE]

just be gentle to her!

[gangstabmw]

Ah man, 1500 miles on my new engine as well

What happened to your iS engine man (its worrying me coz I keep redlining mine) ???

[E30Adam]

Ah man, 1500 miles on my new engine as well

What happened to your iS engine man (its worrying me coz I keep redlining mine) ???

The head cracked mate!

Good excuse for a 2.7 build though

[gangstabmw]

How did ity crack ???? How can I stop mine from cracking ??? Was it overheating ???? I wanna keep my iS for a good few years but I also like to treat it like a sports car so I wanna avoid cracked heads and the like


Thanks

[Jimbob]

From what I ccan tell when the head gasket was changed there might have been a miniscule crack in the head and just bodged up, which has become massive in terms of cracks.

It was overheating for a while which turned out to be the viscous fan, but I was getting a really dodgey tappet kind of noise so I decide the head gasket can get changed, that's when I noticed the crack!

2.7

[gangstabmw]

So overheating caused the crack ??? Mine is always running quite cold (never, ever reaches the middle) so I'll be alright racing it won't I ???

[E30Adam]

How did ity crack ???? How can I stop mine from cracking ??? Was it overheating ???? I wanna keep my iS for a good few years but I also like to treat it like a sports car so I wanna avoid cracked heads and the like


Thanks

Well for starters it's far from a sports car so abuse isn't going to do it any good. You can't stop a head from cracking if it's going to crack, it's just a weakness in the metal. You can take preventative measures like making sure it's always good enough coolant and the thermostat works.

Jims car was running sweet, it's just one of those things and there's nothing you can do about it.

[MONSPORT42]

When I picked my new 2.7 up from Bexley I asked about running in and was told to just drive it and not even bother to keep the revs down. I was cautious at first but anticipation got the better of me and I went for it pretty soon. That was five years ago and it doesn't seem to have suffered in the slightest. Sounds a bit like the advice in Adam's mototune link! You only get 20 miles to bed the rings in properly!!
Each to their own.

[Simon13]

The reason BMW heads crack is the heads are aluminium? and the blocks Iron, They warm up at different rates and move everytime you drive it. My 318is was sweet as a nut like jims same sort of milege too, and ended up cracking in the same place as Jimbobs after i sold it. Pacerpete had the joy of fixing it!

[Guest]

That running in thread is very interesting. It would take a lot of guts to take their advice. Does make sense though. Who's gonna be the first to try it?

[gangstabmw]

The reason BMW heads crack is the heads are aluminium? and the blocks Iron, They warm up at different rates and move everytime you drive it. My 318is was sweet as a nut like jims same sort of milege too, and ended up cracking in the same place as Jimbobs after i sold it. Pacerpete had the joy of fixing it!

What mileage was yours then ??? (Im getting REALLY worried now as there is salad creamy gunk all over my dipstick, non in the sump or coolant tho)

[Jimbob]

That's how mine started.
The other sign of it going was starting the cold when it was cold - if I was to start the car on a morning or after being stood for a 3 or more hours it would misfire for about 10-15seconds then sort itself out.

[gangstabmw]

How many miles did it have on the clock ??

How much would a 2.7 or 2.5 conversion cost and could I pay someone to do it for me as I don't have access to a proper garage

Thanks

[E30Adam]

How many miles did it have on the clock ??

How much would a 2.7 or 2.5 conversion cost and could I pay someone to do it for me as I don't have access to a proper garage

Thanks

There was about 147k on the clock.

A 2.7 conversion is gonna cost you a grand MINIMUM and that's without labour charges. A 2.5 will cost a lot less, just buy a breaker car and swap the runnign gear, could be done for about Ԛ£300.

[Jimbob]

My car had done 147k and I think Simon's was about 140k but I can't really remember. Like Simon said, it's aluminium and warms up at a different rate to the block (at least I think that's what my mechanic said..). But like I said, mine had already had a new head gasket at some point in it's life, and could've been rectified then.
A second hand M42 head is like gold-dust, the cheapest I could get a reconditioned head for was Ԛ£550.
Even though the 2.7 is well over a grand anyway I was gonna be selling the iS soon and getting a 325, so it was the only sensible solution

[Guest]

How many miles did it have on the clock ??

How much would a 2.7 or 2.5 conversion cost and could I pay someone to do it for me as I don't have access to a proper garage

Thanks

There was about 147k on the clock.

A 2.7 conversion is gonna cost you a grand MINIMUM and that's without labour charges. A 2.5 will cost a lot less, just buy a breaker car and swap the runnign gear, could be done for about Ԛ£300.

2.7 conversion will cost a grand minimum? Is there a lot to this conversion I don't know about. So far I have spent Ԛ£150 on eta bottom end, 325 inlet manifold, throttle body, and injectors. As far as I know all else I need is a 325 AFM, gaskets, and a chip and I'm away. Fitting to a 320 head btw.

Obvosuly labour would be a lot, by I'm doing it myself, so I reckon I'm looking at Ԛ£300 in total, and I got the 320i for Ԛ£160.

[Jimbob]

Myself and Adam are doing the conversion,
my ETA bottom end cost Ԛ£145, my donor 325i car cost me Ԛ£280.
then the machining costs are at least Ԛ£150 and also buying shares in German, Swedish and French, the parts I'm getting from them has come to Ԛ£400+
the list goes on!

[Guest]

A 2.7 conversion on a 320 is just swapping the bottom end is it not, no machining needed. Then straight forward replacement parts from a 325 like TB, manifold, injectors, AFM.

If you can get these parts like I did for Ԛ£150, allowing maybe the same again for unforseen complications, I can't see how this is gonna cost a grand?

I can see how it would be more expensive on a 325 donor though, seeing as machining is involved, and taking the bottom end apart, so new shells/bearings rings etc needed.

[E30Adam]

How many miles did it have on the clock ??

How much would a 2.7 or 2.5 conversion cost and could I pay someone to do it for me as I don't have access to a proper garage

Thanks

There was about 147k on the clock.

A 2.7 conversion is gonna cost you a grand MINIMUM and that's without labour charges. A 2.5 will cost a lot less, just buy a breaker car and swap the runnign gear, could be done for about Ԛ£300.

2.7 conversion will cost a grand minimum? Is there a lot to this conversion I don't know about. So far I have spent Ԛ£150 on eta bottom end, 325 inlet manifold, throttle body, and injectors. As far as I know all else I need is a 325 AFM, gaskets, and a chip and I'm away. Fitting to a 320 head btw.

Obvosuly labour would be a lot, by I'm doing it myself, so I reckon I'm looking at Ԛ£300 in total, and I got the 320i for Ԛ£160.

Ԛ£300!!! You clearly haven't looked into this properly. Machining costs alone are Ԛ£150 - Ԛ£200, then you need to buy the bottom ends and a head.

After that little lot ehich is going to take you over 300 for starters, you'll need a bottom end gasket set, a head gasket set, a head gasket and bolts, new big end bolts and shells, piston rings and loads and loads of other stuff. There's so much stuff you haven't thought of you'll have a nasty shock if you start the build and expect it to cost as little as that.

Jim and I have done a spreadsheet with every part that you need and it's already over a grand and we're doing it on a budget. You can guarantee that we've forgotten something.

Even the fluids you need mount up to about Ԛ£50, couple of bottles of crap oil for running in and a decent bottle of oil along with some coolant, it soon mounts up.

[Jimbob]

Correction, we HAD missed off a few things from the list :p (which is almost Ԛ£1300 and as Adam said, that is on a tight budget)
At least I hope so

[Guest]

First of all won't have machining costs (using the 320 head)

I have the head already from the 320 I bought originally.

I have bought the bottom end, TB, manifold, injectors for Ԛ£150, so we are Ԛ£150 so far.

I agree with the gasket sets, and head bolts, so I'm allowing another Ԛ£150 like I said earlier. Oh and AFM.

Now then, I am not taking the bottom end apart so do not need shells, big end bolts, rings etc.

So there you go.

[E30Adam]

An ETA bottom end with a 320 head plonked on the top is not a proper 2.7 conversion and you won't even make as much power as a stock 2.5 lump so it's a pointless exercise.