2.5-2.7

[oze30]

If I already have a 325i.. would it be worth doing the 2.7 conversion? I read in the total BMW that you only get about 5-10bhp when doing the 525/320head combo.. but about 20-30 if you go the 325/eta crank.

Is this a worthwile job?? ( bearing in mind that I will prolly be up for a new engine in the new year as it's pissing out oil from the oil well(?) )

[chu346]

It all depends on your budget. If you can afford it, do the 325/Eta combo for best results as the 325 head is designed more towards power than the 320 head. But if you are going to go all the way (ported,cams, etc.) I shouldn't think that there would be much difference between the two then.

I've gone for the cheaper route which still cost me alot as I replace everything on the engine at the same time.
I'm using a complete Eta engine and modified the head to take the 325 cam. I'm going to get a 320 head and get it ported then stick that on and dyno it when funds allow. Should know the the answer for you when i'm done

BTW the 2.7 is about the torque.

[swindy]

Little side note on this, say I had a 525e and a 320i, what do I actually need to do to get this engine conversion?

Is it just put the 320i head onto the 525e bottom end? Is it really that simple?

Help?

Mark.

[oze30]

If you have a 320, then its a worthwhile mod if you need a rebuild. Just get the 525 bottom end, slip the 320 head on it. I think you get more power if you use the 325 intake manifold. it should all bolt in, injectors im not sure about.. I think 2.5 injectors should work.. though dont quote me

[chu346]

Well you need Eta botttom, 320 head and 325 parts such as injectors and manifolds.

Simple

[oze30]

does anyone know the torque figures from 320-325-327?

[chu346]

Well my engine should be doing 180 bhp and same torque.

But like I said that's without doing any tuning, cams + porting etc.

[m-dtech]

what ecu have you opted for the 2.0, 2.5 or 2.5e ?!

[Brianmoooore]

You normally use the whole sensor and electronics set up from the 320 or 325, along with a 2.7 chip from the zone.
AFAIK the 320 and 325 ECUs are the same except for the chip, so if that's replaced anyway, then it doesn't matter.
Like I said in the other 2.5-2.7 thread that I locked yesterday, I haven't actually done any of this for myself yet, although all the bits are waiting (for some spare time) in my workshop.

[swindy]

OK slight detour here but what if I totally recon my 320i, stick on a chip and 325 throttle body and manifold, exhaust and chip, cheaper but would it be any noticable increase?

Sorry brianmooore, about the other 325 - 327 post, but thanks for the reply anyway.

[chu346]

What do you mean by recon? everything, bearings etc.

It would cost almost the same to recon a 320 as it would to buy and recon a 2.7 lump. All you need to do from there is use the 320 head, use a 325 or uprated cam then swap the chip, manifold, throttle body and exhaust. Doing all this may cost you an extra Ԛ£150 on top of what you would have spent. You'd be crazy not to do it this way

Sticking on a chip, 325 throttle body, manifold and exhaust isn't going to get you anywhere near 2.7 power!

[Eddy]

I think that a M50 swap whold be better and cheaper....
I have thought about 2,7,but there is just to much to put in to get so little....
M50 2,5 24V engine is a nice tunable engine,with a lot of power to start with...

[swindy]

I wasnt thinking of the power being anywhere near the output of the 2.7 thats a bit of a wishfull child. May just have to hunt down a 525e, first port of call the insurance company me thinks. Just feeling the water.

[chu346]

I think that a M50 swap whold be better and cheaper....
I have thought about 2,7,but there is just to much to put in to get so little....
M50 2,5 24V engine is a nice tunable engine,with a lot of power to start with...

True but as my car is a Motorsport cab I didn't want to put a different style of engine in.

If it wasn't a Motorsport, I'd definately put in a M30 3.5

[r_9ore]

Sorry, probably a silly question, what is the "Eta" all about, is this the coding for the 525?(i do apologise, im new )

And another silly question...is it just a case of bolting the 325 complete head onto the 525 complete bottom end to get the 2.7litre?

Or does it need to be the 320 head with 325 cams etc?

or is it better using the 325's complete head and bottom end including pistons and fitting the 525's crank in or by fitting the 525's crank and pistons?

Ive currently got a 325 touring with rattly bottom end and a siezed 320 engine, all i need is the 525 engine and ive got all the gubbins for a 2.7!

[chu346]

The 2.7 engine is from a 525e NOT 525! The 525e is a low revving economy engine. There's many ways of doing this conversion, the cheapest and simplist is shown in this thread:

What do you mean by recon? everything, bearings etc.

It would cost almost the same to recon a 320 as it would to buy and recon a 2.7 lump. All you need to do from there is use the 320 head, use a 325 or uprated cam then swap the chip, manifold, throttle body and exhaust. Doing all this may cost you an extra Ԛ£150 on top of what you would have spent. You'd be crazy not to do it this way

Sticking on a chip, 325 throttle body, manifold and exhaust isn't going to get you anywhere near 2.7 power!

So thats 525e bottom end, 320 head and everything else 325 including manifolds, injectors, cam and sensors.

If you've got the cash you can use 325 head, pistons and 525e block. But you will need to shave a few mm off the block and add adjustable cam wheel as the timing will be out.

[Chaos]

So thats 525e bottom end, 320 head and everything else 325 including manifolds, injectors, cam and sensors.

If you've got the cash you can use 325 head, pistons and 525e block. But you will need to shave a few mm off the block and add adjustable cam wheel as the timing will be out.

yeah but either way ur still stuck with a fairly slow and loww revving lump yeah ? hence alpina using custom pistons and diesel crank for their rev happy 2.7

[jonb]

So thats 525e bottom end, 320 head and everything else 325 including manifolds, injectors, cam and sensors.

If you've got the cash you can use 325 head, pistons and 525e block. But you will need to shave a few mm off the block and add adjustable cam wheel as the timing will be out.

yeah but either way ur still stuck with a fairly slow and loww revving lump yeah ? hence alpina using custom pistons and diesel crank for their rev happy 2.7

no. wrong.

the eta used a lawnmower cam hence the low reving.

not slow either. ok possibly slow compared to council cosworths and jap crap.

[Chaos]

yeah but either way ur still stuck with a fairly slow and loww revving lump yeah ? hence alpina using custom pistons and diesel crank for their rev happy 2.7

no. wrong.

the eta used a lawnmower cam hence the low reving.

not slow either. ok possibly slow compared to council cosworths and jap crap.

the longer stroke means it wont be as quick revving as a 2,5 tho surely.

the crank isnt sposed to be up to high revs strenghtwise either from w hat ive read.

[jonb]

aparently the crank doesnt like high rpms like 7k odd. but you wont be getting that out of a normally tuned engine.

the car revs just the same as the 2.5 which isnt an engine that isnt a "rever" anyways. the torque difference is noticable.

[Sy_325]

So thats 525e bottom end, 320 head and everything else 325 including manifolds, injectors, cam and sensors.

If you've got the cash you can use 325 head, pistons and 525e block. But you will need to shave a few mm off the block and add adjustable cam wheel as the timing will be out.

yeah but either way ur still stuck with a fairly slow and loww revving lump yeah ? hence alpina using custom pistons and diesel crank for their rev happy 2.7

no. wrong.

the eta used a lawnmower cam hence the low reving.

not slow either. ok possibly slow compared to council cosworths and jap crap.

i would love to try something like this... how hard is it to obtain the necessary parts? ie the block and head, are they easy come by?

also, settin an alpina side by side with a rebuilt engine (like above) how would it fair against the alpina on say a 1/4 mile basis?

[M5pilot]

If you made it properly there would be no difference in an Alpina.

A 2.7 ETA based engine with a 325i cam wont rev aswell, you need a cam in a 2.7 to make it rev as nice as a standard 2.5 does.

A 2.5 with a 284 cam revs so so nicely!

[r_9ore]

Chu346 - i take it the 525e has a different crank, hence different stroke to a regular 525 then? what age/model are these 525e's?

Please explain the Eta bit, its doin ma head in! is the eta engine the alpina engine? diesel crank etc?

So using the 320 head's benefit is the timing is easier to set and doesnt require an adjustable pulley?

[chip-3door]

The ETA crank is a longer throw one, the 525e was an emissions friendly model and actually had a 2.7, but using the same bore, so all the extra cc was on the throw of the crank, this obvioulsy means that with the same breathing limits it wont rev as well and wont make any real increase in power etiher.

[r_9ore]

Thanks for that mate, plenty of info!

Why would you need to open the 320's inlet manifold ports when using a 320 head anyway, surely the ports are matched from the start!? or do you mean you have to open the 320 manifold to suit the 325i Throttle Body?

Using the 325 inlet manifold then opening up the 320 heads inlet ports to match sound the best way, bigger and better airflow.

What age cut off are we talking for "late 325i pistons", i dont actually know what age 325 my engine came out of! Does sound like using the 525e's full bottom end is the easier option tho!

I take it the 525e is the same as a 525se? cant find any 525e's only se's?

[E30BeemerLad]

If anyone is interested, I have a 320 head in my garage doing nothing, the head has had the ports taken out to match the size of a 325 inlet & exhaust gasket, plus it has has the valve seats cut to take 325 valves.

The only problem with the head is that there is some corrosion to the water way, which is marked in red in the pic attached. I have no idea of the cost of getting aluminium welded, but there must be a couple of hundred quid worth of machining done already.

The head is yours for Ԛ£40 + postage or collection.

[r_9ore]

Cheers guys, yeah my 325 engine is a late one then! ill keep an eye out for one of them 525e's now i know what im looking for!

[Karan]

2.7 makes a quick e30 whichever way u go about it to be honest.... take advice from here and u'll be all over e46 330s

[Dan318-is]

2.7 makes a quick e30 whichever way u go about it to be honest.... take advice from here and u'll be all over e46 330s

and he would no!! lunatic

[stevetigger]

2.7 makes a quick e30 whichever way u go about it to be honest.... take advice from here and u'll be all over e46 330s

and he would no!! lunatic

Thats what im on about, im gunna rip 330's cool!

[beavis2k4]

so if i was to sacrafice my 325i late engine and rip the head off it, have it skimmed etc, and stuck it on a 525e lump the only thing i would have to change is to get an adjustable pulley for the cam, is that right? or have i lost it again?

ok i have a 320i (late) and 325i (late) and if i was to get a 525e would this still be the best way to do this? i dont mind sacraficing both engines, or would i be better using parts from both the 320 and 325 to acheive the best possible 2.7 conversion?

[stevetigger]

so if i was to sacrafice my 325i late engine and rip the head off it, have it skimmed etc, and stuck it on a 525e lump the only thing i would have to change is to get an adjustable pulley for the cam, is that right? or have i lost it again?

ok i have a 320i (late) and 325i (late) and if i was to get a 525e would this still be the best way to do this? i dont mind sacraficing both engines, or would i be better using parts from both the 320 and 325 to acheive the best possible 2.7 conversion?

Your like me, you get confused! I think you only use the 525e block use all the rest of the 325i engine! Sump too I believe

[m-dtech]

so if i was to sacrafice my 325i late engine and rip the head off it, have it skimmed etc, and stuck it on a 525e lump the only thing i would have to change is to get an adjustable pulley for the cam, is that right? or have i lost it again?

ok i have a 320i (late) and 325i (late) and if i was to get a 525e would this still be the best way to do this? i dont mind sacraficing both engines, or would i be better using parts from both the 320 and 325 to acheive the best possible 2.7 conversion?

Your like me, you get confused! I think you only use the 525e block use all the rest of the 325i engine! Sump too I believe

525e block with a 731 cast head.
use the motronic system from the 320i ie sensors and engine loom