Whats involved in 2.7 conversion?

[Adammcf]

Just wondering out of interest really what is needed to convert engine into 2.7?

[Karan]

do a search mate

but as a roough guideline:

525e or 324td crank
320/323 rods
early 325 pistons with machined skirts (or custom mahle/karl schmidt for high compression builds)
block decked to suit


thats the big bits

then ure gonna need
remap of some sort if ure still keeping AFM or convert to MAF or standalone
cam-284/272
this lot with a good exhaust and 6 branch should see 200hp or thereabouts

then u can get into headwork etc...... to get that extra va va voom

[Simon13]

might aswell adam if your gonna keep the car, and u need to put alot of effort into sorting it out anyway so go the whole hog mate!

[e30bb]

Adammcf:
Is that your excuse?

Karan:
Why early pistons?

[Jhonno]

24v fella..

[Karan]

24v fella..

a good 2.7 should beat an m50 car and generally feel 'stronger'

[Adammcf]

My car already had the early type pistons and was as fast as a UK Impreza. I wonder if someone has already been fettling?
Is there anyway of telling without taking the block apart?

[chu346]

My car already had the early type pistons and was as fast as a UK Impreza. I wonder if someone has already been fettling?
Is there anyway of telling without taking the block apart?

Measure how far the pistons go down!

[e30bb]

This is what I got so far:

money route:
eta crank, 320 conrod, 325 block & custom pistons
(No decking involved - pistons sorted compressions out).

poor guy:
eta crank, 320 conrod, 325 block (decked for better compression) & early pistons skirts shave (stop conrods crashing).

???:
eta bottom end, 320 head* with larger ports to match 325, keeping 325 inlet manifold and exhaust manifold.
(this setup has better torque ???)

*320 head matches 2.7 values but the port holes are smaller, 325 values are larger.

Also:
Re conditioning (a few machine shop trips), 2.7 chip - zone chips(maybe remaping), race cam, vernier timing thingy (the compensate the decking).

Basically: It a C2 2.7 210bhp alpina replica engine.

A few people have done this converison (a cup of coffee and search away my friend).

[Adammcf]

Cool. Sounds like loads of work and money. Im just toying with lots of ideas while I decide what to do with my wrecked engine.

[Eddiejt2]

[quote="e30bb"]



???:
eta bottom end, 320 head* with larger ports to match 325, keeping 325 inlet manifold and exhaust manifold.
(this setup has better torque ???)

*320 head matches 2.7 values but the port holes are smaller, 325 values are larger.

quote]

This particular route is not a lot of work. I have all the parts for this at the mo, just not the actual 320 car anymore. I am still in 2 minds whether to go ahead with it or not.

Is there anyone on this site who has done this particular 2.7 conversion using 320 head and eta bottom end? My worries are fuel consumption, and it not actually being that fast. I curently have an Astra GTE 16v, which does 14.8s 1/4 miles. I really don't want to be dissapointed by the 2.7 if I go for it.

[Brianmoooore]

This thread pre-empts a question I was going to post.
Aquired an eta short engine in excellant condition from my favouritr scrappy last week and intend to use it to make a cheapo 2.7 using one of the 320 heads I have around and the manifolds/sensors/electronics etc. from a totally clapped 325 that I also have. Shan't need to chip the ECU, because it's primary fuel will be LPG, and that has its own ECU.
Two questions - Which cam is best out of the 320 and 325, and what sort of rev limit does the eta bottom end have?

[Jhonno]

eta as standard has a 4.5k rev limit iirc

but Karan's revs to 7k with no problems

325i cam is better i think, not sure if it fits the 2.0 head tho

[Karan]

This thread pre-empts a question I was going to post.
Aquired an eta short engine in excellant condition from my favouritr scrappy last week and intend to use it to make a cheapo 2.7 using one of the 320 heads I have around and the manifolds/sensors/electronics etc. from a totally clapped 325 that I also have. Shan't need to chip the ECU, because it's primary fuel will be LPG, and that has its own ECU.
Two questions - Which cam is best out of the 320 and 325, and what sort of rev limit does the eta bottom end have?

the cams are NOT interchangeable...... the bearings are in the wrong places i think.////

[Simon13]

i believe Ian (temple) made his 2.7 by higly modifiying the eta head and he's had 200bhp on the dyno i think.

Ure a man with some skills Brian, there must be loads of eta heads about for 50p

I wouldn't rev an eta crank past 6k tbh, Karan never takes his above this because it' not worth the risk and theres no power up there!

[Jimbob]

I specifically said to the twats at the rolling road to rev no further than 6400. I leave the crime scene to check the progress of the red touring, then my mate comes runnin round the corner

'you've got a rev limiter!! he's just found it!!'

'yes I know I've got one *gulp* at 7000'

[Brianmoooore]

i believe Ian (temple) made his 2.7 by higly modifiying the eta head and he's had 200bhp on the dyno i think.

Ure a man with some skills Brian, there must be loads of eta heads about for 50p

I wouldn't rev an eta crank past 6k tbh, Karan never takes his above this because it' not worth the risk and theres no power up there!

This engine is intended for my wife's LPG powered touring, which may, in about 12 months time, become my daily run around, so I'm looking for a nice simple, reliable build, with the minimum amount of effort.
All I'm really looking for power wise is to get back the little bit I lose using a single point LPG system, although any extra would be a pleasant bonus.
BMW ECU rev limiter doesn't work on LPG, and it's fairly easy rto buzz the engine in the lower gears. (Seen the rev counter off the dial once or twice.) Think I can set up a rev limiter on the gas ECU, but I need to know what to set it at.

[Andy_magic]

Is there anyone on this site who has done this particular 2.7 conversion using 320 head and eta bottom end? My worries are fuel consumption, and it not actually being that fast. I curently have an Astra GTE 16v, which does 14.8s 1/4 miles. I really don't want to be dissapointed by the 2.7 if I go for it.

I did it last week.

It took me 2 days to swap everything over, the car is transformed.

I haven't done any 0-60 tests as it just lights up the rear wheels, plus I have a small case 4.11 - 1 diff but 50-70 in top is just over 5 seconds and just over 3 in third gear.

It is still running 320 fuel system/ECU so is about as strangled as it could be, the fuel consumption has improved from a 30mpg to 35 and that was in the first few days of doing the conversion, which included a lot of showing off to mates.

It is mega torquey too, 5th gear up hills at 30mph not a problem, next on the list is to sort the fuelling and suspension out.

I haven't been on the forums for ages, partly due to work and not having broadband, work has calmed down and broadband is back.

The route I took was the absolute cheapest, picked up a sh1tter of a 525e with good engine Ԛ£100, gasket set off ebay Ԛ£12, genuine BMW oil filter, cambelt and spigot bearing Ԛ£35, oil Ԛ£FREE coolant Ԛ£FREE budget smoker

[liam012]

didn't you need to change the gearbox andy? i am very interested in this - 35mpg!! no way!

[Andy_magic]

I probably will change the gearbox at a later date but I had a week off work and was house sitting for my dad who has a great workshop etc, so I did it while I could.


The fuel light had come one and I stuck Ԛ£20 at tescos, 94.9p a litre gives 4.64 gallons, 170 miles later the light came on again. 35.56mpg.

The car is hideously under geared at the moment so the motor doesn't labour at all, the first 80 miles of the Ԛ£20 was spent thrashing around and general sillyness seeing what it could do, the second 80 miles was a drive down the A14 from Cambridge at about 80mph (3900 rpm!!) with the odd blast up to the rev limiter in 5th.

With the 320 fuelling it runs a bit flat over about 5k RPM but 325i AFM/TB/Injectors and a zone chip it should run better.

I'm a tight fisted sod and always keep an eye on the fuel consumption, I'll be sure to post more results as I get them.

[m-dtech]

im doing this too, just got a 525e auto.

im taking the auto box and diff.

throttle bodies then turbo soon

[Geeman]

I've researched the 'simple' route myself... and I've been led to believe that the 325 cam WILL fit the 320 head...

[Brianmoooore]

I've researched the 'simple' route myself... and I've been led to believe that the 325 cam WILL fit the 320 head...

But is it better?

[Geeman]

I think it's slightly more 'aggressive' - only what I've read and been told though... you can't beat first hand experience...

[m-dtech]

depends, im going to use a 2.0 head with a 2.0 cam.

but its getting polished and ported as we speak... and 2.5 valves.

[john325tewerin]

So what kind of compression ratio is Andy getting with his "2 day 2.7 conversion"?

[m-dtech]

sounds like standard spec ???

[Geeman]

It sounds like the '2 day' conversion was just a matter of swapping blocks over.

To complete this particular method (the same method as I will try and do sometime) you'd need to add: 325 cam, inlet manifold, TB, AFM and chip. Also, the 320 head's ports would need matching to the 325 inlet manifold.

Seem like a cheap and easy way to get to 190bhp and loads of torque...

[E30BeemerLad]

I thought the 2.5 cam has an extra set of bearings so will not fit into 731 casting?

[Geeman]

Maybe I'm wrong then. Andrew Everett of TBMW fame said this was the way to go. Might be worth asking someone like PacerPete if this is the case. Also, I'm sure that the tech article in TBMW said this... will just check now...

Giles.

[E30BeemerLad]

Cabrio327i Dave will also be the oracle on this subject

Assuming the cam did fit, I'm sure you have to drill some oil ways into the centre bearing/ carrier too.

I'm gonna stick on my 6-branch when i get that from Dave but once I get bored of the power and am in need of some more, I am having serious thoughts about junking the M20 and going for a ridiculous engine swap like the Supra 7M Turbo engine, pretty bullet proof and infinately more tunable than the BMW lumps or being a constant test bed by Turboing the M20 or M30.

[Andy_magic]

I used a late 525e as a donor, they had a compression ratio of 10 or 10.5 - 1 so it's about the same. I know the compression ratio is high though.

With regards to cams, I think the ETA motors had some journals missing and you could use the head from an ETA with a 320 cam but had to drill out the oilways to use it.. Too much hassle.

I've got a really good 320i head that will be receiving some port work so I'll fit that when I can be bothered.

I don't know the power output but it feels like about 175bhp, whatever it is I don't have keep changing gear and it's a right handfull in the wet, just what the doctor ordered.

[Karan]

I thought the 2.5 cam has an extra set of bearings so will not fit into 731 casting?

i also thought this was the case.... but if Andy said that they are interchangeable.... then i'd listen to him

[m-dtech]

i have just bought a 525e as my donor car, taking the engine box and diff.

I have ?731? head thats getting polished ported and the larger 325i valves fitted. re-profiled 320i cam. and jenvey throttle bodies.......

megasquirt ecu now up and running

any ideas on BHP ?????

[E30BeemerLad]

prob 220-230 I reckon maybe more with the TBs

Put a 6 branch on that and you'll see some more ponies