327 spec?

[Borderbmw]

Morning fella's and felleses!?(is that a word?),


I was laying in bed last night thinking about my future 2.7 conversion and came up with this set up:

525eta short block
Gas flowed 320i head
Scrick cam(thoughts ?)
325 inlet mainfold,injectors etc
zone chip
Sport gearbox
Lsd
M-tech suspension
Zimmerman front discs & pagid pads(or willwood set-up maybe)
Standard rebuilt rears
tubular manifold & big bore (but subtle) system

What do you think? any advice/thoughts would be much appreciated?

Oh and its all going in a rebuilt d plate 320i (Lachs silver).

[chu346]

525eta short block
Gas flowed 320i head
Scrick cam(thoughts ?)
325 inlet mainfold,injectors etc
zone chip

Yeah, that sounds good to me!


Does anyone know of any down falls to this way of doing the 2.7 conversion (speak now or forever hold your piece), as i'm going to use the 320i head myself, and would like to know before I buy the head?

Do we need a 320i or a 325i uprated camshaft for this?
and would we be able to use a 325i camshaft for the time being?

Oh and is gas flowing worth the trouble, nessecerary (spelling, i'm drunk, sorry), and can it be done diy?

[320Touring]

Sounds good to me borderbmw!

shrick cam i'd probably say a 282 o 286....

chu346-iirc the 320 head and camshaft are totally different from the 325 one. The 320 one has smaller valves and is a 'flat top' design , menaing more torque on your 2.7...

the 325 head has 'hemi cut' combustin chambers, more suited to producing larger power outputs.

As for gasflowing-if its done well it can make a hell of a difference to an engine... I had a quote from puma motorsport to port & gas flow my 320 head for Ԛ£600...

However, plenty of care and a dremmel could probably achieve similar effects if you have the patience and a steady hand

[chu346]

However, plenty of care and a dremmel could probably achieve similar effects if you have the patience and a steady hand

Sounds good to me.

[Andy_magic]

I'm building pretty much what you mention with the exception of the cam. I can't afford one

IIRC there isn't a huge amount in the difference in valve sizes, I think the 320i has a smaller inlet valve by 1mm. I'm going on what I've been told.

I know the ports are smaller on the 320i head.

The other route for getting 2.7 is to use a 325i block and head, fit the eta crank... But... You really need to have the block machined down to get a decent comp ratio.

If you don't plan on porting the 320i head straight away leave the 320i inlet manifold on and open the TB aperture up to fit a 325i one a the inlet ports where they meet at the head are also small. Fitting a 325i inlet manifold won't line up nicely and you'll get a lot of disruption in the air flow.

[320Touring]

surely if you enlarge the 320 inlet manifold to the same size as the 325 throttle body there will be no problem?!

IE, if the two components have the same circumfrence, then there should be no flow disruption...

[dazleeds]

if you hve a look in the tech guide on here youll find a full how to on the 325to320inlet manifold
or pm me an email addy and ill send you it

looks quite easy if you have a few decent tools and some patience

Daz leeds

[Karan]

525eta short block
Gas flowed 320i head
Scrick cam(thoughts ?)
325 inlet mainfold,injectors etc
zone chip

Yeah, that sounds good to me!


Does anyone know of any down falls to this way of doing the 2.7 conversion (speak now or forever hold your piece), as i'm going to use the 320i head myself, and would like to know before I buy the head?

Do we need a 320i or a 325i uprated camshaft for this?
and would we be able to use a 325i camshaft for the time being?

Oh and is gas flowing worth the trouble, nessecerary (spelling, i'm drunk, sorry), and can it be done diy?

mine has a griffin motorsport head.....very expensive but it seems to run well...

could be done cheaper i guess if u gave ure existing head to an engine specialist, rather than buy a complete casting like was done with my 2.7

Karan

[Andy_magic]

The port size difference applies to where the head meets the manifold, the manifold can opened up to take the 325i TB.

Hope that makes more sense than my last post.

[320Touring]

The port size difference applies to where the head meets the manifold, the manifold can opened up to take the 325i TB.

Hope that makes more sense than my last post.

cool! got ya squire

[Widge]

I'm doin this but on a 325 block and head with an eta cam. I don't see the point doing it with the 320 head when a) It's inherently less efficient and b) I got a cheap crank and already have a 325 engine spare. Not meaning to piss anyone off but I would have thought it will produce more power this way and less hassle in the long run as the ports inlet etc are all matched and all I have to do is get the block machined.

Dunno up to you

Oh I'm doing mine over christmas

[Karan]

u will have to use 325 pistons(or custom pistons with similar shape as 325 head is unique and will require certain shape of pistons.....im sure u know this already.....

also i reckon block decking will be required..

325 head is the better option for power..

[Widge]

325 head is the better option for power..

Exactly

Yeah my exact spec will be:

• 325 Block / head / pistons
  320 con rods
  Eta Crank
  C1 cam
  BBTB
  Possibly 6 branch if I find one by the time it goes in the car

Also I think the block will need 1.5mm of the deck, but it seems to be the better option as it has some features the 320/eta block does not, and I like the bigger valves. As I understand it this will provide the same amount of torque as the "320 head on eta block" conversion as it will have a higher compression ratio, and will also provide more top end power as a result of the combustion chamber shape.

PS BorderBMW if you are going to go to the expense of

• Scrick cam(thoughts ?)
  M-tech suspension
  Zimmerman front discs
  tubular manifold

Then I personally think the money is better spent on building the 2.7 from a 2.5 block and head, just my opinion

[Andy_magic]

It'll take more than that to pi55 me off

My reason for doing it the 320i way is that I have a recon 320i head ready to drop on (although I'll probably open the ports up a little)

IIRC I'll get 10:1 compression ratio using an eta bottom end with the 320i top end so the compression ratio is sorted.

I'm not going for all out power, the car is my only car so it's more of a drivability upgrade than anything else.

As I've said before on here, it will be interesting to get some dyno graphs for both the 325 & 320 methods of getting a 2.7.

I'm sticking with the 320i method as I've got most of the bits.

[Widge]

Fair enough, I've got most of my stuff too,

******ANY ONE GOT SOME 320 / 323 CON RODS PLEASE*************

I'll be up for a dyno comparison, although I'll probably have it rolling roaded any way so we can compare chart on here when the time comes.

More interesting would be the bang for buck rating of the 2, which was cheaper and produces more power?

[320Touring]

I'll be up for a dyno comparison, although I'll probably have it rolling roaded any way so we can compare chart on here when the time comes.

More interesting would be the bang for buck rating of the 2, which was cheaper and produces more power?

yeah would be cool to see which one (the 325 or the 320 head) 2.7 gives the most bhp per wad...I await the results with interest

[StuBeeDoo]

I'm not going for all out power, the car is my only car so it's more of a drivability upgrade than anything else.
I'm sticking with the 320i method as I've got most of the bits.

I've researched this a bit, although I haven't yet had a go myself. As I understand it, it's '20 head for driveability and '25 head for out & out power. If anyone wants to correct me, that's fine.
I don't think there are 2 2.7's with the same spec anywhere other than original ETA's.
Cheers
Stuart

[Andy_magic]

If you can find one theres the so called 'super eta' engine that has the same size valves as the 325i but still with the low rev camshaft and only 4 bearing journals.

These were available from 1987 onwards, my car was registered in may of 86 so should have smaller valves.

325i Valve sizes

in 42mm
ex 36mm

320i (and 525e)

in 40mm
ex 34mm

Super eta

in 42mm
ex 36mm

I suppose i could fit the turbo and manifold i've got to help the air flow in to my engine.

[zaust]

Am i correct in thinking that once my 324 crank is in i will be a 2.7,???
or do i still need to put in a larger piston.

[Widge]

Starting with a 320 block or 325?
If a 325 it'll be 2.7.

[zaust]

1986 2.5 corry racing head and few more bits and peices..

[Widge]

Yeah I'm pretty sure it'll end up as a 2.7.

[Karan]

compression will be horrendous though....decking will be required... i 'think'

[Widge]

Yep it'll require 1-1.5mm off the deck. This had been covered is some other threads though. But you'll have a decent 2.7 at the end of it not one of these asthmatic 2.0 ltr wannabes

[zaust]

no need to touch the pistons at all then ?

[Widge]

I really hope not it's bags of extra expense, according to the article in PBMW you don't need to. if you give me your email I'll email you a copy.

[Karan]

u will have to have them machined possibly on tghe skirts as they may touch the webs of the crank webs (larger on 2.7 crank) however on earlier 325 pistons i dont know if this is necessary....ull have to mock build it to be sure!

[Jhonno]

way i'd do it is put a 2.7 crank into a 2.5 block with a shrick cam n some port matching n stuff with lightened n balanced internals.. however ive gone down another road so its all theory.. one day if i have enough Ԛ£Ã”šÃ‚£ to try it out i'll do it n see what results i get

[Karan]

cos the 2.7 is a stroker.....its a unique engine cos of the shove it gives! it really suits the e30! in mnay ways i bet the feel will be as fast as many modern m cars it was compared to my e34 m5 neway

[Jhonno]

yeah - mind you i think the m5 lump in the e30 is another matter...

have to come have a play with mine once they are both done... for comparison purposes

[Karan]

yeah - mind you i think the m5 lump in the e30 is another matter...

have to come have a play with mine once they are both done... for comparison purposes

hmmmmm ill bring the red iS methinks...LOL

[Jhonno]

316i vs. 318iS.... should be a laugh