Head job??? Advice wanted!!!!

[miniblob]

Right then, the head gasget is well on the way out now on my 325i!!! Using loads of water and the oil is just starting to turn a tiny bit creamy!

Question is, when i get the head off, what other mods do i do!!!! Get the head polished & ported?? New Cam??
Any further ideas for getting more power??

Should i go for a 2.7 rebuild?? (what's involved?)
Or is there a bigger bmw engine i could sensibly drop in at a similar/sensible ish price??

Any ideas of rough costs and benefits of the above??
What gains could i expect from a cam and some head work??

Has all the good bolt on mods at the mo - bbtb, itg, maf conversion, btb 6 branch and 'zorst, chip'd and hit 185bhp on the rollers.
Just wondering what route people would recommend i take??

Would love to get an engine from the new 535 diesel, but i feel that may be a bit out of my price range at the mo!!!!!!!!!
Don't wanna go turbo route either.

All ideas & advice greatly appreciated!!

Rob.

[Turbo-Brown]

Can't hurt to have the head ported by a pro, although it does cost money.

Perhaps go for a mapable ECU and throttle bodies with a properly wild cam

[miniblob]

Somebody put the idea of 6 individual throttle bodies in my head!!!!!!! Sounds cool, but i dunno how do-able it is or what it would cost/gain!!!!!

I believe mine is re-mapable - can't remember what i had but i'm sure it can be remapped on the rollers!!

Got to be driveable daily aswell so nothing too unreliable!!

[cliffybabe]

I'd say 2.7 her Rob and then get her on a rolling road tune up. Have a chat with Stu he's back now, Im sure he's looked into it for Az and myself.

Im considering a 2.7 myself but its running so well and seems to be quick enough for me at the moment, But I know Az is going down the 2.7 route in the near future

[miniblob]

Wasn't sure if Stu was back yet, but i'll give him a call tonight!!
Cheers.

[cliffybabe]

Wasn't sure if Stu was back yet, but i'll give him a call tonight!!
Cheers.

He was back on the zone last night for a bit, He might even becoming to Ace's tonight from what i've heard

[fowler]

i have a crank if you need one for 2.7 the question is what way are you gonna doo it if you go for expensive way
FI is the way to go

[cliffybabe]

u have a couple of cranks dont ya fella

[fowler]

yep 1 sold to stu's mate t

[oze30]

Ben,

Could you pm me the details for the more bhp route ( I think that means more expensive) Just need to work out what parts/rods I'm going to need.
Cheers

I'd go 2.7. You're almost there once you start doing heads etc..

[miniblob]

What exactly do i need to obtain to do the 2.7???????

Any rough idea on costs would be appreciated too!!

Wanna keep it N/A - don't want to go down the turbo route at the mo!!

[oguz327]

Can't hurt to have the head ported by a pro, although it does cost money.

Perhaps go for a mapable ECU and throttle bodies with a properly wild cam

What sort of money are we looking at for a port an polish these days?

[Turbo-Brown]

From what I remember looking a a chap called Dave Bakers website, about Ԛ£700odd squiddles, although that in itself is a guess interpolated from what he charges for a 4cyl head!

But then he does know what he's doing by all accounts.

[Simon13]

99% of time when oil and water mix its the head which is cracked

so i wouldn't spend no money on bits just yet until you are 100% sure the head is ok

i've never heard of gaskets going or heads warping either really

[Brianmoooore]

Got to agree with Simon 13 on this one. Although the head gasket on an engine with an alloy head and iron block will eventually fail through differential expansion every time the engine warms up and cools down, the usual cause of mayonnaise on a M20B25 is a cracked head.
Before you strip this motor down, get it up to working temperature, take off the rocker cover, and, with the engine running, watch for beads of water coming out from the camshaft bearing journals, especially the rearmost two.

[Andyboy]

...or when the head is off and stripped, get it steam cleaned (Gunk and the local jetwash will do ) and look for cracks at the base of the cam bearings around 4th and 5th journal. 99.9 times out of 100 the head's cracked. It could even be a head bolt that's popped off and a cam lobe has picked it up and stuffed it into the water jacket. I had a 323i that did that once - never heard it happen but it used a pint of water in about 100 miles!

Don't bother flowing the head - it's pretty decent as it is. Spend the money on a cam, another chip and a rolling road set up.

If you wanted to though, a 2.7 is still worth doing. You can buy the short engines so cheap now (well, the last 10-15 years) that it's almost stupid to rebuild a 2.5. Once the head is off it's peanuts to get the rest of the engine out.

[reggid]

...or when the head is off and stripped, get it steam cleaned (Gunk and the local jetwash will do ) and look for cracks at the base of the cam bearings around 4th and 5th journal. 99.9 times out of 100 the head's cracked. It could even be a head bolt that's popped off and a cam lobe has picked it up and stuffed it into the water jacket. I had a 323i that did that once - never heard it happen but it used a pint of water in about 100 miles!

Don't bother flowing the head - it's pretty decent as it is. Spend the money on a cam, another chip and a rolling road set up.

If you wanted to though, a 2.7 is still worth doing. You can buy the short engines so cheap now (well, the last 10-15 years) that it's almost stupid to rebuild a 2.5. Once the head is off it's peanuts to get the rest of the engine out.

Pressure test will find any cracks.

Power comes from the heads ability to flow so i recommend doing some head work if your going to do add other parts such as cams 6 branch throttle body etc. Not drastic enlarging of ports which is no good but reshaping in the vicinity around valves and guides which helps the air flow through the geometrically complicated path past the valves. This will make a marked difference if its done properly, but often its not make sure you get someone who is familiar with the head to do any port work. Don't get it polished though.

[Brianmoooore]

Pressure test will find any cracks.
.

It certainly will, but would be a total waste of money if you've already established that it's cracked!

[miniblob]

Will try Brians suggestion before stripping it, and obviousely i'll have a good look when it's off too!!

Might try and find out about getting the head ported - at least find out the cost!

So assuming the head is cracked, what parts do i actually need to obtain to do the 2.7 conversion??
What sort of power should a 2.7 with a decent cam/chip/6 branch etc give me??

Cheers guys!

[fowler]

fuck me you lot its all about power
you want torque thats wat you want to make it feeel faster
easy way is to get 525e Crank ( me)
late325 slugs and rod
320 head job done around 180 break and a a shit load of torque + what ever cam and exhaust you want.

OR

ETA crank (me)
late 325 slugs and rods
Machined late 885 casting head (costs dollars)

up to 225 BHP and about the same torque

OR
early 325 engine which actually makes the 171 BHP quote not 151 BHP in a late car
throwa lumpy cam in it with 6 branch , nice induction eg keep air box and you should see not that shy of 200 and god loads of torque.
so if you have not a lot dosh to spend go for option 3 as i have one sitting in my drive!!!

option 1 best part of 2 k
option 2 best part of 3.5K for a good one
option 3 best part 1k
this all depending on what parts required.
regards
Benji

[miniblob]

Cheers for that fowler - that's the info i was after!!!!!!

Would generally go straight for option 2, but i've run out of money at the mo, so option 3 is looking favourable - although i do get carried away easily so anything could happen!!
I'll let ya know!!!!!

I presume the power/torque would be up slightly from those figures with the maf conversion/6 branch/itg/chip & rollers session?
It was putting out 185bhp on the rollers before - definately don't want any less!!!!!

[Templ8e30]

fuck me you lot its all about power
you want torque thats wat you want to make it feeel faster
easy way is to get 525e Crank ( me)
late325 slugs and rod
320 head job done around 180 break and a a shit load of torque + what ever cam and exhaust you want.

OR

ETA crank (me)
late 325 slugs and rods
Machined late 885 casting head (costs dollars)

up to 225 BHP and about the same torque

OR
early 325 engine which actually makes the 171 BHP quote not 151 BHP in a late car
throwa lumpy cam in it with 6 branch , nice induction eg keep air box and you should see not that shy of 200 and god loads of torque.
so if you have not a lot dosh to spend go for option 3 as i have one sitting in my drive!!!

option 1 best part of 2 k
option 2 best part of 3.5K for a good one
option 3 best part 1k
this all depending on what parts required.
regards
Benji

You need non-325i rods for a 2.7, the 325i rods are too long and the pistons will poke out the top of the block. All non-325i M20 rods are the correct size.

Cheers,

Iain T

[reggid]

Pressure test will find any cracks.
.

It certainly will, but would be a total waste of money if you've already established that it's cracked!

not as much of a waste as looking at it and making a judgement has its ok when its actually not. For 20 pounds why stinge out.
For Sure if you can see its cracked with the naked eye then don't get it tested, that should be a no brainer.

[fowler]

cheers ian doing some other bits in my head when typing post

[miniblob]

I'm just wonderin now what other engine conversions can be done for this money?? Any ideas - or would people just stick with a 2.7?

[fowler]

A good 2.7 is 3K of anyone's money

F/I good 3.5 grand could be done for less depending on boost and parts required

M50 325 out of e36 (can turbo these)

good old cosworth conversion ???

m30 3.5 change

V12 conversion
V8 depends what you want to go for
mini blob ring me on my mobile number in my sig

[tonyppe]

dont know if anyone has mentioned, but PRESSURE CHECKING is a must.

[SGP]

chuck a bit of nitrous into it ya speed freak

[miniblob]

Have though about NOS but i don't really want to double my fuel costs - 'cos i will use it all the time if it's there!!!

Fowler - might try and give you a call at the weekend - cheers fella!!

[fowler]

NOS WILL FUCK THE RINGS DO N@T DO IT
mini blob call me when ever