320i head on 323i?

[sid_nz 0]

Hey all. I have heard from a guy with lots of bmws (including a black 2 door e30 with a turbo 4age....very nice) that the head off a 320 e30 will fit the 323 and the 325 witch I don’t doubt but he also says that it has more aggressive cams or some kind of performance advantage. I have a matt black 323i with adjustable suspension so it’s kind of sorted in the handling department so looking at some extra performance (on a budget) now. Any help would b appreciated.

Thanks, Tom

[williams 0]

both 320 and 323 and 525ee use the same head(valve sizes) uptp 87 if i remember correct then the valve sizes became bigger like 325-cams will work in all heads.will see if i can get the different specs on durattion on cams

for much better performance get a motronic system(less intake pipes that will crack) and chip it-will have better performance and fuel economy no other engine mods neccessary

Edited August 2, 2008 by 2 slow

[QuickSilver 0]

The 320i head and 323i are the same, the 325 head has bigger valves and bigger ports, yes it CAN fit on the b20 but its not worth it, the chamber size will be incorrect for your b20 and compression will drop, so pretty much leaving you with the same power as you started with.

Do an m20b25 swap, not difficult, cheapest gains that money can buy (IMO) Its a great motor, plents of power and torque and a fantastic base if you want to go nutty with mods.

Edited August 3, 2008 by QuickSilver

[Mike 1]

Hey all. I have heard from a guy with lots of bmws (including a black 2 door e30 with a turbo 4age....very nice) that the head off a 320 e30 will fit the 323 and the 325 witch I don’t doubt but he also says that it has more aggressive cams or some kind of performance advantage. I have a matt black 323i with adjustable suspension so it’s kind of sorted in the handling department so looking at some extra performance (on a budget) now. Any help would b appreciated.

Thanks, Tom

Waste of time putting a 320i head on a 323i as they're the same, and 325i head isn't designed to work with your pistons.

If I was in your shoes I'd be looking at the 2.7L bottom end from a 525e. The head off your 323i will work great with that bottom end. The L-jet ECU is a POS that can't be chipped so you should ideally switch to Motronic management from a 325i and get a chip for a 2.7L motor.

An aftermarket ECU such as link would work but not worth the cost unless you had serious mods planned. If your feeling brave you could give Megasquirt a go, its pretty easy to wire up fuel only for L-jet cars, and you get rid of the flappy padle AFM. MS would run you roughly $600 to get it running.

[Andrew 30]

The 323i head I had was bigger than a 320 head? Perhaps there was a change one year?

But yeah - no power gains.

[Mike 1]

The 323i head I had was bigger than a 320 head? Perhaps there was a change one year?

But yeah - no power gains.

There was a big port version of the 323i head, i think this is for the last of them, ie 85 model year. AFAIK its still the same head design, just larger ports, maybe valves too. That would be the ideal head for the B27 bottom end.

Edited August 4, 2008 by Mike

[Andrew 30]

There was a big port version of the 323i head, i think this is for the last of them, ie 85 model year. AFAIK its still the same head design, just larger ports, maybe valves too. That would be the ideal head for the B27 bottom end.

That is what I was using on my b25 old race car motor.

[sid_nz 0]

im fairly new to bmw engines being a former toyota man, my wallet is still recovering....

anyway i know a guy with a b25 block and pistons. i could use all the b23 accesories (alternator, powerstear and wat not) and head and it will run mint?

would it pay to use the 325 ecu?

what are these mega squirt things about? i hear good things but have never seen one in a car or for sale. where would i find one?

[QuickSilver 0]

im fairly new to bmw engines being a former toyota man, my wallet is still recovering....

anyway i know a guy with a b25 block and pistons. i could use all the b23 accesories (alternator, powerstear and wat not) and head and it will run mint?

would it pay to use the 325 ecu?

what are these mega squirt things about? i hear good things but have never seen one in a car or for sale. where would i find one?

A b25 block will run best with a b25 head, they use domed and dished pistons and the head is designed specifically for these, what was refferd to above is the b27 block, (which is the bottom end of a 525e which actually has an increased stroke)

You can use alternator, and power steering pump from your 323 but the rest will need to come from the b25, as the distributor is on the end of the cam and things are different from the 323.

If you get a 2.5, make sure it is a facelift 2.5, which means the computer is motronic 1.3 and is way superior to the old motronic and the L-jetronic system the 323 and 320's use, so definately use the 325 ECU. If you can, just get a complete motor, with loom and ECU attached and in one piece and install that, its just a matter of pulling out the old wiring and replacing it with the new.

Megasquirt is an aftermaket engine management system, you can order it in two forms, ready made (pay extra) or un-wired and in pieces, which gives you the challenge to wire it up yourself. You can then ditch the restrictive e30 AFM which will give you more power, and with megasquirt running the sky is the limit to what mods you want to do, as you can constantly change the ECU to adjust to what you have done.

Edit: Typos and info.

Edited August 4, 2008 by QuickSilver

[Mike 1]

^ As he's said you can only really use the b25 stuff with other b25 gear. the pistons are too different. Your b23 head wont work with the b25 pistons.

The only part you can really use is the 325i loom, ecu and associated timing gear. The ecu should still be chipped to get the best out if it if you went the stroker route. Could run lean otherwise.

Or by a wrecked 325i and swap everything thing and be done with it.

I'm running Megasquirt on my L-jet M10, the guys to deal with are DIYautotune.com. you can hunt around and find stuff a little bit cheaper for one off items but overall they are pretty well priced and excellent service. It is a steep learning curve and not for everyone but definatley worth looking at.

[sid_nz 0]

where do i find a mint b25? I have been looking on trademe and there dont seem to be any b25 on there and hasint been in the last few weeks of looking. Whats a good gearbox to put behind the b25? currently my cars only running a 4 speed witch i find ok but seeing as the last 5 speed e30 i drove was more then 4 years ago i cant remeber well enough to notice a big difference. would the 5 speed make a big difference?

Was just looking on www.drivenperformance.co.nz and they have a mint turbo manifold...seems to be the route i will take having much experence with turbo engines.

[QuickSilver 0]

where do i find a mint b25? I have been looking on trademe and there dont seem to be any b25 on there and hasint been in the last few weeks of looking. Whats a good gearbox to put behind the b25? currently my cars only running a 4 speed witch i find ok but seeing as the last 5 speed e30 i drove was more then 4 years ago i cant remeber well enough to notice a big difference. would the 5 speed make a big difference?

Was just looking on www.drivenperformance.co.nz and they have a mint turbo manifold...seems to be the route i will take having much experence with turbo engines.

Call Ray @ HellBM I can almost garuntee he will have everything that you need, the best gearbox to put behind a m20b25 is a Getrag 260 as it is stronger than the 240, but the if you have a 240 that will fit and work also.

Definately upgrade to a 5 speed either 240 or 260.

[beemwr 46]

Hey all. I have heard from a guy with lots of bmws (including a black 2 door e30 with a turbo 4age....very nice) that the head off a 320 e30 will fit the 323 and the 325 witch I don’t doubt but he also says that it has more aggressive cams or some kind of performance advantage. I have a matt black 323i with adjustable suspension so it’s kind of sorted in the handling department so looking at some extra performance (on a budget) now. Any help would b appreciated.

Thanks, Tom

-the e12/e21 cam for 320 & 323 has a 260 duration cam fitted compared to the e30 325 252 duration, possibly 4-5bhp gain and power all the way therough for a low cost

-the 731 320 head with the 525e bottom end is another choice to a 2.7

-most accidents seem to be caused by being unable to stop in time, I am told, so improving that to suit more power could be first call on the improvement budget.

How could e28 brakes be incorporated into an e30 braking system, is it an option BSers?

[beemwr 46]

where do i find a mint b25? I have been looking on trademe and there dont seem to be any b25 on there and hasint been in the last few weeks of looking. Whats a good gearbox to put behind the b25? currently my cars only running a 4 speed witch i find ok but seeing as the last 5 speed e30 i drove was more then 4 years ago i cant remeber well enough to notice a big difference. would the 5 speed make a big difference?

Was just looking on www.drivenperformance.co.nz and they have a mint turbo manifold...seems to be the route i will take having much experence with turbo engines.

Hey, check if you don't have a dogleg, 1st maybe hard to engage( straight down from reverse) with wear and tear.

323i had either 245 GF or dogleg GJ as standard.

[Mike 1]

How could e28 brakes be incorporated into an e30 braking system, is it an option BSers?

Nothing is bolt on, but can be made to fit with a little effort.

That said for the power levels we're talking here stock brakes will be fine if they are well maintained with good pads.

Was just looking on www.drivenperformance.co.nz and they have a mint turbo manifold...seems to be the route i will take having much experence with turbo engines.

I would be seriously questioning the quality of a $400 stainless manifold. I'm not saying its definatley rubbish, just expect a few problems with it if you do buy it.

Edited August 6, 2008 by Mike

[sid_nz 0]

my mate brought a manifold for his starlet off drivenperformance and its still going mint.

was planning to use standard brakes with better (undecided brand (sugestions?)) pads and some better fluid. should do the trick for now.

[sid_nz 0]

Hey, check if you don't have a dogleg, 1st maybe hard to engage( straight down from reverse) with wear and tear.

323i had either 245 GF or dogleg GJ as standard.

u are very correct. i have found my 1st gear. it is a 5 speed after all. 1st was very difficult to get into the 1st time and now is working fine. thankyou for that. you just saved me buying a new gearbox.

i thought it had traction problems when i thought 2nd was 1st.............

[QuickSilver 0]

u are very correct. i have found my 1st gear. it is a 5 speed after all. 1st was very difficult to get into the 1st time and now is working fine. thankyou for that. you just saved me buying a new gearbox.

i thought it had traction problems when i thought 2nd was 1st.............

check your gearbox out if you have been driving away in 2nd for so long

[sid_nz 0]

only had car 3 weeks and only driven somtimes on weekends.