E30 Zone

Hi all,

Im new to E30 zone and just wanted to a quick question. I currently own a 91/H 318iS and have been quite happy with it since I bought it earlier this year, but since this summer ive seen so many nice examples of 325i sports about, and it's made me wanna change my M42 to an M20.

I want to know if this is a wise move, as ive heard the M20 2.5 block is very weak as the head warps easily then leaks and cracks under pressure? Also, want MPG is expected in town? With my 318iS i get 22mpg even though the owner's manual say 26.9mpg?

Cheers all

Satty

bottoms ends on the 2.5 are bullet proof, your right the heads go but they are not as bad for it as a 318iS is for it!

no contest i've had both cars in question, sport wins it hands down. Finding a good one will be your main problem.

Come on you 4 pot losers, put down that can of radweld and fight your corner !

M42 has timing chain, oil squirters, 4v per cyl, hydraulic lifters, a water pump that works etc. M20 is belt-driven overweight 2v old engineering. M42 is a way more advanced engine. you get adjustable cam sprockets etc out of the factory too. M42 has lots of potential, and is in principal definitely the more advanced and more reliable engine. In my family there have been 3 ISs over the years, no head failures. one had over 200k on the orig head. head failure normally=poor maintenence, i'd go as far as saying they're pretty rare on an m42 in comparison to an M20.
As for fuel consumption, something needs looking at on the injection on yours if you're getting such crap mpg. normal m42 makes high 30s on the motorway at 80+mph, 40mpg at speed limit, and 30mpg around town. even nailing mine everywhere i could barely get under 30mpg. even doing full load mapping on the rollers i managed about 25mpg.
m20s are pretty cool too, just thought i'd stick up for the m42, as its my fav e30 engine.

my old 318iS had 3 heads in 3 years. But i bought it at 12-3 years old.

there's nothing wrong with 2v technology u should know that tim. plus your shaky food mixer out of balance 4 pot is nothing like a silky smooth 6 pot!

i'd say a main reason there are only 100 318is left is because all the heads go? they are a fragile old lump very expensive to fix,and won't take the horrendous abuse an M20 can

of all the Is that are broken on this site i cant recall one that has been broken due to a fauly engine/head?

its either a crash or rust i swear

and if four pots are so out of balance why did they use them in e30 race cars for years on end?

dont get me wrong i love a good six pot as much as the next man but the m20 is a relic!

M20 has cooling issues, if used hard. I can't comment on M42s but I would imagine they would be a bit better. There isn't too much difference in performance IMO. At higher speeds and lower revs, the M20 will pull better, but when wound up, the M42 pulls well!

The M20 is a old design, M42 is more modern, whether that's a good thing or not........The M20 gives terrible MPG in most E30s. Probably because few are running 100%.

325i Sport all the way mate! Simon's right about the old IS's.


BJ.

3 heads in 3 years? dont wanna point out the obvious but there's clearly something else wrong there. BMW don't and never have made an engine that bad! like i say i've done a lot of miles in an m42 with no head problems, and know of several other examples that also havent had any problems. bit of a dumb argument, i know you've had terrible experiences with one, but i do know of a lot of these engines etc and have worked on them a lot and don't see any reason for heads to go, and havent heard of many going either.

there's nothing wrong with 2v technology, have driven 8v golfs for years, but was fully aware that you'll not make the same power and torque per litre as a comparable 4v engine - 4v engines give better airflow at low lift too. in short 4vs are better all round.
yes a six is smoother, i like sixes, dont mind the m20 but waay prefer the m50 (which incidently shares lots of parts with the m42 - go figure). the benefits of the m42 are clear too, depends what you're into.
obviously calling a 4 pot a shaky food mixer is a bit daft, i like the noise the m42 makes at 7+k rpm as mine does, in fact i dont mind the noise all round, but yeah obviously will never be as smooth as a six.

pacerpete wrote:Come on you 4 pot losers, put down that can of radweld and fight your corner !

fpmsl

deffo sport tho no contest for me either
dnt like the feel of the 4pots
16v or not

pacerpete wrote:Come on you 4 pot losers, put down that can of radweld and fight your corner !

206,000 miles and still going strong, never had to buy any major parts for it, bar the diff. No oil leaks, no water leaks, not a thing really, just basic maintenance.

Remember it's suposed to be the baby m3.....4 pot wrightness i say

Pal

Hi all,

thanks for all your comments on this topic, i seem to be gettin mixed views! now i think my 4 pot isnt that reliable!!

But honestly, on Ԛ£10 of fuel in my 318iS in town, i get about 48-53 miles out of it, which eqautes to round 22mpg. with the same Ԛ£10 of fuel, wht would the 325i give me? bcoz this is all thts stoppin me on buying 1, the daily costs, as it wil be a everyday car!!

thanx

In town, Ԛ£10 giving that amount of miles isn't bad. All the time running going nowhere!

i must be making it all up then

how many of u 318is owners have owned a 325i sport aswell, or both at the same time to give a balanced opinion if needed?

a good 325 will be quicker in most situations compared to a good 318is. I've done the races!

"and if four pots are so out of balance why did they use them in e30 race cars for years on end?" because they made a f**king big vibration damper for it! 4 pots are flawed and u know it.

Dan why are the bmw touring cars of today 4 pots then? Mr 42 designer topped himself maybe? or because a 6 pot is better i wonder?

the only thing in common with an M3 is the 16v valve bit and thats where it ends really oh and the doors and bonnet how could i forget.

Dan318-is wrote: and if four pots are so out of balance why did they use them in e30 race cars for years on end?

Weight distribution and handling rather than engine smoothness I would think.

I test drove a few iSs when I was looking for another E30 and as much fun as they were to drive, they just didnt match up to my Sport. I think trying to compare them to my Sport was the problem though.

It felt like I had to work the iS to get it to move whereas the 6pot just moves, if that makes sense.

A 325i can be quite good on fuel if driven sensibly. Im getting about 23-24mpg around town at the moment but I cant keep my right foot out of the carpet

I used to get 28mpg all day long from the Sport on a mix of round town and country lanes and high 30s on a motorway run @75-80mph.

Simon13, just a bit of banter! Calm down!

"Dan why are the bmw touring cars of today 4 pots then? Mr 42 designer topped himself maybe? or because a 6 pot is better i wonder?" This confuses me? The BMW touring car is still 6 pot, and you know what else? It's always at the back!

4 pot =

Ooooh, it is a four pot. Was 6 pot. Still at the back....hmmm.

16v 4-pots are great in race cars, or if you want to drive like you're in a race the whole time. Otherwise 6's are the way forward

Ziggy wrote:16v 4-pots are great in race cars, or if you want to drive like you're in a race the whole time. Otherwise 6's are the way forward

Comment of the thread!

andy prilaux sp is winning the WTCC isn't he? was shackled with 100kgs of ballast he was doing so well this season and one of the main reasons is it's a 6 pot!

The M20 in standard form is much a better engine for everyday driving, but if you dont mind stalling everytime you pull out of a junction then the M42B18 (Not B21 Tims) is for you!

The 318is is totaly different to a sport, they are fun in their own ways. I dont think i would swap a 318is for a sport unless i have seen the kit off

Andrew

It's a four pot!

"The main differences between the E46 and E90 are the replacement of the old 6 cylinder power plant by new 4 cylinder inline engine, and the car being 45mm longer and 36mm wider than its predecessor

All WTCC cars must comply with car specification details known as 'Super 2000' because of the year they were first applied in the old ETCC."

Four pots rule, you can't deny it now Mr Thirteen!

It's been a 4-pot since the start of this season (when they started calling it the 320si rather than the 320i).

Davenotouring wrote:

Ziggy wrote:16v 4-pots are great in race cars, or if you want to drive like you're in a race the whole time. Otherwise 6's are the way forward

Comment of the thread!

Ithangyaw.

Personaly, i couldnt imagine having a bmw without a 6 pot unless it was an M3.
Had four bm's now and they have all been 6 pots, easyer to drive for everyday use and the sound, well you cant beat it.
I was raised on that shit

Personally I'd prefer the M20, I'm just saying there's nowt wrong with an M42 speed wise...

Sports are just drift-ready with LSD hence the attraction for me!

Dont get me wrong, the 318is is all good, less rust, less fuel nearly as quick and more nimble.

What can i do to an 318iS to make it keep up with a 325i on straights?

satty wrote:What can i do to an 318iS to make it keep up with a 325i on straights?

Plenty

As stated by Demlot, really and truthfully, they are different cars, 6pot might be quicker on a straight, but it would have problems keeping up with a 4pot round some bends....and the iS was tagged the baby m3 as that's what it is, nearly as nimble as a m3...

Pal

Im most likely biased but i love my IS. Wether its 4 pot wrongness or not, Im not caring. I do get a lil jealous of the 6cylinder noise from the sports but not jealous of the economy. my IS has astonishing economy if you ask me and its pretty dam quick for a 16 year old 1.8. I Have managed to outdrive a lot of cars i thought that i couldn't on straights and corners.

Yes the sport is a quicker car, of course it is but the IS has its little perks and i like em. The fact you can throw it into a corner adn it just sticks is one of em. Mines now on 123k and so far it seems fine. Still quick etc etc. Prob shouldn't have sed that cos the head will most likely go tommoro due to sods law!lol

I have driven one sport and its completely different idea to the IS. Its rather lazy feeling i must say. Unlike the IS which you have to gun the hell out of to get that power.

I know what id choose though. And when my IS engine does finally decide to say goodbye it wont be a 6 pot that goes in. it will either be another m42 or an s14 if i can afford it.

Both cars are great and i would not say no if a sport came along tommoro for cheap. They are both e30's, quick in different ways so its really up to you.

hammoj28 wrote:Im most likely biased but i love my IS. Wether its 4 pot wrongness or not, Im not caring. I do get a lil jealous of the 6cylinder noise from the sports but not jealous of the economy. my IS has astonishing economy if you ask me and its pretty dam quick for a 16 year old 1.8. I Have managed to outdrive a lot of cars i thought that i couldn't on straights and corners.

Yes the sport is a quicker car, of course it is but the IS has its little perks and i like em. The fact you can throw it into a corner adn it just sticks is one of em. Mines now on 123k and so far it seems fine. Still quick etc etc. Prob shouldn't have sed that cos the head will most likely go tommoro due to sods law!lol

I have driven one sport and its completely different idea to the IS. Its rather lazy feeling i must say. Unlike the IS which you have to gun the hell out of to get that power.

I know what id choose though. And when my IS engine does finally decide to say goodbye it wont be a 6 pot that goes in. it will either be another m42 or an s14 if i can afford it.

Both cars are great and i would not say no if a sport came along tommoro for cheap. They are both e30's, quick in different ways so its really up to you.

Here Here

I love my IS and ya the M42 does struggle with low down torque but it is realy nice to drive when higher in the revs, fells quicker (it probably isnt) when it hits the power and the arse sits down, you Now your going!

Not the M20 but i had a go in my uncles Z3 2.8 (i know not an E30 but a 6pot never the less) it didn't ever realy seam to realy pull and feel quick and felt slightly flat, even though obviosly it was. it was IMO a bit to smooth in some ways but there was a bit of a change when the Vanos kicked in.

So i would agree whith who ever said that driving the IS is a bit like being i a race all the time, but IMO thats what makes it such a fun car to drive. i wont be changing any time soon!

m42 torque is not that low! look at CRX honda engines of the same era! christ the the b16a2 used in civic Vtecs has practially no torque!

The torque in an iS is often under-estimated. It feels quite flat low down probably becuase of it's rather linear delivery.

Whats linear deliver mean?

lol i think this thread's got it just about right now. an m20 is easier to drive around, smoother, uses more fuel, is a less advanced design.
m42 shares way more with the m50 in its construction (in fact that makes a good point about the cyl heads, if you're going to indict the m42 cyl head then you're really gonna have to indict the m50 head too as they're pretty much the same design) and s14 in its driving characteristics than the m20. both engines can be made to go fast, in standard form there's not loads in it, an m20 is a bit faster esp at higher speeds.

M42 is also a really nice design and a well-engineered unit, you get loads for your money and I really dig that. comparing some of the parts of the engines like rods or the heads , the M42 is just a so much more advanced, and just better really. I'll post up a pic of an m20 rod next to an m42 one if people are interested. the m20 one also weighs an extra 100g or so. Same goes for the valvetrain, much heavier and higher wear on the m20, not to mention the fact its got mech lifters. doesnt the 325i have a cast iron crank too? compared to the m42s forged steel item.

the m20 has lots of well-aired difficiencies: head cracking issues in the cam valley between cyls 4-5, rocker arm wear/breakages, head bolts breaking, water pump and cambelt failures.

M42 by comparison - direct acting cams, no rocker arms, no cambelt but duplex chain etc.

i like demlot's comment about pulling away and driving around though, that's true, an m20 is so much lazier to drive around. i actually found going to an electric fan on the 1.8 made mine better at pulling away, was about the only noticeable difference that made.

There's a bit of misinformation on here too. BMW did not use a huge vibration damper on the S42 race cars (the M42 touring car engine of the mid-nineties). the S42 used a small solid billet race damper. i can show you pics if you like. gttechnic who make SCCA GT3 M42 engines do the same. (don duncan, owner of GTTechnic daily drives an e36 318is).

people who say that the only 4 pot they'd consider is an S14 should consider that the m42 was tagged the baby m3 for a reason, and its lighter, costs a lot less and is rhd. a 318is is also cheaper to buy, run and insure than a sport and less likely to have rust issues