N/A Tuning the M42

[Royalratch]

I'm impressed with what Tim_S has achieved for around £2.5K. 200BHP in a reliable and drivable package.

For me, there is a value to this and that is having that power in an invisible drivable package - N/A is a must. I won't go over a certain amount though and once I finish my research, coupled with the Zones' valuable input, I'll make a decision if it's worth it.

A possible second route is a cam/remap but I suspect that £1K's spent there will not yield more than 15BHP genuine output.

As for K&N filters and BBTBs - I have heard as many cons as for pros.

Bexley I have spoken to before - not too impressed with their 'manner.'

Kevin Bird 'regrets' he can offer no tuning for the 318iS.

[Royalratch]

So.

There is no route via Hartge officialy or via new parts bin and practically impossible to do used.

We have the MetricMechanic kits which to say are extortionate is an understatement. Plus they use an adapter to lengthen the crank which though they deem safe, I'm not comfortable with at 7000rpm+.

Ant from A-Tech has said he has seen a few premature failures of this type of engine-build and advises M50/M52 route - but I want to keep it looking normal.

I am now thinking a head skim, Shrick cams and remap. Won't be 200BHP but will be reliable and invisible. Dbilas ITB's are also a fairly priced additional tweak but I don't know what they offer in power gains plus are not invisible.

The reSearch continues.

[Kos]

how does and m52 look normal ? it can look factory instaled but not normal

i think you hit it bang on the hear with the head skim, cams and re map. that later 1.9 m44's had some improvements to the 1.8 m42 in terms of timng chain and guilds iirc. may be worth looking inot that.

if you want to go one further ARP it sp you have peice of mind at your 7000rpm moments

finaly........................................





















flywheel

[Royalratch]

Forgot flywheel. But not a mad light one. Something inbetween the Racing versions and stock. Just a straight swap M20 one perhaps.

1.9 M44 is nice, had one in aborted Touring iS build. Much much smoother, noticeably more torque but no more power. Much more drivable about town tho. Timing case parts are more durable and head has some modifications for better flow and emissions and valves tweaked. But as is well known, loses the forged crank and some other goodies. The M42 was a more expensive unit, The M44 whilst better in some ways is the 'production' version.

Awesome site here on BMW 4-pots:
http://www.motortraders.net/groups/grou ... =1&menu=89

[ShepsEvo3]

My thoughts on this are with Kos, the flywheel will make a noticable difference with the M42. It will not make anymore torque or power available, but the engine will rev more freely and feel more spirited. However, you will also have more engine braking too and you will need more throttle to maintain a highish cruising speed and fuel economy will be reduced in those cases. That doesn't matter if most of the driving is going to be around town, there is nothing but plus's in that situation.

If you want alot more torque low down the rev range, you have to change the stroke. But in doing that, you have to use shorter rods (which has its own downfalls) or use decked or shorter pistons (which has it's plus's).

Head porting and cams will yield some power, but probably with the expense of low down grunt/torque. But you will increase low dow torque with a hike in compression ration in conjunction with more agressive cams and head porting.

So, to get good power out of the M42, you'll need to spend some money, but as has been said here, Tim_S had over 200bhp with great torque with his relatively simple conversion, but remember, Tim did all the engine removal, stripping, refitting himself. So that would have saved a bundle on costs.

Ant is probably correct too, there have probably have been some failures from modifications, but because of the relatively cheap and easy M50 engine swop and ofcourse there is the S14 engine available too.. I guess there hasn't been much call for modifying the M42 engine in this country and hence not much R&D done on them.

There are insanely high prices being asked for S14's right now and most I have seen have had bent exhaust valves and low compression - so unless you want to spend the same amount plus on what you paid for the S14 in the first place just to bring it back to good health, the S14 isn't really an option.

In the past, I've wanted to fit a Rotrex SC to my 318is, but it's been done a few times here since and I now have different plans for i, so I sold my SC.

[Royalratch]

Low down torque is one of the main things I wanted to be honest. I'm up for 'practicing' on my spare M42. Messing with pistons and stroke is a little more than I'd like to do if I wasn't going capacity increase. Seems straightforward fitting cams, removing a head/block to be sent for porting / skimming etc etc.

So for the following, what is the true combined BHP increase?:

Ported / Flowed Head
Skim for compression
Schrick Cams
Remap (but not with solid safety margins)

Gonna order an engine stand ASAP !

[ShepsEvo3]

So for the following, what is the true combined BHP increase?:

Ported / Flowed Head
Skim for compression
Schrick Cams
Remap (but not with solid safety margins)

Gonna order an engine stand ASAP !

Well, Ported/flowed head isn't going to give you any more low down torque without rainsing the CR. If you skim the head and/or block to raise the CR, you will run into issues with valve to piston contact, especially if you want to use higher lift and longer duration cams. But, I think you will just about be able to get a set of pistons, cams and head porting for 2k, but with a remap it will be a little more. If you just leave the CR as it is and port the head and cams, it will not be friendly around town. Raise the CR and have more agressive cams (and you can go quite aggressive and have good lowish idle) the engine will be much friendlier.

I would expect atleast 200bhp from the above without changing capacity. ie, head porting, lighter higher compression pistons with deeper pockets for valve clearance, cams. But if you are changing pistons, you just as well go larger capacity too, as the pistons are the same price.

Exhaust manifold is great... you can't better it. The exhaust system you can better for higher BHP (top end) but at the expense of a huge drop in torque low down! Keep this standard. BBTB's are a waste of time and money without over 200bhp. Also you will loose torque if you fit one of these without other mods too.

[Royalratch]

Thanks for your info dude. Things are definitely taking shape now and if I'd known I could get near 200BHP without larger capacity then I wouldn't have bothered looking at that route.

Something to think about - can I not just enlarge the block to say, 2.0L, then use shorter-rod and recessed head pistons but keep the M42 crank in place? If you have custom pistons exactly as you want them, surely you don't have to use a modified M47 crank and can leave that part of it out?

[Dave_M3]

Interesting thread as I'll be doing the same thing soon once I get some parts together and money to buy the new parts.

My reasons for working on the M42 are;

I want my iS looking standard as it's a 318iS for a start (nearly anybody I know with a good iS thats been modded in anyway is jumping on the M52, S50 bandwagon lately)
Tax for a proper engine like an M52 over here is double what I'd be paying for the M42 and as it will be a daily driver so I'd rather put money into the car rather than give it to our shite government every year.

Having a 318iS that looks standard yet still packs enough punch to see off any standard E36/E46 bar M3s as well as all the jap shit-boxes like Civic, integras etc has its own advantages.

Since I can do all the work myself and have mapping sorted it won't be as expensive as it could be.
I already have the M-power 6 pot side of things covered in my drift/track car





So plan is pretty much similar to what Tim has done.
E36 M42 engine or maybe an M44 block as I can get one for nothing
M47 crank (have an M47 but would like to find an M47n crank)
S50b32 pistons (decked alittle bit and keep a reasonably high C:R)
M42b18 con-rods with custom small end pins.

Already have the lightweight flywheel covered since putting in the 6 speed box

Haven't decided on the extend of headwork yet. may just use a hotter cam.
Planning on using DTA management.

Will be hoping for around the 200-215bhp mark.

Haven't costed it yet but a rough guess is...

engine: free
boring to 86.4mm: not sure yet
Crank: 100 quid
pistons: who knows, trying to see if a mate has a set from a blown S50
small end pins: use of a friends engineering workshop
bearings: circa 200 quid or so, maybe more
Rings: not sure yet
headset: 150
seals and other gaskets: budget another 150
New timing chain parts: 300
Bit of paint and powder coating: 200
Management: Little under 500 for ECU plus making up the wiring
putting it all together: Cost of a new engine stand
Mapping: Friendly rates or if not I might give Sheps a shout


So I reckon it could be done for about 2K alright but better to budget 2500 as you'll always run into a few problems or extra bits you need along the way.

[Royalratch]

Sounds awesome - what;s your timeline?

I'm going more cams and remap route the more I think about it. But if I can squeeze more out via porting/skimming I will.

Can you not enlarge capacity and retain M42 crank?

[Dave_M3]

To be honest mate...

As you want more low end grunt, I'd recommend going on the stroker route.
Cams, porting will only make the car more peaky.
skimming will obviously help across the entire rev-range alright though.

You can increase capacity by keeping the M42 crank but limited really to how much you can bore it and S50 pistons are already pretty close to as much as it can take.


Time-frame?
Once I get the car resprayed in the new year and few other bits sorted, I'll be starting on building it.

I'd like to get it built before this time next year but it all depends on shaking the right trees for money and if and how quickly I can find the parts.

[Royalratch]

Torque is my number one thing.

I may keep my M42 as it's matched to this chassis and grab an M44 as a better starting point. They have their own issues though, single temp sensor feed and ECU etc etc...

[Dave_M3]

M44s only real weakness are the con-rods if your going for high revs.
Crankshaft not being forged wouldn't be a huge problem either unless you are going for big power.
I'd prefer to use a late E36 M42 though as it has the best of both engines.

The reason the M44s seem to have more torque too would be the variable length inlet. Would probably suit what you want nicely for around town etc but the inlet looks shite compared to the E30 one and its not "invisible" as you say.

Might as well have two extra cylinders if your going to be having an inlet manifold that looks differend

[Dave_M3]

You could just get a chip and adjust the timing to give you more low end torque for the moment if your not going to be reving the car hard a whole lot.

[Demlotcrew]

Just stick a LPT on and be done with it, M42's will never yield high power with cheap mods. I bet you could get reliable 250bhp for about 2k with an LPT and EMS.

[Royalratch]

M44s only real weakness are the con-rods if your going for high revs.
Crankshaft not being forged wouldn't be a huge problem either unless you are going for big power.
I'd prefer to use a late E36 M42 though as it has the best of both engines.

The reason the M44s seem to have more torque too would be the variable length inlet. Would probably suit what you want nicely for around town etc but the inlet looks shite compared to the E30 one and its not "invisible" as you say.

Might as well have two extra cylinders if your going to be having an inlet manifold that looks differend

I had a 1.9L M44 from a Z3 and I used the M42 inlet - was still torquier than my iS.

[tim_s]

1.9 m44s are a good mod, I have one in mine at the mo while doing some new 2.1 tweaks and have built another one for another zoner. Oh and the rods are better than m42 ones and are cracked.
For the m3 evo piston'd job, i built one of these with oversize s50b32 pistons (I was lucky enough to find gen oversize pistons!), a flowed head, cams, custom management and so on and at its best it made 183bhp, so 200-215bhp with this setup is a bit on the optimistic side. also an engine like that def won't see off my daily e46 330ci and was tried and tested to be pretty evens against my bro's old 328 sport. The final 2.1 I built was a good deal better and impressive against my bro's m3 evo, although obviously slower!
with a big wallet, an s14 is just right, def the best engine in an e30 imo end of, not to mention being a thing of beauty.

[Royalratch]

Just stick a LPT on and be done with it, M42's will never yield high power with cheap mods. I bet you could get reliable 250bhp for about 2k with an LPT and EMS.

I assume you mean Low Pressure Turbo. Kind of against my whole raison d'etre.

[Demlotcrew]

^ Yup SAAB use them all the time and the internals are identical between LPT cars and non LPT.

[Dave_M3]

1.9 m44s are a good mod, I have one in mine at the mo while doing some new 2.1 tweaks and have built another one for another zoner. Oh and the rods are better than m42 ones and are cracked.
For the m3 evo piston'd job, i built one of these with oversize s50b32 pistons (I was lucky enough to find gen oversize pistons!), a flowed head, cams, custom management and so on and at its best it made 183bhp, so 200-215bhp with this setup is a bit on the optimistic side. also an engine like that def won't see off my daily e46 330ci and was tried and tested to be pretty evens against my bro's old 328 sport. The final 2.1 I built was a good deal better and impressive against my bro's m3 evo, although obviously slower!
with a big wallet, an s14 is just right, def the best engine in an e30 imo end of, not to mention being a thing of beauty.

Forgot to say 215 would be my aim if I was to use the ITBs I have for it.

What had you to make 205bhp?
Pretty sure you said even that engine could give alittle more and all I thought it was was the M47n crank and the oversized S50 pistons?


Aren't the M44 big end caps alittle weaker?
Being lighter is good but I've seen a good few M44s with bottom end problems but not many M42s...
My iS is already pretty much even with a friends 328


I agree with Ratch on the turbo route...
I initally was thinking turbo but then realises how much I hate the power delivery of them and the noise.

[Royalratch]

And the lack of engineering finesse. It's a quick easy route and I generally don't like quick or easy solutions.

[tim_s]

Forgot to say 215 would be my aim if I was to use the ITBs I have for it.

What had you to make 205bhp?
Pretty sure you said even that engine could give alittle more and all I thought it was was the M47n crank and the oversized S50 pistons?


Aren't the M44 big end caps alittle weaker?
Being lighter is good but I've seen a good few M44s with bottom end problems but not many M42s...
My iS is already pretty much even with a friends 328


I agree with Ratch on the turbo route...
I initally was thinking turbo but then realises how much I hate the power delivery of them and the noise.

I've never seen big end caps fail on any engine.
For my 183bhp engine, spec was basically heavily worked over cyl head, cams, 2.1, standalone mgmt.

Be pretty surprised if any standardish m42 could keep up with a reasonable 328. 200bhp+/200ft/lbs+, can do 1/4 mile about as quick as an e30 m3.

[e30topless]

.
My iS is already pretty much even with a friends 328

did he know he was in a race ?

318IS against a 328i = you slaughtered

[Kos]

ratch

the stock m20 fly is about 9kh, the dual mass one on the donk at the mo is about 11kg. the pick up will be better as it is, no denying that, but if you do fit as is you will then realise that going theat extra bit lighter is something you really wish you had done.

stock m20 fly and take it to 7.5kg wh9ch is well with in the safe limits imo. the JB racing one is a lot lighter maybe only 4kg

[Dave_M3]

what extra bits were done for the 200bhp engine so Tim?
I thought that listed for 183 was pretty much what you had for 200...
Ah well back to the drawing board so then and if not, I'll be happy enough with 180
will be going for a silly C:R too more than likely to make use of the knock sensors and reasonable mapping time. Will be restricted to good few from then on but it runs shit on poor fuel at the moment anyway so won't be a huge problem.

Didn't race the 328 but driven both cars and so has the owner of the 328 and he says its pretty similar to his. Obviously the 328 is still far quicker once you reach decent speeds...

318iS isn't completely standardish though.
circa 150-160bhp with the usual mods like chip, heater plate and all that heat exchanger shite removed, live re-map.
M20 flywheel lightened to 5.9Kg (this makes a good difference even on its own)
6 speed box,
4.1 LSD,
205/45 R16s (tiny little bit smaller than 205/55R15s I think)


Of course his 328 will make bits of me again soon though no matter what I do to the engine when he puts in the 6 speed off his Evo drift car, 3.64 210 LSD, and the usual mods like the inlet, cams and re-map

[Demlotcrew]

And the lack of engineering finesse. It's a quick easy route and I generally don't like quick or easy solutions.

I agree which is why im building a 375bhp 2.7 S14. However you wouldn't see me spending money on a M42. (Unless it will be FI)

[flavyphil]

i love my m42 i would love to keep it revy but best bang for the buck would be F/Induction with all the forged bits just a few reinforcements to the engine and you could run 250 300hp all day! but if money was no object metricmechanic would be sick!

[Royalratch]

And the lack of engineering finesse. It's a quick easy route and I generally don't like quick or easy solutions.

I agree which is why im building a 375bhp 2.7 S14. However you wouldn't see me spending money on a M42. (Unless it will be FI)

Engines are engines. I want more N/A power from this engine in an invisible package so everyone who keeps saying M52, FI is not really rising to the challenge!
I like the thinking solutions, from Kos and Sheps.

[Dave_M3]

The MM M42 doesn't actually seem that fast to be honest going by a few videos...
Only manages 0-60 in late 6is to 7 seconds which is only about half a second quicker than my car.

Probably a different story overall and at higher speeds but alot of cash to buy an engine thats only just a little bit quicker

[Royalratch]

40BHP for £6,000!?!?

[Demlotcrew]

Its costing me 5k for 375!

[Royalratch]

Engine builders are the lawyers of the car industry! There's now way they can justify those costs.

[Dave_M3]

Ah but you see... a base M42 costs about 200 quid..
A base S14 costs 3K
I've seen engines built similar"ish" to S42s for sale for about 7-8K with about 260bhp.

350bhp+ S14 is a totally different ballgame though

Thing about when you think about engine builders charging silly mone though is...
If parts are about 2-3K from the list of bits mentioned to get a 2.1 and thats excluding things you always forget about when building an engine like new service parts, hoses etc.

Costs for putting it altogether and being able to put your name on it and happy that it'll last for a few 1000 could be justified to be honest...

Even the labour involved in doing a timing chain on an M42 is usually about 250-450 euro. I'd think it at the more so at the lower end of the scale as its actually a pretty simple job but to a garage it takes up quite abit of time that they could be doing a number of smaller jobs

[Jon_Bmw]

Rally boys think nothing of throwing £8k to get a K series/xe up to scratch. Seriously 4k isn't as expensive as you seem to think it is.

You don't get a lot for £4k IMO from anyone other than a one man band with no overheads.*

*one man bands can be very very good btw.

[Royalratch]

Whop the hell are 'Rally Boys' though.

I don't want to rally. I want more torquey power without being raped.

£4K is a ridiculous amount for 40BHP more whoever you are.