182bhp turbo 318is!!!

[appletree]

just bin messing about on the net and look at this!



Turbos
2 ltr convertions
nos

the lot!

http://www.tdi-plc.com/bmwE30318iS.htm

[maxfield]

Bad experiance with TDI

[gcorky]

170 brake m40......

[appletree]

whats wrong with them?

i was quite intrested in some of there stuff, but if theres bad feed back i might give them a miss

[maxfield]

They had my dads car about 5month and in that time puty BBK on suspension. Engine managment thats about it and now is at bexleys having a 2.5 rebuild

[tim_s]

dude, imo they ask for quite a bit of cash for what they do. its probably a good conversion, but i could build you an m42 with a hell of a lot more power than that for the cash! they're also running a very big bore, longer stroke and higher CR which would generate a lot more heat, yet make no mention of improving the cooling to cope.
their 2l conversion is only 1957cc, and is built using the very average m44 crank. its nothing special, just an overpriced raid of the bmw parts bin. my 2.1 has cost a fair bit less than that and has well over 100cc extra capacity, and a forged, fully counterbalanced crank.
and as for turbo stuff, im sure ant could knock something pretty decent together for less than tdi.
if you're serious about tuning the m42, check out some of the threads on here and elsewhere on the net, as i think you can do better than tdi. a DASC conversion is possible with a bit of work, thats 200bhp and costs significantly less than tdi's 2l, is also a tried and tested conversion.

[fuzzy]

or spend the money on an engine conversion with a higher power output to start with, leaving more scope for tuning in the future

[Demlotcrew]

or spend the money on an engine conversion with a higher power output to start with, leaving more scope for tuning in the future

Well said that man!

Andrew

[tim_s]

lol yeah fair point, but you of all people should know that the m42 has plenty of potential, andrew! as a turbo it makes interesting comparison to, lets say, a YB cosworth
internals are up to muchos power, lots of cars in the states with big power from an m42.

[fuzzy]

dont know anything about the m42, how much power is big power and how much does it cost to achieve that?

[Demlotcrew]

The M42 is an excellent engine as proved by BMW Motorsport with the S42 and is full of potential but i would say that the only limiting factor is the cylinder head design.

Andrew

[Dan318-is]

The M42 is an excellent engine as proved by BMW Motorsport with the S42 and is full of potential but i would say that the only limiting factor is the cylinder head design.

Andrew

What exactly is wrong with the cylinder head?

[tim_s]

m42 head is esentially s50 cyl head with 2 cyls lopped off. s50 has 1mm bigger inlet valves, same exh valve size. 1mm bigger inl valves make f all difference, can be added to the m42 head but not worth the bother over 1mm. not sure whats wrong with it, haven't noticed anything myself

[tim_s]

oh fuzzy big power is same sort of figures as YBs when turbo'd and built to low compression with forged pistons, custom rods etc. is a similar ball game really. there's a 500bhp one i know of in the states, have pics somewhere! when NA and heavily worked on, is comparable ish to bmw s14.

[Demlotcrew]

IF you look at any of the ///M engines you will see how the cylinder head is constructed. The inlet ports are angled really aggressively and have been designed so that if need be the ports can be enlarged quite substantially. But with the M42 the water jackets and the combustion chamber size restrict the enlargement of ports/valves. One will need to do this to get max NA BHP but with a turbo i dont think it would make much difference just turn up the boost make sure the fuelling is spot on and you have power, just like that.

Andrew

[tim_s]

the m42 inlet ports are very similar to the s50b30 ones, i know this cos in order to do my throttle body conversion i looked at the s50 head quite a bit as i wanted to be able to calculate distances from valve to tb butterfly etc to help when figuring out trumpet length for the tbs. although the s50 is slanted a bit more in the engine bay (the m42 is quite upright) the inlet ports are also at the same angle, this is why the injectors fire correctly onto the valve using s50 throttle bodies on an m42 etc.
as far as needing bigger valves for NA is concerned, all the s5x m engines use the same dia exh valves as the m42 (inc s54 and CSL), inlet valves are a max of 2mm bigger than the m42 on the s54. the combustion chamber on the s5x engines is also quite restrictive like the m42. if using a bigger bore on the m42 like me you can lightly enlarge the combustion chamber (if you must!) to get the s54 size inl valves in, i reckon you could get away with s50 sized inl valves without shaving the combustion chamber. it would be nice to have the slightly larger inl valves. not a massive issue to me though, and would rather leave the combustion chamber alone.

heres a pic of an s54 (sorry, can't find a pic of an s50 head atm)


head gasket/water channels etc same position as m4x, slightly larger combustion chamber (like 2mm) cos it runs bigger pistons.

i guess inl valve size will become a bit problematic if going for well over 2/3 m3 power. in this respect the s14 shines with the m10 bore spacing and big inl valves. problem is it has a flattish, wide combustion chamber that is worse for efficiency. with a smaller combustion chamber and longer stroke, m42 opens itself up to working well with high lift cams, so the difference is mitigated a bit that way.
i think ultimately i dont really see inlet ports or valves as much of a barrier with the m42, this is because i think by the time these become an issue, the limited bore spacing and max capacity of the engine is more of an issue. you'd have to be pushing well over 100bhp per litre NA on a 2.1 (which is the max sensible squarish capacity imo) before inl valve size is problematic.

[Demlotcrew]

I know what your saying about the S5x engines but they have two extra cylinders to produce power from you dont. A 2.3l S14 can produce close to 300bhp. I think that BMW must have cast a different Head on the S42 to get that same BHP figure.

Ill go and take a few pics of the M42 head ive got here and a S14 215/240bhp head ive got on a block to show you the difference in the air flow design.

Andrew

[tim_s]

that would be cool, be really interesting to see. never seen a s14 head properly!
i totally agree about the 300bhp thing, god knows what bmw did to get the s42 there, im guessing ridiculous rpm had something to do with it.

the s5x comparison is exactly my point though, i reckon an m42 with a handful of s50 parts should make 2/3 s50 power, cos it would then basically be 2/3 of an s50 if running same cams/fuelling.

think its quite interesting as a comparison between s50 and s14 more than m42. the comparison is quite strange, bmw definitely went for different characteristics with the s50, with bigger throttle bodies, but smaller intake/exh valves, way long trumpets and by the sounds of things smaller inl ports. its probably geared towards being more of a road engine and perhaps tuned towards peaking at lower rpms.

[Demlotcrew]

Some pics;

M42 ports











S14 215/240 Ports



















As you can see there is a big difference between the two heads! The M42 is very restrictive and the ports are only machined at the edge of the valve. You can also see that on the M42 quite a big part of the valve guide sticks right out into the port (yellow part). With this design at high RPM the air will only make contact with half of the valve, this is because of the way the ports are shaped. On the S14 the ports are straight bores right down to the valve seat, at high RPM the valve is still taking air in all round it.

Does that make sense?

Andrew

[Demlotcrew]

Some more pics i took a few ago for S14.net







And one of the S14 left and M42 Right



Andrew

[Demlotcrew]

Some pics of the combustion chamber on the head, its far from being flat.





HTH

Andrew

[tim_s]

nice!
yeah, i see the ports are nicely defined on the s14 head, very oval, quite interesting! big too! whats the dia of the s14 vs m42/s50 inlet ports btw - i used to know but have forgotten. i can see that the valve are better for the air path too on the s14.

you really think the m42 inlet is very restrictive? you'd expect the ports to be a little smaller as the valves are smaller, but i think your photos show that the m42 inlet flows pretty nicely! - smooth casting and machining, ports defined well, nice smooth and straight inlet path, there'd be very little you'd do to flow it! i quite like the look of it! i do of course concede that the valve stem could be better and the s14 ports are better defined and bigger. i think the slight extra turbulence that i assume would be induced on the m42 head by the less defined ports might not necessarily be a bad thing though.

also i'm interested in how the throttle bodies mate with the head on the s14, appears to be a bit of a curve/kink which would accelerate the air, how does the inlet path look with the throttle bodies attached?

i need to see if the valve stem is the same on an s50 now, i can't remember of the top of my head.

i like the s14's inlet path, but i also like the m42 design, was expecting a much more severe difference from the way you were talking! they both look to flow quite nicely imo.

lol, the combustion chamber isn't very flat on the s14! surprising as its quite big, how dished are the pistons?

[tim_s]

btw in respect of the difference in inlet ports, the s50 is pretty much the same as the m42. would be good to get hold of a pic, i'll see what i can do. but the entry to the head is the same on the s50/m42. i do wonder about the small/big port thing, and the difference in valve sizes and throttle body sizes. so the m42/s50/s54 has smaller ports, smaller valves but bigger throttle bodies than the s14! interesting! presumably this combination gives better road peformance...

[Demlotcrew]

you really think the m42 inlet is very restrictive? you'd expect the ports to be a little smaller as the valves are smaller, but i think your photos show that the m42 inlet flows pretty nicely! - smooth casting and machining, ports defined well, nice smooth and straight inlet path, there'd be very little you'd do to flow it! i quite like the look of it!

Its hard to explain but if you look at the two pics i posted of the S14 ports and the M42 ones you will notice i tried to keep the camera angle the same. On the pics you will see that the S14 ports show most of the valve but on the M42 you can only see half of the valve, which means that when the air is coming in at hign RPM the intake of air is not at much as the S14 because all of the air is hitting the valve not just the back of it. IF any porting to be done on the M42 head it would be on the inner side of the port/valve seat.

See here a pic of the S14 port



I have no idea of what the relation between small ports and larger TBs would result in

Andrew

[tim_s]

lol tell me about it.
i understand what you mean about the inlet tract now, but i think that the smaller ports and the short side radius on the m42 are very deliberate to increase air velocity for road use. i'd worry about grinding out the short side on the m42 head cos of this. the radius is wonderfully nice and smooth and slight and gradual, unlike a lot of cars where the curve is a restriction through rough and agressive bends due to crap casting/machining causing muchos turbulence and reverse flow.
i think that the s14 is pretty much a no-compromise race-style engine so velocity at mid-lift and low rpms etc is not a consideration, only max flow volume. thats why you get very big valves and a wide inlet port, and barely any radius.
the m42/s50/s54 etc with smaller ports and a radius will add flow velocity for good torque, mid-lift, lower rpms etc . i don't think i'll alter the flow characteristics of the m42 in that respect as a result of this, mine's a road car, and sure i might gain some flow vloume, but will probably reduce velocity losing torque and mid-lift performance, mb even getting rid of some carefully thought out turbulence in the airstream.

my guess is that the stock s14 has way oversized inlet ports and valves for good track and high rpm performance over road performance, hence the difference between the s50 and the s14, and why the s50 runs even bigger throttle bodies while still running smaller valves and inlet ports. what do you reckon?

[e30_Turbo]

Top info guys, all this stuff is where I'm at with my project, now looking at how to get the best flow around the system and the head is already off to the shop for some work
Has been good to see other pics to compare my 12 valver too I think I'll be having the port's enlarged, welded water channels and some new valves too.

And re the thread topic I'd say 182bhp for that money on that engine is shocking an extra what 40bhp or so for Ԛ£3.9k

If you are a check book modder then it's probably made for you, drop it off, pay, pick it up, sorted. But there are many other options as stated by the men that know (above) all better and much more bang for your bucks!!

[Jamesb318is]

Bloody hell you guys know your stuff!
This is interesting reading

[appletree]

When i put the post up i dint mean i was goinging to do it, just thought it might be of some use to the zone.

av seen the bigger engines turbo/super charger bet never the 1.8 16V

what would be the best causeof modifieing the engine then?

filter, zurst , trottle body, chip?

what else, what sort of RELIABLE power could you expect?

[Demlotcrew]

my guess is that the stock s14 has way oversized inlet ports and valves for good track and high rpm performance over road performance, hence the difference between the s50 and the s14, and why the s50 runs even bigger throttle bodies while still running smaller valves and inlet ports. what do you reckon?

See this is what i dont really know! From what i can tell the M42 would have smaller ports because of its displacement. (Bore vs stroke) but this doesnt explain why it has larger throttle bodies????

I think you need to drive a S14 to get a feel for it because it has really good torque all over the RPM range, PM jonb he was out in my car last night and he said the engine has bags of mid range which i didnt really notice before.

Now on the S14 the best revving engine is the 2.0l it loves ot rev and makes good power, but the 2.5l starts to drop off power after around 7k rpm. This is because the cylinder head is too restrictive, so the ports get taken out even more and bigger valves are fitted to get the engine to breath. Can you see the relation?

Andrew

[M5pilot]

I really dont know why people say S14's have little torque - It's simply not true.

Good discussion with good info here - would be good if we had an Automotive engineer on this forum to explain it properly.

Reading and copying from books is good but doesnt really give you a proper understanding of whats going on.

Good research none the less!

[tim_s]

would be good if we had an Automotive engineer on this forum to explain it properly.

Reading and copying from books is good but doesnt really give you a proper understanding of whats going on.

steady fella! thats a bit harsh! for what its worth i have plenty of letters after my name thanks, sure there's people with more knowledge than me, but i feel confortable enough to talk about the inlet ports on two cylinder heads, what grounds do you have to assume 'copying from books' and not having 'a proper understanding of what's going on'? and tbh if i've not got a proper understanding, pipe up and correct me! isn't that what the forum's all about? and what's wrong with reading, or actually even copying from books - in this context isn't reading about fluid dynamics exactly what will give you 'a proper understading of what's going on'?!

back on topic!
andrew, lol forgot about the extra displacement per cyl. meaning larger ports, oops! i really want to get hold of a pic of the s50 inlet tract to have a good look.
its been a long time since i've been in an s14, i guess it figures that the torque is quite good, it is a 2.3 4 pot with a quite high CR after all!
still quite possible for the inlet path to be tuned towards higher rpms don't you think? certainly is pretty large and the inl valve size is pretty big too. its things like the s50b32 and s54 that have got me wondering, as they're pretty powerful per displacement and have narrower inlet tracts. interesting that the 2.5 runs out of air at high rpms, and is that def due to the inlet tract rather than throttle bodies/valve size etc.? i definitely see your point though with regards to m42 vs s14.
be interesting to see what mine does when finished, i'd done my comparisons based on the s50 not the s14, and in comparison to the s50 the m42 inlet's pretty good! im not sure whether i'll alter my inlet, i think not, as small ports are often better for road use anyway. very intrigued about the s50, and especially the s54 though. find it quite surprising when i think about it that the valve and inlet is so small, esp the csl which puts out what, 360bhp(?), with smaller inl and exh valves than the s14 and what looks to be a narrower inlet tract too! i know for certain that the s50b32 had a similar sized inlet to the m42 and that was 100bhp per litre (ok 'approaching 100bhp/litre' in the real world!). god knows what the deal is with the throttle bodies too, very weird.

[Demlotcrew]

tbh if i've not got a proper understanding, pipe up and correct me!

Ive found another cool pic, its a disected cylinder head of a late S14 head.



Like you said its down to bhp/litre despite the smaller ports (very different designs). What would be interesting to find out is what the Max bhp/litre the S50/M42 can go compared to the S14?

I think that the new generation engines might be designed with financial economy in mind, if you look at the M42 the ports are still cast, they have not been machined at all (is this the same for the S50?) the costs drop as all the S14 engines were hand finished. Im not sure if the new generation of ///M engines are hand made? if not then there might be a connection there, but this is pure speculation.

Andrew


Andrew

[tim_s]

ah, thats pretty interesting. good pic! im guessing bmw built shedloads of s50 engines, i reckon you're prob spot on the role of economics on the newer ///M engines. i had a read of a technical article I have on the s54 and although it mentions that the head is cast in BMW's normal foundry, there is no mention of the cast head then being finished, or any other indications of the engine not being mass manufactured in the normal way. seeing as the article rants about how the trumpets and intake etc were designed on the bmw f1 simulators etc, they'd probably have showed off about the inlet port machining and mentioned if the engine had any semblence of being hand finished. unfortunately there's also little information on the inlet port design, although it mentions the angles of the inl and exh valves.
a lot of the mods from the s50b32 to the s54 are efficiency of the components. really interesting that its more efficient on fuel as well as producing more power and torque and being lighter. impressive! allegedly 105bhp per litre on standard s54, 110bhp per litre on the CSL. i dont spose it can go much more than this, how far can the s14 go on a reasonable-ish spec?
the s50 port i looked at a while back, from what i remember (i was only really interested in the distance between the valve and the cyl head surface so didn't pay too much attention to much else!!! wish i'd looked more closely now), didn't look to be finished in the same way as the s14. the surface of the s14 ports must create some turbulence on the edges, which is probably a good thing.
i've popped a post up on an e36 forum and when i bump into a chap i know who's always poking around s50s i'll ask him to take a pic of an inlet port.

[Demlotcrew]

Well just looking at the Group N spec of the 2.3l its putting out 130bhp per Litre, which is not bad at all!

I think the New S engines are good on fuel because of Vanos, while about town its in off cam mode thus the engine needs less fuel because the cam overlap/lift is reduced by the ECU. Im sure the design of the ports could also play a part in this.

Andrew

[Andy335Touring]

(all the below are just my own ideas based on general theories, i don't have experiance with working on M42/S14/S5x heads or engines but i thought i'd try to contribute some ideas to this interesting discusion)

I think it will be hard to draw any conclusions(sp?) between the S14/M42 and S5x and their power delivery/port designs/valves/TB's/etc because BMW could alter certain aspects of the S5x with the VANOS units where as the they couldn't do that with the S14/M42 ?

The power band on the S50b32 is supposed quite wide, some thing like 2.5k or 3k right through to about 7k, i'd guess if the S50b32 didn't have vanos but was expected to make roughly the same power then it would have to be set up(cams,valves,ports,tb's,etc) more agressively so the power wouldn't start til around 3.5k or 4k ?

M42 head - nice design as it's 4 VPC but it is just a production head, probobly cost a lot less than an S14 head

S14 - More Motorsport design orientated with hand porting/finishing better port design