318iS V 325i Sport

[tomtomiS]

wow u guys are really divided on the the 4 pot /6 pot issue! this makes for entertaining reading

[Demlotcrew]

lol not convinced.
so a bigger heavier engine which overhangs the turrets further, has more weight near the top of the engine, and has a heavier box etc can has 'much' better balance than a lighter smaller engine?

Thats the thing tho, it doesnâ┚¬Ã¢”ž¢t over hang more! The If you look at the position of the Engine in reference to the front cross member it sits lower and closser to the steering rack. The S14 doent have a two part timing cover system. It has not heavy vibration dampener or viscous fan.

angle is possibly slightly different, difficult to tell from pics i have, but the m3 needs that so the bonnet will shut nicely. regardless the m3's cyl head at the front still sits pretty high, i checked on an evo 2 when i was doing all the measuring etc for the plenum, there wasn't that much bonnet clearance to plenum/cyl head. the s14's a taller engine so despite any angle difference it prob doesnt make much odds.

True it sits higher than the M42 but when an S14 engine is sitting on the ground it doesnt want to fall on its side like a M42 does.

the S14 gearbox is heavier and bigger than the IS one, both bolt to the engine at more or less the same point. how does it sit further back?

The getrag box used on the M3 is the same one used by Porsche, its a four piece box. IT has a separate bell housing which holds the box with four nuts to the engine. If you look at the bell housing of this box its almost twice as long as the M42 one and the box it self is about four inches longer than the M42 one.

cyl head is heavier on the s14 so more weight high up.
expansion tank up front really doesnt make any odds. its small, m3 has a bigger rad and oil cooler up there too which will easily mitigate that weight difference!

Thats it tho, the M3 has the same rad as the early M10 318 cars its really small and really light. The oil cooler lines are on the opposite side of the M20 ones to counteract the weight.

to be fair either way the cooling system will make next to no odds.
i just can't see it making much difference either way, I really can't see this much better balance argument - i'd have thought both handled pretty similarly.

I can assure you they dont. I have both cars in my garden with very similar suspension.

as for the not designed to be a race engine for an S42, can't be arsed to argue that. Surely you've looked into the S42 and if you had I'd see no reason for you to say such things. the S42 was lighter and more powerful than the S14 and replaced it, so really seems a bit of a dumb argument

Thing is the S42 is a good engine but it shares nothing with the M42 and the S14 was racing for much longer than the S42 had been, the S14 was more reliable and it all came down to costs. The S14 was built for racing the M42 was built for those who cant stretch/wont stretch their purchase for a ///M.

Andrew

[Demlotcrew]

Some pics





Andrew

[tim_s]

interesting!

lol ok i've just been uber anal and measured an m42 - timing case only adds 70mm to the front of the block. engine length in total is 46cm (both measured with a 30cm ruler as i couldnt find anything technical - they're accurate enough though).
bit of an admission, i can't remember the bore c-c on the S14, but given that the evo has 95.5mm pistons, it can't really be less than 100mm. that means that basically the S14 has to be longer than the m42. 40cm just for the cylinders, before any meat to the side of the pistons which would have to be a few cm min., then timing case, basically i can't see the s14 being under 50cm long.

so basically the M42 would have to sit 5cm odd further forward than the S14 to sit level past the front turrets (although i hasten to add its 10kgs lighter and less tall anyway!)

andrew, if you could measure the distance from front slam panel to engine top and bottom on the S14 when you have time, that would be interesting! then i can do the same on the m42.


some other stuff
-the "heavy" vibration damper on the m42 weighs 900gs.
-the m42 falls to the side on the ground not due to imbalance but the oil pans - not sure what your point there was!!!
-the box still weighs more even if its bigger.

enjoying the comparison though! on this point:

Thing is the S42 is a good engine but it shares nothing with the M42 and the S14 was racing for much longer than the S42 had been, the S14 was more reliable and it all came down to costs. The S14 was built for racing the M42 was built for those who cant stretch/wont stretch their purchase for a ///M.

S42 shares block and head with M42. pretty fundamental really, you could say the same about a race S14 - shares more or less no internal parts with the road car.
sure out of the box the m42 is a much less potent engine than the S14, but fundamentally it has lots of potential and is nicely engineered. i totally agree about previous stuff you've shown like inlet ports and the machining on S14 etc, but that has little to do with the potential of the M42 engine.
im also surprised you say the S42 came down to costs, i would put it down to the fact that it was a squarer more compact and lighter engine as a 2l, and had better valve size. if the S14 was better and it was down to costs, did it not matter that the S42 was more compact, lighter and produced more power?
i also dont see how developing a new race engine from more or less scratch which turned out more powerful than its predecessor could be cheaper than just re-using the S14?

[Chris-W]

-the m42 falls to the side on the ground not due to imbalance but the oil pans - not sure what your point there was!!!

S14's are clearly the outright winner in any 'ease of storage' contest.

[Demlotcrew]

Tims the S14 block is exactly 45cm long.

The S14 slam pannel distance is 29cm

The M42 slam pannel distance is 30.5

So the M42 sits 1.5 cm futher back than the S14

I have both cars side by side.

Andrew

[tim_s]

andrew, that's truly heroic!


thanks for that! you get my pm?
for reference, whats the bore c-c on an m10/S14?

[Demlotcrew]

Just to add, the Race S14 cars shared allot with the road going ones.

Crank/rods/head/valves/TB's ETC.

But the S42 had different castings for the block and head.
Different sump ETC. You can see from the pics of how different the S42 is to the M42.

The point of the engine falling over is that it puts weight to one
side of the car (the drivers for us) And that adds to balance of a car.

Andrew

[Demlotcrew]

The bore of a

2.3l is 93.4mm

2.5l is 95mm

HTH

Andrew

[tim_s]

totally agree about the S42, i think the same goes for S14 though.
The TBs on pics of race S14 I have all have slide thottle bodies, not the originals. I'm really surprised about the rods too, could've sworn they were different too, same for valves, but i'll check for certain later. Certainly race S14s also had different sumps!
S42 castings for block and head are same as M42 unless I'm very much mistaken. what makes you think not?

[Demlotcrew]

Some S14 had the slide throttles but they donâ┚¬Ã¢”ž¢t yield as much power as people think. So many of the Racers didnâ┚¬Ã¢”ž¢t have them.

The exhaust valves were not larger until they got into the 300bhp range.

The lower sump was wider on one side and the oil filter was also uprated to a high pressure one. (you can buy these from BMW for not much more than the stock filter)

The S14 head just had enough meat around the inlet ports for larger intake and its bigger than the Stock M42 head. The M42 head had to have the ports enlarged quite a bit, and for race applications to make sure they dont crack (as the stock ones do quite a bit, when have you ever heard of a S14 head cracking?) they would have closed up the water ways and just generally beefed up the cores.

Same for the block for the RPM of the S42 (which it needs to make its power) it would have to have big end reinforcements.

Andrew

[tim_s]

andrew, as far as i can tell the rods and valves were different in the S14 race cars.
add to this that the pistons, valve springs, cams, sumps, inlet,. exhaust etc were all different, then more or less nothing is shared with the road cars.

as for the S42, i still think its the same casting though dude, even if beefed up. i've been told this (indirectly) by the owner of an S42 in S.A.
fwiw the standard M42 head and block castings are safe to 8k unmodified (other than oil deflector), demonstrated by Jim Rowe (metric mechanic - built sam's 2.1) and Don Duncan (GTTechnic).

A 2l engine with 86.5mm pistons also has no need for inlet valves as big as the S14, the S42 for instance only has 35mm inlets. I also have the dimensions of the inlet tract on the S42 if you're interested, i was going for S42 spec on my head, but they're pretty much unchanged from the M42. I was looking at going for bigger inlet valves on mine (they're not too pricey), but its proved unnecessary for the rpm i'm going to be running, and also may screw low lift flow.

btw i take it you've read the S2000 vs S14 head comparison, demonstrating how the S2000 outflows the S14 evo 3 head at mid and high lift despite having 36mm inlet valves against 38.5mm (E34 3.8 M5 valves iirc)?

[pacerpete]

Haven't you 4 pot losers got anything better to do than measuring your 'bits ' ?

[Pal318is]

Haven't you 4 pot losers got anything better to do than measuring your 'bits ' ?

That's probably coz we need a largish ruler to measure them, as opposed to using a spark plug

[pacerpete]

I heard it's more like micrometers at dawn !

[Frenchy]

I have owned them both ! and the silky smooth 6 does it for me but it drank like a fish ! the Is is very buzzy but good fun and chuckable plus i find it very good on the go-go juice.
My Audi S4 does 25mpg if i behave myself but hit the loud pedal and BP have to put another shift on to catch up !!!

[Pal318is]

I heard it's more like micrometers at dawn !