Hey guys,
Its maybe a odd topic, but as it consists of buliding/tuning mercedeses I decided to post it here.
So here I am, cant figure out what to do.
I have a sure plan to build my ultimate benz, but cant decide.

1) MB 190E 2.5-16v add a huge turbo, rework the internals using forged rods/pistons, programmable EFI etc. This should guarantee me 5-600hp & 10s 1/4mile..
whitch is a blast to drive at sundays

2) MB SEC with 600 v12 engine,rough stereo system,widebody, black ex/interior, lowered, nice wheels etc. Yeah a nice cruising car, isnt it?
Maybe I can even find a way to bore and stroke the beast to 7.3litre, like AMG did...then it should move too...

Yeap, we are talking about very different cars here, the first is fast and more "race spec" but the second has a bad ass imago whitch WILL turn heads...
the fact is I like both of them
What would You choose?

As I'm in the process of putting an '02 LS6 engine in my SEC, I'd say go for the SEC. Boring the V12 might be a problem as most MB engines use a nikasil process on the cylinders and that's not available from most hot rod shops. It could be steel sleeved but that might cost a dollar or three.

Speaking of the v12....
I have heard rumors, that v12 uses the same crank that regular mb 3.0,just 2 pistons at one stroke vs 1 piston (cant describe better in english) http://community.forenshop.net/forums/uploads/W140/post-21-1167307653.jpg
is this true?

a nother pic of v12 crank http://community.forenshop.net/forums/uploads/W140/post-21-1167307682.jpg

That's definitely NOT a M103 crank.. Unless you have tons of cash to burn, I'd go with the 2.5-16V. Just remember, your dealing with three times more engine on the M120 versus the M102. If you decide to go the M120 route, I'd scrap the original ECU and wiring and go with an aftermarket EFI system.

__________________
Current Stable:
01 ML55 AMG
92 500E (a few mods)
87 300E (lots of mods)
00 Chevy 3500HD Diesel Box Truck
68 18' Donzi Marine
06 GT i-Drive7 1.0 Mountain Bike (with GPS!)

PREVIOUSLY OWNED:83 300SD, 87 420SEL, 88 420SEL, 90 420SEL, 86 560SEL, 86 190E 2.3-16V AMG, 94 E320

Aftermarket ecu is the only way to go anyway...there is absolutly no point to try building engine with stock ecu...
But what crank does the 7.3 amg uses?
its just that ordinary 3.0 uses crank with 80.2mm stroke and the 3.6 amg uses 92.4mm stroke crank(S350TD).
And stock 6.0 uses also 80.2mm stroke and 7.3 AMG uses ALSO 92.4mm stroke
I just thought maybe they are similar and that way it would be rather easy to build stroker m120.
Anyway yeah seems like you are right...the I4 is 3 times smaller and 3 times cheaper to build...it was my mistake i didnt concider ALL the things I would need( rods, pistons, injectors etc) and there is a big difference if you need to buy 12 of all or only 4.....So thats only way to go for me.
Case closed , thank you for bringing me back to earth from the clouds

How about bore? If these numbers are also consistent, I imagine AMG used the same pistons for either engine. Same thing for the stock Mercedes piston as well. Manufacturers try to use the same parts in every design for economics reasons. The crank is definitely not that part when comparing M103/M104 to M120.

There's also the fact that they don't arbitrarily pick these dimensions. They pick the optimum bore and stroke based on torque curves, compression ratio, cylinder wall thickness, geometry, ect.

As for Building up an M120, I think it would be an awesome project, just very expensive. Plus the ouch factor will be greater if you break something. There's 48 freaking valves!

__________________
Current Stable:
01 ML55 AMG
92 500E (a few mods)
87 300E (lots of mods)
00 Chevy 3500HD Diesel Box Truck
68 18' Donzi Marine
06 GT i-Drive7 1.0 Mountain Bike (with GPS!)

PREVIOUSLY OWNED:83 300SD, 87 420SEL, 88 420SEL, 90 420SEL, 86 560SEL, 86 190E 2.3-16V AMG, 94 E320

How come you go polars? You got a 4 banger or a 12? Dont like 6/8 cylinders?

I think the 12 is cool and not dipping in to the engine dramatically could yield good results, just charging it or hell ITB's and bumping the compression would yield 500 probably quite easily. And sound really scary. It doesn't necessarily need more displacement, IMHO, 6.0 litres is a lot, especially tossed into a lightened chassis, keep the whole deal under 3800lbs somehow (personally I'm spending ridiculous amonts of cash on lots of carbon fiber for the 300CE). With the 4 cylinder, meh, I dont get it... if you got a choice. They just don't really compete with a bigger engine, and if you use a V6, then you get nearly the same weight/space conservation of a 4 (maybe lighter even?), but good, smooth torque numbers.

Why r4 and v12? Simple,
The v12 is the most powerful engine that mb produced in those days.
why r4-16v? it has superb head (stock head is good for 600hp..)
190 light body and 600hp engine (with aftermarket ecu and a bit stronger internal- lowered compression etc) will run low 10-s....AND its cheap to build strong vs 8-v12...
I had a m104 3.2 engine, but I sold it..all because the head is not so good and real porting/cam specialist are hard to find around here...
As I said my goal is 600hp over that its insane to drive on roads and under that is exciting FOR A WHILE...trust me
If someone who has experiance says that the v12 bottom can take 600 with no problem, I wouldnt even bother to think to 16v..just twinturbos, lower compression + efi...but as no one has ever tried it, its a slippery way to go.
I think under 3800LBS is not so difficult fiberglass & alloy + getting rid of weight?
I live in europa and around here I can find M120 with 1300-1800$...2.3 16v-s are 1600-2000+$...so I dont know...some thinking needs to be done...

It's unfair to compare both engines to the same 600HP goal. Just remember, the M120 will make more than twice as much torque.... That's where the real fun is! The other aspect to consider is that you will be pushing 3 times the power out of the M102 where the M120 would only be a small 200HP jump to 600HP. The M120 will last way longer with such a small increase in comparison. Can the M120 take 600HP?,,,,, Absolutely! You could probably push 1000HP on a stock bottom end.

Now, on the flip side of the coin.... Fitting an M120 in a W201 chassis would be ridiculous if not impossible. So, you have a choice of which chassis you prefer. I personally think a W126 coupe with an M120 would be awesome. Also, running in the mid 10's wouldn't be a hard task with that combination.

There's no question a rolling 190E 2.3-16V would be much easier and cheaper to modify though. Are V12's really that cheap over there in Europe?

I agree with AustinsCE, Why not go with a 6 or 8 banger? The Cosworth head is the least of your concern with the M102. I'd be paying more attention to the bottom end when pushing 600HP. PUMPISH is pushing 560HP on his M103 (he plans to make 800HP). Just because it has only 12 valves doesn't mean it cant make the power with a little forced induction.

Just some stuff to consider...
Adam

__________________
Current Stable:
01 ML55 AMG
92 500E (a few mods)
87 300E (lots of mods)
00 Chevy 3500HD Diesel Box Truck
68 18' Donzi Marine
06 GT i-Drive7 1.0 Mountain Bike (with GPS!)

PREVIOUSLY OWNED:83 300SD, 87 420SEL, 88 420SEL, 90 420SEL, 86 560SEL, 86 190E 2.3-16V AMG, 94 E320

yea the 12 bangers are quite cheap around here cause gas prices are going up fast and people like small cars with mikro-engines.
A guy offered me 95year m120 for 1300$. But If the bottom can take then its even cheaper to build m120 because changeng 16v bottom is a must...when hige-horses are wanted.
My first Idea was : m120 : custom intake/exhaust, 2x KKK K27 turbos (have to find them with right A/R), big IC, VEMS fully programmable EFI, 370cc injectors, COP (coil-on-plug) ignition, stacked head gaskets powerful fuel pumps, bigger fuel lines, fuel rails and head rebuild/refreshing (new gaskets , valve job etc)
then I should be in 600+HP range with good tuning and 8-9psi of boost.
Nice I like it!
300EVIL, do you know if the pistons/rods of m103 are similar to v12 ones?
http://community.forenshop.net/forums/uploads/W140/post-21-1167308770.jpg this is a m120 piston and rod

Adam.
The 102 bottom end is built like a friggin tank.
Only thing that needs to be changed as power go up is the connecting rods.
Look exactly the same as the ones in the pic of the V12 counterpart.

Mere fact is that within reason a 4 banger iron block will most likely be more sturdy than any "V" engine.
..and when pushing those kind of number block flex IS an issue-amongst a lot of other stuff.
Crank will do just fine.Itīs a Swedish forged Bofors one.
Slugs..is something you can get off the shelf as Mahle makes them anyway you basically want them already.(Look into other similar motor combos as well)
The head then...is the TRUE gem.
Again...
354CFM of air @14mm of lift...itīll take a LOT of motor to touch that.

IMO,basically the only thing the 120 engine got speaking for it is the displacement,and whatīs more there IMO IS such a thing as to much power on the street-as i presume thisīll be a streetcar.

600hp out of the 102.983?
No problem.
In fact..local Swedish dragracer extracted INXS of 1300 already back in 89 to run a corrected 7,80sh@330km/h.

To my surprise the M120 pistons are quite a bit different from the M103. As you can see in the pics, the the skirts are a little different and their is more "meat" on the pin boss on the M120 piston. Obvioulsy there is also more fly cuts on the top since there's 4 valves as well.

As for the rods, They do look quite similar but there are some noticeable differences on the big end. It actually appears that the M103 rod has more "meat" down there but it's really hard to tell without some measurements.

__________________
Current Stable:
01 ML55 AMG
92 500E (a few mods)
87 300E (lots of mods)
00 Chevy 3500HD Diesel Box Truck
68 18' Donzi Marine
06 GT i-Drive7 1.0 Mountain Bike (with GPS!)

PREVIOUSLY OWNED:83 300SD, 87 420SEL, 88 420SEL, 90 420SEL, 86 560SEL, 86 190E 2.3-16V AMG, 94 E320

Pumpish has shown us 560hp with regular 3.0...if the pistons and rods are allmost the same, then v12 should be good for 1000hp
But that is way to much for me...
By the way...is the m120 crank forgged?
what about m120 heads? are they ok?...I mean how do they flow? CMF-s..

to Raceing:
How would the 16v move below 3500rpm?...it needs one huge turbo for 600horses...I am afraid of the lag...and how far can go with 16v cams?

2.5-16v. Not that I'm biased or anything.