190e 2.0 and 2.3 8v cylinder head differences - PeachParts Mercedes-Benz Forum

JUNAID786 · #1 04-20-2011, 05:52 AM

hello everyone

i have been looking around for the m103 3.0 12v with not much luck.

turns out they not as common as i thought.

ok so i have a 2.0 8v m102 at the moment.

is this as strong as the m103 but only a 4 cylinder? or just wishful thinking.

further, what is the difference in head design of the m102 2.3 8v?

would i have a problem with valve clearance if i put that head on my 2.0 block? if so, would i be able to mill the block a little bit to fit the head. and would milling the block have catastrophic side effects? ie blown head gaskets and stuff?

thing is, i get fantastic economy from my 2.0l. and changing the whole motor to a 2.3 for 10kw doesnt seem worth it. i know i cant keep the same economy if i want power but im still trying to find a trade off between the two.

i have heard that the larger head will lower compression and so will milling the block. wouldnt this be good for a turbo setup? or will it just weaken the block near the head?

i know that lower compression will result in slower acceleration off the line. im ok with that coz i could save fuel in the low revs and get nice strong boost response when the turbo spools up.

also, can i use the 230e fuel distributor with the new head?

Random Guy · #2 04-23-2011, 08:23 PM

I believe turbocharged engines generally run lower compression ratios than their N/A counterparts. I know my turbo Volvo has a lower compression ratio than the non turbo.

400Eric · #3 06-08-2011, 08:03 AM

Yes, the 2.0 is basically the 3.0 with 2 missing cylinders.

The 2.3 8v has bigger intake valves than the 2.0/3.0, 46 mm vs. 43 mm.
Regards, Eric

Dearlove · #4 06-08-2011, 10:07 PM

****, so a pretty easy upgrade for the 2.0 or 3.0 if you had the head off, would be to port the intakes and use the 2.3 valves!

400Eric · #5 06-09-2011, 01:42 AM

Only if they clear the smaller bore!
Regards, Eric

tjts1 · #6 06-09-2011, 01:49 AM

Quote:

Originally Posted by 400Eric

Yes, the 2.0 is basically the 3.0 with 2 missing cylinders.

The M102 and M103 have different bore spacing. The M103, M104 and M111 4 cyl share the same bore spacing.

400Eric · #7 06-09-2011, 02:29 AM

What is the bore spacing of the 2 families? I have been curious about what the bore spacing is on the 6s.

Different bore spacing or not, the valve sizes of the 2.0 and 3.0 are exactly the same.
Regards, Eric

MAG58 · #8 06-09-2011, 03:30 PM

The Bore spacing on all the M103/M104 6's is exactly the same. Right now I have a 3.2 head bolted on a 2.6 block (it needed a place to live for a bit). As far as valve size is concerned, I can see why the 2.8 M104 is de-stroked but not de-bored. At 88.5mm on my M104.980, if it was running ANY smaller bore size you'd have to eyebrow the top of the bores to clear the valves, putting the 3.2 head on the 2.6 was a joke. You can reach your finger down the exhaust track and feel the itty bitty bore of the 2.6 hitting where my valves would have been.

IIRC all the M102's also share the same bore spacing albeit it different than the 6ers. Idk how close it is to the M117/M119 ballpark though, if it is.

bahaimus · #9 06-09-2011, 08:19 PM

Quote:

Originally Posted by Dearlove

****, so a pretty easy upgrade for the 2.0 or 3.0 if you had the head off, would be to port the intakes and use the 2.3 valves!

Talking 3.0 only, except that by the time you cut new valve seats, bought the valves, lapped them in, did the porting etc, you could have bought a 3.0 M104 engine and made more power and torque anyway

400Eric · #10 06-09-2011, 10:05 PM

Quote:

Originally Posted by MAG58

The Bore spacing on all the M103/M104 6's is exactly the same. Right now I have a 3.2 head bolted on a 2.6 block (it needed a place to live for a bit). As far as valve size is concerned, I can see why the 2.8 M104 is de-stroked but not de-bored. At 88.5mm on my M104.980, if it was running ANY smaller bore size you'd have to eyebrow the top of the bores to clear the valves, putting the 3.2 head on the 2.6 was a joke. You can reach your finger down the exhaust track and feel the itty bitty bore of the 2.6 hitting where my valves would have been.

IIRC all the M102's also share the same bore spacing albeit it different than the 6ers. Idk how close it is to the M117/M119 ballpark though, if it is.

I knew the bore spacing of the 6s is all the same. What I meant when I said "the 2 families" was the "family" of 4s and the "family" of 6s. What I don't know is what the actual bore spacing of those 2 families actually is. The bore spacing of the M117/M119 is about 4.43".
Regards, Eric

duxthe1 · #11 06-09-2011, 10:54 PM

I measure 97mm as the bore spacing for the inline 6 engines.

400Eric · #12 06-10-2011, 08:48 AM

Thanks!

97mm X .0394 = 3.82"! That's barely bigger than the 2.3's bore of 3.76"! (95.503mm) It would seem that the 4 cyl does indeed have a larger bore spacing than the 6 does in order to accommodate it's much larger bore!

Having both the 4 and the 6 on the same bore spacing would've allowed MB to enjoy greater cost savings by having more shared tooling and shared tooling costs, and more and greater shared economies of scale. It just seems so odd that MB did not take advantage of this. It would also have left us with a better foundation to build killer 6s on, with displacement available to us through a larger bore, instead of having to stroke the thing so much thus screwing up our bore to stroke ratios and rod length to stroke ratios so badly. A bigger bore would also really help the breathing too, but we all already know this stuff, how come MB doesn't seem to? It's too bad really, it could have been a win/win for all of us and them.

During this same time period (80s-90s), BMW had two 6s, a "big block" 6 and a "small block" 6. That is something else that MB could have done, building their three liter, and three and a half liter 6s on a block that had the larger bore spacing of the 4 cyl. How hard would that have been to do? BMW did it! (Their 2.5 6s were on their small block and their 3.3, 3.4, and 3.5 6s were on their big block.) I guess they felt they didn't need to bother because they had a V8. Still, it sucks though, thinking about what could have been.
Regards, Eric

duxthe1 · #13 06-10-2011, 01:28 PM

You're confusing bore and bore spacing.

400Eric · #14 06-11-2011, 04:32 AM

No, I'm not. I simply pointed out how the 2.3's bore is so big that it would not physically fit in a block that had a bore spacing of only 3.82", and that that supports the claim that the 4 cyl was built on a block that had a larger bore spacing.

The bore is the actual size of the hole. The bore spacing is the distance from the center of one bore to the center of the bore next to it.

I've edited the post. Perhaps it's more clear now what I was trying to say.
Regards, Eric

JUNAID786 · #15 09-06-2011, 03:24 AM

i found the bottom end of a 2.3. can i use the top end of my 2.0 on that block?