Useful 3.2L M104 Specs and using Honda Connecting Rods - Page 4 - PeachParts Mercedes-Benz Forum

400Eric · #46 09-17-2010, 02:35 AM

OK, now I'm really confused here.
On the M103, the hydraulic "lifter" is actually on the valve side of the rocker arm right on the end of it at the tip. The M104s however, have direct acting bucket tappets that are in the head between the cam lobe and the valve stem tip with no rocker arm involved so I can't see how M104 parts can help M103s or vice-versa. The M103 parts are much smaller and have no resemblance to the M104 parts. Have I missed something here? Did I mis-read a post or two?

I know that the M102 originally had mechanical "lifters" when it first came out and I think it kept them for at least a couple of years so I would think that would be an excellent, cheap way to get mechanical "lifters" into an M103.

The only thing I can think of for M104s is maybe the bucket tappets from the 16 valve M102 should be looked at and investigated?

Mag, didn't you say something about the later M104s having windowed main webs? I've been reading about how a lot of new engines have them now and how it really helps cut down on parasitic power losses in the crankcase. I guess that's yet another power secret M.B. implemented long before most of the other OEMs did although I did see a 1950s Mopar Hemi block that had windowed main webs too (I think it was the little Dodge Hemi). I can't wait to see those old/new M104 main web pics!
Regards, Eric

kynsi · #47 09-17-2010, 04:34 AM

Quote:

Originally Posted by RBYCC

Cam manufacturers such as Crane recommend not to use a solid lifter on a hydraulic cam due to ramp profile.
Can cause damage to the cam...

But on this forum, I'm sure it's being done and making mega power without any problem...

I think it goes somethin like this:

solid type cam first takes gap off, then lifts

hydraulic type just starts lifting.

kynsi · #48 09-17-2010, 04:43 AM

Is the main web the cast iron around main bearings.

As far as I remember 104 has this window 300 and 280. But 280 has more casting profile around it. 103 has no side windows at all.

RBYCC · #49 09-17-2010, 09:07 AM

Quote:

Originally Posted by kynsi

I think it goes somethin like this:

solid type cam first takes gap off, then lifts

hydraulic type just starts lifting.

The problem is that the ramp of a hydraulic cam has a slope that the hydraulic lifter can easily absorb.
A solid lifter would tend to slap or drop too quickly on this profile and potentially damage the lobe.

Ed A.

400Eric · #50 09-20-2010, 08:11 AM

Quote:

Originally Posted by 400Eric

OK, now I'm really confused here.
On the M103, the hydraulic "lifter" is actually on the valve side of the rocker arm right on the end of it at the tip. The M104s however, have direct acting bucket tappets that are in the head between the cam lobe and the valve stem tip with no rocker arm involved so I can't see how M104 parts can help M103s or vice-versa. The M103 parts are much smaller and have no resemblance to the M104 parts. Have I missed something here? Did I mis-read a post or two?

I know that the M102 originally had mechanical "lifters" when it first came out and I think it kept them for at least a couple of years so I would think that would be an excellent, cheap way to get mechanical "lifters" into an M103.

The only thing I can think of for M104s is maybe the bucket tappets from the 16 valve M102 should be looked at and investigated?

Mag, didn't you say something about the later M104s having windowed main webs? I've been reading about how a lot of new engines have them now and how it really helps cut down on parasitic power losses in the crankcase. I guess that's yet another power secret M.B. implemented long before most of the other OEMs did although I did see a 1950s Mopar Hemi block that had windowed main webs too (I think it was the little Dodge Hemi). I can't wait to see those old/new M104 main web pics!
Regards, Eric

Guys?

MAG58 · #51 09-20-2010, 02:35 PM

Patience!

There is no way an M104 lash adjuster would work with an M103. If so I want pics because it has to look fugly.

The later model (.94 and .99) have windowed blocks yes. In the motorcycle world this started to get big around 2003 when the K4 (?) GSXR1k went to some windows between 2 and 3 to even out pressure. VW has had them in the 1.8t for some time (maybe not since 93) and the origional LS1 had a window over the #1 main.

It's great for equalizing crankcase pressure and reducing pumping losses though I believe that there is some sacrifice in stability in the bottom end. I know Roman's M104 is the .98 (M103 block for all intensive purposes) and his M103's are holding big power on a non-windowed m103 block. I've yet to see what the new M104 blocks can hold. In many places, older non windowed blocks are coveted by forced-induction guys since they are stiffer than the non windowed blocks and a few extra lbs of boost (if that much) can make up for the extra pumping losses.

kynsi · #52 09-20-2010, 04:03 PM

There is holes between cylinder and main bearing in M103.

M104 has holes in sides too.

M104 later has strenhnenged holes. Little profile around the edge.

MAG58 · #53 09-20-2010, 10:31 PM

Some M103's do not have a front window though. My 104.98 does not. They do have windows above main bearings 2-6.

All M104's that are the 3.2 or 2.8 have the 'strengthened' windows with the ridges around the windows near the skirts.

JayRash · #54 09-21-2010, 01:44 AM

ok many of us haven't seen the inside of the block.

kynsi · #55 09-21-2010, 08:39 AM

Hmm, if Pumpish is now testin the "weakest" block in hes daily car. It makes us wonder hat kind of power other blocks can handle withaot any added steel.

This is very interesting thread. Iv been thinking these things myself long time. I allmost ordered those honda rods couple years ago, but I didnt find suitable pistons. Also this bottom end durability guestion have been in mind.

By the way om 606 main caps looks similar to 103/104 cap. And those fellows drive continiusly 2.8 bars of boost. Some of them 4bars and egp peaks to 7bars (arrows rods).

Must be some guality in MB...

MAG58 · #56 09-21-2010, 08:48 AM

It's not the 'weakest'. It's the .98 motor and the block is pretty much identical to his m103.

kynsi · #57 09-21-2010, 09:00 AM

Quote:

Originally Posted by MAG58

It's not the 'weakest'. It's the .98 motor and the block is pretty much identical to his m103.

my old motor .98 is opened here right next to me and it has same holes that .94 but more rough edges.

I mus take pics...

MAG58 · #58 09-21-2010, 10:54 AM

Please do. The .98 existed for an extra year in europe that it was not available here and I'm sure the .94 is different as well.

kynsi · #59 09-25-2010, 03:33 PM

Here is the M104 300 24 engine from my old 124 chassis (jokermotor/test engine).

This is one of those M103:s in my garage. Interesting thing by the way some of them (103) have oil sprays machined surface, but no oil sprays and holes or anything.

MAG58 · #60 09-25-2010, 06:26 PM

Hmm. My -24v block looks exactly like the M103 block (below) while my .94 and .99 blocks look exactly like the top block. What's the engine code on the top block?