A great link to General Unimog FAQ's is here (http://www.cs.brandeis.edu/%7Ezippy/unimog-404.html)

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MogXIPHC

http://www.west-4x4.demon.co.uk/page2.htm

http://www.pirate4x4.com/forum/uploads/flexsusp.jpg

Image from West-4x4

404FAQ

Ok, so does any body have good modifications to amp up the M180 in a 404.1 a bit. I would love to get about 150hp from it, but that may be stretching it. I dont want to swap the motor, so don't suggest it!!

There has to be a way to get a few more pony's. Any idea's

404MoPowa

Heads and Dual Carbs:

If one uses the standard single carb manifold, the maximum power would be in the neighborhood 105 hp SAE with the 8.7:1 CR head/cam. The highest output from a standard M180 engine is 135 hp SAE.

The 1963-67 230SL (M127engine) had a four main bearing lower end like the M180 yet achieved 170 hp SAE at 5,600 rpm due to fuel injection and a 9.3:1 CR head. Thus, I believe the lower end of a Unimog M180 engine should be able to take the extra 15 hp SAE generated by a 220Sb head. I have 25,000 miles on my wap and it still runs well. Hope this helps.

Jim Molloy
---------------------
Your easiest conversion will be to swap heads with a 1959-65 220Sb
(body 111/2) or a 1965-68 230S sedan (body 111/1A). Either head will
bolt on directly in place of your original low compression M180 head. I
do not recall the casting number for the high compression head. Jeff Lenzner (rockymountain moggers) just picked up his from my place last week. He could probably give you the number.
The cars you are looking for are the finned body types. The earlier "Ponton" bodies did have an M180 motor but the later engines are more refined.

If you wanted to try the head from a 2.5 liter M108 engine, you will need to find a 1965-68 250S (body 108 II). These cars were the newer non-finned body style.
Hope this helps.

Jim Molloy
Waldersee Farm
----------------------------------

use a head gasket to match the new Hight Compression head, not the old Low Comp Head. Based on this advice, a place to start might be place the High Compression head gasket on top of your block - checking for alignment of water and oil passages. Lack of alignment might be a problem!!

Another check which might be of value is to overlay an In/Ex manifold gasket. Some engine builds used larger "diameter" runners in the manifolds - matched w/ larger valves - right? This can become an issue if you retain your existing single carb manifold. There is a possibility that you may encounter
very little gasket seating area or "pinch" between the manifold and the block - leading to possible induction leaks or exhaust leaks.

Some other list members have done conversions using heads from 230/250 cars and have spoken favorably about the power increase at high rpm - probably influenced by larger valves. You probably get the most improvement when this
type head is used w/ dual carbs and a modified (free flowing) exhaust. I have no experience with this - just an opinion.

Anyway - Just my thoughts - Good Luck. Contact me off-list if I can help.

Bob Jones
Kingsport, Tenn.
-------------------------------

Are the 220SB and 230S heads the same and do they both accept the single carb mog manifold(s)? And is the single carb an OK hook up?
--Answer--
No they are not the same. The 220 SB heads have smaller ports, some are round and some are oval. I haven't seen any 220 SB ports that match up to the M180 intake size-wise. The 230 heads are larger ported and are better suited for fitting more precisely. It is also harder to match up gaskets (head) to fit the 220 SB heads.
-------------------------

My 2.2 with dual carbs and high comp head (that is for sale)
has the stock fuel pump and does just fine.
--------------------

I (coachgeo) also read somewhere to not use any Zenith Mercedes CAR carbs cause they leak to much off camber. Stick with Solex I think they said.

Also if you shave your head make sure you shim the cam towers to bring chain tension back to tolerance. Been there done that with a Mercedes style overhead cam.
===================
EFI

believe Rob Pickering has already developed an EFI system for the 404 - it's what he was running on his RockMog when we did the Rubicon. He has already solved the technical issues - no need to re-invent the wheel! Except for an electrical problem, it worked just great! (He was tapping one battery, and they were recharging unequally - I think that is now solved.)

The phone number on the side of his truck is: (719) 241-5419
--------------------------------

I just completed the trial run on our new fuel
injection system at the ProRock rock-crawling
competition in Farmington,NM. The system performed
flawlessly and made for a great weekend.

We have designed a throttle body system that bolts
onto the the stock M180 manifold, and uses a HEI
distributor.

Although we pushed it to the limits this past weekend,
I plan on doing some more testing before I feel
absolutely comfortable with it.

Rob Pickering
Colorado Unimogs
-------------------------------------

=============
LPG
.........I was reading through my manual and found that the M180 has sodium filled valves! That with the ultra hard seats make the M180 a very good canidate for LPG assuming you can get the compression ratio up to 10 or 11. LPG is also nice because they use mixers instead of carbs which can operate at any angle.
If propane were more available I would probably convert the mog since I have all the parts(except the mixer) from the landcruiser conversion including (2) 25 gallon tanks.

Take it easy,
Kerry Manning

404MoPowa

Ok, so what I got from that was EFI, which I dont think I will do right now. Duel carbs and free flow exhaust. Already have the free flow exhaust minus headers. And installing a 1965-68 230S sedan (body 111/1A) head that should gain me around 15 HP at higher RPM's Is this what you got out of it. I am really just looking for the top end I guess, so that I can tow on the highway, and maintain speed on inclines to a point.

I want that 170HP That would be nice!!!

404MoPowa

yep yep. thats what I got out of it.

Thought I would post what my search came up with though since Im no expert to be quoted.

Remember though Merc. stuff is spendy even from junk yards. Check on the EFI it may be same cost as used head?

404MoPowa

oh and dont forget.... if you maintain a speed of more than 55mph in a 404 for more than 45 min to an hour you "could" help to burn up the transmission!!!!!!!

They are tractors not highway drivers

NOTE: do a search on 404 Trannys here or see the FAQ Tech Sticky about them for more information

404MoPowa
404TrannyIzzues

well, I have maintained 55 for 2.5 hrs many times. I havent had any tranny issues. I am not sure any body realy knows what they can handle. I still want to tear down a burnt up tranny, and see if I can fit bearings instead of bushings. Any body got a tranny they want to send me. I'll split shipping and will bear the cost of developing the tranny.

404trannyIzzues

Nitrous, the poor man's supercharger :D
404MoPowa

here is some oldies with pictures and text to identify them

http://home-l3.tiscali.nl/~wnn367304/Oldies.htm

http://home-l3.tiscali.nl/~wnn367304/oldies/U404S.jpg

404.0 Doka

My guess was : 404 "S"wiss model

Others guessed most in jest:jester:

. Slo
. Spedition,
. Schnell-nicht!
. Smog

. With all the renewed interest in J.R.R. Tolkien's hobbit adventures, I decided the "S" in mine stands for "Smaug". The hobbit name for Mercedes Unimog is Gorbulas Foxburr of Loamsdown.

. Actually, i was under the impression that the S was for the Safari
model...the one ready for all weather conditions - the arctic and the desert. It had the extra piping throughout the engine compartment and into the battery box coming from the capped hole under the front skid plate where you insert the heater that sits on top of the cab on the radioboxes. I'm sure there was somthing else included in the S model but I can't remember right now. Mine's an S and has the proper storage under the box to house the heater with the long shaft.

AND THE WIENNER ISSSSSSS:

When the military needed a good 4x4 at the beginning of the 50's, they liked the 411, because of the perfomance, price and mobility. The only cons they remarked, was the speed. So Ma. Benz developed a longer version with a 220 gas engine. The military (french) asked for 6 units, so the order for the factory was a special one "S" !!!! So they called the purchase order 404 S.
Later, the military corrected the number from 6 to 60,000 and told Ma. Benz it was a typing error. Sooooo the production number was corrected, the bed kept at one foot longer, and the "S" stayed forever.

Bernardo of Argentia an avid Unimoger.


whatzwhatz
404FAQ

Read this little story of a Journey in a Unimog. Though it is not a 404 it will help you understand that they have a tracterish characteristic. Have you ever seen a tracter going over 55mph?

http://www.geocities.com/anto_jordan/unimog.html

ps. This particular Mog is a tad bit slower than usual. It appears to be a 421 with the slow AG (Agricultural) Axles.

404FAQ

I found this surfing today and thought it would be good here. Tons of information. Please note its a word document.

http://stevelaslo.xpreshost.com/mog/unimogoverview.doc

404FAQ
whatzwhatz