1996 c280 head work

[taz069]

Morning all. Here we go. My lil 96 c280 headgasket let loose with only 18 miles put on car since purchace in October. No biggie, only paid $800 for the car and new it was a fixer upper. Will be pulling the straight 6, 4 valve head and taking to a local machine shop for some tunage and valvle job. In reading some other threads noticed some are swapping out the 202 motors for more cid motors. Wanting to stay with the 6. Was hoping to get 35-60+ h.p. from the head work and valve job(3angle?). This will still be a daily driver so most of the upgrades will be bolt on. Cold air? Not for sure on this really don't want to increase noise factor, now a k+n filter is a go. Intake? Would one from a amg fit? Would it be worth it hp wise? Now the exhaust. It has Leistritz exhaust now. Would there be a need to upgrade? Later will add a chip. Going to use the stock cams. Just trying to squeez the most outta this lil critter without sacraficing miles per gallon. Might anyone have a clue as to how much hp can be gained with these mods? Hopeing for a total of 100- 150+/-. That added to the factory 194-200 I feel would be quite a good increase. Just don't want to blow out the tranny or rear end, since the car and 195k on it now. Any suggestions and input are eagerly welcome. Thanks all and glad to be with you.

[Sulaco]

as an owner of a 1994 c280 for 12 years, I can tell you you're asking alot. The m104 straight 6 is one of the most durable, bulletproof, reliable engines ever built. However, not many options for upgrading the power. Though, I can say I've never heard of anyone doing any headwork like you're planning. I bet that would definitely help. Its what amg did in the c36 to squeeze more hp out of it. They also increased stroke (and maybe bore, not really sure yet) by using a different crank to bump it up to a 3.6l straight 6.

K&n is risky. The oil on it easily gets downstream on the mass airflow sensor. That's a pricey sensor.

Exhaust options are out there. The leistritz manifolds are stock and are superb. No idea what kind of gains come from performance m104 manifolds. Probably pricey, though. Everything behind the manifolds is easier to find, and does offer noticeable hp gains. I've heard 20-30 more hp is realistic. I think anyone claiming to have a chip or reprogram for this car is selling you hot air. Never heard of anyone getting any extra power that way. The preupdate w202 is obd2, but there's not much hidden away in the computer.

As for engine swaps, its very very easy. Plug and play. however, only 2 other engines would work: the 3.2 from a 94-95 e320 (240hp), or the very very rare 3.6l from the c36 amg (275hp). Emphasis on very rare. If you found a crashed c36, I'd honestly buy it and use the c280 as a new frame and body to rebuild the c36.

You'd have to break 400hp to cause any trouble with the trannie

[zmatt]

Don't do K&N, they don't give you any performance and the oil even when done right doesn't play with out Bosch MAFs. On a motor with stock compression you wont get 60hp from headwork. If you want to build the motor you are better off getting the 3.2L which slots right in and is plentiful in junkyards. The extra torque will be nice and with a good intake and exhaust its a poor mans C36. If you want to do an NA I6 build I would grab a 3.2, have custom headers fabbed, a nice exhaust, intake, some custom cams would really help and I would also have ITBs made. You will need a standalone ecu to work with the ITBs and Cams, but a good tune will also get you some power as well.


Only then would headwork be a good idea, I haven't seen flow data on the M104 head, so for all I know it already flows well and doesn't need any work. All said and don't that NA build would get you more like 80HP more at the crank. 150hp is very optimistic on an NA build with a stock bottom end. If you want those number you need a built motor, I mean custom high comp pistons, balanced and blueprinted crank, forged con rods, really hot cams and a loud ass exhaust.

A stock 3.2L M104 makes 220hp at the crank so all said and done you MAY get 300 at the crank if you don't build the bottom end. Which makes a lot of sense when you think about it. The mods I outlined will do similar work to what is in an M3 straight 6 and look what it does. Of course the big difference here is the M3 revs to 7900rpm and you wont. The M104 is torqueier than the M50 and lower revving.


If you want big power you need to go turbo. There have been many turbo M104s over the years and they have made huge power.

[taz069]

Thanks Sulaco and zmatt. All of these new terms and engine #'s are a little greek, but a very fast learner here. Just used to chevy 350's. Have built a few of them. On the compression ratio side. I believe the m104 already hovers around 10:1. hence the premium fuel recomendation. Please understand I'm applying what I've learned with chevy motors, and the mercedes is totally new. I will check into the flow caracteristics of the 104 vs the amg. That is a very welcome thought. Like i don't spend enough time on this.lol Just ask my girlfriend. lol

[zmatt]

SBCs are a different beast, but the same basic principles still apply. I know heads are a big deal in chevy world but I think you can get a lot of power out of sbc head jobs because they are OHV and respond very well to big valves and ports. OHC engines are different. Head work is always a good idea, but it isn't normally done until many other mods. OHC heads flow much better than OHV ones so it isn't as necessary. 10.1 sounds high, but it really isn't for a modern motor. Honda motors can be 11 or even 12:1 from the factory if you get into Type R stuff. Nobody to my knowledge makes cams for the M104 so you will need to have custom ones made. I would find a cam guy who knows a lot about OHC engines, you will probably want a regrind on the oem cam, this isn't race stuff so you don't have to get an all new cam. If you do go that route, by all means share the specs with the community, I'm sure there are lots of users who would like to know about it.


Like I said before, for real power in the M104 people tend to go turbo
http://www.youtube.com/watch?v=hZBftsXi0yA

http://turbobandit.com/shop/
http://turbobandit.com/shop/?artnr=166&cat_id=97
http://turbobandit.com/shop/?artnr=164&cat_id=96

Leave it to our nutty European brethren to make shit for the car. I didn't think anyone made turbo kits for the M104 anymore, but they do. If I were you I would get their turbo manifold which looks to be a very nice unit which will fit garrett units and have a local tuning shop help you with the build and tuning. Buy American, use a Haltech ecu lol.

[taz069]

10-4 bud. Was looking at some #'s on that flow thing. One posting mentioned getting an extra exhaust cam and have it reground, for the intake cam if done later will share specs. All Cams,gears, timing chains, etc , all can be done after the head is reinstalled. While the head is off just figured it would be best to have some finite tweaks done to it, will not pull it off again once it is put back on. I do believe it will be a chore. Only want to do it once. Just waiting for my haynes manual to arrive before tear down. 3-4 more days and the project begins.

[zmatt]

Well if its one of those "while its apart" things, head work certainly wont hurt you. A mild port and polish will free up some power on the top end no doubt, I just wouldn't keep my hopes up for more than a few HP at this level of tune.

[taz069]

Yep it is one of those while it's apart deals! Spend some now and enjoy. And not do all the other things and say I wish I had worked on the head while i had it apart. Like base ball got to hit to get to first base. Thanks again to all! This is a wonderful club will do all i can to help and better if possible. Be safe and Drive On!!

[taz069]

Morning all! One more tool and the head comes off waiting on the zxn 12 point 12mm. Well in my teardown have found a few more items to be replaced. The water pump makes a skreeching sound in one spot when turned by hand and feel's magnatized???? And the ac compressor clutch has come apart/seperated, never seen this before. The part that the belt rides on looks good just the front piece=new one more than likely. My question is this. In doing some searches in different forums have heard the cams must be at tdc. But in a manual it says 30 degrees before tdc. What should i do??? I Do not want to mess this part up. The cams are to come out either today or tomorrow. I do know about the chain tensioner. Just wondering about this tdc issue. Thanks all.

[zmatt]

When taking out and re installing cams I would go for TDC. There should be a timing mark on the end of the camshafts and on the crank shaft that shows TDC. When you put her back together you have to line those up if you don't want to crunch your valves.

[taz069]

Intake off god what a chore!! Hope the pic show up!!

[taz069]

If anyone can help with a dowel pin removal it would be greatly welcome!!!! Have a 6m 1.25 thread that i have to find. Maybe that is correct! It's for the pin that holds the timing chain rail in place that is attached to the head. Of all the articles I have read non mention the size of the bolt. They have a ton of pics just no mention of the size, of the dowel pin threads. Thanks all. This is my only hold up !! Don't want to retap it to a different size (standard)

[taz069]

Gonna remove the exhaust tomorrow!!

[Dearlove]

looking at getting custom cams made, ill keep you posted

[taz069]

Found the link!!!!! It is one of the thermostat bolts!! Taking it to ace to find a 10.9 grade don't want to hear it snap off in the pin? Got my fingers crossed !!!! Hope to have the head off this evening. As soon as i find tdc, using the markings on the harmonic dampner and the 4mm pin guides on the cams. Will take a pic when i get that far along. Later all and thanks again!

[taz069]

Some more pics a coming

[taz069]

fighting with my droid x now to down load!

[zmatt]

lol having trouble?

[strictlyspeakin]

following with interest...

[taz069]

The head is off! !! Taking to the machine shop this Saturday. Cleaning parts and getting some things ordered now will keep you all posted.

[Dearlove]

looking forward to seeing what the shop says about the head design on these things/ how they can be improved

[SD202]

<3 M104's Deffinantly want to know what you can squeeze out of her with just a little head work.

[Sulaco]

I may be driving a C43 right now, but my heart is still buried in my 94 C280. I can't wait until I have the time/money to fix her back up the way she was when I bought her. I'm keeping a close eye on this thread for possible HP boost...

[taz069]

Some sad news here. Finally got to talk to a rep that could verify some prices on porting and polishing. $800 to start!! I believe when the dude heard mercedes the price wentx3!! Chevy and Ford heads are in the 300-800 dollar range, with port and pollish included. So sorry to disappoint ya'll just can't afford that now. Will have to put my faith in german enginering!! Will be taking the head for a resurfce and other stuff. I am truley sorry. Not a money bag here! Just a on a super tight budget.

[taz069]

But I do own a dremmel and have polised a set of chevy heads before!!