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!!

[Dearlove]

do it.......

also dont forget the ford and chevy heads only have 16 valves, not 24

get them to take a little but off the head to bump up your static CR

[taz069]

Reporting in. Head dropped off! A valve job is a must!! They sprayed what looked like soapy water on the valve surface and used a air nozzle to blow compressed air into the intake and exhaust ports. There were bubbles coming from around every valve, not a pretty sight. He did advise not to raise the compression, staying that other problems could insue. Seeing that it is already hovering around 10. So just going to listen to an expert on this. Valve job is $225, seals $25,cleaning and resurfacing $70. Once he gets started will find out more of the design if much can be improved upon. ie port and polish. As i stated earlier have a dremel and know how to use it lol. Seals to be in middle of the week. So possibly as soon as this friday can give you all an update. Thanks all have a great day.

[zmatt]

Yeah I was about to say, you don't want to raise the cr much more than that anyways and you don't know what your valve clearance is right now, so you don't know how much room you have to shave. He will most likely put the head on a flow bench and find out its characteristics. Can't wait to here the results.

[taz069]

On another note while the head is in the shop, started thinking on exhaust! Mine is currently running all stock. After 195+k I'm thinking the cats may be a lillte clogged. Since florida has no emmission testing was thinking about hollowing them out, just to free up the flow! Seriously!! Only have a past camaro iroc-z i did this to. Never had any problems or trouble codes. AND IT RAN ALOT BETTER!! How touchy might the computer system be?? As i mentioned the o2 will still be inplace and working. The cats just won't have the innerds. Free flowing!! lol. Any thought's?

[Dearlove]

Oh, please oh please get him to flow test it before and after the job is done, and get the print outs and post it on here!!! that would be awesome information!!!!!!!!!!!!!

[zmatt]

Doing away with the cats wouldn't hurt, but I would also think about the rest of the exhaust. The stock one is very very restrictive, even a cat back would free up some power. Since the head is off anyways, why not do the whole thing and get headers and a full exhaust done?

[taz069]

Here we go. The seals wont be in until the 7th of next month!! Sorry all! Will keep you posted, any ideas on the exhaust? Have a custom shop right down the road, 2 miles tops!! later supper time.

[zmatt]

can they do headers or just the exhaust? Might as well get the whole thing done since you are going through the trouble of head work. unhinged straight 6s sound awesome.

[strictlyspeakin]

Can't you edit your post?

[hvmercy]

PM Denlasoul. He can help you out.

And sorry, I don't know the moderator of this subforum.


sorry don.t know how to delete the misses basket making? Any clues??

[taz069]

edit and delte got it. Head picked up $350 later looks brand new!! Sorry have no flow #'s to post. Was informed by the shop owner if no other major mods were in the works that the german engineers were pretty much spot on. They did have to resurface the head a little more than usual, hence warped. So a slight raise in comp would be seen, not a lot probably less than 1/2 a cc. So from 10 to say 10.25+/-. Was informed that the car had been run hot at some point. Gave them the brief story of only put 18 miles on it. But at $800 purchase price if i spend $1500+ still on the good side of owning a great car with a new lease on life. The shop had also said to go thru my coolant system. Had that in the works already. The radiator was dropped off earlier in the week. Have already recieved the call that there was 30-40% blockage in the radiator. Water pump and thermostat are to be purchased soon. Just a little thing called cash flow, lol. Will send some pics a little later weather permitting. The misses won't let me bring the head in the house!lmao. Thanks again for all your time and patience. Still not done yet, sorry again for no flow #'s. Just going on a experts advice.

[taz069]

Hope these pics339340341342343 come thru good. Some of them are of other motors in the shop

[taz069]

I do know this is a 202 forum just could not resist. The one that say Sonny's on the valve cover is a 864 cubic inch chevy with a 4 stage nitros system. Was told with a torch it would fit the merc. lmao

[taz069]

Back to work on the project. The radiator was junk, so a new one is a must. Head is installed! Was doing the cam cap's when the last bolt broke before torque was reached. Finally recieved all 28 will be installing later today. Water pump ordered! Searching for a ac clutch now. Also will be installing new vacum hoses under the intake today also. Be safe all and have a happy Easter.

[taz069]

Update for everyone!! The lil c280 fired up last night! New water pump new radiator still gotta get the ac clutch. Cross drilled rotors and ceramic pads due in today or tomorrow. All on the up and up!! Thanks again for all the help!!!!:):)

[hipnimahop]

thnx for the posts, I learned New things.

[taz069]

bump

[zmatt]

Any dyno numbers? Is it notably faster after the work?

[taz069]

Sorry z no numbers. But when i do get it up and going it is definatly more noticeable from off the line and overall. Even when it kicks down to passing gear it revs super fast. Heaven help me when i run super premium and get the bugs worked out of my timing sensors(cam and crank). I had mentioned earlier working on the exhaust to free up a few extra hp. Just haven't had the cash lately. Have fun and drive on.

[Vetruck]

Taz- I see you mentioned you owned an IrocZ above- you ever slum on TGO (Thirdgen.org)?

[taz069]

Sorry to say no! They started getting into aluminum pieces then. One piece rear seals and different angle heads for the intake to matche to I can stand. They just changed the whole field for me. If you have ever heard of lingenfelter performance I'd check into that!! Built several motors by his standards and never disappointed.

[taz069]

bump

[taz069]

bump

[RobertCarew]

I might be next in line for this job...or a 3.2L swap...

[RobertCarew]

Ok I think I did it right??*
1-110
2-110
3-100
4-100
5-130
6-130
I just hooked it up an turned the engine over about 6 to 8 times. Is that the right way?*Seems odd 100. 110 .130.

[taz069]

How many miles on your car? This is just my opinion you might have some carbon build up around the vavles. Try running some cleaner thru the gas to remove some of that old gunk. Several peeps love using seafoam. Never used it myself and not for sure if it goes in the tank or not. Your variance I don't think is awful, run some cleaner and test the comp again. Did someone turn the motor over or did you do it yourself? I've always had someone do it while i watched the pressure gauge. I just never did it to my lil c280 since i new the head had to be redone.

[RobertCarew]

184xxx Carbon is what I'm thinking too so far I have used one bottle of seafoam in tank and one in oil...in oil cleaned the hell outta the engine and shut the lifters up real good! In tank it does pretty good I have another bottle I'm putting in today maybe that will do it. First test was just me numbers was scary lol didn't crank engine over enough....But I did an oil change and man it was SO BAD the filter was crushed and had a whole blown in the side ya think it could have built up enough pressure to force oil into the water at the o ring?? But I may not have it much longer....a buddy wants it bad...bad enough he wants to trade his 98 SL500 for it...it runs good needs a new front bumper. ..woman backed into and stuck the hitch into the bumper... so I should be in a SL soon for atleast 2 weeks till title comes in and I use it to trade up lol

[RobertCarew]

Ok I bleed the cooling system today...no more oil just a very few spots floating so that's good! I guess when the water pump was put on they didn't burp the system or anything....I checked the fans when unplugged at thermostat they cut on before bleeding the system after they didn't cut on when unplugged is that good or bad??

[taz069]

#1 With a fubared oil filter their would be no way, at least in my opionion of oil passing into the water passages. A pressure surge for sure if that is what caused it to rupture. I would think the pressure would only be related to the oiling system and not the coolant system. When was the last time the filter was changed?? Your engine has just had a lot of unclean oil circulating thru it!! Hence that is what a filter does, if your was broke???? It could be messy, could be maybe not. Now on the fans it might be that the coolant had cooled off enough not requiring the fans to come on.

[RobertCarew]

Well the sticker on the windshield says jan 2012 for oil change filter looked like it had 500,000 on it lol. I thought for sure today the headgasket went on the hwy...wife passed someone I looked in mirror seen a cloud behind us...heart just broke...rolled the window down and smelled tranny fluid got to where we was going stuck hand by tail pipe hand stayed dry and absolutely no steam at all popped hood water level was perfect. This is after 30 miles and sitting in traffic by the way....but have noticed when I'm hard on the gas on hwy I can smell tranny fluid burning I think it might be time for a fluid an filter change and headgasket might not be bad at all?? I mean honestly I have been trien to make the headgasket show its self but can't do it....and if in the process of that the engine goes.....3.2L here we come lol almost forgot I put a new ovp in the other day and today the fans came on low by there self so that made me happy traffic can be a biatch here lol

[taz069]

bump for js!