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JRE320
01-19-2004, 02:55 PM
I'm in market for some head gasket. Which of the following name brand that will last longer is it GOETZE,REINZ or ELRING? ;)

nokia8860
01-19-2004, 03:02 PM
I see we're all leaking now huh. I dont think its the brand but more of the design of the M104 head itself that lends itself to leaking.

Changing it doesnt even guarantee it will never surface again. Maybe we should do a group buy fix at zim for this so we can get it hella cheaper. :p

manny
01-19-2004, 03:08 PM
Has anybody ever considered getting the head " O " - ringed ?

nokia8860
01-19-2004, 03:11 PM
Originally posted by manny
Has anybody ever considered getting the head " O " - ringed ?

Hey now theres a thought!

JRE320
01-19-2004, 03:15 PM
Actually I'm looling into fixing my E320 1st. Yeah why don't we have a group buy and at same time do it Zim. It might be cheaper.. :rolleyes: ;)

Brabus
01-19-2004, 03:18 PM
How much is it to replace these days?? $2K?

pnsji
01-19-2004, 03:30 PM
actually does not matter what kind of gasket you put. It's just the engine is running really hot temperature and the changing between hot and cold really hit the gasket. Hot and high preasure oil hitting it all the time will definitely make the gasket fail.

I don't think a particular brand of gasket will do much better than the other. Going to a good shop will do good tough. Usually they give you at least 1 year parts and labor warranty for this kind of job.

JRE320
01-19-2004, 03:45 PM
Originally posted by Brabus
How much is it to replace these days?? $2K?

$2K!!! Zim is no dealer so I guess he charges a little cheaper.. :eek: ;)

jnolte
01-19-2004, 04:26 PM
Damn there must be some other way a more permanent solution to the rubber gasket that just cracks and leaks after some time. Anybody ever try installing a new head gasket on the m104 engine at home? I dont think it would be too hard if u had a manual and lots of time. but i have never really "tore" into a m104 engine to see how hard it is to take apart..

pnsji
01-19-2004, 04:52 PM
Originally posted by jnolte
Damn there must be some other way a more permanent solution to the rubber gasket that just cracks and leaks after some time. Anybody ever try installing a new head gasket on the m104 engine at home? I dont think it would be too hard if u had a manual and lots of time. but i have never really "tore" into a m104 engine to see how hard it is to take apart..

One of the reason the gasket is leaking is because the head itself is warped due to very hot and high preasure oil.
When the head is warped, changing the gasket itself will NOT solve the problem. The mechanic has to bring the head to a machine shop, resurface the head and use laser to make sure the head is straight.

jnolte
01-19-2004, 05:26 PM
Originally posted by pnsji
One of the reason the gasket is leaking is because the head itself is warped due to very hot and high preasure oil.
When the head is warped, changing the gasket itself will NOT solve the problem. The mechanic has to bring the head to a machine shop, resurface the head and use laser to make sure the head is straight.

that is just one reason.... is that worst case scenario?

MRP Motorsports
01-19-2004, 05:41 PM
Originally posted by jnolte
that is just one reason.... is that worst case scenario?

Mercedes has gone through a bunch of revisions on the head gasket. The new MLS should solve the problem. Also head studs instead of the factory bolts will help. It was kinda a residual problem from the M103. I believe MB even changed the bolts too. I was actually going over this very same thing with Pat from PGA the other day when we were talking about turbo kits and reliability.

manny
01-19-2004, 05:50 PM
Originally posted by MRP Motorsports
I was actually going over this very same thing with Pat from PGA the other day when we were talking about turbo kits and reliability.

So, what do you think about my O-ring idea ?
;)

MRP Motorsports
01-19-2004, 06:01 PM
Originally posted by manny
So, what do you think about my O-ring idea ?
;)

On a C280, may be? On a 90mm or larger bore (E320 or C36) there is not enough wall between cylinders. They M104 has a long narrow water jacket pass through between the cylinder bores.

You are better off with Head studs and an MLS head gasket. The studs will allow for better/higher torque and less stretch.

speedybenz
01-19-2004, 06:27 PM
So the new Mercedes head gaskets are multi layered steel? That is great news. How many layers are the gaskets, three? IF so then you could set the piston to head clearance a little tighter and pic up some Hp and combustion effieceincy.

MRP do you have any pics of the combustion chamber for the 3 valve engines? Also do you know what the valve stem diameter is?

Also JRE you will have to send me you cylinder head on penalty of death. I want to work on one of those heads in the worst way.

Jeff

MRP Motorsports
01-19-2004, 06:49 PM
Originally posted by speedybenz
So the new Mercedes head gaskets are multi layered steel? That is great news. How many layers are the gaskets, three? IF so then you could set the piston to head clearance a little tighter and pic up some Hp and combustion effieceincy.

MRP do you have any pics of the combustion chamber for the 3 valve engines? Also do you know what the valve stem diameter is?

Also JRE you will have to send me you cylinder head on penalty of death. I want to work on one of those heads in the worst way.

Jeff

I don't have the specifics on the current head gasket in front of me. But I will research it. I don't have any pics of the 3 valve heads. Actually MB is going back to a 4 valve configuration. The 3 valve configuration on the W203 was more for an emmisions benefit. On the M104 the valve stems are 7 or 8mm intake and 9 mm exhaust. The exhaust is sodium filled and the intake is a black nitride coated valve, probably stainless. An M104.981 head flows 258 CFM intake and 189 CFM exhaust at 28" water. These were the M104's highest HP engines for dispalcement 234hp at 3.0L, in U.S. trim (cats, resonator, bla bla bla. According to the head numbers on the flow bench it should produce about 250 Hp NA from 3.0L from the factory with a open exhaust. This head will be flowing well over 300 CFM whe completed.

J Irwan
01-19-2004, 07:10 PM
Originally posted by MRP Motorsports
Mercedes has gone through a bunch of revisions on the head gasket. The new MLS should solve the problem. Also head studs instead of the factory bolts will help. It was kinda a residual problem from the M103. I believe MB even changed the bolts too. I was actually going over this very same thing with Pat from PGA the other day when we were talking about turbo kits and reliability.


what is MLS.?

Regardz,

MRP Motorsports
01-19-2004, 07:46 PM
Originally posted by J Irwan
what is MLS.?

Regardz,

Multi-Layer Steel

speedybenz
01-19-2004, 08:54 PM
Suzuki is running 5mm valve stems on there big bore engines. The intake valve is 36mm in diameter. I am thinking if I pulled my c43 heads I would get some new valve guides made and then use a intake and exhaust valve with a 5mm stem. It would allow much faster cam opening rates due to the reduced weight.

Suzuki is reving these single cylinder engines to 10,500. They have a 94mm bore and 65mm stroke. The shorter stroke allows for the higher rpm limit.

MRP do you have a guess what Mb is using for a piston to head clearance? I would like to use0.030" to 0.035" if I had good rods and 0.040 with stock stuff. I am guessing MB is running about 0.080" or so stock.

Another thing the Japanese are doing is going to very small ports with very high air flow velocity. This Suzuki engine has an intake port with the choke area only 65% of the valve diameter as compared to 80 to 85% for engines built just a few years ago.

This is something I would also do to my heads. I would reduce the intake port choke area down to 65% to speed up the air flow.

OK I will stop before I digress into total geekness.

moebiusgold
01-19-2004, 09:57 PM
I think .030 is pushing things. If you are confident of the spring pressures etc. I quit blowing up Chev SBs when I got over .090. It's not like you just bend a valve most of the time.... It's a pain putting clay in there, assembling everything, rotating it, dissasembling everything. So, this means you're going to put new cams in it? They are way $$$pendy. Not like you can call Comp Cams or anything like that. Bike engine intake ports are very straight. I hate being able to look down my Honda's and see black yuky deposits totally coverying the back of the intake valves.:( Well, good luck! Degree the cams first and take lots of pics so we (I) can drool.

MRP Motorsports
01-20-2004, 06:30 AM
If you need cams you can have them hard welded and cut. Then have them induction harded and/or plated. This very common in racing circuits and very reliable, and the hard weld is harder than the factory casting or billet.

The head performance has more to do with geometry and port angle than port size. Port geometry and port angle are most of the time dictated by Hood clearance; more so than optimum performance. That is why the M103 and M104 engines are slanted 15 degrees and MB went to V configurations on the newer modeles was for hood rake, although the straight 6 is a smoother engine. The M104 head is ver simular to a Supra head, and borrows technlogy from the Cosworth 16 vlv head. That is also why the boxer engines of Porshe and the WRX flow well fromt he factory, no hood clearance issues.

You can get guides for 5 mm valves, since the 5 mm valves are becoming more common in automobile engines. I can get 5mm black nitride stainless valves that are CNC swirl polished and under cut on the back side. If you want to run Higher RPMs and closer tolerances you also need to look at converting to solid lifter buckets. You also need lash caps and consider lash in the cam design.

The OEM valves in the M104.981 head have 8mm valves, but they are back side under cut and polished with a black nitride coating. The sodium filled exhaust valves are ideal for running high compression and boost. They flow very good from the factory and are very robust. The factory head components are good for 7200 to 7500 RPMS.

My porter can increase volume and velocity and most of the time not increase port diameter. It is also important to look at the desired RPM range the engine is running.

Rule of thumb is; Increasing velocity will give you more torque and volume will increase HP. Chocking down your ports will give you better throttle response and torque at low rpms but it will roll off quickly as the RPMS build. You are better by not changing the port diameter and rather change the port angle and bowl area. also unshrouding the valves by running a bigger bore will help. Valve seats and angles here too can improve the flow into the combustion chamber. Look at narrow valve guide protrusion into the the bowl.

You want to increase volume and velocity the same time. This is the trick that make head porters magicians. Just knowing what it takes makes me dangerous engough to not do it myself and contract it out to a pro. My porter has a BSME and all he does is port heads, mostly race engines. I pay for his experience.

I think this is a very important modification. Make sure you interview whoever you decide to have port your head and possible speak to a few people. You need to know if they just grind metal or understand flow dynamics, hig performance engines, and metrology.

speedybenz
01-20-2004, 09:43 AM
MRP,

Thanks for the advice. I went through a lot of what you have said starting some 14 years ago when I first started building engines. The current GSXR's Suzuki's I raced and built until 2002 where pretty damn good on the intake ports, but I saw a lot of guys make there bikes go much slower after doing port work which increased the port sizes even by small fractions.

As you can see from the pic below of my C43 intake port it is almost a constant cross sectional area all the way to the valve. This type of configuration really never speeds up the intake flow to where you get good cylinder filling after the cam rotates past BDC. If you can keep the intake flow velocity very high it can overcome the potential reverson of the air in the cylinder as the piston come back up the cylinder toward TDC.

Also what I and others have found is that you can get the intake flow velocity to or above Supersonic speeds and it will help fill the cylinder at all engine speeds, even up to 14,000-15,000 rpm's.

It goes counter to what lots or most of the engine builders will tell you is good, but I have built and seen too many examples now to know it works. I don't really think the flow velocity ever gets to Mach 1 due to turbulance, but then it would only occur near max. lift on the valve. After that the air flow would slow down some but still keep a very high velocity and this is the main advantage. That very high velocity can really push large quantiies of air into the cylinder even as the piston is coming up towards TDC. And because of this you can degree the cam to stay open longer than you would normally to take advantage of the extra air flow capacity.

But I have also seen ports configured in the convenional sense work very well also. However using the above method still ends up getting you an extra 7-10 percent through most of the powerband.

Good discussion

Jeff

http://www.joeyandmona.com/albums/speedybenz-c43/DSC00556.sized.jpg

MRP Motorsports
01-20-2004, 01:34 PM
Jeff,

I can see where you are coming from and what you are describing is the venturi effect, a valid and effective concept. I almost never agree with increasing port size unless the velocity is maintained or increased. By increasing the port size on a bike you are effectively robbing it of torque. When you something away from nothing you get nothing. Meaning bikes have very little low end torque to begin with. The operating range of a bike is quite different than a V8 or Str8 six for that matter. Street bikes are short stroke large bore configurations typically. This is more similar to a F1 car that runs short stroke large bore bore configurations. Thats is how they create 800+ hp from 2.5L of displacement at 18,000 to 20,000 rpms.

When I design a head for a specific application I start by maximizing the raw casting of the head, Select the valves that support the flow capabilities, have a cam profile designed to operate in the desired power band, and then design the manifolds to support the flow characteristics.

Reversion is a bit more complicated and involves piston velocity and exhaust pulse tuning and the correlation to valve timing. It really has nothing to do with porting or polishing a head.

5.52
01-22-2004, 07:02 AM
Greetings- suggest using updated MB OEM part only.

Here's my experience with M104 in the '94 E320 Coupe: >headgasket replaced by SF Factory Authorized Service with updated part at around 60k on the odo 4 years ago.
>result to date at 116k= no leaks or weeps with Castrol dino 20W-50.

This experience is based upon SF Bay area climates (not to hot and not freezing temps) and very light duty use on the vehicle (less than 100mph freeway and no stop light jackrabbit launches)


hope this experience helps
5.52

JRE320
01-22-2004, 08:29 AM
So what's the OEM part number? :confused: ;)