How much power can be made NA?
 

Is 100bhp/litre possible with the m113? What is the most power people have managed to extract?

I'm struggling to find info or builds where people have tuned the NA lump. 350bhp from a 5.4 is nothing really, it should be possible to get at least another 100bhp out of it, possibly more.
What are the limitations of this engine? I know it's only got 3 valve heads, but some of those yank engines put out silly power with 2 valve heads and push rods!

I'd like to build somewhat of a monster, enough to give a m156 a run for its money. I'll be doing all the work myself, even down to making manifolds.
The plan is to modify the inlet manifold, make 4-1 or 4-2-1 exhaust manifolds, port the heads, stiffer valve springs and a high lift cam. It will be run on standalone with a 6 speed box. A 7k rev limit will get it singing, I reckon 450bhp is an achievable number without going too crazy with the budget.

What are people's thoughts?

Don't waste your money. It will be very expensive and you probably won't get the power you want. Just got forced induction or buy a newer Benz. Take it from someone who has thrown mega money at cars over the last 30+ years. Forced induction takes all of the guess work out of the equation. More air in/out with more fuel = more power. If it was easy to make this engine breathe on it's own don't you think MB would have gone that route? MB needed 6.2L in the M156 to make 500 hp and you would need all that and more with this engine.

I don't believe that for a second.

I don't want forced induction, I'm not aiming for 600bhp+. I'm pretty set on building a NA monster.

The m113 has been proven to make 400bhp relatively easily on factory management. As I'm doing most of the work myself, the costs are greatly reduced. I'll only be paying for materials. The greatest cost will be camshafts, springs and retainers, followed by standalone management.

MB didn't need 6.2 litres to make 500bhp. They needed a new design to keep up with the competition, and also tightening emissions regulations. Technology moves on, the law of physics is a constant.

It's not about displacement; it is about airflow. 3-valve heads don't flow like a 4- or 5-valve setup, and the the single exhaust valve can only handle so much unless you are cramming air in through FI. You are looking at a major $$$ to make about 430HP; tune, cams, intake, full length headers. I have seen claims that you can push it closer to 450 adding ported/polished heads and a custom tune running on race gas on top of that. You are going to be in for at least $10-15k into it by then. For that money, you can run a Kleeman Komressor kit (around 500+ hp), or an M113K engine swap.

Of course they don't flow as well as a head with more valves. Yet you see chevys with 2 valve heads and pushrods putting out silly numbers on pump fuel...

Where have you seen someone put out 430hp? And where are these claims of 450hp? Links? Dyno graphs?
400hp is achievable just with manifolds and an exhaust. I doubt another 50hp would be too much trouble.

I don't think you understand when I say I can make most of the parts myself. It isn't going to cost me anywhere near 10-15k. Not even half that.
Cams - £1000p
Valve springs - £200
Management - £800
Materials - £300
Labour - free

I used to work in a professional race series. We would make about 500bhp from a 5.1 liter SB2 Chevy. This was a roughly $25-30k engine that ran on 103 octane fuel and was toast after about 400-500 miles at the most. The head flowed crazy numbers and you would stall it if you tried to launch at less than 4000rpms. Cams were crazy profiles as well. Valve springs were so stiff that cams had to be forged from a steel billet and then nitride-treated, and still wore the lobes quickly. Pushrods and lifters routinely wore down as well. This was all to get the redline up to 8000 rpms without floating valves. I don’t think that the connecting rods will sustain 7000 rpms for long. They had to be redesigned for the M113K.

Look up “Kleeman K3 M113” and you’ll see a great example of a N/A 5.4L M113 pushed to the limits of bolt-on gains; about 420-430hp. All this doesn’t even max out the airflow potential of the throttle body and maf. You haven’t addressed ported and polished heads or hours of dyno tuning, either. Kleeman and others put a lot of R&D into these numbers. Brabus took the cast iron 4-valve V8 and punched it out to 6.5L but still only came out with 450hp. The 5.8 they made from the M113 stopped at 400, just 70hp/liter. I would love to see you achieve your goals, but I know what goes into it and think you may not have a firm grasp of what really goes into wringing that last 5-10% of potential from a N/A engine with limited resources. By limited I mean anything less than a large shop with dyno, cnc equipment for making cams, porting heads, and either equipment or computational modeling to test airflow and velocity through several different iterations of header, cam, and port designs.

Edit: I have never seen a 450hp M113 N/A, but heard unsubstantiated claims that you can get a few more hp from these by porting heads and then retuning. It makes logical sense, but the only port jobs I have seen are really designed for the M113K. Supercharged applications are more about max flow and care far less about air velocity and scavenging than do naturally aspirated setups, so that might or might not work. Head porting starts at $3K from what I have seen out there, and runs well up toward $8k on the high end. 420-430 seems to be the high-water mark with just bolt-on stuff.

Agree with the comments about difficult to do and the good example of the racing engine.

Octane, compression ratio, fuel injection map and nitrous are avenues to explore before going to a full race engine. Sounds expensive, challenging and uncertain.

Thanks for the helpful post, yet I still think it's incorrect.

I don't how how long ago it was that you were playing with a sb2, but here's a link to a supposedly 844hp sb2. Well over 100hp/l for a lot less money than yours took to build.

https://rover.ebay.com/rover/0/0/0?m...2F392274531112

M113K rods were redesigned for lower compression and increased strength, not the ability to rev higher.

I looked up Kleemann's 55 K3. It's pretty basic and I doubt a lot of thought went into it:

55-K1(N/A): An optimized ECU software upgrade.

55-K2(N/A): K1 + a set of stainless steel tubular exhaust headers and downpipes.

55-K3(N/A): K2 + super sport camshafts.

So this gets us "Up to 435 HP and 585 Nm (433 lb-ft) of torque."

Pushed to the limits? Not even close.
I've seen posts online of their manifolds. They're mid length and the quality isn't great.
They also say their super sport camshafts don't require upgraded valve springs. Not exactly sporty.

So by actually putting a bit of thought into things, I reckon a great deal more power can be unleashed. I don't need fancy equipment or a million hours of test and development. An educated approach is all that's required.
Porting and polishing could have the ability to do a lot, but it's largely untested. I definitely know that the factory inlet manifold stifles things. That would be something worth addressing.

I really don't know where you're getting your numbers from. 3k for porting and polishing? Even if I put 20 hours into my heads it would only come out to £1000 assuming I was charging £50/h.
My labour is free. I only pay for materials. Its useless quoting prices as it means nothing (and your figures are crazy).

By trying to put a dampener on things, you've just reinforced my theory that the m113 can make power. Thanks.

Go for it and report your results back to us. I think you know the consensus now just go build it. Good luck!

Research Renntech E60. Much better flowing 4 valve heads and 6.0L.

We may be taking completely different meanings from "pushed to the limits". The M113 can handle crazy power and torque; I am referring to the maximum flow at real-world engine speeds of the head design on these. They just can't combine low- to mid-rpm air velocity with high cfm airflow without boost. This is why the previous-generation M119 often makes better power than the N/A M113 when modded. These design limitations are just what they are.

I wish you all the luck. Not trying to put a dampener on things at all, just having been of a similar mindset, 20 years ago or so, I went down the rabbit hole with more than one project trying to do things differently. It landed me a job as a mechanic in two professional series, so I can't say that it was't a valuable experience, but often practicality kept me from achieving what I originally thought feasible. I definitely would never hand-port heads again, unless I am just polishing a bit since they are off of the car anyhow, so when I quote that price I am talking about a CNC job that has predictable, proven results. Screwing up a port job and making one section too large can get you the big middle finger from Mr. Bernoulli, giving you an engine that has weird power peaks and a narrow band, potentially making it slower over all.

Tackling a problem when conventional wisdom says it isn't worth it is definitely what it takes to bring progress; unfortunately it just takes a lot more money and resources than most people realize. Again, best of luck to you; I hope that you find the end result satisfying. I look forward to seeing your progress; high cost of parts that produce moderate power gains is a real bummer for these cars and it's always fun to see someone show that it doesn't have to be.

Mercedes motors are super restricted in airflow and exhaust.

I am not an expert but Ive heard multiple places from reliable sources and friends who are technicians and enthusiasts that these motors are badly restricted. exhaust setup alone if done right is good for up to 30hp. Ive seen this on a w202 with a 5.4 swap.


I would be extremely happy with 450hp in my m113 with no forced induction.

They're mid-length because that's what fits best, the quality looked good to me too, I've certainly seen much worse for the price they go for. Even then, they're still a fairly tight fit. The steering shaft is quite close. Long tube's could certainly be made custom, but they still won't avoid the other constraints of the car (IE exhaust port to motor mount height, steering interference etc). I did manage to find a picture somewhere of a fully fabbed 2.5" exhaust, that had what most would call long primaries, but I still want to say they only claimed 40hp out of it, which doesn't really get you very close to your goal (and taken with a grain of salt, it was just a random picture found in Google image search on a Yelp page...).

If you're just after high-revving NA horsepower, go buy an E39 M5. I've driven both cars in anger, they are neck and neck performance wise. What the E55 lacks up top the M5 concedes down low. I chose the W210 for it's smooth, streetable power delivery and simpler design (and stupid cheap market price). The W210 is quite a bit lighter too, which is certainly something to consider in overall package performance.

100+ hp/L would be awesome (and mildly terrifying in one of these), anything's possible. However, if you look at the design philosophy of the M113, the main goals were better efficiency and fewer moving parts. It wasn't really destined as a performance engine, but blowers easily fix that. If you search on here, there are some very old threads by a guy who claimed excellent dyno results from disassembly of the intake manifold and LOTS of port work there. Unfortunately, I think all the pictures are long gone...but if you can walk your talk it shouldn't be too hard to find the hidden ponies in there once you open one up. Used intake manifolds are like $150 on eBay, so it's a rather cheap experiment. It's all about chasing 10th's, like you said. Bigger cam here, port work there, it all adds up...question is will it actually be enough and just how much effort do you want to put in, when you could bolt an OEM blower on for $2500 and be done...

this is mostly good advice, however. some of the record-setting m113 benzes are using N/A m113 heads as they have more potential when ported. i think it was ahmed or blackbenz who posted about this. just some knowledge ive picked up lurking these m113 build threads. i think i heard one of the fastest m113/113k's was built using n/a m113 pistons?

Probably since it would yield a higher compression ratio therefore more power.

Lot of misinformation in this thread. It is possible, but not without a 5-axis CNC machine and every single trick in the book.

‘All the bull**** that 3-valve heads can’t flow are incorrect. You just have to know what you are doing, and no aftermarket Mercedes company knows wha they are doing, they are a bunch of greedy lazy money hungry clowns compared to the LS domestic tuning world.

Are there any News to the topic?

I haven't begun yet. But 500hp+ should be achievable with 38mm inlet valves.

I've got a set of 50mm itb's which I intend to fit. I'm also going to make a set of 4-2-1 manifolds. It will be run on standalone and I'll be surprised if it doesn't make 450. Cams will unleash a lot of power, but whether I decide it's worth the outlay will dictate how much power I make.

And no, CNC is only as good as the person programming it. The only thing CNC achieves is repeatability. This is a budget build and port work will be minimal. I do plan on having a 3 angle valve job though.

Im really exitet to See the results.

To See a N/A V8 Manual Mercedes never realised they should have Made.

Wish u all the best and keep us updated!

What's the motor CI wise? ~331" ish? There's plenty of old school fords and chevys that make the power you're hoping to make. It's all in how hard you wanna spin it I think. Give it a bit more compression, bit more aggressive cam.. and spin the thing.

I will hopefully be swapping a slk55 with the higher compression into my car, and getting a set of catcams. Hoping to get 380ish maybe more. It’s current around 350whp and 365tq. E85 doesn’t seem to want to make anymore power. Trying to get a tune with more timing just haven’t had time.

Also Rennsport factory is developing m113 ITBs just have to figure out how to manage them.

Frankly, trying to make that kind of power is easy.. it's really not that much power these days. The issue is how much comfort/driveability a person is willing to give up. if that's not all that much of a concern, getting to where you want to be is frankly simple.

On the old school front.. I'm putting together a 406" SBC for a street car I have.. I've been worried about being too radical for my taste. It'll be a pump gas motor, but the cam is getting on the radical end for "street" stuff at around .650, but the duration at .050 isn't too hateful being in the 250's. The motor should make ~550 crank hp, but is going to be a loping mess... but should clean up at driveable freeway rpm's. ~2000 rpm.

But things to think about, it's a system, trans/converter/rear gear will start to be important to have the package work as best as it can.

I have a built trans and valve body, it’s definitely much harder to make power on an NA 113 than an ls motor or big block. Also how is it easy to make 400whp on a 113?

Power is power.. the platform doesn't matter per se. It's the lack of after market support that becomes an issue. But that's nothing money can't fix.

As the saying goes: Speed (Power) costs... How fast you wanna go?

Well you seem to have all the answers, how much power does your e55 make?

You mad bro? lol

Not that is matters, but sold my 06 and it was stone stock, looking for a W210 version now. But what I'm looking for it to do is far different than what your goals seem to be. What I can tell you our versions of "making power" seems to be very very different. An E55 isn't the platform I am using for my power vessel.