Newzchspy

Unless it was on a dyno, the benefits of a tune for the NA C55 are negligible. The top end rush you feel is the exhaust work.

tw2

Do you have any before and after shots of the heads? I have seen the after shots in another thread you posted in. Thanks.

Quickvr4

Obviously he wants to mod it but isn't there a way better option. I guess if he prefers, less reliable, older, less power, then modding his C55 is the right way to go. Can't argue that.

tw2

I guess I agree. At this stage of the game a full supercharger kit might not be worth it unless the car is pristine with low mileage. I think they are definitely still worth some headers, cams and an intake.

betrezra

I've had fun with my clk55 eaton build. Kleemann did the install, and with my basic tools I keep it maintained. I prob would not rec this mod or any blower for people who don't want to wrench a little.

This is my hobby not my 100% daily driver so that makes a little difference.

Gl

scrwmpwr

r172 motor swap

wawy

What style of supercharger does Renntech use for the NA 55 engines? Autorotor, Roots or something else?

Newzchspy

Cant use Autorotor since they no longer make them. Last one I' ve seen (Autorotor) is a used in box last year for about $6000.

swedepat

I belive i posted beforeshots on inlet.. i didn´t have any pics on exhaust.

91RS

There really isn't much out there about the Renntech unit. It looks like is made by Lysholm. One thread mentioned it as being inbetween the Autorotor and Eaton for efficiency.

tw2

Sorry to be annoying but I am interested to see what the stock ports look like. I found this one https://mbworld.org/forums/5582012-post8.html which had the after porting shot (looks great BTW), I searched through your posts but could not find the before. If you had a link I would appreciate it.

swedepat

wait a second... i might mix up my posts with a swedish forum,, i´ll have a look.

swedepat

There´s a before pic that i posted in a Swedish Forum called 'Zatzy'.

tw2

Thanks, it is a bit rough around the edges in stock form but pretty much what I expect from mass produced parts. Here is the after photo again for anyone wanting to compare side by side.

swedepat

These edges you can see in the ports aren´t the whole problem.
First, the edges can be up to 2mm big.
But what´s worst, the short radius down to the valve is really really a joke.
The radius in the floor down to the valve that is.
Really really destroys flow with bad short radius.

tw2

Is the stock short radius quite sharp? Does it need a much better curve? Keep the air flowing rather than slowing down and speeding up again? Sorry my porting knowledge is not great.

swedepat

It´s very rough and un-even, almost like a staircase.
And the edges you can see in before picture is all the way around the ports.
Fix this and a nice valveseatjob och grind a backcut on the valves then you got heads that support a lot of power, and gains quite a bit.

Can´t say exactly what gains there are, i´ve read about 20-30hp depending on setup.
With big camshafts there´s a lot more gains.
But, this is ofcourse depending on the setup.

swedepat

Found an another before picture.
In the most important area to get proper VE in cylinders you need to 'diffuse' flow over the valve to increase pressure, this will fill the cylinders better as the earlier areas in inlet is to build up speed and flow in the gasses.
The speed act as an flywheel, and the air keep moving even after the pressure is even in the inlet and cylinder, can you make the pressure higher in the inlet then you will ill the cylinders better.

And the most important area is,, just underneeth the valve upstream from cylinder.
And Mercedes/AMG finds this sharp edges good enough..

I say.. nahhh.. things can improve a lot.

tw2

Very interesting. Its a shame the heads are not the easiest things to quickly take off and do a port job. I would hate to think how much an engine gasket set costs.

swedepat

But it´s well worth it.
I money i spent here in Sweden about 220 dollar to lift the heads.
If your gaskets are okey at valvecover and inlet/exhaust.
the only you really need to change is the headgaskets and new valvestemseals.

and i got ~110mph+ at 1/4mile with no ecu tune yet.

EDgineered

to lift the heads? or just talking about cost on tools to port them? Thanks

swedepat

the cost to 'lift them off and mount them back'.

I did the porting myself = freebie

tw2

I think it is the cost of head gaskets, valve seals and any other non-reusable items which need to be replaced when removing the heads. Do the head bolts need replacing?

swedepat

yes it does, they´re scrap after used them once.
and yes,, it was only cost in material needed to lift the heads.

Rgds.