C55Newb121

I have read several places where people mention doing everything they can to the N/A 55, but I can think of more things to do.

This of course might be biting off more than most would want to chew, but has anyone flow tested the stock heads?

I know that with the 3 valve design, flow is going to be limited compared to a 4 valve design. I wonder what kind of improvements we could see with a port and polish.

Also, while the heads would be off, why not shave a bit off and bump up that compression from 11:1 (correct me if I'm wrong) to about 12:1?

sultanC36

now that sounds intresting
ur a previos LS1 owner it seams thumbs up , we both will have a lot of talk together

C55Newb121

Nope. I wish mine had the LS1. Haha. I was stuck with the 92. I only had the 305 with the TBI. The engine was a dog from the factory, but I remember one guy in particular who built a wicked 305, although he may have been at 335.

Either way, the concept is the same. You could gain some awesome numbers from head work.

I think it would be the same concept with the C55. Port and polish the heads and we'd be looking at some awesome numbers, especially since the head design isn't the greatest to start with.

Do that, and bump up that compression and I think that engine would feel like a entirely new animal.

Hell, I remember Car Craft (or one of those magazines) building a 500 something hp 5.7L engine with just some bolt on parts.

If this car wasn't my daily driver, I would be willing to pay for a port and polish job on the heads to see what kind of numbers we could get. I would end up wanting to get them milled while they are off to increase the compression though too. So, it wouldn't be the best representation of which one is adding the most power.

TemjinX2

I think it would be interesting, definitely the road less travelled. I know the c63 guys are putting down crazy power just from long tube headers and a tune.

sultanC36

i wish we had that sort of info here on this forum , and if one of our suporting dealers , tuners can provide us with this info from the cars that they tune and modefy , i went up from 664WHP to 798.5 WHP with a head and cam swap on my vette ,at the same boost presure , the old heads used to flow 290CFM the new ones flowd 380CFM and thus the power jump .

i know that on our cars there will not be such a huge jump , but i think there is more power to be had with these motors from such work maby 30 to 40 whp

C55Newb121

Well, I plan to look into this. One of the problems I have is that this car is my daily driver. In order for me to do this, I will need to keep my eyes open for spare set of heads to work on.

Either that or I need to buy myself a beater car.

MRAMG1

I can not say anything about the C55, but it has been tried on the C32 with little to no results.

Check around and you will find it.

PS: These cars are NOT mass produced as you know, and the heads from the factory are pretty darn good. You could defiantly get some gains using undercut valve stems, and a GOOD clean up espically at the bowel. But I would bet a large sum of money that it would net less than 30RWHP for a cost of around 2K.

Sorry for the bad realistic news here.

MRAMG1

I picked up about the same gain on a Whipple charged stang. Stock head to an AFR CNC head.

Keep in mind that the C55 is a N/A motor. Which makes it a whole deferent ball game.

C55Newb121

Yes, but comparing gains on an engine like the LS1 heads over the AFR 195 heads, there is a nice gain in power.

Even if it was for research purposes only, I would be really curious what kind of flow rates the stock 55 heads put out.

There really isn't anything that special with the MB heads. Any company that does a good job on V8 heads will do a good job on these heads.

The baseline numbers would really determine if it is worth doing some port work or not.

Has anyone looked at how well the ports are matched?

sultanC36

Port matching is very intresting ummmmmmmmmmmmmm

PTE

You can do a search , under my avtar. You can not remove much material from the cylinder head. These motors are built so close & tight , I have removed .005 just to clean up the surface , after Porting the heads. Have fun reading . Cheers _PTEngieering

C55Newb121

Wow. Those CFM numbers for the stock heads are pathetic! What were the test conditions?

When you ported, was it a hand port or a CNC port?

https://mbworld.org/forums/clk55-amg...-pictures.html

CerBErusM113

Sorry to revive an old post but did anything ever come of this project? I've been reading up on it a bit the last few days.

amgen

A fellow countryman ported the heads on his C55, but he built LTH at the
same time. If I remember correct the crank output was approx 430 hp,
without a tune!!
The important thing is if I remember correct he complained over the rough
edges in the AMG-heads, he was very surprised over the rough casting,
there is obviosly a lot to do there.

He writes here occasionally, drives with a modified SC today.

CerBErusM113

Thanks a lot for the feedback Amgen. 430hp doesn't sound very impressive but pretune does give me hope. Either way if you happen to remember his sn. Please let me know, definitely would like to pick his brain on the approach he took to porting.

EDgineered

Sounds like "Swedepat" 's car. He cleaned up his ports. There is a thread somewhere with the info and pics.

amgen

Swedpat is the name.