jaxtheax

So i am in the process of rebuilding the engine on my 2001 Mercedes CLK55, and i am on the hunt for new pistons!

But there is a downside...

Cost for 8 pistons.
Local Mercedes Dealer - $7992
Mercedes Salvage Yard - $1920

But i have a solution! I found aftermarket pistons at summit racing, the specs seem to be the same as the CLK55 but should i beware that they arent "OEM Mercedes" pistons?

Heres the specs.
Bore (in):3.819 in.
Bore (mm):97.010mm
Piston Style: Dish, with no valve reliefs
Piston Material:Hypereutectic aluminum
Compression Distance (in):1.325 in.
Wrist Pin Style:Press-fit
Pin Diameter (in):0.945 in.
Piston Ring Thickness:1.50mm x 1.50mm x 3.00mm

For the price of $220 for all 8 pistons

What are your views on this?

Pauljay

Sounds rather cheap ($27 PER piston)!

Maybe because labour charges will be intensive? What's the gain aside from price? I would be boring my block if I were going for new pistons, if the engine is open already I'd upgrade everything including cams!

jaxtheax

Im not really worried about labor charges, im doing all the work myself
The only gain is price, i dont want to spend more money on pistons than i did on the car and i am currently rebuilding the engine

suicidal4life

Pretty sure the bores are alusil which means they require special pistons or replacing the bores with cast iron sleeves. There have been a lot of discussions about it over on the W211 AMG page.

betrezra

Can't you get a complete engine off ebay for <3k?

Then you have some genuine spares.

blackbenzz

You want CLK55 pistons? I should have a set. Also should have a E55 set if you want to drop compression. Both are used. Let me know if you want me to dig them up.

GatorMB

There are quite a few variables here to consider,

I was aware the later model AMG engines had special coatings or treatments to pistons and cylinders and the forementioned alusil cylinder is no exception to the rule.

OEM cylinders with cast pistons will have a smaller piston to sidewall clearance than forged (SC, Turbo). The dissimilar expansion rates of the two pistons are dramatic.

The forged piston is preferred for performance use but an AMG specially coated or treated piston will perform and last better than any cheap cast aluminum.

I am interested in the Hypereutectic aluminum pistons you found , I used to shop Summit on a weekly basis when building drag engines.

I am interested in manufacturer and manufacturer process, (Forged or Cast). The build sheet should provide a recommended piston to wall clearance.

A lot of other measurements to analyze as well. A good engine parts guy with a lot of time could probably find a cross. Honda rods are best for Small block chevy in racing applications.
do you have a part# or quick link? Wrist Pin Style:Press-fit pasted from post. The M113 55 AMG is bushed or floating.

Gator http://en.wikipedia.org/wiki/Alusil

da_guitarist

I'm all for boring and going bigger if it's open! You can probably get to 6L pretty easily and then use higher end aftermarket. Under the price.

Has anybody done this aside from Brabus? Curious if there are ECU or other issues to hurdle.

Chadzu

I'm curious as to how exactly you plan to overbore a m113? Not picking fights or anything just curious.

GatorMB

I briefly studied the WIKI on Alusil a compound of aluminum and other metal + silicon which is strong and highly resistant to carbon corrosion.
If the cylinder is cast with the compound boring is ok.
If it is coated or molded in layers boring is not ok.
Boring might require increased cooling system capacity for street use and cylinder test for bore consistency from top to bottom, (x-ray and deck alignment).
650 - 700 hp is a lot of hellcat from this chassis and engine combo.

Piston Material:Hypereutectic aluminum is mentioned in the WIKI and this post, These pistons are still worth researching for street use, possible race.

Pistons can be machined for floating pins if the manufacturer provided enough to work with.

Gator

jaxtheax

Ill PM you

GatorMB

I found this link in the WIKI which is kind of what I was trying to explain.

http://en.wikipedia.org/wiki/Hypereutectic_piston
It seems they are better than the average bear pending the coating and wrist pin style desired.
I am all for floating as any race engine builder will merit but moderate performance use in the street will likely never know the difference.

Blackbenz is the foremost king of M113 I have ever seen, Glad he is paving new paths with this engine and chassis. creeping up on 9 sec.
good luck with the build, keep us posted.

Gator

betrezra

The serious e55k guys are building sleeved 'built' motors for hp/tq weistec boost.

They one going in at euro charged when I was over there getting a tune on my ml.

cm60k

+1 with big vote..

ZAYED,,

Chadzu

Interesting read on the blocks. They may be more rebuildable than I would have thought. I ran across a thread that stated KS has a .5mm over piston set available. Not a displacement builder, but it would be nice to have a fresh motor at some point in the future.