e500slr

I'm curious, how are Weistec forged E55 pistons installed? I thought these engine were not rebuildable because of the coating on the cylinder walls or am I misunderstanding....

hachiroku

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SICAMG

OK so a normal hone for the rings used and your good to go?

hachiroku

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BlownV8

Some serious misinformation here. Do a search on the Internet or this forum for Alusil engine rebuilding. The engine bores do not have a coating but the pistons require one. You can either use coated pistons or have your bore coated in nikasil. You can't run uncoated aluminum on aluminium.

Yacht Master

Not true
Not true
NO
Not true

e500slr

Would you care to elaborate?

Yacht Master

There is more to it than a "hone" to recondition a block/cylinders.
The most important part is to relive or expose the silicone.
The M113K can be rebuilt, reconditioned or have cylinder liners installed.

http://www.electrosil.com.au/KS.pdf

TheTherapist

The aluminium is chemically bonded with silicone then chemically etched within the cylinder wall so only nodules of silicone remain exposed. These nodules become coated with oil and form the coating for the piston to glide upon. Specialised equipment is required to hone the cylinder walls with this process.

You can read more about the alusil treatment here:

http://www.electrosil.com.au/KS.pdf

https://mbworld.org/forums/attachmen...bores_113k.pdf

https://mbworld.org/forums/attachmen...bores_113k.pdf

SICAMG

I can not see this working. How could all that friction and pressure on the rings and walls withstand miles and miles of wear and not fail or wear out? A chemical bonding can only last so long...no??

Sir-Boost-a-Lot

iTrader: (1)

It's not a coating. The exposed silicon molecules are part of the aluminum alloy, which the alusil process brings to the exposed surface for the piston and rings to travel through.

All you want to do with it for a rebuild is a light hone with paste, and new stock style barrel faced rings. Chances are the stock rings aren't worn any discernible amount even with high miles. For a rebuild I recommend a light hone to push back the substrate a few micron, use the stock rings in the same bore they came from while increasing the rings end gap to .020/.024.

Install new rod bearings and main bearings, but use the loosest available versions(purple I believe) for more clearance and margin of error. Be very careful and clean when removing the stock pistons and rods and reinstalling them if you plan to try and rebuild the engine without resleeving the block with iron bores.The alusil bore is very resistant to normal wear but very soft and easily scratched by debris such as metal particles and sand/dirt.


Hachiroku is completely mistaken here, please disregard anything he wrote above before his bad advice costs you a lot of money and aggravation.

hachiroku

sorry for the miss information guys. please ignore my comments. they have been deleted. these engines don't have steel or iron liners.

rockthemullet

Chris knows what's up. I've rebuilt several of these, and didn't even open the ring gaps. Barrel face rings is of the utmost importance... you won't last long with any other, as the ring edge will cut through the silicon and allow for Al on Al contact.

SICAMG

OK so in your opinion what would you do with an engine with 55,000 miles on it. Leave it or...I am thinking ARP rod bolts,head bolts and my oil pump that has been whinning forever since I have owned it.
Do a piston swap? Or will the stockers live with only a slight boost increase. These engines seem to run forever as long as the AFR is on the money all the time.
By the way my plan is for a top speed challenge this September in Loring Air Force base...2 mile run and 1 mile shut down. I will not be turning the engine over 6,000 rpm.

rockthemullet

Rod bolts and head studs can never hurt... if you're just pullied on the stock blower I'd leave the short block alone. If you have everything apart, clean up the heads a little, run ARPs, new timing tensioners, OEM gaskets. For your challenge, focus on massive amounts of cooling.

blackbenzz

If you're going with stock alusil cylinders I'd go the proven route with Mahle or similar that have been made for alusil bores. I'm not sure how many have successfully ran the Weistec pistons in an alusil bore. Don't forget this little tidbit of information Weistec updated their site with for the pistons:

"It is strongly recommended that customers send their M113K engines to our facility for installation of the Weistec Forged Pistons as part of a complete engine build. No tech support will be offered for installation of pistons other than information regarding the bore clearance and orientation of the pistons. Ring gapping information will not be provided."

BlownV8

+1. I would not recommend anything other than Mahle or Kolbenschmidt pistons in an Alusil bore regardless of the alternative piston/coating that someone tells you will work. Until some of the alternatives have a proven 200,000+ miles in an engine, I would not trust them as far as I could throw them.

95ONE

I'm wondering if any of you knew that our aluminum Blocks have Aluminum Sleeves cast in? I certainly didn't know until I bored mine out for steel sleeves.

e500slr

How much did that cost?

95ONE

Since these are just simple liners, and not Performance "T" or Flanged sleeves, It was only around $1,000.

More risks are taken when having a machine shop do this. When I say that, I mean it is easily done, but rarely do you find a machine shop that ever does these properly.

When there is already a liner present, the bore must be cut carefully to not destroy the block. The bore must be cut to an interference fit that is neither too tight or too large. Too tight, and the block cracks/breaks. Too loose, and the liner separates from the block while in use and becomes worthless.

The bottom of the bored hole must be absolutely clean before inserting the liner. Any tiny bit of dirt or debris will keep the liner from pressing all the way down. Then the block gets decked and now the liner looks fine, but when / if the debris breaks loose, there will be room for the liner to drop lower rendering that hole worthless.

Hopefully the machine shop does not try to "press" the liners in, but instead heats up the whole block, freezes the liner, and just "drops" the liners in. In doing so. being absolutely certain the liner is as far down as it will go - also making sure no debris as stated above.

The Step that the liner sits on must not protrude into the bore. Care must be taken that it is a slightly larger O.D. than the sleeve so the piston skirts do not scrape. - Should be taken care of during the final honing process anyway if this gets missed at first.

The liners cannot be so large that they come so close to each other that they almost touch or touch. They will knock each other loose.

Things like this is why so many attempts at these fail on so many other platforms. They are not a bad alternative at all. They just need absolute care when being installed.

Unfortunately, no one finds out about a failure to install correctly until it's too late. I have quite a bit more on the motor to go, so I won't find out how well my block was sleeved for quite a while.

blackbenzz

The Darton sleeves seem to be proven if you plan on going the sleeve route. Although alot more money than a grand

Havoc

True dat!!
I have the Weistec Forged Pistons currently in my SL55 and they are holding up nicely. I'm sure if they ever ate up the cylinders it probably had something to do with having the wrong Ring Gapping since they are now mentioning it..

Hulk

Did weistec install them for you?

Havoc

No, ACG in San Diego did the install. When I mention about the Weistec pistons not liking the cylinders in some guys motors they ask if I knew what they gaped their rings at, so it seems ACG is on the same page with Weistec.. Lucky for me!!

Hulk

You got to bring it to the track bro!