I know I'm a bit late with this, but thoght I would let everybody know that Ross pistons are now available for your Duramax engine build. I have these in stock in various bore sizes and compression ratio's. These are Forged units and come with Hell Fire rings. I DO NOT recommend these for the guys that want to run 100k trouble free miles. It is unknown how these will wear long term, but for a racer motor or a racer with occasional street use, I think these are superior due to forged construction.


I currently have these in a few engines for testing and these seem to be working very well on daily driven trucks. I have these in stock at my location if interested.


http://www.gmdieseltech.com/images1/ross.jpg

http://www.gmdieseltech.com/images1/ross1.jpg
http://www.gmdieseltech.com/images1/ross2.jpg
http://www.gmdieseltech.com/images1/ross3.jpg

how much lighter than stock are they ?

How much more side wall clearance is needed over stock stuff?

is there any long term testing available? could you guess how long they would last in a high hp truck thats street driven where milage isnt a concern? something of a street lightning hunter.

:ro) My crystal ball tells me I need some of the those for my race truck:D Eric I will be in touch!

Also, what bore size are they available in? im thinking max displacement here......

Looks like no oil cooling, just a "deflector" for the jet, but that's to be expected in a piston that wasn't cast.

http://www.gmdieseltech.com/images1/ross3.jpg

Tom, you hit it on the head, thats exactly why I wouldnt trust them for heavy haulers. There are some things we can not get with a forging at this time that we can with a cast. The most obvious is a oil cooling passage behind the rings. The other thing we cant get and is actually the biggest reason I am unsure on how they will do over 100k miles is that the compression ring rides on aluminum vs the stock pistons use a steel insert where the ring rides. I have some cut up pistons, I'll try and get pics of all that.

The piston to bore clearance is still the same as OEM, the forged pistons from my understanding do not respond to the heat as much in a sense of them growing.

Ben, these are avail in any bore size and compression ratio you could want. I have these in .040" over, I am to chicken at this time to try .060" over as I feel we are pushing it when our wall thickness is below .125" I think they would work, but I dont want to find out just yet. The other factor you have by not going in a "common" size is ring selection. Rings are easy to get in the normal .020, .040, .060 sizes.

I dunno how they will do long term, I have only had them for about 6 months and we have not torn down any engine they are in. I have made arrangements with the customers that own them to tear the engine down after a set mileage and inspect them to see how they wear. Its a lot of work, but something that has to be done if we are going to learn anything.

There is no advantage to these as for as weight.

How much longer before you do a tear down, I would like to hear you results before my final decision:)

I'd say it will be late spring, I want to see the truck get 20k or so on it.

that was quick:D

Are these the pistons that has the tops milled down because the wrist pin to deck height was wrong when they were ordered?

Are these the pistons that has the tops milled down because the wrist pin to deck height was wrong when they were ordered?
No, that was an error on Ross's part, those pistons were all sent back to them and these are the replacement pieces. These pistons have been untouched by any machines other then Ross's.

what about ballancing issues

ie cast to forge in gas required rebalancing does the same thing apply:confused:
or arre the pistion match weight to the oem

Anytime your building an engine, its important that everything is balanced. These pistons are matched very very closely according to the build cards in each set. However, they should be balanced along with the rest of the build. They will likely need some clearance work done anyways for valve relief depending on the camshaft selection as well.

do they clear on stock rods etc...? skirts look thicker than on stock dmax pistons...or is it just my eyes?

Ben, lots more meat there but stock rods work just fine.

Anytime your building an engine, its important that everything is balanced. These pistons are matched very very closely according to the build cards in each set. However, they should be balanced along with the rest of the build. They will likely need some clearance work done anyways for valve relief depending on the camshaft selection as well.
:duh:der-de-der i knew that

why use stock rods with those pistons, or stock sized rods?

What other option you got Jesse? LOL

The Crower units that are common now are sized the same as stock and will fit perfectly in these pistons.

right I meant why the hell would you go through all the trouble to put actual stockers back in.

The question that comes to my mind is why would you not .

actual stock rods tend to shrink on these motors at higher power levels, I would assume crowers would be the obvious choice.