Can someone tell me what going on here? QSB MARINE PISTONS!

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DENVERDODGE04

Faster Then You
Joined
Jul 18, 2009
Messages
161
I wanted to post this on Comp D aswell, you guys seem to know your Tech alot more then CF, scroll down where I asked my machiniest to find out what the differance was. He didn't find crap. Do I have the wrong ones or what here. Why the heck does everyone make such a big deal out of these? I have heard that the compression is 16.7 unlike the stock 17.2, triple nickle material, rings are set lower in the piston to keep it away from the heat, thicker rings, yadda yadda yadda! Someone know whats up?
Well Merry Freakin Christmas to Me/New Build! - Page 11 - Dodge Cummins Diesel Forum
 
The lower compression is a result of the thicker Marine gasket. I was under the impression that the marine piston was forged vs a cast standard piston. The top ring to crown spacing should be 8mm from what I know.


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Cummins610 said:
The lower compression is a result of the thicker Marine gasket. I was under the impression that the marine piston was forged vs a cast standard piston. The top ring to crown spacing should be 8mm from what I know.


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Yeah the gasket is making sense now. Did you check out the pics?
 
if your machinist can't find the info, find a new machinist.
 
post a part number

i bet there is a certain cummins wizard here that can give you the specs
 
Piston Part Number 190407 supossed to be a QSB 480x Cummins Marine Piston. We have checked everything, Except the weight and they are just 03-04 pistons??? Hoping Cummins screwed up and just sent out stockers or something here.
 
Features of the QSB5.9-440 HP and QSB5.9-480 HP Marine engines include: Double heat treated piston for 30 percent improved yield strength and 0.2 mm [0.008 in] radius at bowl lip to reduce stress and to make sure no cracking occurs at higher power.
 
Here you go Snedge. stock on the left QSB on the right. Maybe I missed a number.
pistons.jpg
 
The number you posted is a date/build code. The 4 digit number helps identify the piston.


3929 (4943929)- .020 over QSB

You do, in fact, have a QSB piston.
 
Snedge said:
The number you posted is a date/build code. The 4 digit number helps identify the piston.


3929 (4943929)- .020 over QSB

You do, in fact, have a QSB piston.
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Awesome Snedge, you the man! One more question for ya. I didn't realize the compression differance was all in the head gasket and was looking forward to the lower compression. Do you have to do anything to be able to run the marine gasket? And has everyone had good luck running them? Thank you for all your help. DD
 
DENVERDODGE04 said:
Awesome Snedge, you the man! One more question for ya. I didn't realize the compression differance was all in the head gasket and was looking forward to the lower compression. Do you have to do anything to be able to run the marine gasket? And has everyone had good luck running them? Thank you for all your help. DD
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You don't need to do anything special to run it. Cummins used this gasket to lower cylinder pressure due to head gasket failures on the boats. We have seen no problems with them.
 
Dual double same diff, I could have swore the paperwork you sent me on my 480's said dual heat treated.


I drive a doublly, and where the **** are you at? Florida needs a liitle more character so hope on a plane muh fugga.
 
So...to be a smart arse...

Would my 04 pistons be even better....over the last 7 years/200k they have had tens of thousands of heat treat cycles? Better with age...hehe!

Marine gaskets work great....625's and goood orings will last a long time.
 
TMONEYDIESEL said:
I drive a doublly, and where the **** are you at? Florida needs a liitle more character so hope on a plane muh fugga.
Click to expand...


Unfortunately I have a hand full of customers that would not understand the significants of a diesel race in Florida brother. I would so love to be there, but.... just did not work out. Work sucks. :hehe:
 
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