opinion on marine pistons and machined motors

snow ram

snow ram

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Nov 1, 2006
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my 12 valve went under the knife a few days ago and ended up having 14 thousandths taken off the deck and another 10 thousandths off the head i believe.
that matched with a 20 thousandths marine gasket of course doesnt add up properly to stock compression
i was making anywhere from 50-55psi before the truck blew up with a 64/14 and the concerns now are that i am going to make too much boost for the amount of room i have in the cylinders
the debate i am having right now is that is it actually worth the money to have marine pistons put in or have the stock pistons machined down 10 or 20 thousandths or should i just leave them and run it how it is
the truck of course is just built for a daily driver and something to run down the track, probably no sled pulling for this trailer queen....
 
snow ram said:
my 12 valve went under the knife a few days ago and ended up having 14 thousandths taken off the deck and another 10 thousandths off the head i believe.
that matched with a 20 thousandths marine gasket of course doesnt add up properly to stock compression
i was making anywhere from 50-55psi before the truck blew up with a 64/14 and the concerns now are that i am going to make too much boost for the amount of room i have in the cylinders
the debate i am having right now is that is it actually worth the money to have marine pistons put in or have the stock pistons machined down 10 or 20 thousandths or should i just leave them and run it how it is
the truck of course is just built for a daily driver and something to run down the track, probably no sled pulling for this trailer queen....
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The .010 taken off the head will not increase the compression (the head is flat). If you took .014 off the block and used a .020 oversized head gasket, you have .006 more deck then you started with.

Paul
 
Smokem said:
Josh, don't do marine pistons. If all you want is the larger piston bowl there are better options to retain some streetability.
Click to expand...




what are you thinking weston?
 
Smokem said:
It depends on what timing advance, injectors, and camshaft you choose to run.
Click to expand...


new era 435s, stock cam, and i wanted something around 20 degrees.
btw, the injectors have the half mm washers
 
If the head is cut .010 you have lost that much piston to valve . But the .020 gasket gives you part of that .006 back after the accounting for the block. I would think your fine, but if you that far in to it, a cam is the only way to go. In a diesel a good cam selection will have zero draw backs and a lot of advantages. Cooler Egt’s and less restriction in the intake track, or what some refer to as boost.
 
well the pistons are getting machined down twenty-five thousandths under a few peoples suggestions.
im just thinking that now with all of these variables, this thing will be a ***** to time properly.
the only draw back i can see right now is a cold weather start up having that lower of compression, it might be on the verge of being a ***** to start. only good news about the motor is there was only a thousandth or two of cylinder taper...
-Josh
 
the gasket will be twenty thousandths thicker than stock so i can lower my compression. that way when other things get injected into the motor i have a little more room to work
as we talked about it, this should hopefully lower the compression to around 16 or 17 to 1
then i would really like to run around 20 degrees timing but we will see how that goes once the motor is put together and tuned a little
 
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