12v pistons

Murdered12v

Murdered12v

New member
My first post on here so any help would be greatly appreciated. I have a 97 rclb 247k on the clock that's been my project for the past year.
Mods: 5x18 290 bar dfi injectors, 215 pump flowed and balanced to 600ccs max from Farrell diesel service (tuned back to 425ccs) 5k gov springs, .024 dvs, stainless diesel manifold t4 E.D s466/83/1.0 billet wheel and race cover, fass 220 and some other odds and ins (intake, exhaust, intake horn, etc)
I recently blew the factory headgasket and plan to do some porting on factory head while i have it off. But I'm curious at what point do you need to change from factory bowl 12v pistons? I'm currently running 21° of timing (well i was lol) If the stock pistons are indeed limiting my setup what do you guys think would be the best bang for the buck?
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Look up Big Blue24 's build thread on the junker drag truck. He enlarged his bowls while the engine was still in the truck and he's doing well over 400HP.

...I guess if you are budget strapped or just willing to give it a try. Otherwise, get ya some good pistons.
 
I would run current piston until it needs something major. Headgasket job is minor for doing a piston swap. Mys well pull the motor and do everything if you want to change the pistons.

Or consider selling it to me if it sounds like too much haha
 
Unless you plan on competition only, I wouldn't change them.

Stock works fine, compression is up and that's a plus on the street. running a bigger single charger is easier and there's less smoke all around.
 
If it were me I would leave the stock pistons in there, make sure the block is straight, o ring the head and put it back together.
 
I haven't dynoed the truck yet I plan to this coming year when I have it back together. According to the hp calculator (which I'm not relying on) from my track times it calculated 583hp. Porting the head while it is off will add to it and I only had a couple passes on this setup so there is more left in it if I get my afc dialed in. The truck is quickly becoming a drag truck. I was just curious what kind of power people have made on the stock pistons before doing an overhaul. I'm starting to get some blow by and plan to rebuild it next winter anyhow if I don't do it this winter, I'm nowhere near done with this build lol

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Just trying to figure out how much more room I have to grow before I do the next big step (cam, shot peened rods, bigger bowl pistons) and have my bottom end balance while I have it apart. The truck is not my daily by any means. It sees the occasional town trip on the weekend, but mostly just the drag strip on the weekends

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On a 12v? I've seen plenty of common rails 1000hp stock head and bottom end, but the bowl of the piston is much bigger. I've never seen a 12v with 1000hp stock pistons (not saying they aren't out there). I know the rods and crank are capable. But the bowl on a 12v piston is so small compared to a marine bowl or 24v bowl. From what I've read fuel starts escaping the bowl and spraying on the head of the piston much after 22° with stock piston and 145° spray pattern

rockjeep73 said:
We ran a stock bottom end at 1000hp for a couple years. I wouldn't worry about the pistons.
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You can make a lot of power with the stock pistons. Upper 20s timing will work fine as long as you run the thin washers and don't run the thicker head gasket.

But if you're really itching to swap pistons, the Mahle 286210s are a great street/strip piston. Wider but shallower bowl than the stock pistons. Works good with higher timing, but also keeps compression up (~18:1 range). These will give you more bottom end power and smoke less than the marine bowls. These work great until you're to the power level that your rods can't take the higher compression.
 
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I pushed my stock long block besides a fire ringed head, good valvetrain/pushrods, and drop in cam to 1105hp 1800+ Tq , It also made 689 that same day on fuel. At that time on the dyno I had a s478/87 single that lit easily, s475/96 ran even better later on. Timing was around 24-26 and the pistons looked normal, no melted edges, wierd burn marks or anything odd. It also lived at 1600+ egts and I beat the crap out of it.

Fuel was a farrel diesel 13mm with full cuts, and Weston's 5/22 145*
 
Yes on a 12 valve. We ran the timing between 20-30* with 145* and 155* injectors. Stock motor, drop in cam, mildly ported head that was o-ringed, 625 studs.
 
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