Need help 12 valve wont make over 471 hp

widener said:
I have a 96 12 valve the is 40 over balanced with coated positions hamilton big stick hamilton push rods and 165 pound valve springs 215 pump no plate full cut dvs 4 k gov spring .093 lines .093 dv holders port and polished exhaust side of head roller rockers 7x20 injectors s475 turbo with stainless diesel exhaust manifold banks twin ram intake and turbo netics intercooler and 18 degree of timing i have made 10 pulls on dyno and cant make over 471 hp truck is holding 65 pounds of boost and good fuel pressure it dont pop spit or bang just not making any power any help would b great
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Does your truck smoke like crazy?

Does it lope?

Get a fuel pressure gauge because with that big of injectors, maybe they dont have enough pressure for the volume? (time for 13mm pump ;-) )

By 165lbs valve springs, do you maybe mean Hamilton's which are rated as so?:
lift Stock 60lb HD12
1.940” 88 150 155
1.900“ 98 156 165
1.800“ 125 170 200
1.700“ 150 187 240
1.600“ 182 210 285
1.500” 210 225 327
1.400“ 245 245 365

Sounds like you could have an 800rwhp truck really fast if you figure out your issue. Does it smoke like crazy? and at what RPM does the turbo light? Are you sure you are spooling the turbo on the dyno? I have heard of people not being able to spool it on the dyno for whatever reason and then getting a spool valve, or smaller turbo and making more power.

Or... are you just a troll?
 
Dtruck1 said:
Probably takes 50 hp to compress those valve springs.
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165# springs are fairly common on a 12v. More valve area so it takes more pressure to hold them closed(compared to a 24v)

Injectors and timing are pretty unanimous here... Hope the op gets the hint
 
Simple case of too much fuel to early and too much turbo to late.... you needa 5k springs, 24-26* timing along with smaller lines, dv's, holders and you will have a much better running truck. by big stick do you mean his 181 210?
 
Lostnwalmart said:
Simple case of too much fuel to early and too much turbo to late.... you needa 5k springs, 24-26* timing along with smaller lines, dv's, holders and you will have a much better running truck. by big stick do you mean his 181 210?
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^^^^ Like he said ^^^^

Spend some time reading, instead of listening to the locals.

Who in the **** recommended 7x20s? :doh:
 
If that were my truck, the first change would be setting the timing to 30*.
The second change would be reducing the delivery valve size to something manageable so it can be driven on the street, say Bosch 191, DDP 024, stock 181, etc.
The third change would be to change injectors, in my opinion, 7 hole injectors should not be used on high hp 12 valve trucks. Anything 7x.012" or larger would be better served with a comparable sized 5x.014", 5x.016", 5x.018", etc.



I'll bet with 30* timing and some minor afc adjustments to slow down the bottom end fueling, you'll see 550-600 on the dyno. Then add in some 5 hole injectors and you'll see 650+.
 
For everyone asking if the truck smokes, is there really any way on all of God's green earth or frozen tundra that the truck DOESNT oral the coal like a loaded freight train? There's no way that thing is burning even half the fuel its being fed
 
I bought a 97 a while back with 7x16's, full cuts, and 093 holders. The truck had 62/480 twins and it was stupid dirty. Couldn't drive it without a constant dark haze. Applying actual pedal input would black out the sun even at 80lbs boos.

I can only imagine how bad OP's truck must smoke
 
Mr.T said:
For everyone asking if the truck smokes, is there really any way on all of God's green earth or frozen tundra that the truck DOESNT oral the coal like a loaded freight train? There's no way that thing is burning even half the fuel its being fed
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Well, I think we were all asking because if it doesnt, then he isnt getting enough fuel pressure before the pump. If it does, he just has a stupid amount of fuel that cant be used.
 
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