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Mafia member #105
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02 LB7, .20 over 15 to 1 Socal Diesel cut and coated pistons and Crower rods,ARP Head and Main studs.Socal dampener,45% over injectors.








 

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Mafia member #105
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Discussion Starter #2

































 

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Mafia member #105
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Discussion Starter #3
We got this motor already built,My friend had his machinist friend do the build, Went and picked it up he never bagged it up, He wasted the time bagging it up for the ride home in my truck. Once here we un bagged it and it had metal dust all over the inside so we had to take it back apart, We ended up finding that he never even polished the crank and the rod bearings had scratchs in them. Also when he went to get all the weights for the balancing he just moved the pistons around and mixed the rods and all till it was matched. We figured he had the rods and piston right we should of thought and looked closer, This is how he had installed the pistons pics below.

 

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Mafia member #105
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Discussion Starter #4
wasn't sure how much was different with the right to left on a Dmax, I called Guy and he said there is 30 thousands offset.This motor was already built once heads on and tqed,When I picked it up for my friend it was in the machine shop next to a mill that was running the motor had metal shavings stuck all over the rods and crank and bottom of the pistons,We tore it apart and found the crank was not turned and the bearings were scratched,Did not give 2 thoughts of the pistons since he had balanced it all he did was match the weights by swapping the pisons around and when we put everything back and then looked and felt dumb to see that 4 pistons were in the wrong hole.All is fixed now, Guess it was a good thing we took it apart from seeing the shavings since the heads were already on, Sucks for him that he has to get new head gaskets again and had to get new rod bearings. Better safe then sorry.


I will have more pics in a few days were almost finished with this truck.
 

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Gone Fishin...
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Awesome pictures and great info! Hope everything works out for you. Thanks for sharing.

One question though; The first post says 15 to 1 pistons, why the change? Arent stock LB7s 17.5 to 1? So why the change? Thanks!
 

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Mafia member #105
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Discussion Starter #6
Awesome pictures and great info! Hope everything works out for you. Thanks for sharing.

One question though; The first post says 15 to 1 pistons, why the change? Arent stock LB7s 17.5 to 1? So why the change? Thanks!
Yes factory was 17.5 to 1 then the later LLY and LBZ's went to 16.8 to 1. With the lower compression you can run some more boost and also by deliping the pistons helps direct the fuel spray better into the bowl to get a better burn.
 

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Gone Fishin...
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Yes factory was 17.5 to 1 then the later LLY and LBZ's went to 16.8 to 1. With the lower compression you can run some more boost and also by deliping the pistons helps direct the fuel spray better into the bowl to get a better burn.
Alright, I understand that, but wouldnt the higher compression with more boost create more power?
 

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Mafia member #105
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That also would cause more heat that we do not need lower the compression and we can twist more rpm and raise the HP and loose some TQ,Its give and take.
 

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Gone Fishin...
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That also would cause more heat that we do not need lower the compression and we can twist more rpm and raise the HP and loose some TQ,Its give and take.
Gotcha. Thanks!
 
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