DuraMax shortblock work.

RonA

RonA

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Feb 26, 2008
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I was told rods and crank work were a must for a reliable duramax build above 700hp. What needs to be done besides new rods?
 
rods, ati balancer and get the crank balanced. What pistons are you looking at using?
 
RonA said:
I was told rods and crank work were a must for a reliable duramax build above 700hp. What needs to be done besides new rods?
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Proper balance, proper combo speced rotation assy parts and materials, proper spec'd camshaft, proper bearing clearances, Proper TQ specs, Proper machineing specs. new oil pump/water pump. among other things...


BTW do you have your cummins running yet?
 
cranks are hit or miss, many have held huge HP no problem....some have broken basically stock. just on of those things you need to take a chance on unless you wanna pay big bucks for billet..
 
BgBlDodge said:
I'm pretty sure ron knows the basics on building a good engine.
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I would not assume that.(and I know me well)
My 6.7 is down to just the build part. Only need to buy a fuel pump(front cover mount type) and a set of head studs. I'd like to learn a bit obout common rails, but it looks to me like the Cummins is a bit behind in the electronics dept. If it isn't too much more expensive, i might try a brand switch and start collecting parts(and looking for a lighter host again).
 
Magnaflux crank, key crank and cam(if using a factory cam), mahle pistons, mainstuds, Aftermarket rods, ATI balancer. Balance rotating assembly. As mentioned, billet crank if it is in the budget as some factory cranks broke in stock configuration.
 
GRotman said:
rods, ati balancer and get the crank balanced. What pistons are you looking at using?
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I'm going to have to go down south and talk to someone in person first. With the Cummins it was limited to factory pistons because it was going to be a daily driver seeing some mileage. Don't know if the Duramax pistons have the steel insert for the top ring and therefore the same requirement for a daily driver or not. Would be nice to overbuild it a bit on the bottom and then adjust the tuning down. Kind of like the NX mustang only with no balls and not nearly as much class.LOL
 
IMHO, the stock crank is fine, often crank failures are caused by "overlooked" areas of the build.

BTW i run a stock crank...
 
RonA said:
I'm going to have to go down south and talk to someone in person first. With the Cummins it was limited to factory pistons because it was going to be a daily driver seeing some mileage. Don't know if the Duramax pistons have the steel insert for the top ring and therefore the same requirement for a daily driver or not. Would be nice to overbuild it a bit on the bottom and then adjust the tuning down. Kind of like the NX mustang only with no balls and not nearly as much class.LOL
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stock cast pistons do have the steel insert,... you'll want pistons from an 01-05 as they're lighter and stronger then the newer castings. just have them delipped and coated and they'll be good for a decent amount of power. that will also lower the compression to around 16.8
 
RedBowTies88 said:
stock cast pistons do have the steel insert,... you'll want pistons from an 01-05 as they're lighter and stronger then the newer castings. just have them delipped and coated and they'll be good for a decent amount of power. that will also lower the compression to around 16.8
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I had to laugh when i read this post. When I first asked about pistons for the p-pumped 6.7 about a year and a half ago i got nothing but a crickett serenade. I ended up buying 3 seperate sets before we finally settled on something that would work. Thank you very much for this information.
 
Ron, heard that LLM rods are the best factory rods. Still not that great of option, was looking at billet rods. What pistons you thinking about running? How are you guys setting up the mains (gridle)? Whos cam you thinking about running?
 
Mike Holmen said:
Ron, heard that LLM rods are the best factory rods. Still not that great of option, was looking at billet rods. What pistons you thinking about running? How are you guys setting up the mains (gridle)? Whos cam you thinking about running?
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The nearest place that works on DuraMax engines looks to be about 472 miles from me. I want to drive down to talk to them about what I'm looking for. They carry rods, and do most everything for these engines so I'll try to get a quote and a time frame from them. 700-750 single turbo that's durable in an under 3500# vehicle is the goal. Shouldn't have to get too fancy for that. I talked to them about the electronics hook up a while back and they were extremely helpfull.
 
RonA said:
I had to laugh when i read this post. When I first asked about pistons for the p-pumped 6.7 about a year and a half ago i got nothing but a crickett serenade. I ended up buying 3 seperate sets before we finally settled on something that would work. Thank you very much for this information.
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no prob bud.


Mike Holmen said:
Ron, heard that LLM rods are the best factory rods. Still not that great of option, was looking at billet rods. What pistons you thinking about running? How are you guys setting up the mains (gridle)? Whos cam you thinking about running?
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lbz/lmm do have the best factory rods. However you're only looking at around an additional 50-100hp holding if you're lucky. Best off just putting some good rods in and be done with it

look into howards rods, IIRC they come with the top bearings and have oiling provisions that the Carrillo's and crowers don't have. You cont go wrong rally though with any of the major rod producers on the duramax market (TTS,Carrillo,crower,howards).

also, if you'r just looking for around 750 i wouldn't really worry about cam or had work. would it help? sure...but ts really not necessary... lots of guys making the numbers on stock heads and cam.
 
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DIESEL_POWER said:
if your out west call demitri or II
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I'm sure Demitri wouldn't mind a total greenhorn wasting his time asking for tips to build an engine that will at best be at 35% of his power level. I have more respect for him than that. I have none for you or II so why don't you leave this thread alone. I don't value your opinion, and i don't trust you. You ripped me once, I learned. Go BS someone else.
 
:hehe: :hehe: Awesome Ron!


Isn't TTS in California? I'm sure they wouldn't mid talking to you, not matter what the power level really....at least I wouldn't think so.

Chris
 
RedBowTies88 said:
stock cast pistons do have the steel insert,... you'll want pistons from an 01-05 as they're lighter and stronger then the newer castings. just have them delipped and coated and they'll be good for a decent amount of power. that will also lower the compression to around 16.8
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If it was my build I wouldn't cut the pistons. My built motor has stock uncut lb7 pistons in it and they are holding north of 900. In my opinion unless you are going to spray the hell out of it or stuff a lot of air with twins, dont lower the compression.
 
LB7 heaven said:
If it was my build I wouldn't cut the pistons. My built motor has stock uncut lb7 pistons in it and they are holding north of 900. In my opinion unless you are going to spray the hell out of it or stuff a lot of air with twins, dont lower the compression.
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If the Duramax reacts to lowered compression the same way as the 5.9, Lowered would be bad.
 
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