Out with the old, in with the new. I guess i never really knew how much H.P. the o'L Duramax had, This is a pritty good sign it had more than i thought.

http://i30.photobucket.com/albums/c336/rb4341/duramaxrods001.jpg

http://i30.photobucket.com/albums/c336/rb4341/duramaxrods003.jpg

Ha! Nice ;)

That is a great sign of power! I cant wait for that day this happens or I guess I can!

Looks like you caught it just in time too.:)

So do we get specs on the new ones? :D

that bent rod is the same shape as my aftermarket rods. Good choice going with Crower. :cool:

How old a Duramax (what year)? Since it is here, it must be LB7.

How much HP does it take to do that?

How much HP does it take to do that?

1 to many! :D

How much HP does it take to do that?

Ity depends on the tune...but somewhere just above 500rwhp.

Do you have dual Cp3's

I made 718 RWHP on stock rods but after that last DYNO pull it had lower compression :eek::D

that bent rod is the same shape as my aftermarket rods. Good choice going with Crower. :cool:



Care to share what brand of rod bent? Did it window your block, or did you catch it in time?

Care to share what brand of rod bent? Did it window your block, or did you catch it in time?

X2

that bent rod is the same shape as my aftermarket rods. Good choice going with Crower. :cool:

i am pretty sure i know whos rods they are , are you being taken care of or are you s.o.l , i would be highly upset .

(sweet) I hate to see mine

Its an 03 LB7 The rods that bent were factory stock rods, putting CROWDER rods back in it. Yes it has dual CP3's They say when you get around 500 H.P. you have a good chance of bending a rod, let me tell you,i think i believe them now. I was at the end of the pull, at Campbellsville Ky. waiting to be unhooked from the sled, and my crew chief, and top mech. ran over and told to shut it down, he herd it knocking. after tearing it down we found out that the pistons were hitting the crank, i guess because the rods were a little shorter,sure ain't much clearence there. thanks to the trained ear of my mech. we did'nt damage anything but the rods.

OH Yea, Ya'll would be proud of me. I had a friend and fellow puller, that just happends to drive a Dodge, offer to pull my truck back to my trailor so i would'nt damage my engine any further. Very nice guy,great friend. BUT I JUST COULD'NT LET THAT HAPPEN. so i fired it up and drove it to the trailor. OH well if it would have blown a rod out the side on the way back to the trailor , OH WELL !!!

the twin cp3s are what killed it in my opinion.

the twin cp3s are what killed it in my opinion.

Why do you say that. The pump just allowed the motor to utilize all the fuel it could take. I may be wrong but if it was a stock truck with just a dual CP3 would it still have bent the rods. I am not trying to bash you or anything I am just wondering why you say that? From my standpoint it was a combination of all the parts making it exceed the power limit of the rods. Not just limited to one part or another. Or am I missing something?

the dual cp3's are what gave it the extra power to bend the rods

Correct me if I'm wrong, twin CP3's allow more torque through constant rail pressure during the high-load situation of a pull or a Dyno-run or whathaveyou, and when the motor is stressed AND more torque is being applied instead of losing pressure like normal, it breaks stuff like this.

Yes I understand the other pump added horsepower by maintaing rail pressure but how does it come down to just the CP3 pump. The turbo, injectors, programming didn't cause them to bend?

Out with the old, in with the new. I guess i never really knew how much H.P. the o'L Duramax had, This is a pritty good sign it had more than i thought.

http://i30.photobucket.com/albums/c336/rb4341/duramaxrods001.jpg

http://i30.photobucket.com/albums/c336/rb4341/duramaxrods003.jpgThat crower rod looks like a nice piece. I had similar luck with my factory 6.0L gas rods. Mine didn't bend untill well over 700RWHP but I don't make near the torque you guy's do. I wanted to go with crower but thay didn't have a rod in the weight range I was looking for.

http://img160.imageshack.us/img160/7919/jf8ch3.jpg (http://imageshack.us)

http://img405.imageshack.us/img405/8499/compstarfh2.jpg (http://imageshack.us)

The way i understand it, The injectors control the fuel, the CP3 only supplys the fuel to the injector. about 2/3rds of the way down the track, the engine was leaning out to much, the down pipe was glowing red,and it seamed like it was running out of fuel. after researching the problem, we added a 2nd CP3 and that fixed the problem. we ran great for a season and a 1/2 but during that time we kept adding thing like water injection etc. I think we just exceeded the H.P. for the rods. The CP3 is not the blame its the combo. of all things. we knew we were over the limit of the stock rods, we held our breath at every pull, and it lasted longer than we thought it would.

You see quite a few trucks with 500 rwhp.running around.I have a buddie that is making 550rwhp.it is a dailey driver,and weekend puller.Mine is a little under that(500hp).I'm betting you were making quite a bit more than 500rwhp.That or you were on a real sticky track.

You see quite a few trucks with 500 rwhp.running around.I have a buddie that is making 550rwhp.it is a dailey driver,and weekend puller.Mine is a little under that(500hp).I'm betting you were making quite a bit more than 500rwhp.That or you were on a real sticky track.

The temp was about 32* with probably 40% humidity when we was pulling. The air and track was awesome and it was having its best pull. So those two factors finally pushed it over the edge. At 500-550 horse I would not be very afraid of the rods, I would just have the thought in the back of my mind. At 650+ hp I would start looking under the truck after every pull to make sure you cant see the crank through the side of the block.

i bent all eight rods in my truck with a single Cp3 and #7 was bent just as bad as the one Nail it has pictured.

Hey Nail-it, you are a true die hard duramax man by not give in to lettin a dodge pull you off. Way to represent the duramax :ro)

Hey Nail-it, you are a true die hard duramax man by not give in to lettin a dodge pull you off. Way to represent the duramax :ro)

You have that right. He is the most die-hard chevy duramax guy you will ever see. I know because chevys stickers turn up every where at the shop and on my ford truck.:Moon:

I have no idea where all those CHEVY stickers came from, HEE, HEE HEE

How much torque are those engines making on the dyno?

How much torque are those engines making on the dyno?

I really have no idea. We dont like to get caught up on dyno numbers because thats all they are is numbers and those numbers change on every dyno but if I would guess in the 850+ ftlb range.

Well obviously but dyonoes are a great baseline for tuning 'safely' rather than on the street and much more accurately.

I dont know anything about the Duramax performance side really. Are you guys making this power through stock transfercases and stock rear ends, drive shafts, axels? Like I'm only putting down around 420/400 and i have EVERYTHING built on my car because that stuff just breaks so easily.

teh only driveline mods necessary for that power is a built tranny

tuning is everything! you could bend rods on stock power level if the rest of the tuning is wrong. Tomac and I put hundreds of pull and passes on the drag stripe with every thing you could throw at it less the dual fueler, once the added fuel came into play it didnt take but half a season to bend our rods, like I said i was over 700 RWHP and over 1400 Ft lbs of torque when it lowered my compression, I still drove it seven hours home with bent rods, Had a little tic from the piston hitting the crank. :eek: :D

tuning is everything! you could bend rods on stock power level if the rest of the tuning is wrong. Tomac and I put hundreds of pull and passes on the drag stripe with every thing you could throw at it less the dual fueler, once the added fuel came into play it didnt take but half a season to bend our rods, like I said i was over 700 RWHP and over 1400 Ft lbs of torque when it lowered my compression, I still drove it seven hours home with bent rods, Had a little tic from the piston hitting the crank. :eek: :DTHAT LITTLE TICK; WAS IT ALL THE TIME? OR ONLY WHEN YOU START IT?

THAT LITTLE TICK; WAS IT ALL THE TIME? OR ONLY WHEN YOU START IT?
It was when it was idling you could hear it, it even droped a cylinder when idling, once i was home from danville i only started it once more to pull it into the shop to tear it down. figured i gambled enough. :D

should i check the compression? what should it be at on the cylinders? or should i not worry about this- should i expect weird noises when its this cold out?

Can never tell on cold start up unless its smoking more than it did before. You can do a compression check, not all gauges will read the same, so check the numbers in all eight and get back with me.

minimum 300. There should not be more than 50 psi difference between a suspect cylinder and the average compression of all 8 cylinders.

minimum 300. There should not be more than 50 psi difference between a suspect cylinder and the average compression of all 8 cylinders.
The rule of thumb is that if there is more than 10% differance between any and all the cylinders there is something wrong.
And the magic number is 340 PSI.
A compression gauge is like a dyno, not all the same but is a great tool to get the gob done. So if you dont get 340 that dont mean your motor is junk.

The rule of thumb is that if there is more than 10% differance between any and all the cylinders there is something wrong.


where did this information come from?? is this new gm spec??

where did this information come from?? is this new gm spec??
Engine 101

being a smart a$$, doesn't get you anywhere

where did this information come from?? is this new gm spec??


I dont know where it comes from but thats what Ive been taught as well.

being a smart a$$, doesn't get you anywhereAre you refering to me being a smart ass? Im just stating facts. Sorry if i affended you.

i was just going off of the gm spec that i was aware of

i was just going off of the gm spec that i was aware of
The question was: Were you calling me a smart Ass?

your engine 101 comment was smart a$$ish, so yes

your engine 101 comment was smart a$$ish, so yesIt is in engine 101 that it states 10%, any class that has to deal with engine building or diagnoses of any engine with two or more cylinders in almost all cases will tell you 10%. It was not a smart ass coment. Your numbers were correct, right out of the GM book but that will get you about as good of a job as that would come out of some dealerships. I post on here the best i can in the real world. If you think im a smart ass you really dont know me. Do you have some problem with me that i dont know about?

no, i thought you were being that way with me

no, i thought you were being that way with meWell I wasn't, Life is too short not to get along. If i dont have something to add in a positive fashion i dont post. So can we shake hands now?

Well I wasn't, Life is too short not to get along. If i dont have something to add in a positive fashion i dont post. So can we shake hands now?


:beerchug:

Cant we all just get along? LOL.

THis little tread that i started, created a lot of talk and a lot of info. Thanks for all the advise and information When Brad And Robert, [ Unlimited Performance] Here in Dickson Tn. gets this Duramax all put back together, i'm going to try to make all the pulls i possibly can this year. Maybe i'll get a chance to meet some of ya'll

THis little tread that i started, created a lot of talk and a lot of info. Thanks for all the advise and information When Brad And Robert, [ Unlimited Performance] Here in Dickson Tn. gets this Duramax all put back together, i'm going to try to make all the pulls i possibly can this year. Maybe i'll get a chance to meet some of ya'll


So whats your plans: rods (thats a given :D), cut pistons? , all out build or?

Well, while we are so deep into the engine, it would be smart to go ahead with pistons. Forged, cut pistons are what we are studying. we are looking to the cost.

Are the stock Durmax cranks really that strong? Do you worry about spinning rod bearing or anything?

tuning is everything! you could bend rods on stock power level if the rest of the tuning is wrong. Tomac and I put hundreds of pull and passes on the drag stripe with every thing you could throw at it less the dual fueler, once the added fuel came into play it didnt take but half a season to bend our rods, like I said i was over 700 RWHP and over 1400 Ft lbs of torque when it lowered my compression, I still drove it seven hours home with bent rods, Had a little tic from the piston hitting the crank. :eek: :D
X2

should i check the compression? what should it be at on the cylinders? or should i not worry about this- should i expect weird noises when its this cold out?Come over on a cold day and I'll start old red,at 331,000 mile you can hear some weird noises :eek: and see some smoke,it runs grate and gets 18 to 19 mpg ? with lots of noises cold

Are the stock Durmax cranks really that strong? Do you worry about spinning rod bearing or anything?

yes stock dmax cranks are plenty strong.

spinning bearings has nothing to do with HP level as far as I know.

Oh yeah i was just cruious our LS1s seem to spin bearings every now and then didnt know if it was a Duramax problem. When i went to the dealer to get my headgaskets done (but didnt go with them because they wanted 6k) they suggested i just buy a new truck because the next thing to go on it would be the crank.

Oh yeah i was just cruious our LS1s seem to spin bearings every now and then didnt know if it was a Duramax problem. When i went to the dealer to get my headgaskets done (but didnt go with them because they wanted 6k) they suggested i just buy a new truck because the next thing to go on it would be the crank.There not that bad. Salesman must been down in car sales that month.

Haha it was December 07 so the ecconomy wasnt that bad. The same dealer also told me there was no way an injector cup seal could cause a pressurized coolant tank so i waited a year and im just now getting around to replacing them myself.

Haha it was December 07 so the ecconomy wasnt that bad. The same dealer also told me there was no way an injector cup seal could cause a pressurized coolant tank so i waited a year and im just now getting around to replacing them myself.Wow he really didnt know what he was talking about.

X2 They ALWAYS !!!! try to sell a new truck. I worked at a Chevy dealership, as a new car salesman from 1987 till 1990. if someone from the shop would bring me a buyer, they would get a bird dog fee.

Oh yeah i was just cruious our LS1s seem to spin bearings every now and then didnt know if it was a Duramax problem. When i went to the dealer to get my headgaskets done (but didnt go with them because they wanted 6k) they suggested i just buy a new truck because the next thing to go on it would be the crank.

As good as a LS1 is it biggest problem is it's oiling system it weak at stock HP levels. That's why spinning main bearings are typical

Yeah i have an upgraded oiling system on my LS1 so bearings arent as much of an issue. 7qt pan, high volume high pressur epump (70psi hot idle, 100psi WOT) and remote filter. Our cranks are good rods are only good to about 550rwhp or so though. 01 and later rod bolts are good to 7000rpm too.

Yeah thats one of the main reasons i didnt go with the dealer is the service guy got tired of arguing with me so he brought out their disel tech to explain to me how it couldnt be an injector sleeve and i got mad and just left.

Yeah i have an upgraded oiling system on my LS1 so bearings arent as much of an issue. 7qt pan, high volume high pressur epump (70psi hot idle, 100psi WOT) and remote filter. Our cranks are good rods are only good to about 550rwhp or so though. 01 and later rod bolts are good to 7000rpm too.

Yeah thats one of the main reasons i didnt go with the dealer is the service guy got tired of arguing with me so he brought out their disel tech to explain to me how it couldnt be an injector sleeve and i got mad and just left.

Wow sounds like you have a nice setup

As good as a LS1 is it biggest problem is it's oiling system it weak at stock HP levels. That's why spinning main bearings are typicalLS1's don't have weak oiling systems or spinn bearings unless dealership mechanics have ben working on them. You would be supprised at what a stock Ls short block will take.

Bump for an update Barry.