First aluminum duramax rod!!

[Diesel power]

Somebody has to try them to see if they work or not right. That's how things are proven. As stated, this is not for a DD application.

Which leads me to believe that the duty cycle is not very high seeing as only a seasonal life expectancy is all they are likely to last for. I can't see them being cost effective-at least not until putting Top Fuel Dragster rated parts in diesels starts netting Top Fuel Dragster money!

But who knows, other good may come out of this. If the rods hold up to the torque and HP estimated to be thrown at them, at least it will give a chance for the rest of the drivetrain to start failing and start recieving improvements as well!!

Correct the duty cycle is whats important( AKA Enlongation) the way we lessen or slow the amount of enlongation is to, lower RPM ,and Lower recipricating wieght, Both have been addresed in this application.

The recipricating wieght has been droped tremonously due to wrist pin , piston and ring package design, also the small end of the rod is much lighter(aluminum) We have about 250g less just in the piston assembly alone over the mahle/stock piston assembly. That speakes volumes to the resistance to rod enlongation.

The RPM at which these rods are normally designed for (8500-11000 RPM) is significantly less, again counter acting the enlongation efffect.

 

[Diesel power]

Perminant enlongation is the thing we dont want. during opperation it's normal to have any where from .0050-.0070 of enlongation and you have to allow for that as well, this is no doubt a whole different can of worms......that most will not want to deal with.

 

[dmaxvaz]

so you are using a aluminum big block chevy rod with some custom pistons with a smaller wristpin? kinda what it looks like

 

[Diesel power]

so you are using a aluminum big block chevy rod with some custom pistons with a smaller wristpin? kinda what it looks like

I guess every aluminum rod looks that way

But no not a BB chevy rod, remember the d-max rod is offset.....Yes custom is the word! Everything has been changed.

 

[Josh2002cc]

What makes a rod only good for competition but not good for daily driving? If it will last at 1500hp in a race truck for one season, why wouldn't they hold up for say a 700hp daily driver for an extended amount of time?

 

[Turbo Buick 6]

Perminant enlongation is the thing we dont want. during opperation it's normal to have any where from .0050-.0070 of enlongation and you have to allow for that as well, this is no doubt a whole different can of worms......that most will not want to deal with.

What makes a rod only good for competition but not good for daily driving? If it will last at 1500hp in a race truck for one season, why wouldn't they hold up for say a 700hp daily driver for an extended amount of time?

Hp plays very little in the life expectancy of an Al rod. Although perminant stretch is what people think breaks Al rods it is not the key factor. The metal stretches back and forth every time the piston goes up and down but it springs back to shape. This fautiges the metal and after so many times the metal starts to work harden and eventually breaks. The industry standard for determining when it is time to replace Al rods is how many runs or hours they have on them, since they could begin to work harden but never show any stretch. This is one of the reasons you never want to buy Al rods used unless you KNOW for a fact how much they were used. I ran Al rods on the street in one of my 302s in high school for over 2 years befor one let go

 

[Bako_Dmax]

Hp plays very little in the life expectancy of an Al rod. Although perminant stretch is what people think breaks Al rods it is not the key factor. The metal stretches back and forth every time the piston goes up and down but it springs back to shape. This fautiges the metal and after so many times the metal starts to work harden and eventually breaks. The industry standard for determining when it is time to replace Al rods is how many runs or hours they have on them, since they could begin to work harden but never show any stretch. This is one of the reasons you never want to buy Al rods used unless you KNOW for a fact how much they were used. I ran Al rods on the street in one of my 302s in high school for over 2 years befor one let go

Good explanation.

 

[Diesel power]

Hp plays very little in the life expectancy of an Al rod. Although perminant stretch is what people think breaks Al rods it is not the key factor. The metal stretches back and forth every time the piston goes up and down but it springs back to shape. This fautiges the metal and after so many times the metal starts to work harden and eventually breaks. The industry standard for determining when it is time to replace Al rods is how many runs or hours they have on them, since they could begin to work harden but never show any stretch. This is one of the reasons you never want to buy Al rods used unless you KNOW for a fact how much they were used. I ran Al rods on the street in one of my 302s in high school for over 2 years befor one let go

Can i call you on the phone?

e-mail maybe?

thanks

 

[Turbo Buick 6]

Can i call you on the phone?

e-mail maybe?

thanks

[email protected]

 

[JoshH]

But no not a BB chevy rod, remember the d-max rod is offset.....

Offset how? That's the first I've heard of that.

 

[Turbo Buick 6]

Offset how? That's the first I've heard of that.

Generaly on an offset rod the small pin bore is not centered over the big end.....if you are looking at the motor from the side. Called an off center motor. Stock buicks are this way but when you went to stage blocks you could get on center or off center blocks.....requires a different intake because the one head sits a little further forward.

I didn't know the D-Max was an off center engine though.......is it?

 

[JoshH]

I remember reading the wrist pin is off center in the piston (hence the arrows saying where up and forward is), but I don't remember reading anything about the rods. That being said, they do install a certain way in the engine so maybe they are.

 

[Turbo Buick 6]

I remember reading the wrist pin is off center in the piston (hence the arrows saying where up and forward is), but I don't remember reading anything about the rods. That being said, they do install a certain way in the engine so maybe they are.

The piston pin offset is in a different direction. All pins are offset towards the drivers side. All engines have that offset in the piston. The rod offset would be front to back.

I will try and take a pic of a buick rod later tonight or tomorrow so people can see what an offset looks like. Its pretty subtle and is most pronounced when you lay it on its side on something flat.


Now I'm curious if our engines are on center or off center.

 

[The Neens]

Can i call you on the phone?

e-mail maybe?

thanks

Damn, now the rest of us are gonna miss out on some good tech info

 

[Turbo Buick 6]

Damn, now the rest of us are gonna miss out on some good tech info

My inbox is still empty:hello:

 

[Turbo Buick 6]

Also rod stretch is caused by rpm, not power. Almost all rods that break from elongation break on the exhaust stroke. Most of us dont spin our motors hard enough to do this so that is why we see our rods shorten from cyl pressure. Although my personal choice would have been Titanium 6al 4v I am interested to see how long Al will last.

 

[LBZ]

Damn, now the rest of us are gonna miss out on some good tech info

We can hold Paul down and beat the info out of him later

 

[Diesel power]

Damn, now the rest of us are gonna miss out on some good tech info

The tech will stay here, i was gonna ask a few header questions..



anyway, the stock d-max rod is offset from the factor, it is offset at the big end of the rod, i dont think it is at the top, but i'll send some e-mail pics so you guys can see what im talking about.

 

[Diesel power]

i sent paul the pics of the rods, it is clear that the offset is on the big end and it's about .250 offset and it is only on the oilsquirter side. The small end of the rod is centered.

 

[ripmf666]

the LB7, LLY pistons area made to run rights and lefts because there is a .030 offset on the piston wrist pin, On the factory LBZ pistons there is no right or left piston to worry about.