Why you need stronger rods

[Otto J]

THis is what happens to a 109 block when you break a rod or 2
This is Len Freemans(LVGN) motor from a few weeks ago

 

[Otto J]

2

 

[Otto J]

If you put that nice eagle crank in put some nice rods also!!

 

[Otto J]

Carnage consists of the block,crank,2 rods, a billet roller cam, a set of roller lifters(most are stuck in the block) and a complete set of intake valves.
This was a girdled 109 sith steel mains

 

[gndemon]

What did it take to do this much damage? Just so I know what not to do to mine.

 

[YeaItsSlo]

Originally posted by gndemon
What did it take to do this much damage? Just so I know what not to do to mine.

yeah, tell us please..

 

[azgn]

I think mid 9's at 143

 

[86brick]

Detonation??

 

[gndemon]

Originally posted by azgn
I think mid 9's at 143

That's ok high 9's will be good for me. For at least a mouth or 2

 

[Intercooler]

Just curious why the edges and beams of the rods look rusted or brown? I honestly haven't seen rod failures in these motors but I am learning. What rod options are there? I thought Eagle was working on it but haven't checked in a while.

 

[TurboDave]

Originally posted by KLHAMMETT
Carnage consists of the block,crank,2 rods, a billet roller cam, a set of roller lifters(most are stuck in the block) and a complete set of intake valves.
This was a girdled 109 sith steel mains

Hmmm, those look like stock rods... If so, why? Sounds like a lot was done to try and make the motor live into the 9's. But a chain is only as strong as it's weakest link

 

[Otto J]

They were stock rods, And IM not gonna say how hard the motor was being run,but it was as AZ GN says.But it broke 2 connecting rods,Probably the first broken one broke the second 1. He said it just stopped suddenly,No noise or anything,Just stopped.

 

[Otto J]

Originally posted by CallMeMud
Just curious why the edges and beams of the rods look rusted or brown? I honestly haven't seen rod failures in these motors but I am learning. What rod options are there? I thought Eagle was working on it but haven't checked in a while.

It broke about a moth or so ago and has been sitting with a hole in he side of it,So probably moisture.

 

[Intercooler]

Looking at the side of the beams (polished regions) I don't see any brown. I would think that would rust first. I wonder if he lost oil pressure and it got hot. Especially the big end of the rods! How many spun bearings. Hopefully he is tearing it down to try and figure it out.

 

[Tony87gn]

Started to scare me for a second when you said if you are putting in the eagle crank get nice rods until i read mid 9's. I will be only going mid 11's so i hpe Im fine

 

[xlr8ngn]

That brown is rust. If you look at the bearings, you can tell if it got hot. Just talking, that is why race motors and street motors have different clearances. A race motor has more clearance, because friction causes heat, and heat has to be taken away from the bearing. It is carried away with the oil, and the larger the clearances the more oil flows and the more heat can be carried away. If you have tight clearances, the flow of oil is less and heat can build up and cause a failure in high HP applications. Again, just talking.
Looks like the crank was externally balanced. The rod beams are polished. Looks like some weight was removed from the crank to balance, so must be light weight pistons. I can't tell, but it looks like some of the main webbing may be polished a bit? Any details on the build?

 

[Tony87gn]

Thats exactly what my Eagle crank looks like. I had metal taken out as well because I didnt have enough money to buy the parts to internally balance it. Looks like it is externally balanced then.

 

[Intercooler]

Originally posted by xlr8ngn
That brown is rust. If you look at the bearings, you can tell if it got hot. Just talking, that is why race motors and street motors have different clearances. A race motor has more clearance, because friction causes heat, and heat has to be taken away from the bearing. It is carried away with the oil, and the larger the clearances the more oil flows and the more heat can be carried away. If you have tight clearances, the flow of oil is less and heat can build up and cause a failure in high HP applications. Again, just talking.
Looks like the crank was externally balanced. The rod beams are polished. Looks like some weight was removed from the crank to balance, so must be light weight pistons. I can't tell, but it looks like some of the main webbing may be polished a bit? Any details on the build?

Does it look like it got hot down there to you?

 

[xlr8ngn]

Does it look like it got hot down there to you?

No way to tell without looking at the bearing. The brown is rust and can be seen on the side of the rod in pic 202.jpg. It is also on the chamfer of the oil passage in the crank, on the counter weights, etc. Unless there was a defect in the rod, catastrophic rod failures without warning typically occur from detonation. The chamber pressure goes out the roof before the piston gets to TDC, causing the piston to cock sideways in the bore and bind. It all goes down hill from there. But in our engines, typically the webbing breaks first, but this block was supported by a girdle. Six of one, half a dozen of the other.

 

[750H.P.V6]

Guy's,

I've been in touch with Len and he sent me these same pics last week. Not all the info is currently available since the motor hasn't been completely disassembled yet. The crank is still in the block and Len hasn't attempted to remove the big end of the broken rod.

If the rod bearing is burnt up it is an oiling problem, if the bearing is fine (within reason) then the failure was either related to detonation or possibly the rod failed in tension due to continued high RPM use. The jury is still out.

Better rods are always a good idea in my opinion. It is always better to over build any high performance combo rather than under build it. BTW, the rust is probably due to the fact that the engine at for a month with oil/water in the pan at the chassis shop while the roll cage was being worked on.

Neal