Con Rod Discoloration on a blown 03 RX1

[pig]

Hi guys,
I have a blown RX1. The con rod on piston #3 failed. It appeared that the nut got loose and bent bottom con rod. The rod put a rather large hole on the side of the crank case. In addition. one of the bolt or the blown rod is completely bent out of shape but retained on the upper con rod.

Upon on the tear down, the bottom of the con rod along with the crank shows significant discoloration (sign of overheated). I suspect that this overheat is the initial reason that cause the nut to loosen.

Have you guys experience this type of overheat? (only on piston #2 and 3). If so, if I rebuilt the motor, what are the things I need to watch/do to ensure that the rod/crank does not overheat?



Thanks in advance!

Dave

 

[BETHEVIPER]

i have crank, rods and pistons if your interested
just search in my posts for the list of stuff i have for this motor.

 

[pig]

Hi BetheViper,

I can't seem to figure out the search feature... Can you provide me a link to the list of parts that you have?

Thanks!

Dave

 

[BETHEVIPER]

sorry, my classifieds passed the sunset, ill pm you a price

 

[rxrider]

To prevent it from happen again you could send in the crank to modify the oil feeding holes to increase oil pressure at the bearing surfaces.

Here's a few companies offering that service
Falicon - http://faliconcranks.com/
APE - http://aperaceparts.com/

 

[pig]

Rxrider,

Thanks! You are correct.

After some more tear-down and inspection. It appears that there is just not enough oil running through the rod/crank. To compound the problem, the journal bearings have rotated out of alignment, thus cause some pitting on the rod bearing surface.

This is a lot ugly than I thought...

 

[DaveyBoy]

Is this stock or modified

Discoloration is caused by lack of oil,tight clearances

If a rod bolt came loose you would have this happen I have heard of this happening supposedly on a 03 i belive race24x was his screen name here and he had a similar issue if i remember right i will search his post and see when i get a chance.

I cant believe that the oil holes in the crank are not adequate for a stock engine more info please

 

[pig]

Unfortunately, this is a completely stock engine...

The cylinder bore still have honed marking.

 

[rxrider]

Blown as in a destroyed motor hmmmm, thought you ment a blown (turboed or supercharged) RX. There is no need for modifying a crank in a stock (145 HP) motor.