Topic: Overheated rod small end a problem? *pic*

[Swoop]

Hi,
I have one rod that shows signs of overheating of the small end compared to the others.
Fitment is good, no cracks or scoring....nice and smooth to the touch.

Would you use it?

Thanks
Steve

[Swoop]

Tough question?

[scottly]

Steve, it's a tough question to answer without more info, like how hot did it get? The color will help determine that.

[Swoop]

Thanks....I’ll post up a pic soon.

Steve

[Swoop]

The one on the right is blacker at the top....they all have some extent of discoloring.....is the heat or burnt oil.
Click on the pic and it will rotate ....damn ipad.
Thanks

Steve

[PeWe]

Wrist pin look bad too?
I had rods with bluish small ends, wrist pins looked bad too. All 4 rods replaced with pistons, probably 2 valve guides too...
Like this. Rust happened after the event 1984...

[Swoop]

My pins had the two outside dark lines that are on yours but nothing in between.

[BPellerine]

I have never seen used pins that did not have some sort of lines where they run in the rods,so that would not be a worry to me if they measure out ok,and they are not pitted,the rods dont look like they were severely overheated in the pic,but look for any scoring on the inside of the small end,and check the rod for straightness,if all is ok I would use them in a street engine that wont be beat too hard.bill

[Swoop]

Thanks everyone.

[754]

I think the dark part on the side, that was not wearing against pison, makes it look worse..
If they are smooth inside, you should be good..

 I can't look at PeWe,s and say some  could not benefit with running an oil cooler.

[PeWe]

I think the dark part on the side, that was not wearing against pison, makes it look worse..
If they are smooth inside, you should be good..

 I can't look at PeWe,s and say some  could not benefit with running an oil cooler.

I'm still not sure what caused that burn out. Carbs were not jetted lean. I guess it was the ignition that was wrong. 10 something in CR is more sensitive. Easy to forget checking 2-3, maybe too advanced by point wear.
I remember it was a problem with Mikuni VM29 carb bots cracking up. This should have ended up in higher idle, but not.

Engine was not hot nor ambient temp high either.
But it ran very hot a month earlier in Jugoslavia that might have blueished the rods before the final detonations. Wide open 4-1 since I started the journey with a silent baffle that was too restrictive. Too open means leaner.

Next pistons had less CR since head was done for the higher domed melted ones. Less CR worked fine on longer high speed travels.

If the small ends look fine inside with visible hone pattern they must be fine.  If used with 836 and/or higher CR I should replace the rod. Stock rods are available on eBay for not that much. Look for same rod marking for same weight?