small block HELP...keep spinning the same bearing - Page 4

JohnM · #61 (**permalink**) 11-23-2008, 04:43 PM

Hello All

sorry for the delay as I was out of town on business.

Now for the good news...the engine is finished, and is back in the car and broken in. Lots of oil pressure, no leaks, drips or KNOCKING NOISES!!!! The engine builder took care of it and did right by me.

I have attached some photos of the (previous) new crank that was installed, one engine build ago!!!...which started this thread. The same connecting rod bearing turned again after just 45 minuted of run time...see previous posts

The crank is has about a -003 groove cut down into it...but not all the way around...maybe just half way or even a little less. The groove tapers down to nothing on the top side. The groove is just on the one side of the journal...for one connecting rod, the second half of the journal for the second connecting rod is clean and nice..no marks etc...no blueing or discoloration from heat etc.

Its hard to believe how rusty the crank got just sitting in my garage after being exposed to rain in the back of my truck on the way home from the builder

I also decided to go with new connecting rods this time around

any thoughts?

Again thanks all for you advice and suggestions etc

John

vector1 · #62 (**permalink**) 11-23-2008, 05:15 PM

that groove actually looks like it was cut, i would be expecting more of a tearing, and between the two rods, wow, definitely different.

good luck with your new engine, sounds like you have somebody who'll stand behind it.

JohnM · #63 (**permalink**) 11-23-2008, 05:53 PM

It had to be something with the connecting rod.....I just find it odd that the damage is not all the way around the journal just on 1/2 or less..on the bottom side toward the oil pan and not the top side toward the engine.

even if the connecting rod was bad or that bearing was bad shouldn't the mark be all the way around?

John

CHANMADD · #64 (**permalink**) 11-23-2008, 07:14 PM

What crank and Rod's did you use? I hope your builder champhered the oil holes this time around. If you look in the 3rd pic it appears that the crank has been worn away on the bottom side of the journal. Not enough oil and/or an oval big end?

JohnM · #65 (**permalink**) 11-23-2008, 07:22 PM

the crank was a SCAT cast crank...the rods also were "stock" eagle rods. The oil holes are all chamfered etc.

so far so good.....I am in NE Ohio so weather is not good, hopefully we will get a couple of days that I can try it out

John