KatfishRacing

iTrader: (6)

Ok, I have the engine apart and have found the problem. The #6 rod bearing is TOAST and the #5 is pretty worn.
<img src="http://www.katfishracing.com/images/bearing5n6.jpg" alt=" - " />

Obviously the crank under #6 is worn.
<img src="http://www.katfishracing.com/images/crank1.jpg" alt=" - " />

Now what? Do I replace the crank, #6 rod and all the bearings, or do I have it machined? Are there other options?

Thanks for the help.
Mike

zZAndrusZz

Stroker!!! <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> Or you could just have the crank machined, and replace all the bearings. Good luck with it!

KatfishRacing

iTrader: (6)

Im not going to stroke this one, for 4 grand I would rather be blown than stroked.. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

Just so I dont appear to be a total idiot when I go to the machine shop, do I have just the #5 and #6 part of the crank machined or all of them?

cablebandit

iTrader: (37)

i would do all....i never liked a mismatched crank tho people do it

zZAndrusZz

If it were me, I'd do em all, you're gonna get all new bearings anyway, hopefully. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

Andy

Will Race 4 Food

Mike,
have you determined now WHY the bearing spun? They don't just spin for no reason. The engine is telling you something. Check out your oiling system. Zero oil pressure, even for a short period = spun bearing.
Cheers. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

BADZ

iTrader: (5)

I would turn down all the Journals to be simetrical and go with a longer rod...

Will Race 4 Food

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by BADZ:
<strong>I would turn down all the Journals to be simetrical and go with a longer rod...</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">If you spun the bearing, it won't be because of the rod length. It has an oiling problem...Check out your filter religiously, and magnetic drain plug when it on the road. Did it ever have low oil pressure during hard acceleration/deceleration? Again, spun bearing = oil system problem.
Cheers <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

BADZ

iTrader: (5)

I was not refering to why it happend but only the question as to a fix. That's it...

Will Race 4 Food

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by BADZ:
<strong>I was not refering to why it happend but only the question as to a fix. That's it...</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Good advise also.... <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

KatfishRacing

iTrader: (6)

I have been looking into why it spun as well as how to fix it. The day before the symptoms begain I noticed that the oil was over 1 qt low. This is normal for the car, burns about 1 qt every 3000 miles. The oil pressure had dropped a bit was running around 30 instead of a little over 40 at idle. The pressure did increase with accelleration before the symptoms began, but not up to the level that it normally did.

My guess as to what happened is that I went a little too long after my cam swap before changing oil a second time, let it get too low and starved the bearing.

I am going to upgrade the oil pump while I have the motor apart, and I have definately learned my lesson about being religious on the 3000 mile oil change!

Mike

<small>[ June 13, 2002, 06:29 AM: Message edited by: KatfishRacing ]</small>

cantdrv65

iTrader: (3)

When my engine gets about 1.5 quarts low and I accelerate hard the oil pressure will Drop on hard accel!! IMHO this is what causes spun bearings in the Ls1...They do NOT like to be run low on oil.