I have a Fast Burn 385 (zz4) crate motor in my 85 Z28. The last time i had it at the track i noticed a slight knocking sound just above ide. At the same time i noticed i had no oil pressure at all... So i shut it down and trailered it home. After draining the oil to check for metal i decided it was time to pull the pan and check the rods, sure enough the #3 rod was noticeably darker in color than the others. I then pulled the cap off and there were the remains of the spun bearing and a scored crank.

My questions for you guys are:

Is it likely that my cylinders are damaged from the metal?

And what would be the most cost effective way to get my car back together (i.e. new crank v.s. machining mine), hopefully under $1000....

And what brand of bearings, crank, rods, pistons etc, would you recommend if need be...

Also, what should i think about doing as far a preventative maintenance while i have it tore down this far?

thanks for reading this far and thanks in advance for any input....

 

Chances are the cylinder walls are fine. Pull it out, pull it apart, clean it all out, turn the crank, resize the rods, hone the cylinders, reassemble with new bearings and new rings.

 

Thats kinda what i figured, what kind of bearings should i get?

 

Federal-Mogul 2555A for the rods and 4663M for the mains (in whatever undersize you need after turning the crank), and 1235M for the cam would be fine.

 

awesome, thanks.... hopefully i can have it ready by spring...

 

If you were sufficiently motivated, you could have it done by the end of next week.

 

That would mean paying a shop overtime to get it done. Most machine shops would take at least 3 weeks to get it done based on how much work they have.

To get all the machine work done and new bearings, gaskets, rings etc, I doubt you'll get it rebuilt for less than $1000. With a spun bearing, the crank should be magnafluxed to make sure it isn't cracked. Since the rod was cooked, a simple resizing probably won't help so a new rod should be used. Of course now it should all be rebalanced.

I spent the extra bucks and bought coated bearings. Just a little more protection.

 

I missed the part about the rod being discolored, I thought you were talking about the bearing. That rod'll need to be replaced. If you got lucky, your machine shop might have a set that's close in weight. You could magnaflux and turn the crank, but buying a new one will probably be cheaper.

 

well i have called a few local machine shops and gotten some very different quotes everywhere from $525.00 to $1,500. And all i told them is that i wanted the crank magnafluxed and machined and balancing a new rod, and hot tanking my block to clean it... why would they be so different? and how should i base my decision on what shop to use? $525 sounds nice but its kinda sketchy sounding compared to the other, higher quotes...

 

wow! That sucks. My machine shop down here in Mississippi will do it for 250. Where do you live?

 

i'm in indianapolis... i'm hoping to find someone reasonable....