turned out to be a defective rod bearing...a huge chunk was ripped out of the #2 rod bearing. I should be back up and running by this friday

 

car is up and running strong with a new set of bearings...next problem is a slipping brand new spec super twin "ss trim" clutch. Not happy about this next problem at all...

 

Personally, I think you wasted your time. The stock motor will be reliable with good tuning on E85 and proven to 600whp+.

You are better off keeping the stock bottom end and maybe swapping rod bolts than you are honing an in car drop in build. Contamination from honing, clearances being correct, cylinder bore consistency, wrist pin fitment and getting a ring seal as good as the stock pistons had are areas of concern.

Furthermore you increased compression ratio to 9.0:1 pistons, then lowered it back down again with a thick Cosworth headgasket which was a waste.

 

Wow... I can't say that I am surprised.

I did not read the whole thread or get to the last page until my post showed up.

Basically what I wrote in the above post seems to have held true. You lost the engine shortly after the build.

What concerns me even more is that you believe that there was a "defective rod bearing". I don't believe that for a second. They don't just fall apart on their own.

Furthermore if you did not replace your oil cooler, your motor WILL fall apart again as the metal from the damaged bearing recirculate the oiling system and spread back throughout the engine again.

Lastly, it would be a RARE occurance to have bearing damage without CRANK JOURNAL damage so if you just replaced your rod bearings and put the engine back together, I am sure that we will see you posting a new update shortly that the same rod bearing spun again in the first 500 miles.

Sorry to be the bearer of bad news, but there is a reason we do NOT recommend drop in builds. They will never be setup for reliable use and there is A LOT that goes into building a PROPER engine build.

 

Just to clarify, I should have said this earlier after much deliberation I decided to pull the balance shafts, have the clearances checked, rotating assembly balanced etc...this ISN'T a drop-in setup anymore despite the title of the thread. oil cooler, lifters, and entire head and block was replaced and/or hot tanked, flushed etc. The current motor has a brand new crank, bearings, etc.

The motor as it sits now was built by a competent machine shop that is very familiar with evo's or the 4g63 motor. It now has Eagle rods, Weisco 1400HD pistons, stock head gasket, Clevite bearings, ARP main studs, etc...

The last issue was something of a "freak" occurence that the machine shop has never seen before. The #3 rod bearing lost a chunk of material that apparently was due to a manufacturing defect. We picked it up before it got bad by cutting open the oil filters. It did not spin the bearing. There was a small divot in the bearing going down to the steel with the surrounding bearing surface undamaged, weird. Machine shop insisted that it is a defect. It did not damage the crank journal. As of now the motor is back up and running strong on 33psi and E85

 

Update: almost 500 miles on her and still going like a raped ape!! I will keep updating this thread once I get some 1/4mile times