so the title says everything
after 60K miles on stock bottom end i've got number 8 rod bearing problem and cracked number 1-3 pistons on stock engine (only mod is ported heads and stand alone ecm) !!

the first question is ,is there anything about number 8 bearing ? i've seen some people had same problem

i'm going to build a engine that can handle 250 shot and i'm really on budget
there is my list for new engine


reliability is very important to me , i don't want to repair engine soon


1-Sealed Power L2490NF30 - Speed-Pro Forged Pistons

2-king sl series main and rod bearing

3-JE Pistons J103F8-40305 - JE Pistons Pro Steel Piston Rings

4-Clevite Engine Parts SH1349S - Clevite Camshaft Bearings

5- arp heads and rods bolts

6-cometic mls head gaskets

7-fel pro gasket set

i'm going to rev the engine about 6700-6800


what's the best rod bearing and main bearing clearance for my setup? 0.002?

any advice's for oiling system?

going to set 0.04 for piston to wall
0.025 for first and 0.030 for second ring
is that the best ?

what's your opinion about retarding the stock cam about 4-6 degree? i know i will lose low-end power but the high end power is more important to me

please answer the bold notes , thanks

 

no one??? i'm going to order the parts !!

 

As far as oiling systems many people tend to over complicate the matter and end up spending money on parts that are actually a step backwards. So definitely stay away from modding it without proper research. Higher pressure is not necessarily a good thing if the rest of the system is not up to the task.

In regards to retarding the stock cam, the benefits will be minimal at best and you're better served swapping in an aftermarket cam matched to your goals. The equipment required to do it properly will set you back as much if not more than a new cam that will make more power.

 

A good main and rod bearing clearance is between 0.0018" to 0.0020"

As far as ring gap, check with the manufacturer.

Instead of throwing arp bolts in your stock rods, I'd just buy new rods altogether. After buying the bolts and resizing them there will be little price difference.

 

Did it crack pistons 1, 2 and 3? If so, you need to find out why....or that might be the fate of the new engine. Maybe I don't deal enough with engine failures, but that sounds very unusual. Makes me wonder if the tune was bad.

Why exactly are you running a standalone ECM on a mostly stock motor?

http://www.enginebuildermag.com/2001...ston-problems/

 

You don't have a bearing or piston problem.

You have an engine management problem.

Until you spend money on that, you will spend boat loads of cash on pistons & bearings.

 

I use a melling select pump and an upgraded oil pump drive, I have never used king bearings, I prefer Clevite 77 H series for any main bearing.