My motor was assembled by my dads machine shop, hes not use to honda motors, but does great work. After 1500-2000 miles my block started to knock. Pulled the motor and here is what we found:

Eagle Rods / ACL Bearings





This is a turbo motor, but i figure i'd get some good replies in here. The clearances were within OEM spec, but on the tight side. Any ideas on what the cause is? Were thinking overheated bearings because of the clearances? Any other ideas?

 

damn......bearing damage always sucks

you say the specs were within OEM but a little tight? i would say that might be the problem. find out what the exact specs were on the bearing clearances.

what kind of oil were you running? did it get worse over time? or did it just start knocking out of the blue? were you beating on it or just driving it normally?

good luck

 

have you checked the main bearings?

 

with a turbo u should have went on the loose side

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by .CUBISH. &raquo;</TD></TR><TR><TD CLASS="quote">have you checked the main bearings?</TD></TR></TABLE>

x2... what was the clearance on the rods and mains?
I'm not a big fan of ACL's ...but thats just me.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by non-VTEC &raquo;</TD></TR><TR><TD CLASS="quote">damn......bearing damage always sucks

you say the specs were within OEM but a little tight? i would say that might be the problem. find out what the exact specs were on the bearing clearances.

what kind of oil were you running? did it get worse over time? or did it just start knocking out of the blue? were you beating on it or just driving it normally?

good luck</TD></TR></TABLE>
We plastigauged number 4 rod bearing and it was .0010". I was running 15w40 rotella. I was racing , around 5000rpm i felt a suddent loss of power, i let off got it under the light, checked the oil, ect.. Oil was fine, but thats when i heard the knock. I pulled the valvecover to make sure it wasnt in the head. Got the car back to the shop, got it on the lift and could tell it was coming from the block, pulled the oil pan, had some shavings/flakes pulled the rod caps and found this.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by .CUBISH. &raquo;</TD></TR><TR><TD CLASS="quote">have you checked the main bearings?</TD></TR></TABLE>
We only pulled one main cap and it looked fine.

When i pull the crank and rods to take to the machine shop, i'll check the rest of the mains.

 

Clearances seem to be a little on the tight side, detonation, and possibly to thick of an oil also

 

I've seen excesivley rich put enough gas in the oil to do that. What were your a/f ratios?

 

That is overheating from not enough clearance and detonation. Ck the side rod cl. also.

 

not enough clearnace. and maybe the street tune u had done?

 

ouch, .0010?

thats out of spec and scary tight. This is a b-series?

why the 15w40?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 743power &raquo;</TD></TR><TR><TD CLASS="quote">ouch, .0010?</TD></TR></TABLE>

It was tighter then that, .0008"

Yes, b-series