Rep Power: 0

I have a 2005 lx civic which I am doing a stock rebuild on due to heavy oil consumption (1 qt every 500 miles). At this point the block is prepped and nearly ready to be put back together however I have a couple of concerns. For reference my bores measure 2.952" and Crank at 1 & 5 main journals are 2.1646"

#1 My piston ring end gaps are as follows:

-Top (.014")

-Second (.019")

-Oil (.018" - .019")

The honda manual states the following specs:

Standard or New , Service Limit

-Top 0.15-0.30 mm (0.006-0.012 in.) , 0.60 mm (0.024 in.)

-Second 0.30-0.45 mm (0.012-0.018 in.) , 0.60 mm (0.024 in.)

-Oil 0.20-0.80 mm (0.008-0.031 in.) , 0.90 mm (0.035 in.)
My top and second compression ring end gaps fall slightly outside of the "Standard or New" spec, however the oil rings are well within spec. I am concerned that the compression rings will allow for some excessive blowby leading to issues such as oil consumption miles down the road but then again the oil control ring gaps are good to go. What do you all think? I am considering getting the bores oversized .020" and starting fresh but those numbers above aren't crazy far out of spec so might not be necessary.

#2 My Main bearing oil clearances at journals 1 & 5 are slightly too large using oem Brown bearings. They apparently discontinued production of the next 2 larger sizes (black and blue) and I haven't been able to find aftermarket bearings equivalent of the oem black or blue size YET. Any recommendations short of machining mains?

Any experienced opinion will help. Thank you very much

 
Rep Power: 367

OK, this one might require an expert...
@ezone , more your alley
104k miles

 
Rep Power: 518

What are all those weird maths numbers? I am but a simple parts replacer. Really, it is rare to actually get that deep even with a simple rering.

1 quart on 500 miles is a hell of a lot of oil. You positive only 100k miles on that rig? Block has a vin tag, does it match the vehicle vin? Odometer discrepancy?

Did the engine knock? If yes, replace the engine.



Sounds like its beyond cost effective. Boring and buying more pistons is not cheap imo.


If it did not knock and had no lube related issues, if the cylinder walls still show the original crosshatch pattern from honing, it would probably have been a good candidate for a basic simple in frame rering. Rings from Honda. Clean the piston grooves and install.

I bet a used engine is cheaper than what you want to do to this one. Used unit plus strip it and replace rings, head gasket, timing components, reseal oil pump, with genuine Honda parts may still be more cost effective than your major overhaul your way.




God I still hate typing on a phone.

 
Rep Power: 518

I'm avoiding dealing with the. Numbers because in a shop meat factory we rarely, if ever, actually get that precise. Simple matter of 'if it's wrong, what can you do about it-- because that's gonna take a lot more money than was in the bid or estimate.

Experience comes in handy here. How bad do I expect it to be without opening it up to see,, vs estimate used replacement with bench refresh.

Idk price of a used engine but there comes a point where that is likely the more cost effective fix.