B18c1 OEM rebuild dead after 10k miles?

[jjrosales79]

Ok, here is the low down. I had to rebuild the motor due to a spun bearing back in 8/08. After going over my options I decided the best choice was to do an OEM rebuild with a few aftermarket parts. Here is the build:

B18c piston set w/ rings 81.5mm
B18c engine gasket set
B18c OEM oil pump
B18c water pump
B18c timing belt
ARP head stud kit
ACL bearing set w/ thrust
Machining - bore, hone, polish
Head resurface
Hondata S300
Hondata intake manifold gasket

This build was based to be a street driven car w/ boost to be added after I got the suspension, braking, and other parts that needed replacing. I got this rebuild back and had noticed that the motor was eating oil. At the time I did not think nothing of it because I figured I would need to break it in and then assess after about 2k miles. Was I wrong, less than 3 months later the motor began to knock. This I learned was due to the motor eating about a quart of oil a week and the bearings had begun to warp due to not realizing the severity of the oil issue. Keep in mind there was no oil leaking on the ground, as I would have noticed this quickly. There was some leakage on the head, but it didn't seem like a quart a week. So I get the bearings switched out and discuss this oil leak problem with my mechanic. After a couple more months I begin to realize that at high RPMs (5k & up) the exhaust would smoke and once I shifted it would blow out the smoke. Again I directed this to my mechanics attention. I continued to keep an eye on the oil, but at $7 a piece for Castrol full synthetic it becomes a problem. So, 3 weeks ago I finally set up an date for the car go into the shop to check this out, plus I chose my suspension (function & form) and was to have a water temp & oil pressure gauge installed. A week later I am taking my Sunday cruise and on the way home I hear a rattling in the motor and then a load bang. This I now assume was a rod bolt coming loose and it put a crack in my block. Which virtually renders the motor useless now. Now I am just looking to get various opinions on the motor or what the cause of the issue may or could have been? This car was driven daily and as one could expect had some hard driving done, but nothing to over the top.

 

[CAFROG]

so you leaked or burned oil?

Leak...well...thats a leak

If your burning oil...new motor...sounds like the rings were not grinded down correctly or were the wrong ones in general (the smoke coming out sounds like piston rings)

How'd you break it in?

 

[jjrosales79]

nah, there was no leaking, that one could notice quickly. break was normal everyday driving, didn't really do hard rev driving till after 1st oil change, which was about 2k miles.

so oil leak into the piston would cause burning and quick consumption?

 

[CAFROG]

....yeah...you burn it right our through the exhaust valves.

from what I've read...it is better to be strategically hard on the motor when breaking it in....

Down shifting and such to seal the rings

But I can't see that being the reason your motor blew.

i think it has something to do with the rings though....not necessarily the way you broke it in

 

[CAFROG]

out not our

 

[jjrosales79]

yeah, that's how i drove it. down shifting at about 3-2.5k. the motor would hit good, it was fun to drive. i just knew something was screwing with the oil.

 

[CAFROG]

you put it together or a shop?

if a shop....what kind of shop?

I would;ve used OEM bearings...which also come in various sizes (by color)

but other then that and the rings....I dont know what couldve been wrong

 

[jjrosales79]

a local tuner shop, in TX. the shop does pretty much all hondas.

what would be the difference between the bearings?

 

[esi42]

Oem bearings are better because of all the sizes they make. The sizes are desginated by a color code system. With most aftermarket bearings, you just get STD size. Most hondas use a combination of colors so thats why people prefer oem. You can run STD size aftermarket bearings if they are within spec, a lot of people do. If its a 10k rpm race motor, I wouldnt recommend it. If its daily driver, youll be fine. Oh yeah, oem bearings cost WAY more too.

Did they check the crank after the first spun bearing? Maybe it had microcracks that led to bearing failure.

Did they have to rework the rod that had the spun bearing?

Same oem rod bolts?

The oil use is puzzling though. I 2nd the rings theory. Something was wrong there.

 

[CAFROG]

The bearing size could have been a factor...or the crank^^ (but not sure on mileage and mashing-smashing history of motor) I've been told though...that a 'regular re-build' (not changing piston size over re-build specs) should be straight forward in terms of bearing selection....Honda/Acura parts dept. can lead you to the correct bearings for.....lets say a 81.5mm re-build piston.

Something was binding up most likely.

 

[jjrosales79]

everything was reworked. i saw the parts myself before it was even put together. now if there were micro-cracks that could not be seen with the eye, then that's a different thing. it looked clean, all ports were machined and polished. it was just the oil that was getting guzzled. gas mileage was decent. when this happened it had just hit the 10k mile mark, during that time the motor maybe saw 8k rpm 10 times, and that's being generous. most shifting or smashing was done between 6.5-7.5k, because from my observations of dynos most of the peak power is distributed between those ranges. again this was not done very often either, didn't want to kill the motor. this project was not something i rushed into, i took some time and thought into what i wanted the car to do and be used for. this car was never gonna be a track car. it was just something to enjoy and play with.

as for the bearing, thanxs for the info. i'll keep that in mind as i proceed w/ the reconstruction of this motor.