sirt_eg

Ls/vtec low compression.

Took out the first piston and rod and found out there was some up and down score on the wall and piston. Before taking it out I pour some oil in to see if its leaking but it's not. The car never burn any oil before but the only problem was it had a bad compression and smoke was coming out of the breather hole.

Was just wondering if it might be the piston that is causing the low compression. the ring seems to look fine. I'll try and get pictures up.

Former User

Might the headgasket have been bad? I assume the valves are fine?

sirt_eg

no leaks in the valve's or anywhere. It might be a headgasket, but its a ge ls/vtec headgasket. torque to specs, but I guess I'll have to find out.

sirt_eg

here some pics,

cylinder walls. Need honing? doesn't look that bad and can't feel any deep scratchs.


piston score. Looks pretty bad, I dont know what the cause of this. any suggestion? for sure its not useable, but the ring and everything is still good. weird.

Former User

Any excess free play in the wrist pin and rod bearings for the bad piston? How about the crank journal? Was the engine knocking?

sirt_eg

took the rings out and guess what happen. not a pretty sign. engine wasn't knocking at all.

Former User

What do you think caused that damage? Did the piston collide with the head? Are you sure there wasn't a problem with the rod bearing?

TravisCadello

Holly **** man that looks nasty. seems like a bad wrist pin.

TravisCadello

and yes it needs to be Honed.

sirt_eg

rod bearings are fine. there acl and hasting rings. Is the piston suppose to move side to side on the rods? I wouldn't know but I guess its time for some new piston cause I know noone sells only 1 p73 00 piston.

jmyers09

did it ever spark knock before you took it apart.

Former User

There should be very little end play. Did the bad piston have the most end play?

sirt_eg

nopes, never spark or knock. it just gave me a low compression and the car just shutters and dies some times when sitting on neutral.

Former User

How long was the shutter and die thing going on?

sirt_eg

it only did it for like 3 days than we took it apart.

Former User

Was the block recently rebuilt?

sirt_eg

okay let me get this straight so everyone will know. The block is rebuild. hone, wash, micropolish crank and balance, itr water pump, gsr oil pump, machine ls rods, and jdm p73 pistons. It only had 5k miles before the head had a bent valve and was rebuild.

The car ran fine before, it was fix and put togather in milwaukee. I did a compression test and it came out perfect straight number across but once I got to minnesota I trade my car with my older brother cause I didn't want the car anymore. He drove it for like 2 weeks than the car started to act up. smoke coming from the breather, car shutters and dies when sitting on neutral (sometimes), and he told me if he takes the car to 100 and lets go of the gas and puts it on neutral the car will die, so he has to start it up, but the car runs after that.

Head is rebuild with a valve job, new seals, valves, springs, retainers,and resurface.

maybe it just needed tuning, which I told my bro. It just running on a basemap ls/vtec high compression. also its only running 240cc or 270cc obd1 si injectors.

Former User

Sounds your rebuilt engine has been through a lot in the last couple weeks.

TravisCadello

did it have full oil. thats what it looks like. oil starvation. that or u should had let it break in longer. daam that sux id be one mad mother ****er if i were you. Good Luck.

sirt_eg

its not my car anymore so I'm not mad. It did break in for 10k miles. The head was rebuild around 5k miles than I drove it for another 5k. Never abuse it or red line it. It only happened when my older bro drove it. I guess he got too excited over the car. ohwell.