i quit

[SilentNight1647]

I hate to nitpick but OHC motors don't have cam bearings, but besides that you are completely right a master kit for an SBC is $178 my cost right now, and by master kit I mean everything down to the cam. A kit minus the cam, lifters, timing chain, and rings is still like $128. Granted an SBC is not the best comparison but the point is the greatest expense is going to be getting it put back together which is going to cost the same whether you reuse old stuff or not, if it was me I'd save the little extra I'd need and rebuild the whole thing and not have to worry about it. I've scrapped together motors before but they are never intended to last more than one or two nights at the race track. As expensive as it may sound trust me rebuild the whole thing or you will regret it. Good luck getting it rebuilt. Oh, let whatever machine shop you take it too order the parts, generally you will get a better deal on labor because they make their money on the markup of the parts, and trust me they can get it cheaper than you can even if you know somebody.

[TheNeedForZ]

Since you claimed you don't know much about engines...how do you know it has spun a bearing? Did your mech tell you that or does the engine sound bad after oil pressure is back to normal?

 

If it did spin a bearing, the bad news is there could be damage to the crank journals(scuffing) which requires crank be removed and regrind. I am not familiar with the belly side of a Z31, but if you can drop the oil pan without crossmember getting in the way, then theoretically you can change bearings and examine journals from the bottom without pulling the engine, but it's very tricky.

 

Before you go for a total rebuild, ask if you really need it. I'd be bummed if I rebuild my engine to fix an electrical problem. An engine that needs rebuild is one that is ALWAYS down on power(worn tolerance), but it won't give you a problem one day and be ok the next day. Rebuilding an engine will tighten up the tolerances and that's about it. An engine is a system with many components including electrical ones and sensors. After years of service these components expire at different times...that gives you the feeling that you are having car trouble all the time; the parts are taking turns to die just to mess with you. These problems cannot be addressed by rebuilding the engine.

 

If what happened to you happened to me, I'd buy a low mileage engine of the same type(Vg30et ? how much are they?) and swap it in in a weekend. I'll put the damaged engine on the engine stand to replace the bearings. After I fix the damage I'd sell the rebuilt engine or keep it as a spare.

[typhoone]

the mechanic that i took it to said that it was a spun bearing, and he knows his job pretty well. i know, from what i've read/heard, that i need to basically get the crank replaced, that is the point of getting the crank kit. lol and even if i don't absolutely have to have the motor rebuilt, i might as well get it done while it is out. who knows, if i am able to save up some extra money i might beef it up a little at the same time.

[mobythevan]

the mechanic that i took it to said that it was a spun bearing, and he knows his job pretty well.

 

Don't put so much faith in people's guesses. You never know exactly what is wrong until the engine is pulled and torn down. Unless he pulled the engine already and checked it out it is just his best guess. If you ran it out of oil just assume the worst until it is torn down and inspected. If you don't have much money this is a perfect time for you to start learning how to do everything yourself.

[SilentNight1647]

I doubt you will need to replace the crank it takes alot to junk one. Now that you have oil pressure again does it run rough or knock? If not drive it till it dies and save up while it still runs, if it knocks take it out and tear it down. From their make a descion on what to do even if it just to sell it. And remember a complete car with a blowed up motor is worth less to most people than a car with no motor and a box of parts.

[m4xwellmurd3r]

Even if it does have pressure now, it still could be hurt pretty bad. If it does knock, how bad is it?

I spun a rod bearing in my old bug, and I swore it sounded like someone hitting the case with a 10lb sledge hammer.

[typhoone]

as long as i don't get on it hard and try to accelerate it sounds fine, but if i actually floor it it sounds.....bad. a really bad knock and when in park and you rev it up there is a weird sound, which the mech told me was the messed up bearing.

[SilentNight1647]

If their was any oil left in it when you melted the line drain the oil and look at it, alternatively take the oil filter off and cut it it open, you are looking for metal shavings, chips, and misc. pieces if you find any then there is a a very good chance you tore up a a bearing.

[typhoone]

well I just got off the phone with 2 people. my supplier found me a rebuild kit & crank kit for a total of $600 shipped. the other is my buddy Shaun who is basically a nissan guru around here. he has an RB25DET 280z that is just nasty. he said he will rebuild it & everything for $300. so yay me. I will have the parts ordered monday and then I will just go from there. wish me luck.