A few issues with my RB20, need help

[RB20DET_Z]

Ive done a bit of searching and have found some bits of info here and there, but wanted to get some peoples oppinions on the issues Im having with my RB20.

 

I was driving the car from Miami, FL to Asheville, NC and along the way the following issues came up:

 

-Blew out the plug from the old turbo H2O line fitting on the back of the head. Fixed it and kept driving.

 

-Blew the tranny main seal shortly after that. Tranny fluid leaked onto my exhaust and the transmission well burst into flames on I-95. I pitched the car into a muddy shoulder and put out the fire. Tow truck got stuck in the mud and it took about 2 hrs to get the car out. Sourced a main seal from a 300zx and replaced it.

 

-Another 70 miles later the freeze plug on the back of the head blew out, temp gauge didnt go up (bad sensor?) and i ran the car with no H2O/coolant for IDK how long, but it overheated pretty badly. At that point I had the car flat bedded the rest of the way to NC.

 

So the car is sitting in my back yard with no freeze plug. I went to start it up this morning and it turns over fine, no ticking or whinning from the engine or head (thank god, I dont think its warped but cant tell yet). The car is very low on oil though, and Im worried that it might be related to the overheating incident. Ive run water through the radiator and let it pour out the open freeze plug and I dont see any oil in the water. When turning over Im not getting any smoke from the head or exhaust.

 

Is it possible that some damage to the head caused oil loss? I just had the head ported/polished/decked, new Tomei HG with ARP studs installed, so I seriously doubt the HG is blown (unless the head got warped).

 

Ive heard you can use a plummers expandable plug to replace the freeze plug and they work fine. Anyone have any experience with that?

 

Even if the head is warped it should start up, it will just run like crap, right?

 

Im going to do an oil change, plug up the block and see if its alright. Anyone know of anything else I should check before starting it up again?

 

Any input would be appreciated. Wish me luck.

[fentin_fury]

man is that a s****y trip! Is the oil burnt - still has some lubrication quality to it? I hope so - and be looking for metal frags in the oil once you drain it - use a magnet.

 

a blown head gasket can cause oil/coolant to mix - for sure. However being that low on oil (as you described) sounds more like it was being consumed. Pull the plugs and look at them.

 

It should start with a damaged head gasket - and it may run fine. Watch for bubbles in the coolant, wath that temperature guage! Hope everything is fine

[RB20DET_Z]

The oil was burnt, yes. When the car overheated I pulled the dipstick and the oil was practically smoking. Is it possible that I blew something in the bottom end that caused the oil consumption?

 

And yes... it was a unbelievably s****y road trip.

[fentin_fury]

once it is that hot - who knows. I bet the piston walls are scored. Broken rings/pistons? So many things COULD be bad - and maybe none. Check that oil carefully for bearing material. Copper is not magnetic - so let it sit for a while and see if anything settles to the bottom - say in a glass jar.

 

I would be suprised, given what you say, that the bearings - all of them - have not been affected. I suspect at this point that starting it will do no harm - but if it is banging away - shut it down!

[RB20DET_Z]

Well I plugged the head with a expandable freeze plug and that seems to do the job. Did an oil change as well. Battery is damn near dead and even with a jump box and a jump from my other car it was turning over but not catching. It rumbles like it wants to start, i can feel the pistons cranking over a bit, but it just wont fire up. Im gunna change the spark plugs tomorrow as Im sure theyre all fouled up after what happened, just didnt have the time to get to it today.

 

Im thinking that the bearings are shot. The engine was squeaking and shreeking horribly when it over heated, sounded like the bearings were going. I didnt see any metal shavings in the oil, gunna check it later once it settles for copper. Im starting to think that Im gunna need to pull the block and replace the bearings/rings. If thats the case the car will be out of commision for quite a while untill I have the dough to build the bottom end a bit more as long as Im taking it apart.

 

I imagine once I do get it fired up Ill be able to tell more accurately whats wrong with it.

 

Looks like I could be another few grand deep into this engine before im gunna get it running right.

[Careless]

for the price of the RB20, I would look into getting another motor. Then you have a spare motor to build up with better parts and practice head porting on, and you have a spare block to fit with some forged goodies.

 

I would not rebuild the bottom end of that RB20 because you might need a line-hone, a good grinding on the crank, and your cams are probably starved of any lube + cylinder walls a little scorched.

 

If it starts up and runs like a bag of ass, get a new RB20, with no transmission. It will be a heck of a lot cheaper, and you end up getting the entire engine, with the turbo and everything, so you have spares.

[RB20DET_Z]

Yea, I was thinking the same thing. I was just looking at prices of another RB20 and $750-$1K seems better than pulling a building out my existing bottom end for the reasons you just described, and as you also mentioned, ill have spare parts and can take my time building my existing engine.

 

If the engine isnt running at 100% when I get it fired up Im gunna source another longblock and just swap it. That would only take me a few days as apposed to a month of build time. Oh well, good thing I bought another car when I got to NC. Seems like Im gunna need it for a while.