The oil light came on idling at a red light the other night after some hard pulls, however my pressure gauge did not show a loss in pressure when the light was on (what causes the oil light to come on? Is it strictly a pressure loss? I later tinkered with the plug and it may or may not have been loose). I was a few blocks away from the house and I noticed this noise.

The sound in the video only shows up at around 2500 RPM briefly. It also doesn't seem to really be there when the engine is cold. Tomorrow I will cut apart the oil filter to see if I can find bearing flakes.

I'm really scratching my head as to what that noise could be. Almost sounds too rapid to be a big end bearing. But the fact that it's not there when it's cold is a little unsettling. I've also read on lots of RB forums guys think the sound is coming from the head, which this one kinda does, and it ends up being a big end bearing. Any ideas?

Funny how I bagged the living s*** out of this engine all summer last year and the first few hard pulls this year she gives me problems.

[youtube]http://www.youtube.com/watch?v=vaOz7zgrgrQ[/youtube]

Sounds like big end bearing to me.

yeah...sounds like you spun a bearing which = rod knock. i wouldn't run it any more in hopes you can save the rod and crank.

Sounds exactly like my WRX did with the bad rod bearing. Stop running it, the bearing may not be spun yet.

did you fit restricters to the block when you built it?
may have been pumping all of the oil into the head...

Carl H wrote:did you fit restricters to the block when you built it?
may have been pumping all of the oil into the head...

Yes. I don't get it. Why would it all of a sudden spin within the first few hard drives this season. I bagged the s*** out of it all season last year with no ill effects . I pray that the crank isn't scored yet.

I did have the sump overfilled last season and I forgot to this year. That may have done it. Guys on SAU recommend 6L in the sump!!! Lol.

odd, i do roll with 1qt high in the pan.
how is the pump, you have a collared crank right?

Carl H wrote:odd, i do roll with 1qt high in the pan.
how is the pump, you have a collared crank right?

Not sure how old. It's the stock RB20 pump. I inspected the internals when I built this thing and it looked fine. But it gives good pressure and I didn't see the pressure falter at all. Yes I had the extended collar pressed on.

Edit: This is all speculation. I don't even have the motor out of the car yet, let alone inspection of the bottom end. Who knows what happened.

what bearings where used and what was the clearance?

its VERY easy to get dirt into an engine when assembling..

was the crank checked for straightness?

Pulled it apart tonight. I immediately knew what happened when the bearings were clamped on the journals.



Nothing a ballpeen can't straighten out.



Hey guys, it's ok if my bearing shells look like bacon, right?



At least the journals look ok.

Yep. She starved of oil . I think I remember the corner that did it in actually, a sharp U-turn at about 7k. Lucky it was on the street and not a track where I may not have noticed it. I also forgot to overfill the sump. f***! Damn RBs and their starvation issues. A few more hard pulls and it might have been a different story.

This is how THREE of the six big ends looked lol. But at least the journals look half decent and can be reground. But in the spirit of this build I may even gamble and just polish them up, new shells, and slapper back together. Experienced guys, what do you think?

have the crank polished, spec out the bearings properly and roll with it.
damage looks minimal.

did you torque the bearing caps to the rod with the bearings before you installed them in the motor?

Yes. I did that to mic the bearings to figure out oil clearance. Everything was in spec.

make absolutely sure you check the line bore on the block as well as the big end of the rods. typically when something like that happens the big end of the rod ovals out and with multiple rods doing it, it could have messed with the line bore on the block as well as warped the crank. there's no point in doing all the work to put it back together if you don't check that and it fails on you again.

Ok thanks for that robbie. I think thats good advice.

also, be sure to remove all the plugs in the block and bottle brush it all out.
would also be a good time to grub screw the crank and such to clean out the gum that has been centrifuged into the crank cavities.

robbie2883 wrote:make absolutely sure you check the line bore on the block as well as the big end of the rods. typically when something like that happens the big end of the rod ovals out and with multiple rods doing it, it could have messed with the line bore on the block as well as warped the crank. there's no point in doing all the work to put it back together if you don't check that and it fails on you again.

And double check that your piston return springs aren't worn out!

But seriously, do it right, do it once. Do it half a**, do it twice. This is good info for me because I've never read anything about running the sump 1 qt over. I think I'll start!

Carl H wrote:also, be sure to remove all the plugs in the block and bottle brush it all out.
would also be a good time to grub screw the crank and such to clean out the gum that has been centrifuged into the crank cavities.

Why/where would one grub screw the crank?

basically you drill out and tap the factory oil plugs in the crank, all sorts of fun stuff gets spun into them and its practically impossible to clean the crank properly without removing the plugs.
its one of those places people miss, if you have to take the motor apart and remove bearing metal then you'll want to do this as well.
whenever mine goes i plan to do this as i was in somewhat of a hurry to get my block together.

Sounds like a big chore. Lol. but I can see why would would do that. I imagine that upsets the balance too no?

shouldnt affect it too much, if you're getting it polished you can have it checked at the same time.
just remember to loctite the screws in place.

Well what the f*** f***.

I rebuilt it. All was well. Every clearance was within spec. Seemed to be running great. 1.5 weeks later, same f*** thing. Another spun bearing sound. I am beside myself. What the f*** is causing this thing to starve the bottom end like this? I had 6L in the sump this time, hardly revving it to 6500. I had a few hard pulls on it but nothing major. Last time almost every big end was burned, and the mains showed signs of burning too. I suspect that with the same time frame and similar symptoms, this isnt a f*** coincidence. Oil pressure is fine. It's like someone jammed a f*** eraser in every oil feed or something.

Any ideas before I push this f*** thing into a river?

was the crankshaft checked for straightness?

did you pull the main oil galley plug and clean it?

post pictures of the bearings when you get it apart...

Carl H wrote:did you pull the main oil galley plug and clean it?

Sure didn't. Which one are you referring to? But I dont understand how this happened right after swapping heads. And now it's happened again in the exact same timeframe. I didn't touch the bottom end the first time this happened.

The Sau guys are suggesting knock. Im running 8.3:1 with 16* of timing. I'm sure it isnt knocking. If it was knock, for it to kill the bearings in that amount of time would be amazing.

RRRRB wrote:was the crankshaft checked for straightness?

No unfortunately I forgot to get that done.

RRRRB wrote:post pictures of the bearings when you get it apart...

Thats what the big ends looked like to varying degrees last time. The mains were less severe which stands to reason.

how much boost/power were you making on 16* timing

Also who clearanced the bottom end? there are lots of things that could contribute to the problems your having, and not doing the things that have been suggested could likely be the reason your having issues..

Straight 6 engines are very prone to bent cranks simply from improper storage or tipping it over etc...

The bearing pictures you posted doesnt look like a contamination issue to me thats generally more distinct and inconsistant..

Id suggest taking it to a reputable machinest to have all this checked, including the main line and perhaps have someone else assemble the bottom end... engines are not complicated as long as everything is inspected clearanced and put together correctly you WONT have issues... ive assembled quite a few engines many over 500whp and a few over 700whp and all are running to this day...

what type of oil do you run?

^ what this guy said.

email me your maps, i'll check the tune...i've done a few ecus now :p.

RRRRB wrote:how much boost/power were you making on 16* timing

Also who clearanced the bottom end? there are lots of things that could contribute to the problems your having, and not doing the things that have been suggested could likely be the reason your having issues..

Straight 6 engines are very prone to bent cranks simply from improper storage or tipping it over etc...

The bearing pictures you posted doesnt look like a contamination issue to me thats generally more distinct and inconsistant..

Id suggest taking it to a reputable machinest to have all this checked, including the main line and perhaps have someone else assemble the bottom end... engines are not complicated as long as everything is inspected clearanced and put together correctly you WONT have issues... ive assembled quite a few engines many over 500whp and a few over 700whp and all are running to this day...

what type of oil do you run?

Bout 14 psi on the 6262. Should be just shy of 400 whp with my tune.

I did all the measurments. I used plastigauge on the mains and a mic with an inside mic on the big ends. I'm a mechanical engineer. I do downhole tool design for the oilfield so I'm well versed in tolerances, mechanical measurements, assembly, etc. I assembled the original RB30 which like i said ran for two seasons filled with racing. I had also replaced the rod bearings the first time I built it.

I agree with what you said about engines. They are simple and should run correctly as long as like you said everything is checked correctly. Some people make them about to be some kind of mythical beast that need an engine whisperer to be made to run properly. A shop that wanted my money told me if i reused my rings it would smoke like a chimney; they wanted to build it for me. I've rebuilt it twice now aligned the rings properly and it hasn't burned a drop.

Something is f*** with something. Here's the sequence of events:

Buy RB30 and RB25DE head
Completely disassemble bottom end - clean - replace rod bearings - reuse mains - assemble
Race for two seasons
Buy RB26 head - put on RB30 block without touching bottom end
100 km of driving - developes knock - disassemble, bottom end is cooked
Rebuild with new mains and big ends
100 km of driving - develops knock - and I imagine bottom end is cooked in same fashion.

Something to do with my RB26 head? Seems like a bit of a stretch.

If I'm gonna haul that thing into a shop I might as well have it forged :/. But I want to make sure it isn't some finnicky thing causing this that would be outside the realm of an engine builder.

I was running 5w30 Mobil 1 the first time it went, and it was just some s*** dino 5w30 this time. I was just running it for a bit and i was going to switch to German Syntec 0w30 which is more of a 0w40.