I'm sorry to hear about your situation.

Obviously this won't help you at this time, but a couple post mortum notes may help down the road or prevent someone else from making similar mistakes:
You mentioned you added 15W40 oil after the fact - were you running 15W40 to begin with?
If so this may have contributed to the problem in that a thicker oil will cause an increase in oil pressure (significant increase depending on the oil) - beyond what the aftermarket relocation kit was likely able to hold.
An important note is that higher oil pressure is NOT a good measure of lubrication. In fact, quite the opposite.
I remember a post a few years back in which one poster was convinced higher oil pressure = better lubrication, and ran 20W50. It took several members to convince him he was making a grave error.
The lubrication system is designed to run within a specific range (hence specific recommendations for oil viscocity), and oil pressures outside this range (low and high) indicate oil starvation is either happening or is imminent.
S2000 oil pressures are high to begin with and using an oil that's outside the recommended range (with an OEM oiling system) is not advisable or warranted.
15W40 is simply too thick for a an S2000 with stock oiling and bearings. You were likely starving the bearings of oil (marginally) well before the blown hose dumped your sump.
Lastly - there is nothing in the RP formulation that will provide a benefit in the setup you're working on. Every bit of data I've seen regarding the specs and performance of RP has shown little benefit over conventional oils and performance levels (in many areas) short of much less expensive oils such as Mobil 1 EP and Pennzoil Platinum. Frankly speaking, the only oils I'd consider if I was making a high HP turbo car would be Redline or Amsoil. Both oils have proven performance benefits over any other oil available in the U.S. market. Amsoil currently makes the absolute best 10W30 available, and Redline offers several robust sythetics.
You need to modify your oiling system and bearings if you're dead set on running a thicker oil. There's nothing wrong with running a 10W30 in a high HP FI setup. In fact, I'd consider running Redline 5W30 due to the tight clearances in a turbo's bearings.

 

slipstream444 Posted on Jul 17 2008, 06:02 PM
Allthough I'm no fan of 40 weights anymore (.. I have used a 0W-40 one OCI) I don't think a 40 weight is too thick for the S2000.
Btw.. Honda has the 5W-40 as an alternative viscosity for lower temps (IMO! because of the 5W) so one should not have any problems with it.

If this below is the RP 15W-40, then this pdf shows it's 14.9 cst at 100C.
Yes, that's "thick" but will not cause bearing failure.
http://www.royalpurple.com.au/files/...H/rpmoamps.pdf

No oil, or even a short period of no oil, is bad for crankshaft journals.
Ask me how I know.......

 

My point wasn't to blame bearing failure due to using the wrong weight of oil at all - that was obviously due to oil starvation. I didn't communicate my point very well and apologize for the ambiguity - I'll blame it on rushing a post due to time constraints. Let me please clarify.
My argument is more at start-up, when a 15W40 will certainly not flow very well - unless the ambient temp is already 50+C.
Additionally, it takes longer for the oil to get to operating temperature than it takes your car to get to three bars on the coolant temperature indicator - especially with a thicker oil - during which time oil pressures can be higher than normal and "marginal" oil starvation can occur. A spike in oil pressure due to revving the engine to the redline during this transition phase (three bars on the temp guage makes it seem okay - but perhaps the oil was too thick due to being too "cold") could have contributed to blowing one of the oil lines to his remote setup.
His car showed very good leakdown numbers, but cylinder wall lubrication is not the issue here.
I totally agree with you - once the oil is completely up to temperature, there likely wouldn't be an issue. It's getting that thicker oil up to operating temperature where the issue is.

BTW - I'm still trying to find the Shell synthetic oil you've been using. Unfortunately, you can't get it here.

 

A fast way you can find out if the lower end knock is from a crankshaft main bearing or if it is a connecting rod bearing is one by one removing a cylinder from firing.

While the motor is running, pull a connector off of one of the coil packs.
Doing this you will be taking the pressure off of that connecting rod and its bearing.
If the knocking noise was to stop when removing the cylinder then you know you found your bad bearing.
If after you try one by one, eliminating each cylinder the noise never stops, your main bearings are the cause.

Hope this helps! Good luck.

 

slipstream444 Posted on Jul 18 2008, 03:58 AM
Very true!
Yep
I doubt that.
Maybe up top = valve train.
Wouldn't the oil pump's bypass prevent that?

Shell Helix Ultra X 0W-30.
AFAIK it is/was OEM Volkswagen diesel "pump

 

I can't answer that.
However, since the OEM oil filter setup is being bypassed and it's a remote setup - it's reasonable to assume a surge in pressure would affect external lines. I know of a number of external setups that deliberately relocate the oil pressure sending unit to the remote filter mount for that reason and to measure any pressure drop caused by relocating the filter system. Remember, when the filter is screwed onto the side of the motor, any pressure feedback would be much faster than if the oil has to be routed through lines to a remote filter block and then back through lines to the engine again. The lines become dangerous weak links, as demonstrated in this example. If the lines are too small to handle the volume or too weak to handle the pressure - the results become self critiquing.

 

slipstream444 Posted on Jul 19 2008, 08:40 AM
With the pump being the only source of the pressure, it can't be higher anywhere else in the system than at the pump.
IOW, the pump's bypass vavle prevents pressure build-up in the system.
With cold & thick 15W-40 oil, it starts to pump oil back into the sump, not force it through long thin oil lines.

Yes, my guess is that the lines broke due to vibrations, bad material, etc.
Yes.. by itself that's true but the 15W-40 had nothing to do with it IMO.