Jump to content
SAU Community

Recommended Posts

Crank stuff

Ive noticed that std rb30 cranks are cross drilled. I guess like most production cranks. The common knowledge is that at higher rpms oil has a hard time getting to the big end journal when it has to fight centrifugal forces acting against it. As a result its usually the big ends that go first normally due to insufficient oil supply...which commonly happens in the higher rpm range.

Has anyone come up with any mods (crank or otherwise) to overcome this, whether its a critical issue or not? Or perhaps even thought about it? I am aware that it helps by running higher oil pressure to overcome said forces, but high oil pressure also robs horsepower, creates excess friction and heat to both the oil and bearings. Obviously if a billet crank was being made soley for performance applications it would be a straight-line or straight shoot.

Block stuff

I know there are a few block mods to do to most rb30 bottom ends to allow them to handle more power for racing/performance situations.. Like drilling out the main feeds to 7mm and the bearing shells to suit. Some even goto the length of grooving the block(not caps/girdle) so you can run gtr bearings with the multiple oil holes on the top shell.

Has anyone thought about or tried perhaps 360 degree grooves. So both block and cap have oil flow around the bearing? You would have to mod the bearing with oil holes so you could take advantage of this, but i would think it would allow for a constant oil feed to the mains/big end.

Obviously with all these extra passages for oil to flow pressure would drop and you would need to either up the pressure or get a higher flowing pump to provide enough extra oil for these extra areas.

Anybody have any thoughts/ideas/tip or tricks?

Link to comment
https://www.sau.com.au/forums/topic/269253-bottom-end-stuffs/
Share on other sites

The humble old RB30 is a very durable device. Just look at how many are still driving around on the roads..

What sort of punnishment are you thinking that you are going to apply to your engine?

In standard form, with standard oil pump, they are prone to some oil issues at hi revs only.

But from what I have found, the problem lies totally in the oil pump itself.

The pump does not like and cannot handle prolonged hi revs. We have had cracked pump housings and such, but never had any oil issues anywhere else with the stock RB30 configuration.

Unless your building a monster engine to do insane revs, it seems to as if your trying to fix an issue that does not yet exist for this engine.

in this part of the forum, look up 'RIPS', he has done some very crazy things with the RB30.

If anybody has struck such issues, it would be him! and he would know how to fix them!

This is all in reference to high end pure race motors...not road cars. Drag, Drift and circuit cars only. Not including peoples road cars that see track work either.

Yeh ive seen the RIPS stuff and followed some of his/their work. Very good stuff. I agree with you bubba. He seems like he holds quite a few secrets close to his chest! But with good reason. It would be nice to know if there are some things he does that he hasnt eluded to publicly. Especially when you get up in the high horsepower and big rpm areas!

Everyone i know who races hybrids have to keep revs low and always seem to have bottom end issues. Often seen in engines pushing 600hp+ and see anything over 7500rpm.

The cranck my be standard but im sure it will be all about the clearences, stud size, clamping torques, oil gallery enlargments including bearing shells, i wonder how much nascar engine spec is applied to a meir nissan 6 ?

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Yes to both! Yes to standard ECU and tune, but exhaust is aftermarket. Unsure on brand. Actually have it sitting in at my desk haha! I have to set it up on my laptop but this is a great next step, will do. So I generally try to shift before 4.5K RPM most times. I largely don't do a lot of high-rev driving, but I will take it up to red 1-2x a week max, as I know the occasional "Italian tune-up" is good for these cars.  Oh wow, is this way better than what I'm getting. Does this mean there's a good chance I have an issue?   Thanks for all the info so far guys.
    • Old Son, did you re-use the Holden ABS in the new shell or try a different module?
    • Yeah, nah. I had the actuator rod off it today. The arm will not move at all. Neither out, nor in. Yeah, you'd think so, but I've been thinking about that. Even when the actuator rod fell all the way off at the beginning of this saga, it would build more boost and faster in lower gears than it would in higher gears, and you'd think that that was the opposite of what should happen. But I strongly suspect that there is a thing with the gearing getting the revs to rise faster, that there must be some transient effect with the gas flow rate rising quickly, that you don't get with the more steady state case of the higher gears. Keep in mind - the gate is not shut in either of my weirdnesses. So things are not "normal". We normally think about a turbo spooling up (below the wastegate target) with the gate shut. I have all sorts of mental models running now where the gate is a little bit open, and having it stuck open allowing gas out while it should be going through the turbine has all sorts of weird effects (in these mental models). I'm thinking in the higher gears, the ex mani pressure builds to the point where enough gases spill out the wastegate to just prevent the pressure rising much more at all, or just creeping up, all the whole the revs are increasing and getting closer to the point where a gear shift becomes necessary.
    • Is it possibly wastegate actuator itself is sticking, or even the rod to flapper? Otherwise I reckon things are getting a bit rusty/worn   Also odd it won't boost in 3rd to 5th, but will in 1st, I'd expect the other way around with it slightly open as there's more time on your way to redline for it to spin up
    • Does anyone know ow what these two plugs are for and if they should be unplugged? Just put the dash back together and can't remember if these were plugged in before or unplugged! (Blue and white plugs) 🤦🏽‍♂️
×
×
  • Create New...