Forged Rb25 Lifter/possible Oil System Problems.

[DanielH]

Hey guys, just finished tuning my self-built rb25 and I am having problems with the lifters bleeding out and ticking after sustained rpm.

Mods list as follows:

Stock bottom end fully rebuilt with Ross forgies

Oil pump collar

Shimmed oil relief valve in pump

Camtech 272/9mm cams with performance springs

5/8" baffled sump breather plumbed into original location for PCV, both cam covers vented to a catch can.

Oil slightly overfilled.

I have searched and searched but found no definitive answers on what could be the main cause for this, the best advice I've had so far suggests the valve springs are getting soft when they get hot causing valve float, but I would have thought this would cause me lifter pump-up, not bleed them dry and cause loud ticking.

I am currently running shell mineral oil as the engine is still young and the rings aren't fully seated, but the oil is still clean and doesn't smell burnt.

It is tuned on 21psi and probably somewhere around 250-300kw, it's not in a drift car but it cops a hard time on the street, the limiter is set to 7k and this happens after back to back runs pulling to the limiter and ripping skids.

I'm not convinced that this isn't something to do with oil thinning out or oil starvation yet, but stupidly I don't have an oil pressure gauge on the car right now.

Any help would be greatly appreciated, sorry for the long post.

Daniel

[89CAL]

You've left out a few important things. What oil pump? Did you use oil restrictors, if so what did you use? What weight oil?

Im running very similar power, boost and also running the same valve springs and dont have any issues.

Get an oil pressure gauge as well

[DanielH]

Sorry I left them out because there is nothing changed.

its stock apart from what I mentioned, low K's stock rb25 pump with wide drive collar fitted, stock restrictors, forgot to mention no VCT (rb20 cams).

The sump breather is fitted to the inlet side at the top of the sump near the engine mount and baffled to keep the oil out, works well at venting the crankcase.

Shell 15w40 oil.

I'm trying to get onto the gauge as soon as I can.

How hard do you push your car? What kind of rpm do you push it to and do you hold it there for long?

Thanks mate.

[DanielH]

Also do you have cams? I think the 272's are possibly playing a big role in putting extra load on the lifters and maybe causing valve float.

[89CAL]

I have 256 poncams. Ive not heard of such a thing, but trying to think if ive seen any hyd cams any bigger than 270. Dont remember.

What weight oil?

Also, why rb20 cams, why that size without vct? Sounds like it wouldnt be much fun off boost

Edited January 4, 2015 by 89CAL

[Dale FZ1]

You've got a new engine screwed together, but no indication if the lifters were freshened up and scrubbed clean before installation?

[89CAL]

You've got a new engine screwed together, but no indication if the lifters were freshened up and scrubbed clean before installation?

I was sorta thinking this as well, but was putting it at the back of my mind for the moment

Now that I think about it though, my old RB30 did this to its lifters one day:

They are entirely different lifters yes, but crazy things do happen. Might not be the worst thing in the world to pull the cams out and have a look.

The one lifter failing in the RB30 meant I had crazy lifter tick all the time

[DanielH]

I did mention the oil weight, which is 15w40, the head was reconditioned and had the cams/springs fitted a fair while ago, the lifters haven't been touched in a long time, the bottom end has only done around 3-4 hours work.

I chose these cams because I'm running an rb20 loom/ecu, already had tomei adjustable cam gears and just wanted the simplicity of it, it's just a street car, I love the way it drives I just need to sort out the lifter issue.

They have no issues pumping up, they pump back up fairly quickly if I hold it on around 2000rpm.

Edited January 4, 2015 by DanielH

[89CAL]

Oil cooler?

I would suggest doing an oil change with some good synthetic oil (assuming run in is complete), see how that goes

If you pull the oil cap off is there plenty of oil splashing around in the head?

Im running out of ideas that dont involve removing the lifters for a look

[DanielH]

Yeah plenty of oil getting to the head, and yeah the rings have all-but seated so ill give it a service soon, can anyone recommend an oil that will possibly help keep the lifters pumped up a bit better?

And I'm not currently running a cooler, or the factory heat exchanger, that was my concern but then the oil hasn't shown any signs of being burnt?

I have oil temp and pressure gauges to put on it soon and get a better idea of what's going on in there.

[89CAL]

Hmm I wonder if the oil is thinning out too much wothout the heat exchanger or a cooler.

Id do the service and put the gauges in asap

I use penrite 10 tenths 10w40. Only problem I ever have is on cold start I have a little bit lf lifter tick till oil gets around the head but other than that no issue

[DanielH]

Yeah I'll get onto it as soon as I can, powercruise is in 2 weeks here and I don't wanna have to put standard cams in as a last ditch effort

Ill look some more into different oils and try that, failing that ill have to pull the lifters apart and clean/inspect them all.

Thanks mate.

[89CAL]

Get gauges on ASAP. That might tell more of the story. Although not sure where you are going yo put the oil temp sensor as usually I would expect this to go in a line to an oil cooler to save false readings from engine heat

[AngryRB]

I think the cams maybe too much for the lifters, My Ls1 has this lifter problem too but I don't know the history of the car, on Ls1 forums a lot of them have to go aftermarket lifter with a cam swap,

There's some info on this site, its talking bout LS1's but its still about lifters, the stiffer springs and aftermarket cams put more load on the lifter apparently.

www.oztrack.com.au Ls engine trouble info ( article)

Edited January 5, 2015 by AngryRB

[GTSBoy]

Although not sure where you are going yo put the oil temp sensor as usually I would expect this to go in a line to an oil cooler to save false readings from engine heat

Sandwich plate. Oil is not going to be colder than the side of the block the sandwich plate/filter is bolted to (except possibly when the engine actually IS cold).

[DanielH]

This is another issue I was trying to figure out, the only adapters I have for the filter are oil cooler kits with filter relocation, no sandwich plates, I don't really have the room in the engine bay or the time to fit an oil cooler kit in the next few weeks so that's a last resort, if I can identify the oil is getting hot.

[89CAL]

Are you planning on driving it at powercruise? If so I would suggest finding the time to install an oil cooler

[KiwiRS4T]

And put in some 100% synthetic oil.

[GTSBoy]

the only adapters I have for the filter are oil cooler kits with filter relocation, no sandwich plates,

Really? I bought some 2" stepper motor gauges off an eBay vendor and got a plate to go with. And that was one of many options for getting such a sandwich plate. I'm sure I've even seen them at AutoCheap etc etc.

[DanielH]

I might just play it safe and smash one of my oil coolers on it, least ill have somewhere to fit my gauge senders.