When your 25 starts a knockin.......

[GTRgeoff]

Adults only horror story. Please keep the kiddies away.

Recently I've been doing a lot of on road acceleration runs to tune my IC water spray and water injection. All has been going well except I forgot to drain my catch can back into the sump regularly and with a whole lot happening didn't keep my eye on oil levels. The can is too small to properly settle out the oil with the sump drain open so I have a tap and I lose some oil to atmosphere through the filter.

Anyways yesterday is a bit warm and I have the window down when a van goes past and I hear this godawful rattling.....and I realise it's coming from my car, reflecting off the van.......OH MY GOD......oil pressure is a bit low....don't panic...pull into a servo and switch off.

The oil is off the dipstick so in goes some more, about 1 1/2 litres and I fire up. Rattling a bit and then it stops so I'm driving home and then I hear it......just when I'm trailing the throttle a little there's some rattle.....maybe the gearbox, it's pretty noisy with this new oil in it, isn't it, I'm just looking for trouble, right? Try it at the next lights, just bring the revs up a little and ease off and...rattling! Dammit.

Once home and into the garage the noise comes at me like a Leopard tank is driving around next to me. I pull open the hood and listen a little and I'm not convinced it's a big end, too tappety so off with the oil filler cap and it seems to be coming from about number six exhaust area and at the same frequency as the cam spinning.

I've since dropped in some stuff supposed to free up the lifters but it still persists and is down on power....not the full power stuff but just lethargic. I can really do without this sort of activity but looks like a partial head pulldown to have a look and see where the drama is. Just hope I'm not convincing myself that it's not too bad....

DAMN MY INATTENTION TO DETAIL

To be continued..........

[Steve]

Sorry to hear, I hope it works out ok.

[JimX]

Is this sound synonymous with the ubiquitous ringland failure?

(sorry for the big words, I was just reading the grammar thread in the wasteland )

[GTRgeoff]

Ring lands...did four pistons due to a turbo compressor seal failure and didn't get any of this. Still only 30000 since that rebuild. The only way to find out will be out with the cams........

[Revhead]

It might be as simple as a blown exhaust gasket or loose manifold bolts... the lack of oil etc makes me doubt this a little, but it's a damn sight easier than stripping the head down

[GTRgeoff]

Rev

nice pic BTW, I bet Ipswitch to Toowoomba doesn't take long at that speed although the hill would be interesting...

Unfortunately it's appearing very much to be a lash adjuster but I will be putting together my audio enhancer to get a clearer idea of the location before anything gets stripped. Lucky i got a spare or two....

Thanks for the thought. Very much appreciated.

[GTRgeoff]

Latest update for the interested:

Turns out I ran #3 big end and scored the journal lightly. The residue in the sump looks like gold dust!

I started with the head off, checked the bores and popped the cams off - everything looking good - which can only mean bad! Torqueing the exhaust cam down I snapped a bolt that had an existing fine crack so a bit of hassle but better to find it now.

Next the engine is supported and the cross member comes out so the sump can come off. Off with the big end caps and #3 is identifiable straight away as the problem but the others are getting close anyway and the crank journal is scored on #3.

No choice now - needed a new engine stand so a 1500lb job for $110 will do from alltools Thommo. Pull the block out and put oil all over the floor of the garage (it's all mine tho so no landlord to p*** off) and off with the cradle and everything is sweet down there but....I have cracks showing in #1 and #5 pistons (stock 30000km 0.5mm OS) and a yucky looking deposit on the #2 bore low in the cylinder like water was sitting in the rings?????

Well this bit I don't do so I will be off to a reco shop to get the journals freshened, pistons pressed off and GTR 8.5:1 jobbies fitted and clearances checked as well as new rings, bearings and basically everything else I can think of but I will still do the buildup myself.

This site has been awesome though and I owe a coupla donations. Finding out that lower comp and stronger GTR pistons will fit @$120 each from the local Nissan dealer is wicked. I already have the good conrods (not the ones with the knob) so thanks to whoever posted that thread and a really cool mate who I have done a lot of favours for surprised me with an autometer oil pressure guage that matches my boost guage as a thanks and chrissy pres so no more low oil pressure.... He rocks and has a cool 180 with a new RB20 install so I am shaking at what that will do with the boost wound up.

New front mount should be here soon and I'll get the dump of BATMBL soon and then my only dilemma is what computer to go for.....

Any suggestions??? Prefer piggyback like the SAFC or the Greddy eManage.

[Cubes]

hrmm gold dust you say.

When I bought my car on 66,000km's the engine was and still is perfectly quiet. Apparently he used to run Magnatec 10w40.

Dropping the first few oil changes I noticed a lot of gold looking bits in the bottom of the pan. I ignored it hoping it would go away and it did. Still today its running fine with no nocking and has had a hammering running 17psi, compression test that I did last week with a set of plugs is still up at around 140psi. Its now got 148,000km's on it.

It will be interesting when I pull the motor out and check out the bearings.

Is it possible you can get a couple pics of the damage so that I know what I'm looking for?!?!?!

[GTRgeoff]

No probs, I'll be getting a small digi tomorrow so I'll post up then.

I have noticed the 33 doesn't have a magnetic sump plug just to collect those nasty bits as a warning.

The good news is I have been told (by She Who Must Be Obeyed) to do a good job of the build this time...do everything.

[Cubes]

Thanx..

[Kinks]

The good news is I have been told (by She Who Must Be Obeyed) to do a good job of the build this time...do everything.

Licence to spend

[Cubes]

If your spending $720 on a set of pistons why not spend another $680 and get a set of forged pistons?

[GTRgeoff]

Just the evidence suggests that i don't need to with the lower compression ratio, so I can spend that money on the Greddy and tuning.

Still have a lotta bucks to spend and value for money is the key. I already have enough power for the track and this round of mods will give me more again, which may not lower lap times dramatically. More power means more speed and earlier braking so other components will have to work even harder. I just need reliability now and earlier boost.

[GTRgeoff]

OK here is the bearing (17)

and the journal on the conrod (12)

and a piston lightly cracked (24)

and one I prepared earlier and drove for 2500km (28)

[Cubes]

Why not polish and clean up the heads combustion chamber (reduce detonation levels) run a set of Forged pistons with a 9:1CR? Lowering the CR will reduce response and spool time.

With a higher compression there is obviously more heat hence why cleaning up the combustion chamber and running a set of forged pistons that can handle that heat better will give you the best of both worlds.

Maybe have a chat to Sydneykid as he is in to the track scene and I rememeber him being down the path of a 8.5:1CR and stating next time it will have a higher CR.

Munro is currently building up his street GTR. It is running a 800hp turbo with a 9.5:1 CR.

What sort of power/boost are you going to be running?

Just throwing a spanner in the works..

Thanx for the pics...

[Steve]

skylinegeoff, sounds like a very understanding minister for war and finance you have there! Good luck with the rebuild.

Do you have a link to the thread that details how to tell the difference between the good rods and the crap ones? Or a photo detailing what to look for?

Cheers

Steve

[GTRgeoff]

Steve

spent 2 hours searching and trying to tie my decision making process together after chasing up Joel's research (into an early grave was one comment) but couldn't find the thread. The evidence was that if it has a knob or protusion on the rod just down from the gudgeon it is RB25det and if it doesn't, it's an RB26dett conrod. I can't substantiate this tho.

I haven't got a limit here but I have to be reasonable about what i do. My brief is to build it so it won't need to be done again for a long time.

So my goals are to:

only slightly improve power

bring power on earlier or spool up faster so around 3000rpm would be nice, have a rigoli modded stock turbo @11psi

prevent detonation again and improve reliability.

Whats going in at this stage:

Hybrid 800hp FMIC (considering hi temp electrical conduit for the ducting as an experiment)

New rings, bearings and gaskets.

tidy up bores, crank, journals, and maybe chamfer BE oilholes

possibly a balance if cost effective (still running factory rev limit so I'm not sure of value for money)

Greddy e-manage complete with tuning

boost controller, either autospeed anti wastegate creep or turbosmart 2 stage

new pistons, and here the dilemma continues.

Go the GTR pistons @ 8.5:1 about 120 ea (not sure if that includes rings, doubt it) and live with lagginess on the road. I'm sure it will be fine on the track.

Slap in a new set of stock 9:1's (about 100 each from japan + rings) and hope the Greddy looks after it.

Contemplate N1 forged (do these come in 9:1????) at a little more than GTR.

Forgies, say Wiseco 9:1 87mm from 1400 with rings and pins, and the associated machining (this is looking better all of the time) so I get better driveability and maybe more durability if detonation occurs unexpectedly (I've had bad fuel before that dumped $30 worth through in 1 hour of driving, lotsa black smoke and no power and was fine after I filled up again in the wife's auto)

Anyway I think i need some convincing, so all of the wise ones are welcome to advise, Warpspeed (wanna let me buy you a coffee and pick your brain?), Sydneykid, and anyone else with an experience or opinion.

I have lagginess below 4000rpm but then it comes on like the proverbial sledgehammer. Through the roundabouts out here I can usually outhandle other 33's and roadbikes and the power is enough to blast back up to them but the lagginess sees them getting away just out of the turns. I'm not really interested in getting another turbo.

[GTRgeoff]

Joel

sorry I wasn't forgetting you. sure the combustion chamber will be tidied up, and you have just about convinced me on the forgies but I have to evaluate the up front costs, pros, cons and long term. I need to get some more info yet, some quotes from my guy in japan who used to send me stuff when I was importing cars as well as other prices and then I can decide, but the lag issue is really grinding me down on the GTR pistons.

[wrxhoon]

skylinegeoff , u can get oversise gtr pistons from nissan for $96 + gst ( .5 oversise standard are even cheaper )and rings $ 290+gst ( trade prices ) but u may have to shop around ( try different dealers )bearings and gaskets are fairly cheap like $130 -140 for big ends and about the same for mains gasket set about $300 but u dont get the 1/2 moons that got at the rear of the rocker covers .

if i was to use new pistons i would always rebore and go oversise pistons and be carefull cause the top ring is chrome u have to hone the bore with a thick stone otherwise it will blow smoke .

if u use forgies use a well known brand and make sure the clearence is correct as u need more clearence than stockies .

[RBVS]

if your keeping the stock turbo a good little trick is to grind out the wast gate a mil or two, you can take more but have to modify a bigger gate to cover the hole. if you got the engine out, it would be easy. resalts being better flow and less lag.