What Is Wrong With My Rb26?

[Beer Baron]

gnome infestation is not usually so common in the early RB series, i have heard of one or two cases of it in late model (34) RBs though.

i think if you get the brotec beak upgrade kit for the woodpecker that should sort out the problem.

[Jordan]

You should have thought to include a polaizer if you knew you were going racing.

[The Dan]

I have a leakdown tester  but you will need a compressor to do the test , i can do for you if you like and i maybe able to give you a more educated guess as to whats wrong with it .

If its a bearing you will do more damage to the crank by running it but if you pulle it out you should change the crank with a new one anyway , if you spin the bearing then conrod through the block is possible .

If the crank was machined they would have used undersize bearings .

Injector can be noisy warm or cold .

A lifter can be come noisy when the clearances grow , there nothing wrong with the lifter , just bigger clearance . you can check with a filler gauge but you need to take the rocker covers off .

The lower comp on the 2 cil maybe because they had the valve clearances to tight ( to have a quiet engine ) and the valves are starting to burn a little .

Did you check comp before ?

You are correct in saying a leakdown test wont tell you if it leaks for valves or rings but it will still tell you more than a comp test .

To much oil in the cil thats the reason comp went up so much ( you made the combustion chamber smaller ( like having higher comp ratio ) .

<{POST_SNAPBACK}>

A leakdown test WILL tell you whether it is rings or valves. You will hear the air passing out the exhaust or inlet if its a valve or out the rocker cover breather if it's a ring.

Being a GTR engine it will have shimmable buckets so you will need FEELER GUAGES to check valve clearances. If you don't know how to do it then take it to a professional.

Have you done any engine building before?

The bearings won't need to be oversize if the crank was just polished. There would be no need to machine the crank unless there was damage to it from the previous bearings.

What clearances did you measure on the big end's and mains?

What piston to bore clearance did you have?

Did you use new rings?

Did you offset the ring gaps?

Did you get the alloy dowels taken out of the crank and replaced with threaded studs? (you should have)

What oil pressure does it have? (idle, cruise and full noise)

I would not remove the engine until you have seen the condition of the shims and cams. Check these first before doing anything else.

[Duncan]

...Have you done any engine building before?

...What clearances did you measure on the big end's and mains?

...What piston to bore clearance did you have?

... Did you use new rings?

...Did you offset the ring gaps?

...Did you get the alloy dowels taken out of the crank and replaced with threaded studs? (you should have)

...What oil pressure does it have? (idle, cruise and full noise)

Gday mate....answers in order (I hope)

Nope, I just read the instructions. I did have some help and had professionals do the head reco and the bottom end machining.

Unfortunately I'm not sure, the bottom end shop did it and said they were OK for standard bearing size but did not give me the exact measurements....never again.

As above

Yep brand new standard nissan rings. measured ring end gaps before installation and they were within spec (once again I didnt note the measurements)

Yep offset per the manual no ring gap pointing to the front, rear or side of the bore

Nope, bottom end has to be stock for class regulations.

Oil Pressure is perfect about 6ish dead cold, rises to 8 if given a little rev cold. Was correctly at about 2 at the end of the race. It looks fine which I think is kinda wierd if it is a bearing problem?

And...where do I get a leakdown gauge and what is the approx price for a decent one?

[Duncan]

Well I know everyone has been holding their breath with anticipation about an update, so the good news is we tore down this motor today.

First up we can rule out woodpeckers or gnones, unless they were made of metal and hit the turbine wheel.

First hint that all was not great was when we pulled the intake pipes off there were metal shavings in the intake, both sides of the cooler. I assume this is not "a good thing"

Pulled the turbos off, rear one looks like this:

Anyway, from there there are not too many mysteries....like everyone said a spun big end bearing, no surprise among the sea of metal filings in the sump.

Block is light scored, should buff right out.

Crank slightly damaged, may need machining undersize, will see what the machine shop says on Monday

[wilch]

whoa, longest tear down ever!

I wouldn't rule out the gnomes yet. They must have been hindering this tear down to make it take a whole year, and they must have also used their special powers to erase your memory of them.

[Duncan]

lol...you know in a funny co-incidence it is exactly 12 months since I stuffed it! rushing I am not.....

[MANWHORE]

What killed the turbo though, that is the question.

Doubt a knome being sucked into the intake could do that

[PHATR32]

the knome could have had steel fillings in his teeth!!

anyways, what did cause the damage on the turbo? loost bolt? socket??

[Duncan]

never found what actually did the damage, I guess it could still be in the intercooler it wasn't in the intake, plenum or motor (well bits of it were...but not the whole thing). Either way seems it is a bad idea to have large metal objects hit a turbo blade

[MK2]

Guess if youre missing a socket or something after you buttoned it up might be a clue

ed- damn that looks hurty expensive...

Edited August 27, 2006 by MK2

[nobby]

So....what is wrong with my RB26?

Recently rebuilt by a engine builder with very suspect abilities. Completed 2000klm since rebuild including 4 oil changes. Running standard computer and standard boost. Rev limit is 8500.

Last 1000klm since running in finished have been a practice day at Wakefiled Park, a race meet at Oran Park and a race meet at Wakefield. In the last race at wakefeild I heard a knock on the last lap, finished the cool down lap and parked it.

The problem - there is a knock/tap in the motor. rises with revs

Oil pressure is normal (great)

Compression test results:

# - Dry test - wet test

1 - 10.5 kg/cm2 - 12.5 kg/cm2

2 - 12 kg/cm2 - 14 kg/cm2

3 - 12 kg/cm2 - 14 kg/cm2

4 - 12 kg/cm2 - 14 kg/cm2

5 - 12 kg/cm2 - 14 kg/cm2

6 - 11.5 kg/cm2 - 13.5 kg/cm2

Battery was boosted by a running car, engine was dead cold. No leakdown test

The noise sounds like it is coming from the top of the motor, maybe at the front or maybe I am imagining it. I put a screwdriver on the head next to my ear, and looked like a person with a screwdriver in my ear.

Anyway....lets have some educated guesses about what is wrong...answers to come sometime in the next few weeks when I get around to pulling it out.

[nobby]

try this, a mate of mine recently had a crank angle sensor fail and the engine made knocking sounds like you describe, and my r32 gtr has just developed the same sounds, you could expect if the sensor fails the timming is out badly and as a result engine knock so try checking this, also check coils, igniter . i`m hopeing for both our sakes its as simple as this, and back on the road again. it may not be the fault of the engine builder at all, and as past experince has tought me dont be to quick to assign blame. so good luck with your car

[Duncan]

haha thanks but there have been some updates since my original post

Both turbos needed new bearings due to metal in the oil farking them, and obviously the new blade.

Big thumbs up to John at Precision Tubros in Wetheril Park, he has put them back in 1 piece quick and cheap

Still waiting on confirmation of the bottom end damage / whether it will buff right out or not

[GTRgeoff]

How interesting mate.......surely you heard this happen or was Kel driving [ducks and runs].

This has almost taken as long as my track car but I've just had approval to pull it in and start dismantling.

So how much was the turbo rebuild and did it include steel exhaust wheels?

[someonestolecc]

[Duncan]

1200

new wheel, 2 sets of new bearings, machining housing oversize 10 thou and balancing the whole thing. Assembly and disassembly.

And all in 3 days

[Duncan]

BTW no Kel was not driving, and 12 months later I am still very busted for blowing it up before she got to drive it properly.....should be back together soon.

The more I think about it the more I recokon a nut or something was in there right from original assembly...it never made any bad noises until the bearing spun.

But I never put it on the dyno or checked compression, didn't get around to it....might explain why I was OK in the tight stuff but the baddies got away on the straights

[GTRgeoff]

Steel Wheels on the back end or the stock ceramics? No damage at the back end whe the foreign object went through? PM me the shop details please mate? I wanna keep the TT concept running even if I am going to sell the car and get something else for track.

[GTRgeoff]

Oh and the nut was the one behind the wheel.......