Rb25Det Neo (R34 Gt-T) Valve Clearances (Solid Lifters!)

[Ruxis]

Hey guys,

I have a severe ticking noise from a lifter on the intake side.

I researched the entire Internet looking for a service manual for the neo head and none exist in English >.<!

I found in a thread on here the valve clearance is .38mm for intake .5mm for exhaust but today I saw on a sticker on my bonnet In and ex .2mm

I pulled both rockers off today (as I bought both gaskets) and planned to go off the bonnet reading and expected to find 1 clearance out compared to all the others with .2 clearance, measure that shim and bobs your uncle!

Sadly... I put a feeler gauge of .3 through all valves easily! Was questioning if it was a non turbo bonnet with that stamp but it had rb25det on the same sticker. No NEO though, so thought it MAY but highly unlikely is a r33 bonnet.

So last resort so I can actually know what size it's suppose to be I'm asking, has anyone done this job before?? Does anyone know the valve clearance of a R34 GTT RB25DET NEO engine???

Let me just emphasise it is not the same as a 33, it is solid not hydraulic lifters with a NEO head.

Jarrad.

[Aggroman]

Oh Jarrad, you come to me for everything else why not this..

You need to be better learned in the ways of the internets as I have an english version on my pc.. the answer for you is in the pic below

[JonnoHR31]

Havent downloaded it but should be english

http://www.skyline.se/dokument/R34_All_Workshop_Manual.pdf

[Ruxis]

Hmm .31, sounds about right. Haha do you have a NEO head dave????

Should of came to you

I looked through that but couldn't find it >.<!!

[snozzle]

there is something wrong there, rb25det neo valve clearance for stock cams are meant to be .20 on both sides

i have done a poncam install on an r34 and all valves were 0.20 before i took the stock cams out (had to reshim to 0.40 or so as per tomei specs), it was a while ago but im fairly certain ! They have half the valve clearance of rb26's hence the lack of ticking like the rb26s

Edited April 9, 2012 by snozzle

[Ruxis]

See two different answers! I'm so confused!

I threw .25 under WITH EASE! And .3 with ease on all too.

Hmm so much confusion

[KiwiRS4T]

What's your problem?

My R34 Manual which I have on DVD shows the same table as post #2 and if you want to see it with your own eyes you can download it yourself from Paul's website:

http://www.paulr33.com/

The table says .36 for inlet and .53 for exhaust so yes your .3 blade will fit under both.

The clearance for the Neo DE is the same as for the DET.

[DVS JEZ]

Did u try a bigger feeler gauge then .3mm?

Did u find any that the .3mm was really loose under?

Was there any abnormal wear marks on any of the cam lobes?

[Ruxis]

Well how come snozzle and my bonnet say .2mm???

Yeah I fit a .38 under one but it was tight as. So on the angle I was on that probably would have been right.

When I was doing it I thought f*** this I'm just gunna have to pay someone to do it, (as I live in Newcastle and I was at my folks I need to get home in a few days), so I kinda gave up with it and boxed it up cause I didn't know how long it'd take, (was easier then undoing everything :S) plus we don't have micrometers and no one is open on a public holiday to even try to borrow them, that's if I was willing to take the cam shaft off that day to get the shim off!

So plan B, I'm going home tomorrow and I'm gunna do it without dads help (eeep), so I won't rely on the transport.

But first I wanted to know what clearance is right, it seems the clearance should be .38 but idk why my bonnet says differently :S

And there were no wear marks JEZ, few black marks on them but looked more like just being old, was very smooth to touch

[DVS JEZ]

Which cylinder do u think is causing the loud tick?

Can u try disconnecting the suspect cylinder/s coil pack when its running and see if the noise is still audible.

Also try disconnecting the VTC solenoid and see if the noise is still audible

[Ruxis]

I think it's from the intake side on one of the back valves.

Yeah I can do that, if it's slop in a lifter would disconnecting a cylinder do anything??

Is my vtc solenoid under my timing belt cover??

[DVS JEZ]

Vtc solenoid looks like a little penis near cyl 1 injector.

The reason for disconnecting the spark is to see if the noise is in the rotating assembly ie piston or rod

[Ruxis]

ah righto, ill give them a go probably tomorrow, heading home today so ill be pulling it to pieces then.

[Ruxis]

FOUND THE BASTARD!

1 shim on the intake allows a valve clearance of .63mm!

double the specs!

calling nissan tomorrow, i called them before and they said they should be able to help me out, but i didnt know the size at that time.

anyone know somewhere else i could buy it from in newcaslte if nissan cant get it???

cheers for the help everyone.

[GTSBoy]

The real question is....how did it get like that? Just shimming it back to correct clearance won't fix the cause, just the symptom.

[Ruxis]

not to sure, cam lobes look fine.

and its the 5th cyl, if the shaft was bent youd think 6th would be bad too.

it was noticeable then after the track it got a lot worse, so maybe it started from the first track day then worsened on the second??

no idea as to why, thats what the brilliant minds here are for

[GTSBoy]

The likelihood of the camshaft being the cause is quite low. I'd be wondering what could happen to the valve stem or the seat. Closing tolerances are usually easy. They're caused by valve seat recession (most of the time). But opening tolerances are another beast.

[Ruxis]

well thats good haha. looks like an expensive part with alot of screwing around.

hmm... so the question is, is the valve getting a bit sticky and not going down as easy as it should causing wear,

or, was the valve for some reason, maybe even manufactuer fault, it was out of spec, then with high revs it could of cause chatter in the vavle that over time wore it down?? (probs less likely)

or is the valve not going down low enough?

hmmm, cant think of much more.

or am i talking crap?

what do the geniouses think???

[DVS JEZ]

Did u do a comp or leakdown test? Curious if the cylinder is down abit

[Ruxis]

nah never done one, and car is still in pieces.

hmm which one would be best to do??