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

[DVS JEZ]

A leak down test is best as the pressurizes the cyli der and u can test if the valves are leaking ie the valve that has more clearance, normally this is due to a foreign object, slightly bent valve or a valve seat that has moved but doesnt have to be one of those.

Did the engine idle smoothly?

[Ruxis]

Yeah Righto, can it determine how long the engine is going to live for aswell??

How much does one of them roughly cost??

Yeah smooth as. 5 or so seconds the odd choof but I've heard that on my mates gtr with 30,000kms on it too so thinking it's normal.

[DVS JEZ]

Yes skylines do tht 'choof' as u say intermittantly. If it idles smooth and doesnt sound like a constant missfire then it shoukd be ok.

Im just trying to work out why the clearance is what it is

[Ruxis]

What's with that??? Is there a reason behind it??

Yeah idles good, accelerates hard, and smooth through the rev range.

Hmm yeah not sure ay. Should I just see how it goes? (changing a shim would he a cake walk if I had to do it again.), or should I dig deeper now that it's open?? I could possibly lift the bucket off the valve stem and look down there for anything noticeable?

[DVS JEZ]

Take the bucket out and see if the valve top is mushroomed or worn down.

Has the engine been rebuilt before?

[Ruxis]

righto shall do,

nah man this car has never been touched, for example had stock head deck and speaker, speakers were blown, replaced them and it had all original wiring, had no alarm, paint had never seen clay, polish or wax (fixed that problem). exhaust had original bolts, gaskets etc never cracked.

previous owner must of purely used it for a daily and never touched it.

[Ruxis]

ok pulled the bucket out and the valve gear all looks normal compared to others

there is one difference, the liner that the bucket moves up and down in has some wear marked (in an up down direction), would that be from it being out of spec and being wobbly though??

[GTSBoy]

Measure the thickness of the top of the bucket, the shim, diameter of bucket and the bucket bore. Compare all this with at least a couple of the known good ones and see if anything stands out. You're going to need a micrometer, verniers and possibly an internal micrometer (or some trustworthy calipers that you can put down inside the bucket bore and then measure with something else).

[Ruxis]

im getting a brand new stainless digital set of verniers (which could measure inside and outside) really soon, hopefully i get them tomorrow so i can start putting it back together!

plus i got feeler gauges? :S

if not i got a set of non digital ones but there kinda hard to read when it comes down to the .00mm

i measured the old shim for a new one with the calipers on it and a feeler gauge on the ruler part of the calipers haha. still, if i didnt have them i wouldnt be going on the putty road cruise this weekend

shim arrived today

[Ruxis]

would all the buckets be the same thickness??

wouldnt you think theyd all be different by a little like shims?

[GTSBoy]

They should all be close to the same thickness. Differences between them should be less than between the box full of shims though.

[Ruxis]

yeah they look all the same, went over a few of them with the calipers and there identical (NEARLY GOT A PAIR MIXED UP!!)

so idk what else to check??

thinking of boxing up and see how she goes?

[ei2hrb]

Hi I have a r34 2.0l non turbo has a rattle: in the head after 2000 revs around num6 cylinder and is missing on tat cylinder also would this have something to do with the vtc or would u think there is something wrong with the valve clearance any help would would be great full cheers

[GTSBoy]

Something wrong with the valve gear on that cylinder more likely than anything else.

[Hanaldo]

This topic has come up at the right time.

Does anything change the valve clearance settings? Ie. My head has Tomei Type-B Poncams and Performance Springs valve springs and retainers, as well as custom bronze valve guides. I never double checked what the head shop shimmed my valves to, so I don't know what numbers they used. Should my valve clearances still be using the factory settings or should they be different?

[GTSBoy]

Depending on the shape of the lobe, a cam manufacturer might specify a different clearance to the original spec. Usually a little larger clearances. I don't know what the spec for the B Poncams is.

In service, the clearances only change through wear or other misadventure (such as valve seat recession).

Edited June 29, 2013 by GTSBoy

[Hanaldo]

I see. Well that mayyy explain things if the poncams required looser clearances. Current theory that Lithium suggested to me to explain my power issues as well as a few other things like hot start problems etc. is valve clearances being too tight. When I had my head reconditioned, the shop installed my cams and set my clearances, but the guy said they were pretty much spot on anyway. I would think he'd have used the specs on the cam card rather than looking up factory settings, but you never know...

Guess I should get off my ass and check the clearances already!

Edited June 29, 2013 by Hanaldo

[ei2hrb]

What do u mean by valve gear

[GTSBoy]

Springs, valve stems (particularly the tip), guides, retainers, followers (buckets, shims, whatever else might be involved depending on the particular engine).

[ei2hrb]

I t sound the very same as if it was a hy draulic lifter that wasn't gettin any oil .so do you reckon I may pull the head off it