# Valve clearance help! Pictures inside



## Bellis_GTR (Nov 18, 2010)

Okay guys long story short my car was overheating the first year i had it. after lots and lots of swearing and fixing sh*t I found out the head was cracked. My friend and I got the head off and placed it the grass on a tarp (working in a complex in visitor parking) We wanted to see if we could see any cracks on the head (before I knew) and We both didnt know if you flipped the cyl head over the lifters would just fall out so easy. We managed to find everything except for one head stud washer.

After all that I found a great rebuilt head but it did not have lifters or shims. So I said that's okay I got mine from the old one. At the time I didn't know your not suppose to mix them up and they need to go back in the same valve they came out.

So now Im at the stage where I need to do valve clearance and I am very confused. I have the service manual and reading page en-19 and down on the procedure for valve clearance. 


Does anyone have experience with this? I took some pics of a couple measured shims and lifers. 

Is this the proper way to measure them? Or does it need to be exactly in the middle of the shim ?



















Then I put the shims in at random spots. But put the smaller size shims in the intake side and bigger size shims in the exhaust side since the manual says they are tighter because the exhaust cams are sodium filled. Not sure what that means tho lol



















Now I have everything back in place and ready for what I think the next step is. Using feeler gauges and measuring the clearance. This is where I stopped. I would really like to continue doing the work my self and with friends then pay a shop atm.

as it sits. 









Would it be easier to do valve clearance with the head off or on the block? I haven't torqued it down yet.

You should know this is my first "big" job working on this car. So please excuse me. I know I could of made the post with out the story but just to give background. If you read this far thank you so much. Any help would be fantastic. 

link to service manual page EN-19 also on EN-85 amd down

GTR R32 Service Manual

Thank you!

Brian


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## r33-sky (Sep 27, 2009)

I am lead to believe that there are a set of 'datum' shims for what is now going to be a fresh build/shim, without these you have one hell of a job on your hands - do-able but you'll need some mighty patience.


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## Marky_GTSt (Dec 31, 2005)

> Then I put the shims in at random spots


How exactly did you think that would help ?

Your supposed to check the clearances with a blade first and note them down, remove the shims and measure them, then any that can be moved to make the correct required clearance on any given valve are moved and the rest that are to thin/thick are replaced with the correct thickness to make up the desired gap for the rest of the valves.

you then refit everything, check the clearance and if you did the math right they should all be good.


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## RonniNielsen (Jan 14, 2011)

I would take the smallest of them, and stick them in one side, then measure the gap on eatch.
then take out the shims, measure thease, and then figure out what shim would be required!

For an example! if you got a clearense of 0.45 mm and you need 0.30 and corrent shim is
3 mm think, you just need a 3.15 shim.

It will take some time though. 

you might only have to buy a few to get it together..

Ill make a guide on sunday how to do this, as im at this stage in my build.

Ron


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## David (Apr 25, 2003)

Basically take the head off again.

Remove one cam and do one bank at a time.

Position the head on a bench such that the valve can open without hitting anything.

Rotate the cam such the cylinder 1 cam has no lift (lobe is 180 degrees opposite the lifter)

Get yourself a set of metric feeler gauges and measure using the feeler gauge the gap between the cam and the lifter.

Note down the gap this is the clearance you are setting.

Turn cam and repeat for all inlet side

Remove inlet cam and fit exhaust cam

Repeat measuring procedure for exhaust cam.

Now knowing the shim thickness for each valve, current clearnace and desired clearance you can work out how much you either need to grind the original shim down by, or buy correct height ones from nissan.

If you are very lucky you will be able to swap the shims arround until you have the correct clearances. But I very much doubt this as every head is different, so I think you will have to either have the shims ground if too tight or buy new ones.

It also takes ages and if you are grinding them yourself you may take 2-3 goes to get them correct.

Note also when i say grind I dont mean an angle grinder, if you have no facilities you may get away with using some fine wet and dry on a sheet of glass (they need to remain perfectly flat)


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## Marky_GTSt (Dec 31, 2005)

RonniNielsen said:


> It will take some time though.


But they allways do.... However even with this fancy scrambled engine it will still only take the same time as before.

I used to have to do this a lot on Motorbikes, Its easier on the RB26


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## Corsa1 (Sep 8, 2003)

Why take the head off?


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## David (Apr 25, 2003)

[email protected] said:


> Why take the head off?


Mainly to save your back and make it easier to get into as the cams and shims will be going in and out multiple times. There is no advantage to doing it with the head on.

Just ensure you move the bottom end with the cam such that you dont bend any valves on the corresponding piston.


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## Marky_GTSt (Dec 31, 2005)

David said:


> Mainly to save your back and make it easier to get into as the cams and shims will be going in and out multiple times. There is no advantage to doing it with the head on.
> 
> Just ensure you move the bottom end with the cam such that you dont bend any valves on the corresponding piston.


Im fairly sure I have only had to remove the cams once when doing this. Been a long time since I did a set of shims, But IIRC you only need remove them once unless you get one of your measurements wrong...


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## Corsa1 (Sep 8, 2003)

But if you do it right you will only remove the cam once per side. It would be a dear job if you at to take the head off ever time you at to reshim.


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## David (Apr 25, 2003)

My point is that it doesnt look like he has fitted the head yet as it is just laid on, so taking it off is going to be easier (can you accept that?). As for one go, all our shims needed grinding and rather than take a chance and go too far we wanted them perfect clearance, so ground them in two stages. We also did a cylinder at a time.


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## Bellis_GTR (Nov 18, 2010)

Wow guys thanks for the quick replys. Iv been at work all day, so I couldn't reply.

I placed them in random spots because they were already mixed up. I forgot to mention I measured all of the shims and wrote them all down prior to putting them in.

Right, the head is not bolted down as of yet. I am replacing all the old coolant and vac hoses underneath the collector before it goes back on, and bolting the intake side to the head then drop the head on. I removed the head with the collector and turbos still attached. It was extremely heavy since our backs were almost at a 90* angle lol.

Would it help if I posted all the shim measurements? Rotate the cam 180* opposite of lifter, then measure gap? I must of read wrong I thought you measure with the lobe contacting the lifter. But then again how would the feeler gauges fit. 

Here's a pic of the block if this helps. Looks like its close to TDC and I got an pm saying I should turn the crank and put the pistons down in the bores a bit. Then put the head at TDC after everything is complete then from there turn the crank back to TDC.










and here's one of the car just for looks  (since thats all it gets cos it doesn't work! )










RonniNielsen that would really help out a lot since I cant seem to find links to anyone actually doing this rather then just explain how too. Thanks for all your help guys. I cant thank you enough. This has really helped. All im waiting for are Throttle chamber gaskets and exhaust mani gaskets then full reassembly can begin. I hope I dont need to order new shims lol


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## GT-R Glenn (Nov 9, 2002)

Wow....!


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## Marky_GTSt (Dec 31, 2005)

OK, The cam lobe does indeed need to be pointing away from the valve for measuring the gap, The fact that you know the shim thicknesses at each valve is usefull.

So now, measure all 24 gaps and write them down, and you should end up with 2 tables of numbers, its a simple job of shuffling the shims untill you have as many as possible with the correct gap, the rest you will need new shims for.

By all means post up your gaps and shim thicknesses and lets see what you have. 

Use this format...

Gaps on the left Shims on the right

INLET EXHAUST INLET EXHAUST
12 0.0 0.0 0.0 0.0
11 0.0 0.0 0.0 0.0
10 0.0 0.0 0.0 0.0
9 0.0 0.0 0.0 0.0
8 0.0 0.0 0.0 0.0
7 0.0 0.0 0.0 0.0
6 0.0 0.0 0.0 0.0
5 0.0 0.0 0.0 0.0
4 0.0 0.0 0.0 0.0
3 0.0 0.0 0.0 0.0
2 0.0 0.0 0.0 0.0
1 0.0 0.0 0.0 0.0
CAM WHEEL END

The forum has formatted out my gaps, I hope you can still see how to write the tables, its simply 4 columns of numbers.

Once you have your numbers in those 2 tables it should be obvious what needs to be done.



> I cant seem to find links to anyone actually doing this rather then just explain how too


What more information do you think will be available ?


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## GT-R Glenn (Nov 9, 2002)

rb26dettvalveclearance - tyndago

RB26 tip height • Speed Talk


The SkyLife: Rb26 Engine Assembly - How to Build the RB26DETT Motor


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## DrGtr (Jul 18, 2009)

Andy with the shims using the supertech oversize valves the shop here told me that they want 3mm shims and then if needed they will trim the valve a bit to suit what do you think about it? what size shims do you approximately use for this valves ? tomei [email protected] and tomei buckets.


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## Corsa1 (Sep 8, 2003)

It sounds like the valve is sitting a bit high on the seat, as when we have done the same set up with the tomel buckets and cams we aim for around the 2.5mm size shim.


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## blue34 (Jul 28, 2005)

Make sure you don't forget to zero the micrometer (ie close it fully and press zero) before taking measurements.


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## GT-R Glenn (Nov 9, 2002)

Good grief...
You need to measure your assembly and shim each one to what they need to be....


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## Bellis_GTR (Nov 18, 2010)

Thanks a lot guys. All this info is great. 

I'm just so use to seeing it done step by step wou pictures and all that. But this is just fine  wish I posted this when I first had this problem. It would of been done by now. I knew posting on here would get me great answers. 

Thanks again! 

Ps. Pics for your time helping me


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## DrGtr (Jul 18, 2009)

[email protected] said:


> It sounds like the valve is sitting a bit high on the seat, as when we have done the same set up with the tomel buckets and cams we aim for around the 2.5mm size shim.


2.5 isnt too small for that set up? did you use supertech valves? 
you saying that they will cut my valves 0.5mm? thats toooo much difference you had. i hope that it will be only 0,010mm-20


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