Enuo
Glorified Electrician
By swapping the shims about
turbo build
- Thread starter Azzydot
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pollyp
Club Member
no, all the shim thicknesses are uniquely matched for that specific valve assembly.
nissan specifies min/max cam shim clearances cos it affects valve timing.
too tight = valve opens prematurely/closes too late and reduces compression
too loose = valve opens too late/closes too late and reduces compression.
unlike tappets (where their clearances can easily be adjusted with a screw), overhead cam clearances require swapping shims of exact thicknesses which is a pita or can be expensive to source new ones.
clearances are usually checked and corrected on a warm engine after it's been running.
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pollyp
Club Member
it's printed on the underside of the shim eg 253 = 2.53mm
but they're usually either faded, worn off or out of spec due to wear.
that's why you should instead measure their exact thickness at several points with a micrometer or digital calipers as accurately as possible and mark it down.
logging which shims are where, what clearances they provide and how much mm to add/subtract to reach back to the ideal specification will tell you which shims to swap about and which ones are missing and need replacing.
Enuo
Glorified Electrician
Baby steps Paul...
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Thanks for the comment I paid 38 pounds for 2 and the head gasket are from bulleyes, I have put 2 should be good, looks good as well
and after the clean up I put them both on with set at 39nm all 10 bolts then 78 mm 2nd time all 10 bolts, coming on the timing chain Polly did help with the video was really simple but don't know if it's lined up right
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after the head gasket was done I thought I will give the timing chain a try and cam shafts all fitted, broke a the tensioner and screw still in there, thought I will take it off with gripper Tommow, and about the shims everyone is right it comes in Diffrent sizes, if it's wrong like frank said the cam shafts won't it and will rattle on valves, I got the closest I can with timing and the shims, can anyone tell me if it's right ? Also I try to turn the engine over it turned but really tight ? Is that normal ?
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frank
Club Member
there,s 4 and a half links between the 2 dots eh stani (should be 5)
Stani1029
Club Member
there,s 4 and a half links between the 2 dots eh stani (should be 5)
Yup then 7 from exh dot to idler, which we can't see
frank
Club Member
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Frank I have got 5 links in middle ? and both dots got one each so that's 7
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pollyp
Club Member
why do ppl use 2 HG?
a normal single genuine HG and proper remapping can safely handle 10psi, in which case imo would've just got the victor reinz for the same price.
appearance can be deceiving, an careful eye for detail n precision n systematic checking n measuring n cleanliness is more important for building a reliable engine.
did you thoroughly clean and lube the headbolts?
after 78nm you did remember to slacken and then goto 35nm and angle tighten 60deg yea?
how on earth did you wreck the tensioner and snap its bolt?
unless you forgot to fully retract the tensioner into its housing before fitting and just forced the chain over it when it got stuck?
and forgot to clean the bolt threads and overtightened it when it got stuck?
mechanics 101, all threads should screw in freely by hand with ease when under no load until the bolt head/nut face contacts the surface.
if the nut/bolt fixing is getting tighter/resistive before the component is fully secure, back off, reclean and reoil the threads and try again till it secures smoothly.
if the torque feeling reaches a peak and then begins to lower, then the metal bolt or thread is overstressed and failing/stripping.
a normal single genuine HG and proper remapping can safely handle 10psi, in which case imo would've just got the victor reinz for the same price.
appearance can be deceiving, an careful eye for detail n precision n systematic checking n measuring n cleanliness is more important for building a reliable engine.
did you thoroughly clean and lube the headbolts?
after 78nm you did remember to slacken and then goto 35nm and angle tighten 60deg yea?
how on earth did you wreck the tensioner and snap its bolt?
unless you forgot to fully retract the tensioner into its housing before fitting and just forced the chain over it when it got stuck?
and forgot to clean the bolt threads and overtightened it when it got stuck?
mechanics 101, all threads should screw in freely by hand with ease when under no load until the bolt head/nut face contacts the surface.
if the nut/bolt fixing is getting tighter/resistive before the component is fully secure, back off, reclean and reoil the threads and try again till it secures smoothly.
if the torque feeling reaches a peak and then begins to lower, then the metal bolt or thread is overstressed and failing/stripping.
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I just thought I'll get the gasket while I was buying other tools today so I got what they had, I have done same as manual says with the right torque readings and nice balance on my hands, the nut snapped after it was half way in and try to pull the chain off
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Polly I am doing how micra k11 manual says my tdc is set and the chain goes to 1 o'clock dot on the idler sprocket it's on the bottom chain I haven't took that off yet, thought it's set from befores owner, I was doin the top chain only and just doing as manual says
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Stani1029
Club Member
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Right so I need to take it off and make it 5. Also I had my pointer at tdc but my idler sprocket goes to 1 o'clock not like franks 4 o clock ? Does that mean I need to take bottom one off ?
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Not sure where you managed to get that figure from :/
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I said it clearly I got 2 headgaskets 19 pounds each makes it 38 pounds
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Thats what i meant , not sure where the £2.19 Came from
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Probably for the best pal
Enuo
Glorified Electrician
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I'll rather coz it's taking lots of time and don't wana muck about with engine and blow the parts inside it by my lil mistakes
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frank
Club Member
we all learn from trial and error azzy
you just need to walk before trying to run, just run low boost on a stock engine to start with, then develop in stages
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Frank your right for me it's low boost or give my engine someone who can do it for mewe all learn from trial and error azzy
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I would angle at research rather than relying on help
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I can do that bit I know why it's not timing as the bottom isn't timed or lined up that's why the top is always wrong and shims in wrong sizesI would angle at research rather than relying on help
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Enuo
Glorified Electrician
I think what Noddie is trying to get at is that if you research how the whole engine works for example and how all of the components interact, then you'll know enough to work it out yourself and any other problems you have in future, rather than repeatedly asking for help on multiple smaller problems.
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I asked for help as I followed the manual and I done same but coming on timing it don't line with my bottom timing so I asked,
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Not exactly the tone I intended. I am aware however that this forum reacts very well to people who do their own research then ask specific questions but people who ask lots of questions get little help
You may just get lucky by turning the engine over until the lower chain lines up and then checking the top chain to see how far out it is when at TDC. Otherwise the only way to time the engine up from a totally unknown state would be to strip it down, i.e. take the side cover off and do it visually as per the instructions. If you read and followed the instructions to the letter, you would have timed up the engine before stripping it down. It would time up perfectly if you had done. I don't know how good the online guide is, but there's little substitute from a Haynes hard copy sitting next to you.
Same with the shims, since they all fell out, you will have to build up the head, use a set of feeler gauges and check if the clearances are within spec. I would personally measure the shims before building so you know what they are before fitting, which will make swapping them about, (if required), much more simple.
Not intending to sound like a preacher here but it seems like this maybe a good opportunity presenting itself to learn from mistakes and gain some knowledge rather than hoping for all the answers
Same with the shims, since they all fell out, you will have to build up the head, use a set of feeler gauges and check if the clearances are within spec. I would personally measure the shims before building so you know what they are before fitting, which will make swapping them about, (if required), much more simple.
Not intending to sound like a preacher here but it seems like this maybe a good opportunity presenting itself to learn from mistakes and gain some knowledge rather than hoping for all the answers
Totally agree with what said in above posts, but i was in the same situation last year (ask Frank ) so i know how azzy feels a little, Haynes manual is my Bible but it is also like the religious Bible (not got a clue what it is talking about a lot of the times ). I feel a lot of the questions are more confirmation that its being done correct and not wanting you guys to build it (would help me out tho if you could). Could he not take it apart again set the timing on the block and pay for a rebuild on the head and put back together??? (asking this cos i will prob do the same next month when do the grassers head hehe)
) so i know how azzy feels a little, Haynes manual is my Bible but it is also like the religious Bible (not got a clue what it is talking about a lot of the times ). I feel a lot of the questions are more confirmation that its being done correct and not wanting you guys to build it (would help me out tho if you could). Could he not take it apart again set the timing on the block and pay for a rebuild on the head and put back together??? (asking this cos i will prob do the same next month when do the grassers head hehe)- Status
