Valve clearance....

1 Valve clearance.... 18th June 2016, 1:21 pm

Gostek

Events Organiser

Posts : 1431
Join date : 2013-12-29
Age : 44
Location : Wigston/Leicester

So I've got my new cams cheers

but now i need to shim them suicide

Problem no1 engine which i'm building came to me in tesco bags so I've got 16 shims but no idea where they've came from....

Not much thinking I've measured them more or less got same thickens on one rocker arm.

Now I've found this guy
https://www.youtube.com/watch?v=lastgWJ4Ooo
Looks easy enough... So I've measured fist two shims and got clearance 0.33 and 0.43 so to get them to 0.1mm I've put 0.22mm and 0.30mm (closest on my feeler gauge set) compressed them spun the cam few times etc but now I can't put anything in there (0.05 doesn't fit)... So I'm doing it wrong checking at the valve? I've noticed (or maybe I'm doing it wrong) but clearance is different between cam and rocker than is between rocker and valve which to me it should be the same....

So any idea lads what I'm fooking up this time?? Shall I just measure them at the cam?
Oh by the way cams are brand new tomei 260 deg but that shouldn't matter I think

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2 Re: Valve clearance.... 18th June 2016, 2:40 pm

Mr B

gtir technician

Posts : 4087
Join date : 2012-05-05
Location : B's workshop thailand

Have look at last 2 posts in this thread
http://www.gtir-motorsport-club.com/t3469-head-clearances-adjustment
You got keep rocker square and not tilt it, having 2 sets of measuring blades helps,
I do it between shim and rocker as if make some blades up just for the job it quick and more consistent in results than cam and rocker. Did you measure all shims with point micrometer or decent digital mic and spacer ( old valve cut even length makes good tool for accurate shim measuring without need of point mic ) keep clearance closer to 0.15 is what I tend to do but what shims you got and what thickness blades you got if using punched discs to pack shim cups tends dictate the range a bit . Think you going need take step back and remeasure and see what results you get .

3 Re: Valve clearance.... 18th June 2016, 4:50 pm

Gostek

Events Organiser

Posts : 1431
Join date : 2013-12-29
Age : 44
Location : Wigston/Leicester

This is plastigauge all over again lol... I've got digital verniers which fit nicely in to shims

I've had a look at manual too but for some magical reason when I measure at the shim and put bit of feeler gauge under the shim It comes up too tight suicide

I've spun cam few times to crush it too... I've just done one measuring it at the cam and I've got 0.1mm at cam 0.15mm at both shims so I'm not far out and it seems to be square... I'll have to mess about with it bit more I guess...
One of those jobs which you wish you newer had to do it....

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4 Re: Valve clearance.... 18th June 2016, 6:18 pm

Mr B

gtir technician

Posts : 4087
Join date : 2012-05-05
Location : B's workshop thailand

It is more of a pain when start from scratch with mixed up shims & new cam.

If you making shim discs from proper hardened tempered engineer blades 6mm punch is too big really, imperial 7/32 or 15/64 is perfect fit & they sit flat & are easy get out again .
Is couple threads on it, Mr burrows recently done this & modded his 6mm punch/joggler so undercut slightly making discs perfect size.

5 Re: Valve clearance.... 18th June 2016, 6:25 pm

Gostek

Events Organiser

Posts : 1431
Join date : 2013-12-29
Age : 44
Location : Wigston/Leicester

I've got 5 mm joggler it fits perfectly and they're not hard to get out

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6 Re: Valve clearance....

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