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valve shim resizing....how poor
http://gt4dc.co.uk/forum/viewtopic.php?f=13&t=2659		 Page 1 of 2
Author:  datajon [ Mon Nov 17, 2008 10:22 am ]
Post subject:  valve shim resizing....how poor
Found this on a cylinderhead seems not the usual Toyota finish for a valve bucket shim. :lol: guess what it came out causing other problems.


Image
Author:  Muddy Water [ Mon Nov 17, 2008 3:07 pm ]
Post subject:  Guess
:shock: Ummm! Not good.
I would hazard a guess that this happened to an ST185 CS with a forged engine.
The cause being a sticking valve spring.
Author:  Diceman [ Mon Nov 17, 2008 3:57 pm ]
Post subject: 
another product of "yee-ha engine works" then.

How much are shims? Is it really worth trying to grind one down? I am sure it coudl be done and finished so as to not cause any issues - but erghh that is shocking.
Author:  Muddy Water [ Mon Nov 17, 2008 5:09 pm ]
Post subject:  Pure Speculation
My guess in a previous post is pure speculation. :?
(Perhaps datajon can enlighten us).
It's based on a known problem with 400+ bhp ST185's and shims literally flicking out of their seats. That's why it's advised to go for the shimless bucket conversion.

It's not unusual to find shims that have been skimmed to size in race prepared engines - I have heard that it is common practice.
However, the finish on that one is shocking. :shock:
I wouldn't have thought that the shim itself caused a problem - more like compounded to a problem.
Author:  datajon [ Tue Nov 18, 2008 1:26 am ]
Post subject: 
shim cam out due to rough surface, poor adhesion due to the *bleep* surface thats what went on..

the spring failed from impact from the shim jamming between bucket and camshaft lob..

even found the impact spot on piston...nothing gets pass me..


SPRING DID NOT FAIL CAUSING THE PROBLEM FACT. , its clear as day what went on.

muddy water you have no idea, you don't understand whats gone on.

the ra for a cam shim should be low, that surface finish is over 300 please don't tell me to suck eggs when you know jack about what it should be.

i am fully aware of the rev issues with the 3sgte.. :lol:
Author:  datajon [ Tue Nov 18, 2008 1:33 am ]
Post subject: 
the fact is they ground the shim down to the size, the fact is it caused the problem, the fact is i have all the broken parts, the fact is i fully understand how to work things out like this , fact is i even get paid for this sort of stuff, fact is you know jack and you should wise up, its not speculation its hard facts, so be careful who you use when it comes to this sort of work.
Author:  Sirius [ Tue Nov 18, 2008 12:38 pm ]
Post subject: 
Hi Jon,

I don't think Nigel was having a pop at you, he seemed to be just having a guess at what might be the cause.

Quote:
(Perhaps datajon can enlighten us).


I also think that he genuinely wanted you to make further comment regarding the shim, and was not trying to provoke you.

Like you say you do this stuff all day, I don't think many of us would dispute your knowledge and where there are questions, its always meant as genuine interest for reasoned debate.

I for one get loads of stuff wrong and am happy to be corrected, but I like to learn so am always intererested to learn why something works differently to how I thought.

Cheers, :)

Mike
Author:  Muddy Water [ Tue Nov 18, 2008 3:15 pm ]
Post subject: 
Thanks Mike.
Quote:
I don't think Nigel was having a pop at you, he seemed to be just having a guess at what might be the cause.

...that's exactly right!
Sorry you took it the wrong way DJ you obviously misunderstood what I wrote.
Quote:
I would hazard a guess that...

Quote:
My guess in a previous post is pure speculation.

I was only GUESSING what might of happened based on the evidence provided.
I didn't have all the details, engine or bits in front of me.
Author:  datajon [ Tue Nov 18, 2008 4:19 pm ]
Post subject: 
sorry muddywater...I was ott with my remarks..

I measured a few springs from the cylinderhead.

static height 44.25mm

at 34.25mm = 22.0 - 22.5 kg = stock spring based on two samples.
Author:  datajon [ Tue Nov 18, 2008 4:31 pm ]
Post subject: 
few more images

Image
Image
Image
stock 140,000 miles of service
Image
Author:  datajon [ Tue Nov 18, 2008 4:46 pm ]
Post subject: 
Must admit get a similar finish using the bandsaw cutting 3.25" steel bar.. :wink:

Image
Image

:lol:
Author:  two_OH_five [ Tue Nov 18, 2008 7:13 pm ]
Post subject: 
I've got a nice barsteward file at home Jon if you wan't to go for a better finish next time :lol:
Author:  Sirius [ Wed Nov 19, 2008 12:02 am ]
Post subject: 
Thanks for posting the pics DJ,

Its especially interesting to see the 140k mile stock shim!
Author:  Muddy Water [ Thu Nov 20, 2008 5:02 pm ]
Post subject: 
Quote:
sorry muddywater...I was ott with my remarks.

Apologies accepted. 8)
Must have caught you at a bad moment. :wink:
Mind you, if I'd come across this I wouldn't be very happy either, especially as shims aren't that expensive.

Quote:
static height 44.25mm
at 34.25mm = 22.0 - 22.5 kg = stock spring based on two samples.

Please excuse my ignorance, :oops: but ...
Do I read this as static height 44.25mm and 34.25mm with a 22/22.5 kg load? :?

Do I assume that you found stock springs in the head?
Author:  datajon [ Thu Dec 18, 2008 10:35 am ]
Post subject: 
just an update.

found more problems with this said head that was installed by the said person.

all the buckets are worn, some shims have worn badly..

rest of the cylinder head is okay, just buckets & shims that are not okay.
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