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| Valve Resession https://ausmini.com/forums/viewtopic.php?f=2&t=92655 |
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| Author: | Darrell [ Mon May 16, 2016 8:38 pm ] |
| Post subject: | Valve Resession |
Do 940 heads suffer from valve recession when running ulp without a fuel additive? my no 2 exhaust valve stem has severely worn down maybe 1/8 in all the others are fine and clearance settings standard. |
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| Author: | simon k [ Mon May 16, 2016 8:47 pm ] |
| Post subject: | Re: Valve Resession |
yes they do... but you might have one soft valve stem too? |
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| Author: | Darrell [ Mon May 16, 2016 8:49 pm ] |
| Post subject: | Re: Valve Resession |
That's what I was thinking Simon seeing as the others don't appear to have the same issue. |
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| Author: | drmini in aust [ Mon May 16, 2016 9:36 pm ] |
| Post subject: | Re: Valve Resession |
Is the valve sunk into the head, or is the valve stem looking lower when assembled? If the latter, perhaps it has a mk1 exhaust valve there (are 2mm shorter) and 3x oversized 12G940 exhausts. |
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| Author: | Tim I [ Mon May 16, 2016 11:38 pm ] |
| Post subject: | Re: Valve Resession |
Valve seat recession will close up your clearances, not make them larger. |
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| Author: | 9YaTaH [ Tue May 17, 2016 8:00 am ] |
| Post subject: | Re: Valve Resession |
simon k wrote: yes they do... but you might have one soft valve stem too? or poor oiling to the upperworks? hows your oil pump? |
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| Author: | Darrell [ Tue May 17, 2016 9:10 am ] |
| Post subject: | Re: Valve Resession |
Stem is definitely worn, oil pressure is fine, will pull the head off and take a look only done around 10000 ml since rebuild, just seems odd that its only one valve. Thanks for the input guys. |
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| Author: | simon k [ Tue May 17, 2016 11:23 am ] |
| Post subject: | Re: Valve Resession |
Darrell wrote: Stem is definitely worn, oil pressure is fine, will pull the head off and take a look only done around 10000 ml since rebuild, just seems odd that its only one valve. Thanks for the input guys. sounds like one soft valve... the rebuilder or a previous owner might have bought a cheapie to replace a damaged one. If you run a file against the side of the stem tip you'll be able to to tell without taking the head off limited experience talking, but the best value valves I've come across I bought from minis plus - the online store is in transition, but these are the inlet version... http://www.minisplus.com.au/old-shop/pr ... d-race-ser send an email to see if he still has the exhaust version |
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| Author: | Darrell [ Tue May 17, 2016 6:24 pm ] |
| Post subject: | Re: Valve Resession |
Thanks Simon have run the file over the stem and yes its definitely soft had a burr on one side where the rocker wasn't making contact. |
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