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What's wrong with this picture
https://www.ausmini.com/forums/viewtopic.php?f=2&t=81365		 Page 1 of 3
Author:  Mr Miyagi [ Tue May 07, 2013 2:07 pm ]
Post subject:  What's wrong with this picture
New Minispares 1.5 Forged Hi-lift rockers.
New engine build less than 1 hour old and set at 15 thou.
4500rpm max.

Diagnosis anyone ?

Image

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Author:  Mick [ Tue May 07, 2013 2:13 pm ]
Post subject: 
Is it possible your springs reached their absolute end? Number three looks pretty crushed.



EDIT: Available individually. Check the rest for damage too.

http://www.minispares.com/product/Class ... |Back%20to
Author:  Lillee [ Tue May 07, 2013 2:18 pm ]
Post subject: 
Ouch.

Firstly 15 thou way too small, 19 though or more esp on high lift cam. Everything expands when hot, so even set to 20 or 22. Run hot at near idle (2500 or so) to bed the cam in, let it cool down, re-torque the head down and guess what, reset all the clearances again as they will all be out. Recheck everything, then take it for a power run.

Are the oil feed galleries in alignment and clean? When installing brand new, pump an oil can into the galleries in the rockers to make sure they are full, it takes a long time for oil to get up there sometimes and there may be air pockets. To me it looks like the shaft and bush ran dry, "welded" itself to the shaft and hence the rocker was bashed apart.

Lastly all the rockers look all out of alignments somehow... they should be centred on the valve tip, see how most of them are off centre? I wouldn't have run it like that to begin with. Are you sure the right rockers are installed in correct order? Roller tip rockers have Left and Right oriented, so yes there is an order to it, not 100% sure with forged
Author:  Lillee [ Tue May 07, 2013 2:26 pm ]
Post subject: 
Mick wrote:
Is it possible your springs reached their absolute end? Number three looks pretty crushed.


Yeah I think there should be a washer between the spring and the rocker no? Can't remember, my rollers have shims...
Author:  bent65 [ Tue May 07, 2013 2:57 pm ]
Post subject: 
Mick could be right because if your lash is too tight and you hit coil bind, then the load through rocker arm goes through the roof. (if .010" too tight has tipped you over then you were already very close to bind height!) If there is/was good clearance then maybe check if the bush has nipped onto the shaft through expansion or if bush has crept into the pedestal and grabbed, again putting extra load into arm. Looks like some marks on bush showing arm has turned on bush. I think GR has played with these arms with success on some pretty angry springs so may be able to shed some light?
Author:  MiniBill [ Tue May 07, 2013 3:20 pm ]
Post subject: 
Damn thats bad luck , maybe dodgey metal ?
Author:  awdmoke [ Tue May 07, 2013 3:37 pm ]
Post subject: 
I think Mick was right first up too.
coil bind = something must give.

Been there, done that.
Image
Author:  Convertible Mini [ Tue May 07, 2013 3:40 pm ]
Post subject:  Wow
Trying to achieve the impossible. Too much cam lift and not enough Valve travel. Spells Bang!
Author:  bent65 [ Tue May 07, 2013 3:49 pm ]
Post subject: 
awdmoke wrote:
I think Mick was right first up too.
coil bind = something must give.

Been there, done that.
Image


Pretty strong rocker arms, pushrods and right foot to do that to valvesprings!
Check bind height vs installed height (minus lift) on the bench, its cheaper.
Author:  miniDave [ Tue May 07, 2013 3:50 pm ]
Post subject: 
The set that Kev put in my engine were all over the place. One of them you could hardly move on the shaft and had to be'doctored' Adjuster screws all over the place but when fixed and set at a bigger gap than you have, has run OK at 7,000rpm on GR's dyno.
Author:  bent65 [ Tue May 07, 2013 3:54 pm ]
Post subject: 
miniDave wrote:
The set that Kev put in my engine were all over the place. One of them you could hardly move on the shaft and had to be'doctored' Adjuster screws all over the place but when fixed and set at a bigger gap than you have, has run OK at 7,000rpm on GR's dyno.

Might be the answer if they were too tight on the shaft to begin with. The pic looks like the bush has grabbed and arm was forced.
The Harland Sharp rollers always need reaming onto minispares shaft.
Author:  SuperCooper [ Tue May 07, 2013 9:28 pm ]
Post subject: 
Valve spring binding with cam/ spring / rocker combination.

Were these set up?
I had that problem on my 7 port head with the cam/ spring and 1.5 rr rockers.

Had to get it set up accordingly or springs would bind.

Could this be why your rockers have bottomed out and snapped?
Author:  drmini in aust [ Tue May 07, 2013 10:02 pm ]
Post subject: 
These rockers are NOT forged now. they are grey cast iron.
I found this when I machined the tops of minidave's so they were square with the nuts.
[edit] and no, they are not made in UK now.
But I agree with above it looks like coil bind. I use c-AEA526 springs with 1.5 rockers, standard ones don't handle the extra valve lift.

@lillee,
As for the misalignment on the exhaust valves, even Cooper S forged ones look like that if you don't fit their 4 standard spacer washers (exhaust rockers only).
Author:  Mokesta [ Tue May 07, 2013 10:41 pm ]
Post subject: 
Ummm, two rocker studs should be long and two short. Yours are all teh same length.
:lol:
Author:  adios57 [ Tue May 07, 2013 11:57 pm ]
Post subject: 
Why run your engine at 4500 with only one hour operation?
Run at 2000 for 20 minutes to bed the cam followers in and the new cam.
But after that run it in.
I know some don't do it but these are old design engines and I think, do better if run in properly.
They are not race engines.
Be thankfull you have not done anything worse.
I hope you were monitoring the oil pressure when it was running and primed the oil pump or filled it with peteroleum jelly to get the pressure up asap.
A properly run in engine will pull better from low gears and last longer.
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