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Shims lifting on angle due to cam regrind
Posted: Tue Apr 15, 2014 1:54 pm
by 22Silver
Supposedly my car is still at the mechanics because the valve shim is tipping due to the cam regrind and a thicker shim, and the only recourse is either full billet cams or replace something with shim-under-bucket lifters as opposed to bucket-under-shim
Anyone know where I can get something to fix this issue?
Re: Shims lifting on angle due to cam regrind
Posted: Tue Apr 15, 2014 3:05 pm
by sailaholic
Sounds like you've got two of the 3 fixes. Third is put smaller/factory cams in.
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Re: Shims lifting on angle due to cam regrind
Posted: Tue Apr 15, 2014 3:07 pm
by 22Silver
That's going to be a temp fix until I can find these little suckers locally
Re: Shims lifting on angle due to cam regrind
Posted: Tue Apr 15, 2014 4:40 pm
by sailaholic
Oh, 4th option might be HLA that have been locked solid.
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Re: Shims lifting on angle due to cam regrind
Posted: Tue Apr 15, 2014 5:50 pm
by 22Silver
NB8A has hydraulic bits?
The guy who did the cam grind said "I had the most aggresive cam that BP engines could get (NB8A cam) and that the extra lift and more aggressive slope is tipping the shim. Is it possible at all he ground for a VVT engine? I can't for the life of me find an example online of that happening and listing symptoms.
Re: Shims lifting on angle due to cam regrind
Posted: Tue Apr 15, 2014 6:01 pm
by manga_blue
You need these shim-under lifters to allow an NB to run aggressive cams.
http://miataroadster.com/store/product/ ... make=MAZDAMaruha/Tomei sell a similar set in Japan but they're much dearer and harder to deal with.
You would have to purchase these from Bill at MiataRoadster and then get your head guy to measure, locally order and fit the lash caps. Precision Shims in Croydon is one good source for the caps.
http://www.precisionshims.com.au/
Re: Shims lifting on angle due to cam regrind
Posted: Tue Apr 15, 2014 6:13 pm
by 22Silver
thank you manga!
Precision in croydon can make a custom set for me, as long as I can give him the diameter of the lifter.
Loos like 45mm to me.
Re: Shims lifting on angle due to cam regrind
Posted: Tue Apr 15, 2014 6:18 pm
by sailaholic
He can make a full custom shim under bucket lifter system? How does the cost compare with miata roadster units?
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Re: Shims lifting on angle due to cam regrind
Posted: Tue Apr 15, 2014 6:28 pm
by manga_blue
I thought he only made up sets of lash caps in accordance with sizes given by a head specialist. Are you sure he can make up solid lifters as well?
Re: Shims lifting on angle due to cam regrind
Posted: Wed Apr 16, 2014 1:22 am
by 22Silver
You're right.
Re: Shims lifting on angle due to cam regrind
Posted: Wed Apr 16, 2014 4:31 pm
by 22Silver
He carries various buckets in stock though, supposedly.
Re: Shims lifting on angle due to cam regrind
Posted: Sun Apr 27, 2014 5:38 pm
by 22Silver
Change of plan. We're machining the lip off the bucket, hardening it supposedly, and then machining an internal shim for each bucket.
Re: Shims lifting on angle due to cam regrind
Posted: Sun Apr 27, 2014 7:25 pm
by project.r.racing
manga_blue wrote:You need these shim-under lifters to allow an NB to run aggressive cams.
http://miataroadster.com/store/product/ ... make=MAZDAMaruha/Tomei sell a similar set in Japan but they're much dearer and harder to deal with.
You would have to purchase these from Bill at MiataRoadster and then get your head guy to measure, locally order and fit the lash caps. Precision Shims in Croydon is one good source for the caps.
http://www.precisionshims.com.au/
this is what i did. used the same 2 suppliers. $200 for the lifters and 16x $5 for the caps.
Re: Shims lifting on angle due to cam regrind
Posted: Sun Apr 27, 2014 7:26 pm
by project.r.racing
22Silver wrote:Change of plan. We're machining the lip off the bucket, hardening it supposedly, and then machining an internal shim for each bucket.
sounds sh*t...
Re: Shims lifting on angle due to cam regrind
Posted: Sun Apr 27, 2014 8:35 pm
by hks_kansei
project.r.racing wrote:manga_blue wrote:You need these shim-under lifters to allow an NB to run aggressive cams.
http://miataroadster.com/store/product/ ... make=MAZDAMaruha/Tomei sell a similar set in Japan but they're much dearer and harder to deal with.
You would have to purchase these from Bill at MiataRoadster and then get your head guy to measure, locally order and fit the lash caps. Precision Shims in Croydon is one good source for the caps.
http://www.precisionshims.com.au/
this is what i did. used the same 2 suppliers. $200 for the lifters and 16x $5 for the caps.
I'll remember that.
The stupid cost of the Jap SUB conversions have been a big limiting factor in my caring if I put in bigger cams.
$200 plus getting shims locally in the right sizes is much better.