Shims lifting on angle due to cam regrind

22Silver · Postby **22Silver** » Tue Apr 15, 2014 1:54 pm

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?

sailaholic · Postby **sailaholic** » Tue Apr 15, 2014 3:05 pm

Sounds like you've got two of the 3 fixes. Third is put smaller/factory cams in.

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22Silver · Postby **22Silver** » Tue Apr 15, 2014 3:07 pm

That's going to be a temp fix until I can find these little suckers locally

sailaholic · Postby **sailaholic** » Tue Apr 15, 2014 4:40 pm

Oh, 4th option might be HLA that have been locked solid.

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22Silver · Postby **22Silver** » Tue Apr 15, 2014 5:50 pm

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.

manga_blue · Postby **manga_blue** » Tue Apr 15, 2014 6:01 pm

You need these shim-under lifters to allow an NB to run aggressive cams. http://miataroadster.com/store/product/ ... make=MAZDA

Maruha/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/

22Silver · Postby **22Silver** » Tue Apr 15, 2014 6:13 pm

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.

sailaholic · Postby **sailaholic** » Tue Apr 15, 2014 6:18 pm

He can make a full custom shim under bucket lifter system? How does the cost compare with miata roadster units?

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manga_blue · Postby **manga_blue** » Tue Apr 15, 2014 6:28 pm

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?

22Silver · Postby **22Silver** » Wed Apr 16, 2014 1:22 am

You're right.

22Silver · Postby **22Silver** » Wed Apr 16, 2014 4:31 pm

He carries various buckets in stock though, supposedly.

22Silver · Postby **22Silver** » Sun Apr 27, 2014 5:38 pm

Change of plan. We're machining the lip off the bucket, hardening it supposedly, and then machining an internal shim for each bucket.

project.r.racing · Postby **project.r.racing** » Sun Apr 27, 2014 7:25 pm

manga_blue wrote:You need these shim-under lifters to allow an NB to run aggressive cams. http://miataroadster.com/store/product/ ... make=MAZDA

Maruha/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.

project.r.racing · Postby **project.r.racing** » Sun Apr 27, 2014 7:26 pm

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...

hks_kansei · Postby **hks_kansei** » Sun Apr 27, 2014 8:35 pm

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=MAZDA

Maruha/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.