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The mkiv Supra Owners Club

Bucket less shim conversion MR2 Cross breeding!!


StuartW

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Hi All, Need to go bucket less shim conversion on the Drag engine, Can anyone confirm that the MR2 mk4 (could do with engine code) has bucketless shims as standard?

 

I have been told they drop straight in as a replacement.

 

If so then i guess you measure the existing 2JZ shims and order new MR2 ones from Mr T of the same thickness??

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  • 2 months later...

ok sounds simple!

 

I have the shims fitted size and the clearance and the desired clearance, I should allow for the new valves and seats to "Bed in" does anyone have experience in how much to allow for on a 3 angle seat job?

 

does anyone know the stock thickness of the buckets? they are tricky to measure..?

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Do you mean a bucket with no shim, do you have a micrometer ??????

 

yes and yes, but you need to measure the internal as you cannot easilly measure the bucket as its a bucket! BUT i have a plan....I can use my bolt torque stretch gauge and then convert the measurement to MM...BUT it wont work very well because the centre of the top of the shim is recessed for oil gallery and the bucket will not fit between the jaws of my gauge unless i disect the bucket first!

 

Also as the buckets are not new so they are not all the same and we are talking quite close tolerances here.

 

I have found this old Micrometer in my tool box, I zeroe'd it and the average bucket measures as shown which is 98 of an inch! Can anybody please look at the pic and convert to MM for me as i am CRAP with imperial:blink:

 

 

attachment.php?attachmentid=126994&d=1232210470

Vernier inches.jpg

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Just clarify what you need to know again? :)

 

I should allow for the new valves and seats to "Bed in" does anyone have experience in how much to allow for on a 3 angle seat job?

 

does anyone know the stock thickness of the buckets? they are tricky to measure..?

 

Also i need to work out the thickness of the actual shimless buckets, and to clarify that the DTI reading 5 posts up is 2.46mm or what the stock TT bucket measures when new.

 

Much appreciated Chris...I am currently stuck on this :-)

 

p.s. i am being cheeky now but after i followed wiseco's Piston instructions i figured i need 0.20" for top Piston ring end gap clearance and 0.18 for bottom, Does that sound right?

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Every stock bucket needs measuring and adding to the stock shim fitted to it. The celarances with the new valve seats need measuring using a thin set of shims if there's no clearance at all with the stock ones. if the seats are done properly on a Serdi machine and the valves are perfect there is no need for any bed in allowance. Just aim mid range of the recommended clearances. You then need to work out what thickness shimless buckets you need.

 

Bore size times whatever Wiseco recommend for the application, don't have the sheets to hand. If you haven't filed dozens of rings by hand don't practice on these. I bought a beautiful digital ring grinder as I was spending hours doing V8 and V12 rings by hand. Should have bought one years ago. I'd do yours but need the block to check the clearances in really. If you bugger up doing the ring gaps you end up with a new rebuild that runs like a 170,000 miler engine :) Or seizes under load...

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As Chris has already said, you need to measure every bucket and shim as 1 piece. Me and Tony (well mainly Tony :D) have been doing this with mine ready for some new cams and the shimless buckets.

 

If I have done the calculations correctly from the list I have my bucket sizes range from 2.39 - 2.47, so its not possible to ask what there exact sizes are as they are not the same.

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Just a a bit more info on the 1zz shimless buckets.

 

They also fit the 3sgte head without issue as i did this to mine.

 

The rev3+ 3sgte uses shim under buckets.

 

Also the range of thickness's of the 1zz shimless buckets is quite narrow, so triple check your measurements as there's not alot of thickness to play with!

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I am working on a MKIV head next week, but I think there's enough valve tip protrusion above the top hats and collets to allow the stems to be ground shorter and with a set of the thinnest shimless buckets you could use race type under bucket top hat shims to allow cheap valve adjustment with very very minimal inertia gain. The shimless buckets themselves can be ground inside, to make them a bit thinner, with the right gear. Farndons and Arrow Precison will make bespoke buckets. All sorts of possibilities if you are keen ;)

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  • 3 weeks later...

Ok so i am nearly there!

 

I have got a new dial mic and re measured all of the shims fitted to the buckets (Suprising what a difference there was)

 

So i need to check my calculations

 

If i take the thickness of bucket and shim 5.335mm and add the clearance of .670 it makes 6.005, if i then take away the desired clearance of mid range 0.300 it leaves me with 5.705 or 5.70 as the new ones come in .02 increments.

 

Can someone confirm this is correct please?

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i had second thoughts so did it this way and came up with the same results..

 

Bucket and shim 5.335 Add clearance of .670, then take .300 (My desired clearance) away from .670 leaves me with .370, then add .370 to 5.335 and it comes to 5.705 ;-)

 

hope that is right?

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Chris can you check my calcs on above please?

 

Also i am now ready to order the Bucketless shims but my friendly Toyota guy (Steve Manley) quoted me £18.04 each = £433!! that was trade discount!

 

I am sure it was mentioned that a set was like $200 or £150 anybody?

Edited by StuartW (see edit history)
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Chris can you check my calcs on above please?

 

Also i am now ready to order the Bucketless shims but my friendly Toyota guy (Steve Manley) quoted me £18.04 each = £433!! that was trade discount!

 

I am sure it was mentioned that a set was like $200 or £150 anybody?

 

Not cheap are they, just doing a head at the moment ourselves.

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