100thou shims for 20v

[quibel_nz]

anyone know where i can get some new shims for my 20v silvertop ... my engine man says they need to be 100thou (2.6ml ish), yes its heavily modified

being underbucket i spose i could use 2x 50 thou shims as i cant spit them out .... like shim over ...

OR

does anyone know of valves that slot into the 20v silvertop with a longer stem

Q

[vvega]

no option on vales
you could built the tops up on them
you cant buy that bigger shim

and thats abou it

base grinds are bad mmmmk

[quibel_nz]

largest shims ive found so far are 65thou and ive had a big look .. i dont expect that il find any but you never know .. as for building th estem up ... mmmmmmmm .... ild rather put 2x 50thou shims under the bucket

Q

[vvega]

yeah been though this before toyota just dont make a massive shim for them
though in saying that
yamaha might

have a looksee

v

[matt dunn]

being underbucket i spose i could use 2x 50 thou shims as i cant spit them out .... like shim over ...

Ah, yes it can.
My 20v spat two shims out at different times just after the head was done.
They are bucket shaped and fit over the stem and the the bigger bucket goes over the top ( as you prob. know.)

Mine rocked to the side and jammed the valve open. Twice. On different valves. I would not put two in as there will be nothing to stop the top one sliding around as if you look under the bucket the surface is flat.

Only possible if you can weld the two shims together??

Matt

[ChaosAD]

Im assuming you have re-ground cams, right?

If you do, go to your cam grinder and ask him if he can do a set of 'lash caps' for you.
They are little magnetic caps that sit on top of the valve stem, theyll be the same thickness as was taken off the cams and will bring the shim sizes needed into the range that is available.

If the factory shims actually sit on the valve stem then you may have to do away with the shims and use only lash caps. But id talk to the cam grinder about that first.

BTW, I wouldnt reccomend getting the valve stems lengthened.

[atmosports]

100thou shims, would be custom made, we make them all the time for other engines, any good machine shop & some reconditioners/camgrinders etc should be able to either make or supply something suitable. Don't use 2 shims above, yes they tip over & jam, seen broken cams,camcaps etc , I have even seem single shims tilt over in underbucket setups, very rare but can happen.

From memory Yamaha don't do thicker shims either, as I'm sure that we've been done this road before, but should be able to match them up, probably off another bike or maybe a car like 5v/cylinder Audi etc.

As for valves, there will be no specific off the shelf straight fit in a 20V job, but you can buy stainless blanks with the right head shape/size/angle etc & then face/grind to length & if necessary change the retainer grooves to suit or just change the retainers. It is not as expensive as it sounds. Don't build up the stems or bolt something on to them, it will fail end of story, just like welded up cams, the weld will crack off & destroy your motor, spend the $$ & do it properly, get a cam ground on a new blank, don't weld up an old one.

[quibel_nz]

SORTED ... FYI ....

Being that the 20v shim is underbucket it is actually part of the lashcap or bit that sits ontop of the vavle stem ...

Franklin cams can get these in 140 thou to suit the 20v and they are a direct replacenment for the factory 30thou items. then you just need to get them cut down to the right size

at $10+ per lash cap its not cheap considering you need 20 of them but witha grind and lashcap it still owrks out over 300 cheaper than a billett cam grind ....

thanks for the info boys

Q

[ChaosAD]

I still reckon the extra $300 is worth it. Then your not limited to such small lift & durations.

BTW It probably would have cost you about $10 per shim to re-shim your 20v anyway.

How are you going to find what size to machine the lash caps to? measure the clearance, machine the shims, re-measure, re-machine etc?

[TrouserFxGt]

largest shims ive found so far are 65thou and ive had a big look .. i dont expect that il find any but you never know .. as for building th estem up ... mmmmmmmm .... ild rather put 2x 50thou shims under the bucket

Q

seems strange that the manual says that you can get 0.0906" shims. Shim #29

[quibel_nz]

chaos ... limited lift and duration .. cant go much bigger than 295 with 10ml ... trd only list to 315 with 10.5ml

trouser fx ... yeah true .. but toyota dont stock them and they cost more than 10 bucks a shim

Q

[vvega]

chaos ... limited lift and duration .. cant go much bigger than 295 with 10ml ... trd only list to 315 with 10.5ml

trouser fx ... yeah true .. but toyota dont stock them and they cost more than 10 bucks a shim

Q

bout 1000 buck to grind a blank that will bolt in and....
is made to your spec's ramps duration lift etc

v

[ChaosAD]

cant go much bigger than 295 with 10ml ...

Shit, thats bloody big for a re-grind! must be cos its a 20v. Youd struggle to gehan 272 deg and 8.35mm lift with a 16v cam regrind