Valvetrain Talk

[OMGGTR]

Hi guys

In the process of building my 1st rb26 i am a little bit distressed as i have not enough knowledge on this part of the build so i come here for some to shed some light thanks

1st question, decided to stick with Tomei type B poncams 9.15mm lift cams

on inspection of my lifters noticed they were fairly bad as they have heeps of gashes in them from the shitty camshafts, price of tomei lifters are $500 not inc freight OEM are like $58 for one!

The TOMEI Solid Valve Lifters RB26DETT are recommended to be used when upgrading the lift of the cams to over 10.25mm. The items are composed of chro-moly steel, cold forged to be stronger and light weight (32g).

that is the description of the Solid lifters from TOMEI notice how they say recommended to be used with cams over 10.25mm.... can i buy them still ? and use with 9.15mm cams?

2nd question is why are they called solid lifters? are the oem ones not solid ? they look pretty solid to me lol explain this please?

Cheers guys!

[GTSBoy]

Both OEM and any other lifters for RB26 are solid. The RB26 description for the Tomei lifters is probably just a cut'n'paste of the description for their other RB engine lifters (other RBs use hydraulic lifters) - hence the silly language involved. And this would also be why the confusing language about what lift to start using solid lifters at - other RBs need to be converted to solids once you start using high enough lift cams.

In your case, using the Tomei lifters with 9.15mm cams will be no problem.

Edited October 8, 2011 by GTSBoy

[zebra]

In your case, using the Tomei lifters with 9.15mm cams will be no problem.

Not if they are designed for small base circle cams.

Might be worth double checking

[OMGGTR]

one of the only reasons im sticking to these cams are that any bigger lift eg 10.xx mm cams would be so big that apparently the head needs to be cut a bit to fit them using a dremmel tool or something so i shit myself n thought ok maby i just stick under the 10mm lift lol

any1 able to confirm zebra?

[GTSBoy]

Not if they are designed for small base circle cams.

Might be worth double checking

But are any of the Tomei cams like that? Aren't small base circles the territory of regrinds? If the big lift Tomeis generally need the edges of the bucket bores to be cut, then they're not likely to be on a small base circle.

Worth checking nonetheless, just to make sure, coz I could be quite wrong.

[zebra]

Yeah im not sure, But as im sure you know some of the jap stuff can be a bit odd ball like that

George.

How bad are the scores in the lifters? is it just the shims that are scored?

[OMGGTR]

i have a build thread in the overhaul section OMGGTRS Rebirth i just uploaded pics have a look

The shims look ok but im sure ill have to buy new shims and redo all the clearances

[zebra]

Just had a look, Unless you have already taken the shims out they are just the shims used to set the clearence.

They are only a few bucks each, and will need to be changed with the new cams anyway.

Just a pain in the ass to do.

Need to measure current clearence on all cam lobes, remove cams and shims, measure the thickness of the shims and order thicker or thinner shims to get the clearence you need.

[zebra]

dammit you replied before I finishd typing lol

[OMGGTR]

do i put the new cams in 1st then measure or do i measure with the old cams ? im lost lol

i have the engine manual shows all the standard clearances cant i cheat that way ?

[zebra]

do it with the new cams

[zebra]

make up a chart like this, makes the job much easier

[Gerg_R31]

Correct term is 'under bucket shim' (and there is 'over bucket shim' & 'solid bucket')

Rb26 clearances - 0.018" ( +/- 0.001") intake & 0.015" exhaust ( +/- 0.001")

Measure with feeler gauges when the cam lobes base circle is above the bucket

Face valve/ cut seat/ order thicker shims to close the gaps

Machine tip of valve/ shim to open

Too loose it will rattle and cause premature wear

too tight it will stay open causing loss of compression

I've had to machine a 26 head out for poncams a couple times

[r33_racer]

Those clearances seem a little loose. Sure its not the other way around? Or are those the factory lash settings?

We run 0.010" on intake and 0.013" on exhaust.

[zebra]

I really need to do the clearences on the 1J.

But cbf..it can rattle for a little longer

[r33_racer]

Its a toyota, im sure it can take it!

[Gerg_R31]

They are the factory settings

the exhaust usually has a bigger clearance as it expands more during thermal expansion,

but with the rb26 exhaust valves being sodium filled, the sodium absorbs more heat, which stops the exhaust valve expanding, and allows for a smaller clearance

[r33_racer]

That makes sense with the factory valves.

Both our valves are s/s. I guess that explains the different lash settings.

[Gerg_R31]

Yeah stainless steel has a more controlled thermal expansion rate which ill set to oem specs, inconel and titanium even better control which ill set to 0.012" intake & 0.014 exhaust

[OMGGTR]

question still stands can i use tomei solid lifters with 9.15mm lift cam ? if i get some yesses or no's i can look into something different or purchase..