high lift cams and valve clearence you should use.

[30psi 4agte]

I have finally got my car going ( write up soon in members rides) i have high lift cams 9.5mm and the 1sz conversion. I set the valve clearence to .279 on the exhaust and inlet to .200 but its very nosiy even when hot.

Is this too be expected with big cams? or should i be able to get rid of the tappet noise?

I have always believed that with big cams you use larger clearences ???

[joecoolmk2]

I have always believed that with big cams you use larger clearences ???

why? i can't see why you'd need bigger clearances. just set them to normal and see how you go.

[oldcorollas]

if the base circle was ground badly (like one of my cams, 0.15mm difference ) then you may need bigger clearances.

could be noisier due to ramp rates combined with the extra clearance?
i'm guessing it's not easier to reset them smaller now? can you reset say.. the front half and then compare noise?

[joecoolmk2]

just use shim steel and see how it goes, if it's better than redo the clearances properly.

[takai]

Hm, are you sure .200? 0.02 i can understand. Im running the stock clearances on my cams with the 1SZ conversion, and unless i just cant hear it ver the sound of the exhaust mine isnt making any undue noise.

[30psi 4agte]

Hey OC

Yeah thats my thoughts on the issue. -- the ramp rate causing the noise cos all the valve clearances are spot on!

Its just one of those things! I think its is normal to be nosiy but im not 100% sure.

In the end is is better to hane a noisy lifter/ tappet than a tight one!

Anyone else had this issue?

[oldcorollas]

depends if it's thou or mm (or mil ) i assumed mm...??

[30psi 4agte]

Hm, are you sure .200? 0.02 i can understand. Im running the stock clearances on my cams with the 1SZ conversion, and unless i just cant hear it ver the sound of the exhaust mine isnt making any undue noise.

Yeah cheers TAKAI typo m8 they are mm

What do you call stock clearance??

FRom memory they 0.006 - 0.010" I
and 0.008 - 0.012 E

ALL of Mine are 0.007 I and 0.010 E so they are well within spec.

EDIT that actually makes the inlets .179 mm

[takai]

I assumed thou given the decimal places.
The factory specs are:
Intake = 0.15 - 0.20mm
Exhaust = 0.20 - 0.30mm

[oldcorollas]

totally different motor, but in K series, 0.2/0.3 is noise.. but 0.12/0.18 was quiet.. very big difference in noise.
try 0.15/0.2 and if it makes difference... you are on track.... set, then try and get everything warm and check clearances when hot....

[takai]

Yeah, even those are cold clearances, i noticed that the expansion of the 1SZ buckets is far less than the stock 4A buckets. Maybe i should update the guide with that.

[30psi 4agte]

I may have to go smaller in the clearance its not a easy thing to do though Most of them buckets are ex japan too


Takai : thats what i started thinking too !! -- they might expand less ( less metal to
expand ?? )


OC
So on you engine what was the factory clearance and what clearance did you end up with to quieten the engine down when you put cams in ??

[oldcorollas]

3K head, mixed valve train gear, but with rockers..
0.2/0.3 i think was the factory hot clearance (it has been a while since i've been near my books )
regardless of oil, 0.2/0.3 was always noisy...
the cam had variation in base circle, so i would rotate for each lobe to highest (lowest? minimum) clearance and set to 0.12-0.15, and 0.15-0.18... all done hot, then checked later when hot...

bear in mind this is totally differnet setup with lots of slop everywhere... but smaller clearance made difference...

also.. with the base circle variation, it was possible to have 0.15 clearance in one spot, and then less than 0.05 on another part of base circle...
might be worth checking if you have an even base circle (just rotate and feeler gauge it every.. 30deg? of base circle... if it is lower on some parts, it might rattle around...?

(on K motors, with 3mm more lift, the rocker gemoetry also makes a big difference to noise, but you don't have that problem..)

[30psi 4agte]

i have checked clearance throughout base circle as they are new cams - no variance.

They are billet from crow.

[gianttomato]

Surely Crow Cams gave you a spec sheet with the clearances to use?