Valve Lash/Clearance help.

[leelbuk]

Just fitted some Whifbitz 264 cams and have measured the clearance as recommended and I'm glad I did! I'm not sure on what the tolerances are for Whifbitz cams (I've PM'd Paul for these) but either way they are all pretty tight. (I did not measure them before so they could have already been this tight on standard cams)

 

My measurements.

 

 

My questions are:

 

 

 

1. Has anyone had experience with Whifbitz cams and still knows what the lash tolerances are?

 

 

2. The engine obviously hasn't been run with these cams yet and I have just changed the stem seals etc however the cams have been turned a couple of times (I checked and double checked clearances). Is this enough or does the engine need to be started and then the clearance checked to make sure everything is bedded in?

 

3. Most of the values that are in spec (assuming standard Toyota tolerances apply) are borderline on being too tight. i.e. a lot of the intake clearances are 0.15mm and seeing as there is an amount of error involved with feeler gauges (the human factor) they could easily be very slightly under 0.15mm. Should I have all these changed/surface ground by 0.05mm so that they are all mid spec? I believe I've read that wider clearances are noisier but carry less risk of burning valves?

 

4. Does anyone do/know anyone that would be able to surface grind shims for me? At the moment it looks like I'll have to change most of the shims and at nearly £10 each it's a lot of money if surface grinding was a cheaper alternative for the same thing.

 

 

Any help is greatly appreciated as I've been trawling the internet and piecing together all sorts of information to try and help me here but feel I need something definitive for my specific situation. Thanks for taking the time to read this!

Edited December 5, 2010 by leelbuk
Numbers added to questions (see edit history)

[Terminator]

Clearances are checked cold, engine not run, many engine builds have the cam clearances adjusted with the head off the car, as it is easier. I know nothing about Paul's cams.

[leelbuk]

Clearances are checked cold, engine not run, many engine builds have the cam clearances adjusted with the head off the car, as it is easier. I know nothing about Paul's cams.

 

Thanks Phil - I've checked these cold, just wandered if the clearance would change after the engine was turned over a couple of times, to make sure everything is bedded in.

[jagman]

4. Does anyone do/know anyone that would be able to surface grind shims for me? At the moment it looks like I'll have to change most of the shims and at nearly £10 each it's a lot of money if surface grinding was a cheaper alternative for the same thing.

 

 

I have resurfaced shims using a sheet of glass and fine emery paper, then used coarse grinding paste , but it takes ages and you rub off your finger print on your index finger, by the time you have taken a few thou off , the 10 quid seems cheap !! ,,,,,But it did work

[dcarrter21]

I mite be able to do it on our grinder at work. Ill see if its free tomorrow

[Scooter]

I have a fair few NA shims about (99% they are the same) I could measure a few and see if they are thinner and if we get lucky I could pop them in the post? ...........

[Terminator]

Thanks Phil - I've checked these cold, just wandered if the clearance would change after the engine was turned over a couple of times, to make sure everything is bedded in.

 

I see no harm in turning the cams round a few times by hand.

[leelbuk]

4. Does anyone do/know anyone that would be able to surface grind shims for me? At the moment it looks like I'll have to change most of the shims and at nearly £10 each it's a lot of money if surface grinding was a cheaper alternative for the same thing.

 

 

I have resurfaced shims using a sheet of glass and fine emery paper, then used coarse grinding paste , but it takes ages and you rub off your finger print on your index finger, by the time you have taken a few thou off , the 10 quid seems cheap !! ,,,,,But it did work

 

I did think of something like that but was worried that I might not get it completely flat and risk spitting one of these shims out.

 

I mite be able to do it on our grinder at work. Ill see if its free tomorrow

 

Mate, I should have thought that you might have something suitable where you work! If you can do it then it'll mean some notes your way!

 

I have a fair few NA shims about (99% they are the same) I could measure a few and see if they are thinner and if we get lucky I could pop them in the post? ...........

 

Just checked parts catalog and you are right, they are the same! If you do have some smaller I'd definitely pay for you to post them and I'd vow to keep whatever I shims I swap out and offer them to anyone else on the forum who needed them for them same deal!

[leelbuk]

4

I have resurfaced shims using a sheet of glass and fine emery paper, then used coarse grinding paste , but it takes ages and you rub off your finger print on your index finger, by the time you have taken a few thou off , the 10 quid seems cheap !! ,,,,,But it did work

 

On this subject, does anyone know if the shims are solid hardened throughout or just case hardened? If the latter I would be worried that grinding/sanding these would result in accellerated wear or deformation later on if the hardened material was grinded off. I've read posts from Chris Wilson saying that you can grind them on the bucket side of the shim so I'd hazard a guess that they are hardened all the way through?

 

Starting to look at this more seriously as I need 19 shims and this is nearly £200 from the stealers and might take a while if they have to be ordered.

 

EDIT: Had reply from Paul - his 264 cams use standard lash in case anyone digs up this thread in future

Edited December 6, 2010 by leelbuk (see edit history)

[d_d]

I have had no problem after surface grinding my shims, so id deem it to be a safe practice.

[dude]

4. Does anyone do/know anyone that would be able to surface grind shims for me? At the moment it looks like I'll have to change most of the shims and at nearly £10 each it's a lot of money if surface grinding was a cheaper alternative for the same thing.

 

 

I have resurfaced shims using a sheet of glass and fine emery paper, then used coarse grinding paste , but it takes ages and you rub off your finger print on your index finger, by the time you have taken a few thou off , the 10 quid seems cheap !! ,,,,,But it did work

 

 

We can do this Adam

[Chris Wilson]

Through hardened, I do them for my own builds if I don't have easy access to new ones of the right thickness. I tend to buy a few quite thick ones and keep them for when I need to grind a bespoke one. They are a bit tedious to do as taking much of a bite off one will flick it off the magnetic chuck and put a gouge in it. Skyline ones are even worse as Nissan never seem to have stock, to the point I had six sizes of blank ones turned up, and then had the through hardened at Wallworks, so I can grind my own in house now.

 

http://www.chriswilson.tv/simon7/simon.html