Valve clearances

[Surly_Z]

I've just put this old/new engine in, and after a good service and 100kms I noticed valve 'tapping'.

I now adjusted the valve clearances a second time (one cold, then one hot) and have discovered:

- intakes 3 and 8 have 0.00mm clearance

- exhaust 6 has 0.28mm

- exhaust 12 has 0.00mm

 

I assume that because I cannot adjust the pivot nut (as it has no more room to adjust) that there maybe some head work to be done?

 

Second question, does anyone know a good shop around brunswick/city/fitzroy area?

I should probably get it sorted soon, the thing sounds like a machine gun!

[Scoota G]

No more adjustment? could you put up a photo??

[Surly_Z]

I'll try get a photo up soon. Essentially there's the lock nut which holds theadjustment, then the pivot which is the height. The above ones are tightened, therefore increasing lash gap, but they're at their max so I can't increase the gap anymore, yet there's no clearance?!

 

Photo soon!

[.]

I'm with Scoota? What the?? I can only imagine that some non standard parts have been used. Sorry to have to ask but you do realise that you need to spin the cam so the lobe on the valve you are checking is pointing up?

[Scoota G]

Some times there is a fair bit of sludge in the pivot point hole and maybe it's jammed! That could lead one to believe that they are at max because to increase gap you go down . . Maybe?

[peter mc]

sounds like you are not checking them right are you checking them on the back of the lobe ?

[dazzed]

Turf the head and get another one, preferably with solid valve seats dont waste anymore time friggin around with it , is kappoot, haddit, most likely the rest of the engine may require some attention too.

[Surly_Z]

Argh don't say that, Ive just put the engine in!

 

I've gone by the hayne manual, so I'm checking them correctly. No 7 had sludge and after loosening nut found it sat properly.

I'll go have another play with it monday and get some photos.

 

Thanks for the help guys - it's one of those things that should take me 30mins, but has ended up being quite annoying!

[dazzed]

sludge is something that is found in a engine that has never had any attention ,that could be the sign , old , you have to weigh it up

[Surly_Z]

I'm with Scoota? What the?? I can only imagine that some non standard parts have been used. Sorry to have to ask but you do realise that you need to spin the cam so the lobe on the valve you are checking is pointing up?

 

I've gone by the Haynes instructions, which seem a little vague - It doesn't mention to rotate each valve you're adjusting, just to make sure Cam#1 is up for 1,3,7,8,9,11 are adjusted, and when Cam#1 is down, then the rest.

 

So just to clarify, all adjustments therefore need to have the appropriate Cam in up position. Eg if I'm doing valve #2, then Cam #2 must be pointing up?

 

 

[luvemfast]

So just to clarify, all adjustments therefore need to have the appropriate Cam in up position. Eg if I'm doing valve #2, then Cam #2 must be pointing up?

Yes, the clearance is on the base circle diameter. Once the cam lobe puts some preload on the lash pad, there will be no gap.

 

[Surly_Z]

Yes, the clearance is on the base circle diameter. Once the cam lobe puts some preload on the lash pad, there will be no gap.

 

Just re-adjusted, with the Haynes gap sizes, but NOT by their instructions. Seriously, if anyone has read their method is doesn't make sense.

Anyway, no more machine gun sounds, just a nice L28 purr!

 

Thanks for the clarification guys, it was just a simple job that got me confused!

[dazzed]

aaahhhh  you didnt say it was a L28, i just assumed it was a 240z with a E88 head as your symptoms are common to this head , so as it turns out it was a manual problem, dang

[DatPilot]

Only just read this!

Im in Canberra too, woulda come by to help as I have only just done this on my L24e.... made a BIG difference.

Pity about the snapped rocker cover bolt though... and the snapped 'ezy-out'... oh and the snapped tungsted carbide drill bit.....

Looks like it will be cheaper for me to get another head instead of paying $250 getting all the machining and tapping done to fix this monumental f-up.

[Surly_Z]

aaahhhh  you didnt say it was a L28, i just assumed it was a 240z with a E88 head as your symptoms are common to this head , so as it turns out it was a manual problem, dang

 

Yeah, whoops!

 

I drove her again today, and the tapping has come back slightly - so hopefully just another re-adjustment and it should be fine, I've got a feeling I hadn't done valve 5 properly.

 

So to clarify, on my L28 N42 head that the gaps for intake HOT = .30mm, exhaust HOT = 0.25mm, with appropriate cam lobe in up position.

[dazzed]

put number 6 exhaust cam lobe facing up , adjust too a loose 10 thou  then have a look and you will see another lobe facing up if its an inlet adjust too a loose 8 thou this is hot too remember,  remember the first valve you adjusted was  cylinder 6 exhaust or number 12 valve, now turn the motor over approx 90 degrees  and adjust the next two that face up and so on untill you end up with number 6 cylinder exhaust valve facing up you have then adjusted all the valves  theres a bit more too it than that but thats the basic start bit complicated going into the rest of it, if you are confident you have done all this to a tee and still have noises you have wear in cam and lifters/ rockers , maybe chain ,guides , let us know how it pans out cheers.

[Surly_Z]

I will do, thanks.

I've got a mate giving me a hand on Wednesday, so hopefully we'll get it sorted.

 

I think your process is a lot quicker than mine! I pretty much rotated each one and adjusted, bit silly really.

Fingers crossed it's just my bad adjustment, and not anything else.

[Surly_Z]

put number 6 exhaust cam lobe facing up , adjust too a loose 10 thou  then have a look and you will see another lobe facing up if its an inlet adjust too a loose 8 thou this is hot too remember,  remember the first valve you adjusted was  cylinder 6 exhaust or number 12 valve, now turn the motor over approx 90 degrees  and adjust the next two that face up and so on untill you end up with number 6 cylinder exhaust valve facing up you have then adjusted all the valves  theres a bit more too it than that but thats the basic start bit complicated going into the rest of it, if you are confident you have done all this to a tee and still have noises you have wear in cam and lifters/ rockers , maybe chain ,guides , let us know how it pans out cheers.

 

dazzed! You're a legend! My mate and I got valves adjusted in 10mins, and now runs perfectly.

 

Seriously, I have no idea what the Hayne's manual was talking about. It's method was incorrect, so were the clearances for both Hot and Cold gaps...

 

Anyway, thanks again. Can't wait for the rain to clear so I can go for a fang.