M30 rockerarm adjustment

[Driftben]

Hi all
iv been trying to find the tappet clearances but haven't had any luck on the search and I haven't got my haynes manual with me?

Does anyone know the clearances when cold?

[leeparkes]

0.30mm

[Driftben]

Thankyou kindly ;)

[chris_335]

it aint eva 0.30mm thats huge

[gareth]

it aint eva 0.30mm thats huge

cold 0.30mm
hot 0.35mm

unless you want to burn the valves out or something?

[chris_335]

realy thats a huge gap

[gareth]

it's huge valve!
mine is set to that and it's lovely and quiet

[chris_335]

Yer True Well I Have Bin Doingine So Thankyou kindly ;)

[chris_335]

i think my cam is worn by about 1mm at the max. HELP

[gareth]

ouch! that'll be either blocked spaybay or the banjo bolts for it working loose then

new cam time i guess. time for an upgrade?

[chris_335]

yer a upgrade sounds good. but do i need to adjust the arm to fit the worn cam

[gareth]

if it's worn on the lobes, no amount of adjustment will help it.

what does the wear look like, can you get a pic or describe it?

[chris_335]

well it feels like a very small lip on the lobe but never bin to sur when i say small i mean small very very small less than the 1mm i put

[gareth]

when they wear, there will be a step where only part of the cam runs on the follower. if there is visible wear, it's technically done for and has worn through the case hardening layer (it's like a hard shell on the metal) however, at this stage, it will probably not be too bad, just keep an eye on it.

the worse rhe wear gets, the more of an impact loading it will put on the followers and this will in time lead to breakage

where did the 1mm come from? is that the valve gap you have now or something?

[chris_335]

k thanks for the info wil keep a eye on it. want a full head rebuild soon with big cam.
and the 1mm was just a rought quick gess

[Driftben]

I had about a 1mm indent in the cam lobe when I snapped a rocker. Wouldn't bother buying a new cam if your going to put the original lifters in.

[DRIFTBOY]

I run my clearences at 0.26mm cold and I've had no problems yet.

[Driftben]

Does it sound tickery martin?

[chris_335]

mine was can it tick if the gap was to small

[leeparkes]

M30's seem to run better with a bit of 'tick'

I adjusted mine to 0.25 by mistake, it was virtually silent but once id rectified my mistake and went to 0.30 the engine seemed more perky!

[DRIFTBOY]

Does it sound tickery martin?

A little bit, but not the worst I've heard.

Never managed to get it quieter so I don't worry about it now!

[Driftben]

Well u think it's only the hydrolic tappets which are quite quitet. Don't mind the sound as long as it runs when I'm finished with the rebuild
engine will be going it quite soonish.