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adjusting tappets


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Place in neutral, disconnect the battery, remove the spark plugs, remove the rocker cover then use the fan to rotate the engine so the valves open and close as per manual.

dont forget that "open" means the spring is in its depressed position.

I take it you have the feeler gauges? I have always used a slight dragging fit - that is put the feeler gauge in, and it should have a slight resistance when you pull it out, only slight though.

Others with years of experiance may correct me!

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Hi hugh, it all depends on the tappets,!!!

if they are new, then 10 thou will be ok,   [  original cam !! ], but not right !!!!!!!!

but if they are old and worn, then they may well have a  ..indent.. in the rocker finger

so your 10 thou, will end up may be 14 or more !!!

thats why some engines feel a bit tappetty, wen set to original figures

you can slacken  some rocers right off, and look on the under side to see if there are any ..indents.. there,.

but also you got to ..push doon hard.. on the adjuster screw,

as this will ..displace any oil that has got between the parts,.

My self, I like to turn the engine over a few times with a spanner,

this gets rid of all the oil in the bearing journals, cam lobes ,ect,

so that when ye set the rockers, they are set at  a setting that wont ..alter..

when you turn the engine over to  ..re check them ..

as happens, when ye ..just set them as standard ..

and on a standard cam, I ended up with 7 thou,  tight fit,.

and by the time engine was turned over a few times, this ended up at 10 ish   [ no indents in rockers ]

as all the oil had flowed away, so increasing the gaps

and the engine was a lot lot quieter, doing it this way,

So, find out what are the rockers indented at,  subtract that from factory figure,  [ 10 thou ] and subtract 3 thou more, and that will doo,  

try and set them , just as you would, and you will find that by the time ye got them all done,
the first ones are ..tooo big again..,  try it, !!

regards marcus

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As Marcus said, after you've gone around once, you check & you sometimes need to go around again!

1.  Open bonnet
2.  Remove valve cover
3.  Put cold beverage on the deck near the battery (or brake master cylinder)
4.  Sit on tire
5.  Hum to self while setting tappets, curse occasionally as needed
6.  Do not over-tighten valve cover bolts when putting it back on, or you'll bend the valve cover
6.  Remove beverage before closing bonnet when finished

It's actually the least stressful but most repetitive maintenance you perform on the car, more like those weird oriental exercises you see people doing at the beach at sunrise.

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Help if I am standing on the passenger side of the engine bay which tappet do I adjust 1st is it left to right or right to left. If no 1 spring is fully closed do I adjust the one next to it no 2. I am getting in a bit of a pickle with this

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royboy66 wrote:
Hugh, you should see 2 tappets move together  ie  2&4 , then its the rule of 13, ie if valves 2&4 are fully open,check/adjust valves 11&9  etc etc

Im popping to my Nans in Shawbirch this morning, I will try swing by  ;) :)

Roy 8)
Thanks for the offer Roy but I am going out at ten this morning and will not be back untill 2.00 family commitment.I think I have adjusted a couple wrong way
Cheers Hugh

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ok no worries, you should be ok if you follow the rule of 13, just keep score of the ones you have adjusted,

always rotate the crank in the normal direction of travel though,

(Tip, if you not sure which direction, take dizzy cap of and look at rotor arm as you turn crank around ;) )

Happy Tinkering

Roy 8)

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'nother tip.
Take a tub of grease, or better vaseline, with you to adjust the tappets.
As you do one, put a smear in the slot of the adjuster screw, so you know you have done it.

It will soon melt and dissolve in the oil once you finish, and is easier than a dirty piece of paper or card.

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aren't you supposed to set them when the engine is hot? i had a lot of bother with mine, the p/o had set them cold and when the engine warmed up and everything expanded the valves couldn't close, giving me no compression....no bang....no go.
Would run for about 15 mins then conk, left it about 30 mins and it would run again.
Hair pulled out a few times but finally found it was the tappets had been set too tight

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All the normal advice including the factory manual say do it cold and the quoted clearances are also cold.

If you do them hot then you need smaller gaps and you need to ensure you do them all at the same temp, which is tricky as it all cools down quite quickly and, if you're anything like me, you may be taking yoru time!

Also, when cold they don't burn your fingers  :-/

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908 wrote:
Thanks Craig I am not sure what thickness feeler gauge should I use.

This depends on what Cam you have or if the car is on a standard cam?

Buy a manual do not attempt to do this job with out the correct settings.

Do the adjustments on a cold engine. The valve must be full closed.


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Well I have done the tappets thank you all for the advise to my great shame once I got my head in gear it was quite easy. I just could not compute the job at 1st big thanks to you all again.
On another note I changed the broken front wheel stud aswell tonight Thanks Tim but when I looked at the other wheel nuts I took off the front wheel one of them had a split down the thread :-/. I am now going to replace all the wheel nuts and studs will Stag studs and nuts fit a GT6 :-/

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