Jump to content

Tappity tappets


Recommended Posts

Spent about 30 mins today setting the tappets on the Spit. 10 thou all round says Mr Haynes, which i duly set.
The car now sounds like a worn out sewing machine!
Is there a knack to setting tappets that i don't know?
My attack was to set each one when it's opposite valve was open, i would assume that no rising part of the cam was then in contact with the pushrod of the tappet i am setting.
It's easy enough to start the whole process again i suppose, just wondered if anyone had any pearls that might help.. :)

Link to comment
Share on other sites

There is always the possibility of wear in the contact face of the rocker. If the face is worn the feeler may bridge the hollow rather than going into it. When that happens you set the clearance much wider than the 0.010" you think you are setting. Try setting one valve to almost zero clearance then check it for how much it moves once you remove the feeler. If you have a lot of motion the rocker face is probably worn concave. Reset the clearance now!
A narrow feeler blade, a 0.010" wire, a dial indicator, or a clickadjust tool will measure the clearance without trouble from rocker face wear.

Link to comment
Share on other sites

tiggrr1 wrote:
If you can't get it worked out,

I'm not too far away if you need a hand  :)

Hi Steve,

Cheers for the offer of help. I may take you up on it soon, or just use it as an excuse to nip round sometime  ;) Hope you and Gaz are both well... Along with your cars!

Thanks too for the suggestions made so far. The worn rockers actually sounds like a realistic answer. I will dismantle them next time i'm meddling and check them out. The suggestion of the rockers sliding on the shaft sounds plausible too. I did think the springs on the two outer rockers were a bit feeble at centring them.. More worn/fun to embark upon i guess  :)

Link to comment
Share on other sites

Hi Dunc..... :)

Simple Moss vids here showing the rule of 9....

And the click-adjust tool in action to compensate for wear

Wear will be in be rocker arms twisting, cam followers, cam lobes, rocker shaft, push rods, adjusters, rocker arm lobes, valve guides and none will be the same. But the gap at the rocker lobe face to the valve should be 10 thou COLD ENGINE or as near as dammit worn or not.

If you don't want to get a click-adjust tool, whip the rocker shaft assem off and check the rocker arm lobes wear, note each one down numbered 1-8 scaled to not worn/bit worn/lots worn, also any lift in the shaft and lessen the feeler gauge thickness accordingly when setting. (or get a micrometer if you want to get really technical ;) ) its not perfect but should get you somewere near.

Aftermarket new rocker arms and shafts are poor quality and you usually end up with play in the shaft from new, I know...bin there done that... so have a play with your old ones, (unless they are totally knackerd ofcoarse... ;) )

I have a spare shaft assem with good rockers if you need any mate....!

Link to comment
Share on other sites

I must admit in the end I gave up with the rockers, even though I'd renewed the shaft / followers / springs etc the tappets sounded crap, I ended up changing to a tufrided shaft and put in Harland Sharp rollers from the US. OK not so cheap but it now sounds like a swiss watch and much cheaper than the rockers Jigsaw are selling (about £120 cheaper including delivey / duty etc)

The new replacement rockers you buy now  from Rimmers etc are from India and only last a short period - so I ruled them out.

I know it's not everyones cup of tea but there are some small benefits of ratio change so letting the engine breath better but that was not the reason for doing this - I just wanted to remove that dam noise.


Link to comment
Share on other sites

uksnatcher wrote:
Good to know Rob, any chance of a link to the Harland Sharp rollers?

Personally I like the klonky, tappy noises from the classic engine  but at the end of the day, we all know the noise aint good and max flow is good...even if it does cost lots of pennies....(shy)

I used these guys http://www.chequeredflagracing.net/ The guy's name is Joe. They included the machining of two of the rollers to clear the two outer pedestal (clearence on the overall diameter) - total charge including delivery to the UK £197.00 + £43.00 duty & VAT. You will also need a oil feed to the top of the head if you fitted them, I'd already got it so no additional expense.

Just take a look at the other stuff Chequer Flag offer - those drive shafts  8) 8)


Link to comment
Share on other sites

Jeeze, who would have imagined that setting the tappet clearances could end up such a potentially pricey job!
I had heard of the rule of 9's but didnt use that technique on mine. Since there are only 8 tappets to set and the wheel was a comfy perch i just took my time and did them one cylinder at a time measuring the opposite valve to the one that appeared fully open.
Thinking back though, some of them felt quite tight (<10 thou) before i set about them. I guess the P.O had adjusted them to compensate for some wear.
I'll have another play at the weekend (won't get a chance till then) and see if i can make it any better.
I'll strip them down too Gaz and let you know what i find  :)

Link to comment
Share on other sites

mine rattle a bit as well, i took the rockers off and carefully filed down the edges as they were worn, this helped quieten mine down a bit as did setting then to a tight 9thou, still noisy and some  move more than others so i just ignore it, cant here it with the roof down anyway  ;D


Link to comment
Share on other sites

You don't need roller rockers to fix the tappets. With new standard rockers and a camshaft and followers in good condition, the tappet noise should be virtually inaudible.

Having said that, added valve lift does make roller rockers a nice upgrade option. I'd probably have installed them myself already if they werent a) quite expensive and b) required an extra oil feed that robs the crankshaft bearings of oil  ??).

Link to comment
Share on other sites

1381 wrote:
b) required an extra oil feed that robs the crankshaft bearings of oil   ??).

Is this really an issue? Pressure relief valves bypass the oil flow that can't be utilised, if not providing sufficient oil flow for both then the pressure would drop and Larry lime light would rear his ugly head. So you would know quite quickly if it was robbing you crank.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...