tappit settings

[rocket man]

hi can enyone tell me the easyest way to set the tappits up on my super rocket and what the clearences
should be

[Richard]

Yes
turn the engine until one inlet valve is fully open and set the other one to --depending on your book and year as i seem to have conflicting info to either 10 or 12 thou (I set mine to 12) then turn the engine until the other inlet valve is fully open and set the other one.
Do the same with the exhaust valves and set to 12 or 15 thou (again I set mine to 15)
Job done.
Just a tip make sure the top of the valve stems are flat and do not have a dimple in the centre from tappet wear as the feeler gauge will bridge that and the tappet clearence will be to large
Richard

[LJ.]

Now with my crappy hearing, I dont hear a tappety tapet. A friend only a couple of weeks ago made known to me that my left exhaust one was noisy. I re set it when engine was cold... as you should, but made no difference. Some engines require themselves to be hot for adjusting, if you do adjust when hot then make sure there is some sort of gap when valve is closed or you could end up burning a valve away.

The job is made so much easier if you have the nut and allen key adjuster. The hex type screws (Allens) are available from C&D or Draganfly and well worth the money spent.

[MikeN]

Heres a tip.
 You can use your tappet adjusters as a micrometer.They are threaded 26TPI on a BSA .Therefore ,with zero clearance a quarter of a turn will give you your 10 thou clearance (or as near as makes no difference).Knowing this, you can now set the 12-15 thou in a similar way without using feeler gauges.
 This method is also useful if the ends of your valves are dimpled.
This is more handy to know when working on a Triumph which is a bit more fidddly to access than a BSA.
Mike

[69Bonni]

Oh Thats a handy one Mike

Are Triumphs 26TPI too?

Steve

[MikeN]

Steve,
Yes. According to ex-Meriden man and Triumph restorer Hughie Hancox,thats how they did them at the factory.

[69Bonni]

Mike ... Nice one!

I'll remember that i have beem meaning to stick mushroom adjusters on the Bonnie for a while.

Really handy to know, another little trick of the trade, Thank you!

Regards

Steve

[snowbeard]

great bit of info Mike!! 

[fido]

At the bimble on Sunday there was a Douglas 80. The owner says the tappets have to be set at 0.025" or it won't run properly 

[Richard]

Mike
That is a good tip and as such I will keep the square headed tappets rather than change them to allen key jobbies.
What about the clearance would 10thou on each be ok, as in the Rupert Ratio book he advocates that the C15 can have no clearance when cold and be fine, so if that is the case would 10thou in and ex be ok on the S/R
Richard (minety uk)

[rocket man]

thanks lads for all the info very handy

cheers dave

[MikeN]

Mike
That is a good tip and as such I will keep the square headed tappets rather than change them to allen key jobbies.
What about the clearance would 10thou on each be ok, as in the Rupert Ratio book he advocates that the C15 can have no clearance when cold and be fine, so if that is the case would 10thou in and ex be ok on the S/R
Richard (minety uk)

Richard,Im flattered that you think I might know the answer to your question,unfortunately I dont.Im just passing on the tip.I set my A10 exhaust clearance to 1/4 turn. plus a bit more.
 I used to have a cammy Velocette that ran on 25 thou clearance on the exhaust. Ive always wondered why designers dont design their cams so you set them at say 2 thou and this gives you the required valve events.It would make engines a lot quieter.Im sure there is a good reason.
  I have the feeling we will be informed shortly.
Mike

[MikeN]

Mike
That is a good tip and as such I will keep the square headed tappets rather than change them to allen key jobbies.
Richard (minety uk)

Richard,
  I would still fit the allen screw adjusters (in fact I have) the allen key makes a good pointer /indicater when making adjustments.
Mike

[Richard]

Thanks Mike
I hope someone does as mine always seems noisier than others, I know I have an alloy head and I believe a spitfire cam but I always wish for a quite engine, my lightning was worse which was one reason I parted with it

Richard(minety)

[trevinoz]

Tappet clearances depend on the camshaft fitted.
The long stroke A7 are both .015"
334 cam - inlet .010", exhaust .016"
356 cam - inlet .008", exhaust .008"  Later changed to .010"
357 cam - inlet .010", exhaust .012"   This is the setting for maximum power. Will be a little noisy.
Trev.