Valve Clearances (Again)

[puremalt]

About to do my tappets this w/end, anyone advise as to the procedure. The rule of 9 springs to mind. Does the engine (x flow 1700 s/s) need to be hot or cold? Will I need to turn it over to ensure the valves are all fully open during the job (ie how do you set the gap on an open valve as the rocker is pushing it open isn't it?)

Scuse the errant stupidity that I've displayed somewhere in this thread. 😳

 

 

 

 

 

 

 

 

 

 

 

 

 

 

[Peter Carmichael]

You set clearances when the valve is fully closed.

[Graham Sewell]

Assuming a standard Caterham spec 1700 supersprint engine, the engine needs to be cold as in left overnight. Then, if you are lucky, you can use either rule of 9 or 'on-the-rock' methods. On my engine the difference is < 1thou so I use the quicker 'on-the-rock' method.

 

Low tech luddite - xflow and proud!

[John E]

You set them when cold. Either put the car in 4th gear and rock it or get a decent spanner on the crank case pulley. Use a ring spanner that fits otherwise you will round off the bolt and knacker you knuckles

Take out he plugs cos it is then easier to turn the motor over. Put something over the holes otherwise you may end up with more than maladjusted valves

When adjusting the sum of the two valves concerned will add up to 9. For example if number 8 is full open ie the spring is fully depressed then you adjust number 1 which is now fully closed ie the spring is relaxed and you can move the rocker arm.

 

Run Baby Run

[Graham Sewell]

My crankshaft pulley requires an odd sized allen key to turn it! Finally ordered an adapter from snap-on for a standard ratchet drive - much easier.

 

Low tech luddite - xflow and proud!

[Nigel Riches]

I set a D.T.I. with a magnetic base over the "open" valve to be sure of picking the fully open position, possibly being to picky, but it works good, regards Nigel.

[YW Sin]

 

I did the same stuff for the first time a few weeks back and I am pasting this old message from a very kind guy c~~~ed, Len Unwin who helped me out.

Hope it will be some help.

 

Ah, by the way, NEVER USE OPEN END SPANNER to turn the adjustting bolts as it can damage them!! Also be sure to use soket that fits PERFECTLY to the nut.

When I did mine it was so tough, I though I must have forgotten to unbolt some thing. My solution was to use fully closed "L" shaped extruded spanners and tapping the end of the grip gently with a rubber hammer.

 

 

From Len Unwin:

 

The adjusters on the crossflow are usu~~~y quite easy. The nut that you

adjust has a thread which is not the same as the rocker into which it fits,

[a bit like when you cross thread a nut onto a bolt]. The very first time

they are adjusted the nuts are always very stiff but with the age of the car

I would have thought that the tappets would have been adjusted in the past.

Best tips are NEVER use an open ended spanner, it will break the nut, to get

the nut moving try a socket and ratchet, best is a six point type to give

the nut some support,. They will move and once you set the tappets .022 thou

inlet .024 exhaust do not be tempted to set them sm~~~er to get them

quieter. It does not matter from which end you count but numbers 1,4,5and 8

are exhaust and 2.3,6 and 7 inlet.

Adjust :- 1 when 8 is fully open [~~~ the way down]

2 " 7 "

3 6

4 5

5 4

6 3

7 2

8 1

 

 

 

 

 

~~~ standard 1.7 X-flow