Yes people, its that time again, I've been busy in the garage this morning with my digital camera and various tools, and today i will be giving you the lowdown on changing your hydraulic lifters on your YB engines
First we start off by soaking your new tappets for 24 hours in fresh oil (or in my case, 16 weeks
)
After your tappets are nicely soaked (this is to remove all the air out of them) we can then start on the fitting in the car
Remove the cambelt cover so you have access to the cam pulleys and set the cam timing to TDC (take car out of gear to do this and turn the engine clockwise using a 24mm socket on the crank pulley)
Once you have done that, you may find it a good idea to blob a bright colour on each cam pulely and the belt, and the oilpump/distributor drive pulley - to aid refitting later (unless you are fitting a new belt at this point too)
Remove any strutbraces and your HT leads, and your breather pipes (if using an aftermarket breather system)
Once this has been done, you can then remove the camcover - this is the worst part of the job (likewise refitting it) as we all know how much of a time-consuming arse the 16 camcover bolts are to undo and refit
)
We then remove the cambelt and put it to the right of the engine, being carefull not to damage it if we are to reuse it
Once this has been done, we can then remove the cam bearing caps. This is to be done with care. I personally find it easiest to slacken all 5 caps first, and then remove the front cap (which includes the main pulley bearing within) and then allow the cam to spin to find its natural resting position (this is just slightly anticlockwise of TDC)
Once you have remove the exhaust cam, taking note of the camcap numbers (1-5 with 1 being at the front of the engine and 5 at the rear), we can then remove the old tappets. To make this very very easy, you can use a strong magnet - mine is an old fishtank magnet.
Remove all the tappets on the exhaust side, check for any debris you may have dropped into the valve spring holes and then refit the new tappets, again, using the magnet to aid refitting. Once you have done this, repeat for the inlet cam side of the engine.
When refitting the cams, allow them to find their natural resting position, just off TDC, and then refit the caps, noting the number stamped onto them. When refitting the camcap nuts, use a blob of locktite or other threadlock and then torque upto the specified value in the technicians manual.
Once the new tappets and the cams are refitted and torqued up correctly, it is time to refit the timing belt and camcover. When refitting the camcover, make sure you use a new gakset (if using the paper one, or wipe clean the gasket if you are using a Cometic item) and also use new half-moon seals on the front caps. Place a bit of engine sealant onto the front half moons to aid sealing at the corners where they meet the gasket.
Once this has been done, you can refit the cambelt, after aligning the cams at TDC - this is where the blobs of colour come in handy
Check that the tension of the belt is correct, on the longest length (near the distributor), you should be able to turn it no more than 1/4 turn before it becomes tight
Refit your breather system, cambelt cover and HT leads
Before finally starting the car, check the oil level and make sure all tools are removed from the engine bay area. Remove the LT feed to the coil and turn over the engine on the starter to flow oil into the head and untill the oil pressure light goes out. Once this has been done, refit the LT lead to the coil and start the engine, watching out for any leaks and listening for any un-due noises.
While the engine is warming up, go to the kettle and get the most important part of the job done - a brew
Once run upto temp, check for any leaks and check the tightness of the camcover bolts again.
There you go - one easy tappet change, time taken, approximately 2 hours, and thats including the brew break
I hope that you find this guide helpful and informative, and that you enjoy reading it as much as I enjoyed producing it