Another Type 4 1800 AP Engine Project (going 1911cc now 1971cc now 1992cc finally 2056cc)

Valve Geometry - Lite - Theory

This is what I did as i put in a cam with a bit more lift, but you can check alignment if you change any part of the valve train.

As background, assuming VW set geometry the way everyone says it should be it should work like this..



The rocker spins around the middle of the shaft and at the middle of the lift the tapper is in line with the valve...

If you increase the lift, the starting point is the same as push rod is the same so the middle point of lift the tapper has past being in line..



So to correct this you lift the rocker with a shim. As the push rod is in the same place the rocker has to rotate a litte further back so the tappet starts at bit more of an angle because you've adjusted the gap from the top of the valve to be the same as the start 0.15mm and the cup is back on the pushrod, so now the sweep is still longer but at the middle point the tappet is back in line with the valve stem



Installing swivel feet has a slightly different effect on geometry. Because of the swivel bit on the end the adjuster is rotating about a point a pit higher.. you've effectively made the valve stem longer so you're just lifting the rocker to get the sweep to match this new point.

If you've increased the stroke of the engine the rockers are further away from the pushrods by more than the shim would so the middle of the sweep would be too early so you need longer pushrods.. you'll then need to go read the article in the last post.



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Valve Geometry - Lite - Practice

This is what I did as I put in a cam with a bit more lift, but you can check alignment if you change any part of the valve train.

So I set up a rocker on the head with tappets already in, swivel feet will only go in from the bottom.

Torqued up the nut to 10ftlb at set up a dial gauge on the spring retainer away from where the rocker will swing

Get the piston at TDC and firing on the cylinder your looking at. Both valves should be shut so tappets are easy to spin up and down. If you're on the wrong TDC valves bill be just open a smidge so tappets should be hard to move if they were close to being set.

Adjust the tappet to be just touching the valve tip "no lash",



If you can zero it or keep this number

If its intake spin crank anti-clockwise as this operates just before firing ( if its exhaust go clockwise to get valve to move), get it maximum lift to check how much lift you're getting... it won't be what the shop said.. chances are intake is more exhaust is less... apparently, this is common. Also, check spring is not bound.. still has room left between coils to squash some more if it wanted to.

You can now work out what half lift is and wind crank back until gauge reads the half way value.



At the start shown on the left full lift top right, and half lift, bottom right.

You can see the adjuster is not in line with valve stem..at this point

So it needs a shim, I went 0.5 then 1mm.

This is where spotting it being vertical got hard so I got some small spirit level bubbles and glued them to a magnet. Put one on the spring, level the engine in the stand, using the bubble on the spring, get it half lift moved and popped a level on top of the tappet.



Do the dial gauge thing



Check the bubbles



Double checked horizontal...



Good to go.

Adjust tappets as in Rocker Gear Install above....

Stand back and get ready to put ancillaries back on







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Ancillaries Part 2.

Sorry been a bit side tracked at lunch time in work. I have been getting on slowly in the garage though so better catch up a bit.

Oil Pump

Re-opened the oil pump and removed the light greasing I’d done and replaced with Vaseline, it melts and dissolves into the oil easier and less risk of blocking an oilway.

Some say pack it full of vaseline, some say none it'll pull just fine... I went for enough to make cogs seal to each other and the casing. Makes a nice noise then.. and it worked like that on the last build so stuck with that method.

Lining up the ‘key’ on the back of the pump with the cam slot makes putting it in easier. Case bolts to top and bottom of opening not in yet. Got some new M8 sealing nuts from off of t'interweb too.



Cleaned all the mating faces with carb cleaner, plenty of non setting gasket stuff around the base, new paper gasket , even more goo at the bottom of it as guess there’ll be oil sitting in there.



Pop it on and gently tap it home. Should go in quite steady if it’s all straight, gentle tapt each side get it starting

Bolt it all up, torque it to 14ftlb and hopefully no leaks!

Front Pulley

Polished the life out of the front pulley where ut rubs the front oil seal.!

Had a few light scratches on it bit of old 400 grade oiled up and fit it in a drill held on spin with a cable tie…



Shiney , shiney



There’s a couple of seals, small o ring for the crank and and big seal for the case. Gone for double lipped viton ones rather than the stock VW ones, no more expensive and thought it worth a go.

Thesre’s a big thick washer to hold it al on and don’t forget the woodruff key (and get a magnet ready for when you knock it off putting the hub on)

Had some Curil T to hand so used that to seal the pulley seal to the case, oiled up the crank with the o ring on



Pulley seal needs to go on flush tap it home gently and evenly.

Pop on the hub and big washer and torque it up to 23ft lb



Its got the big washer to stop the fan ripping the oil seal on there too so I don't misplace it

 

It's an oil pump.

 

oops typin gtoo quick..better go back...

 

Oops seemed to have forgotten to finish this.. @Gnasha the nuts were

https://www.burtonpower.com/nut-m8-flanged-with-seal-pp6196.html

£ 7.13 incl vat and postage

 

Many thank

Many thanks

 

Many thank

Many thanks