Rebuilding cylinder head - NOW WITH PICS

I'm currently fitting a 2l 16V into my car, I have had the head off and skimmed, but no other 'internal' engine work done. Since I bought a complete "head set" of gaskets, I have the valve stem seals.

How easy is it to replace the valve seals? I read the Haynes manual and it says you need a special tool to push the seals down with, if you don't use it you'll damage the seals and have high oil consumption, etc. Also, is it worth the hassle, since I'd have to spend ?30 or so on a valve spring compressor. Also, worth lapping the valves in while I'm here?

i'm sure the place that skimmed it would have done that if you ask them, you'll kick yourself if you don't do them and it smokes like hell, we use a bit of pipe you have to make sure you don't push the middle down as the spring comes out, only ever had one problem, and that just hadn't been pushed home completely.

volkswarren said

i'm sure the place that skimmed it would have done that if you ask them, you'll kick yourself if you don't do them and it smokes like hell, we use a bit of pipe you have to make sure you don't push the middle down as the spring comes out, only ever had one problem, and that just hadn't been pushed home completely.

Yeah, I wanted to do as much as I can on my own. So I only asked them to check and skim the head…..

hi, I've always put the seals on with a suitable long socket to press them into their position in the head, but the real 'special tool' is the little plastic sleeve which should come with the set of seals. This is a small tapered tube of very thin clear plastic which fits over the top of the valve stem and lets you smoothly slide the seal over the stem -especially the little ridges where the collets fit. This stops the delicate rubber seal from being chewed up by the metal edges.Use lots of oil as well. The last head set I bought didn't have one of these provided and I had to manage without….maybe that's why my car is still smoking a bit???… :roll:

Oldfart said

the real 'special tool' is the little plastic sleeve which should come with the set of seals. This is a small tapered tube of very thin clear plastic which fits over the top of the valve stem and lets you smoothly slide the seal over the stem -especially the little ridges where the collets fit.

never seen this, and i've fitted loads of head sets, where do u get your gasket sets from??

Definetly do the oil seals, otherwise it's head off again when they fail. I posted this a while ago - this is what the special tools looks like…..



Found it in this uselful list of VW tools

My local VW dealer said they could get one and they hadn't had one one in the garage for years - probably a fob off as I didnt want to pay one of their fitter monkeys to do it. I ended using a socket, doesn't need much effort to get on. The little plastic sleeves should come with the new seals.

Cheers

Right, I'm going to give it a bash then. I guess if I can't use a regular socket to push the seal far enough, I'll purchase a long reach socket or try find the proper tool…..

volkswarren said

Oldfart said

the real 'special tool' is the little plastic sleeve which should come with the set of seals. This is a small tapered tube of very thin clear plastic which fits over the top of the valve stem and lets you smoothly slide the seal over the stem -especially the little ridges where the collets fit.

never seen this, and i've fitted loads of head sets, where do u get your gasket sets from??

Its just a little tube made of Mylar that sits on the end of the valve after youve pushed the valve into its guide, then you pop the stem seal over it.
It just prevents the valve tip from cuttung into the seal.

Ive got one someplace……now if only i could find it… :dontknow:

You can make one very easily out of either thin-wall plastic tubing, or shrink-fit tubing (available from electrical suppliers, e.g. Maplin).

I found a short piece of plastic tubing that was just too narrow, softened it in steam from a boiling kettle so it fitted part-way over the valve stem, and hey presto - one "valve stem seal tool".

You'll need a small socket, (9mm?) with a central hole big enough for the valve stem to fit through.

I found that a magnetic screwdriver/grabber was a real help with the valve collets - they can be very hard to get out/off otherwise.

AliCabrio
PS - got my valve spring compressor from; http://www.fine-tools.co.uk/

Well I've started, I did a 'test' with one valve, later regretting choosing inlet No.1 since its the most awkward access! The collets came off easy enough from capillary action of some grease holding them on. I had a right mare trying to get them back on, until I figured to turn the head round so they're dropped in vertically. I know what you mean about getting them in though! I started going slightly crazy! Unfortunately I've had to pack up, due to some ominous black clouds out there.

I tried my FLAPS but their valve spring compressor was ?60, so I went to - believe it or not - Halfords, whose similar tool was ?35. I've checked prices with my favourite online tool suppliers (and the link supplied - thanks!) and they're all around that mark.

I feel somewhat relieved that I haven't just bought the tools in vein - I tried pulling out the old valve seal and it was really brittle and just fell to bits. So at least now I know the engine will have had a complete top end rebuild, once all the stuff is done. Wish me luck….

good luck

Good luck!

It'll be worth it for that "I re-built this engine myself" smug feeling as you cruise down the local drag…..

…..checking the oil-temp and oil light every 30 seconds…..


Ali Cabrio

Things are going well, I stripped the head and gently gave it a clean up with a wire brush. All the valves have been lapped in (the exhaust ones took much longer, because they were much dirtier and the carbon was caked onto them, I guess because they become so much hotter). Then lots of washing with brake cleaner, then reassembly.

Initially it was really frustrating and took ages, but once I'd developed the 'knack' of slipping the collets on before compressing the valve, its going fine and I've got the process down to 10 minutes each valve, including cleaning all the parts super-clean, then slipping the valve stem seal over, then putting it all together and oiling up the area before popping the hydraulic tappet over.

In the end, fitting the valve stem seals is a non-issue - they slip over the top of the valve with no troubles, maybe because I soaked them in oil beforehand. Then pushing them firmly onto the valve guide is easy, an 8mm 3/8" drive socket does the job nicely.

6 valves done, 10 to do tomorrow……

And good luck from me  

…and good luck from me…soon you have the exciting moment of starting the engine…and hoping a) it turns over b) it fires and c) it doesn't make any banging /tinkling/ screeching noises that tell you things aren't quite right!!!
Hopefully, you get that slightly scary feeling of cautious success, where you frantically riun around topping up the coolant, followed by those worrying few minutes when you think 'where the f**k did all this smoke come from, as the grease and oil burns off the manifold!
Then you have a beer… :mrgreen:

Ok, job more or less done now, all I have to do is refit the cams then attach it to the engine again. I tried to take pics of the reassembly but the flash didn't go off, so the pics didn't come out great and I've tried to enhance them in Photoshop. Anyway….


Laying out the parts ready for cleaning and refitting. Note the dish with oil in it, smothering the valve stem seal in oil.


The middle valves are most awkward, I needed to dangle the head on the edge of the workbench. Valve stem seal is pushed in with an 8mm x 3/8" drive socket.


Close-up showing the valve stem seal in place. Note the red stuff, which is engine assembly lube, a thick and sticky lubricant


This is the trick I found works best. I put the bottom spring cup in, then both springs, then the top spring cover, then the collets, before fitting the valve spring compressor tool over it all


The tool is fitted and very gradually I wound down the spring, during which I ensured the tiny collets were more or less in place. Once wound down enough, I could push one collet onto the recess and the assembly lube held it there; then a wound down a little further and I could push the other one in. Then wound it all up again.

After this, a test 'press' on the valve is done, to make sure everything stays in place (but you can see the collets going on properly), then dousing the valve in engine oil, followed by a blob of assembly lube which would stay in place even if the oil drains away between now and startup. Finally, the tappet is cleaned up and popped over the top.

Not sure whether this is a cunning tip, or just worth bearing in mind.

While I had my cylinder head off, I changed the fuel filter.

When I came to start the engine, I had to turn it over for quite some time before it caught and ran.

This probably had the desirable effect of circulating oil to the cylinder head (and getting the oil up to pressure) before the engine actually started, and raised the revs above cranking speed.

Might be worth bearing in mind if you're concerned about the head being properly lubed before the engine starts.

Ali cabrio

you get the same cranking effect by taking the lead between the coil and the distributor off. crank it for a bit and then hook it back up again and start the engine. the tappets will still be a little noisy for a min or two. best way is to rebuild the head using the red engine assembily lube on the tappets though.

Paul - which assembly lube did you use on your head rebuild, and where did you buy it from?

Also, did you get your valve stem seals from VW or GSF, or somewhere else?

I'm about to rebuild my 1.6 8v head this week, and want to get it right first time (I hope!)

Cheers

Rich

The stem seals came as part of the kit of gaskets for the top end of the engine. I bought the engine assembly lube from Demon Tweeks, it should be readily available from there and other similar places - its also called cam lube, if that helps.