Club 80-90 Forums

Hello,

You've got profiled pistons, so you will be ok.

What are you doing about the valve guides, and the seats.

Still have to fight through 2 layers of spam to get to your photos..

Keep at it...

Cordialement,

In process of setting up new account for photos. Hopefully this will resolve the spam problem.

Have no further progress to report at moment apart from further cleaning of parts.

After machining of heads was just going to lap in valves and refit.

Now having second thoughts on reusing heads and may purchase new pair (approx £450.00)

Do not want to rebuild everthing and still have the same problem with pressurisation of cooling system?

Have cracks in the heads between valves as all seem to do. Talking to someone today who had a similar problem and he resolved it by replacing heads.

Interested to read that you had the heads skimmed. My understanding is that the important surface is the small circular step just below the 'surface' of the head. So was it the larger flat surface that was skimmed or the narrow edge that mates with the cylinder liners?

Good idea to renew the clutch - I'm wishing I had done the same when I overhauled my cylinder heads/liners/rings/valves. At least it's a fairly easy job dropping the engine. Good thread.

As I said earlier using a chemical metal to fill the pit holes (which is what causes seal failure) then ensuring the mating face is wiped clean, is a much better method if the rest of the head is in good order.
this method applies to the jacket faces too.

Decision now made to reuse heads. Was not worried about the sealing faces more about the cracks between valve seats?

The rubber seal face will be okay without any filler after the machining. The engine block faces are also good.

The machinists skimmed the flat cylinder head face, liner gasket face and the vertical face of recess for liner. Liners now fit into head resess without any tightness.

Hello,

Cracks between valve seats.....

Been happening since the twin port beetles...

There are (only) 2 main areas of worry.

1 : misfire on tickover, and at startup.

2 risk of dropping a valve seat.

The proper, rather expensive way to do it is by cutting out the valve seats with a dremel type cutter, grinding right to the bottom of the crack. aand then TIG welding all new metal in, followed by machining to fit and ream new valve guides, which are used for the reference to machine the new valve seat housings, then preheat to fit the seats, then seat cutting, then valve lapping,..might as well have the plug threads helicoiled,, and loads of new studs...

In the real world.. you can use a technique called 'peening' to close the cracks and 'stake' the valve seats

I havn't done a video of this yet,

Use at least new exhaust valves, and spend time 'lapping' them in.

Use a die threading tool to clean up all the threads.

There is a demonstration here:

http://www.youtube.com/watch?v=dB6LAQR87MI

Take your time..

Its a VW thing..

Cordialement...

Make sure you carefully use the VW sealing compounds as well they shpould be included with the gasket set.

Would anyone recommend a particular gasket set? seems to be a few around

Brickwerks do a good quality set at an ok price.

'Victor Reinz' but make sure it comes with the rubber gasket sealant, VW Heritage set it does, GSF it doesn't. Best to check on the 'phone before parting with cash

VW sell sealant

After busy few weeks got back in garage and onto engine yesterday and built up cylinder heads.

Going to fit barrels and heads today hopefully. Just sitting down now and reading the haynes manual with a cup of tea.

Also watched Sarran 1955 video on air cool rebuild. (Nice piece of what looks like 203x133x25UB on the bench at start of video or is it euro beam section?)

Got my gasket set from Just Kampers and it includes 3 tubes of sealer. 2 tubes of Dirko-S and unnamed small white tube?

My gudgeon pins do not slide in by hand as in video. Propose to clean these with scouring pad so sliding fit?

Hopefully will try and post some photos this evening.

Personally - I would heat the pistons up slightly with the wifes hair dryer rather than scour them.
We used to put pistons and rods into a bucket of hot water to remove them on big old diesel engines - You wont have this option if the rods have to be fitted before the crankcases are joined

As said ^^^ for christ sake dont go doing anything abrasive to the pins nor pistons,leave them alone and warm the piston cool the pin
mm

DuaneEddy wrote:Personally - I would heat the pistons up slightly with the wifes hair dryer rather than scour them.
We used to put pistons and rods into a bucket of hot water to remove them on big old diesel engines - You wont have this option if the rods have to be fitted before the crankcases are joined

yep.. what he said^^

heat the pistons in the oven put the wrist pins in the freezer for a night