Finding and preparing a new to me AMF

[Little Dog]

When I removed the head I reversed the tightening procedure. I then lifted the head cleanly, I think the clean lift is the reason the manual specifies a two person lift, and it has been stored gasket face up as recommended by Audi. I've checked the head for flatness and it easily passes to Audi spec.

However these heads have a bad reputation on the internet for blowing head gaskets once they have been disturbed. Furthermore if the head does warp Audi recommend a new head. But why not have it skimmed?

Having checked a number of engine remanufacturers websites I think the problem is the hardened valve seat inserts which are very close to surface to be skimmed. The inserts have to be removed and refitted after a full skim, or as one machine shop offered, the skim can only be a lite skim.

Furthermore the valves protrude beyond the head surface. Any increase in that protrusion would need to be added to the piston protrusion when selecting the correct head gasket.

It's too early to say if my efforts will be successful but I did think before I started that the head would be difficult to warp, it is short in length, deep and wide. A bit of a lump; not like a straight 6 cylinder head which must be far more difficult to remove without warping.

 

[TFG]

Does the 3 cylinder head have a reputation for warping? From a quick search on google, I'm not finding much.

This is an excellent thread btw Phil. Very informative and an invaluable reference

 

[Little Dog]

Does the 3 cylinder head have a reputation for warping? From a quick search on google, I'm not finding much.

This is an excellent thread btw Phil. Very informative and an invaluable reference

Everything I found related to 4 cylinder heads and some of that I think resulted from poor workmanship. Perhaps the reputation isn’t justified for 3 cylinder?
I found it easy to work on.

 

[Little Dog]

There has been very little progress recently with Little Dog's new engine; he is sat in the front garden with a trickle charger connected. I'm doing my best to get a car out of my lockup so Little Dog can go in.

This is all the A2 progress I have to report:

I have booked a five month early MOT, I don't want the new engine smoke testing before it has a few miles on it.

I've fitted new seals to the injectors:

 

[Little Dog]

MOT was yesterday, had a couple of minor jobs, exhaust joint blowing, only three out of four washer nozzles working. Good clean inside and out and off to the MOT test station. The MOT tester actually questioned the car being in for a test " is there a reason why it is being tested 6 months early"? My answer was simply yes but he wanted to know more. So I explained it was getting a new engine and I didn't want the new engine smoke testing before it had run in. Off he went to test the car and I got a pass, no advisories. Not bad for a 21 year old car with 175k miles.

In terms of this thread I wanted emission test results to compare with the new engine next year but didn't get what I expected. Last years emission results and all previous years have been exceptional:

Just 6 months and 2.5k miles later the results have slipped:

Also the test pass limits have changed, is that an error or have new limits been placed on older cars?

Of interest to me here is the actual values increasing by around 50%. What is that a sign of, a failing engine?

 

[Howey]

Yeah tester has selected wrong age rating for the car.
Regarding smoke levels, a good blow out directly before the test can make whole world of difference however that test reading for me is perfectly acceptable and I would be more than happy with it if it was my car!

Interesting neither test is showing engine speed readings that's a bit naughty really

 

[Little Dog]

With no progress now for over 1 month even the tiniest amount is worth celebrating. Split edges repaired with PVA glue. large splits strengthened with garden frost guard sheet and PVA. Black finished restored with black shoe polish:

 

[TFG]

That looks great Phil. Chapeau. I didn't think it would be possible to repair one of those covers. They always feel very insubtantial to me. Have you got any closer-up shots of the bits that you've repaired? Is the "frost guard sheet" you mention the lightweight white stuff that you drape over the top of plants?

 

[Little Dog]

I had three problems, four if I include it looked a bit tatty.

It had ripped. I opened the inner and outer skins either side of the rip and poked in garden plant frost protection sheet to bridge the rip. The white stuff that comes in a roll to protect plants in the garden overwinter, we have loads of it used at the moment. I then brushed in PVA, squeezed out and cleaned off the excess and clamped with special tools while the glue dried:

Surface tears, glue down and hold with low tack masking tape while the glue sets:

Inner and outer skins delaminating. Split deeper if necessary, brush in PVA, squeeze out and clean off excess glue, special tool to clamp while glue dries:

General tattyness improved by applying black shoe polish,

The essential special tool, many required:

 

[PlasticMac]

I had three problems, four if I include it looked a bit tatty.

It had ripped. I opened the inner and outer skins either side of the rip and poked in garden plant frost protection sheet to bridge the rip. The white stuff that comes in a roll to protect plants in the garden overwinter, we have loads of it used at the moment. I then brushed in PVA, squeezed out and cleaned off the excess and clamped with special tools while the glue dried:

View attachment 122342

Surface tears, glue down and hold with low tack masking tape while the glue sets:

View attachment 122343

Inner and outer skins delaminating. Split deeper if necessary, brush in PVA, squeeze out and clean off excess glue, special tool to clamp while glue dries:

View attachment 122344

General tattyness improved by applying black shoe polish,

The essential special tool, many required:

View attachment 122345

Horticultural Fleece.
Mac.

 

[TFG]

Thanks Phil. I think I may have to have a go at this myself, as I've got all of the necessary to hand, including the essential special tools!

 

[TFG]

I've found what looks to be fairly significant pitting on two of the valve seats in my cylinder head. I'm a bit gutted about this, as the rest of the engine looks to be in very good condition internally. The camshaft bearings and balancer chain and related gears in particular just don't look 23 years old. The bores appear good too. But it looks as though I'm going to have to darken the door of a local machine shop to get this sorted out

 

[Little Dog]

I've found what looks to be fairly significant pitting on two of the valve seats in my cylinder head. I'm a bit gutted about this, as the rest of the engine looks to be in very good condition internally. The camshaft bearings and balancer chain and related gears in particular just don't look 23 years old. The bores appear good too. But it looks as though I'm going to have to darken the door of a local machine shop to get this sorted out

View attachment 122497

My valve seats had slight pitting at 100k miles. I was able to lap a continuous grey band on all 6 so avoided a trip to the local machine shop.
I’m not so lucky with the bores, they look glazed to me. I can see the honing marks but can’t feel them. So off to a machine shop for an opinion. If my valve seats had looked like yours I would have been taking the head too.

 

[TFG]

Took the head to my local machine shop. They tried to drop the valve seats back a fraction (around 0.1mm) to restore the surface. That did the trick with the smaller seats. The larger ones have had to be replaced. He's also given the head a very light skim. Just enough to clean the face up. It's turned into a bit of a costly diversion.

I now need to buy a new set of valves. The seats on the old ones look to have gone a bit concave to me and while I've got it all apart it seems silly not to sort them out. Does anybody have a recommendation on make? I slo see that 7Zap list two different lengths of valve for both inlet and exhaust. Later ones appear to be shorter. Is there any view one whether the later-spec ones should be used, when replacing, or should I stick to like-for-like? I'm wodering if the spec change was brought about by complaints of burnt valves.