V8 head refurbishment

[Botang]

Originally Posted by A8 Doc

Pistons don't look bad at all really. Though if rebuilding some nice lightweight ones and some new lightweight rods too? Bit higher RPM then!

Whilst the engine is apart port your exhaust outlets and your intakes. Buy a porting and polishing kit and flow your heads mildly, don't go too extreme as it will have the opposite effect.

A fully rebuilt 4.2 V8 with flowed heads and lightweight pistons would be veeeeeery nice. Some mild cams for sir and a remap over the top would be a nice increase.

A thought.... If there are any kicking around and they fit is the later S8 cams into the engine?

The heads are ported and polished as standard!

[A8 Doc]

Really? Any pics of a standard head?

I'm amazed!

[Botang]

So was I when I took it apart, the effort that they have gone to is incredible they had even removed any finishing marks from the oil pickup.

[Conan_the_Librarian]

The strip down continues....

Current state,


The heads are strip down and ready to go to AVP,


The Crank Shaft drive for the cambelt came today and you can see the missing key!



So that confirms what happened. Why? Doesn't do to dwell.........

Next back to the starting problem. I still love my car!

Could you provide the amount of time and $Money that your rebuild took? We saw one bent valve....it's cost?

Your supplier for the parts? via the mechanic or the machine shop?

Is this rebuild now a spare or are you going to sell it?

I am in a similar situation, I have a used 4.2 L as a swap and therefore the original engine is up for "re-conditioning" or rebuild if I find that more than a few valves are bent.

Thanks

Looking @ your photo...it appears that the old sprocket has lost it's interior "key lock"? ... & the "gears" appear to be worn down compared to the new sprocket. Would this be the reason for any (your) timing skip?

To me, it appears that it's very possible cause/effect for timing issues on high milage engines.

Thanks

[Conan_the_Librarian]

Originally Posted by wizzard1222

Could you provide the amount of time and $Money that your rebuild took? We saw one bent valve....it's cost?

Your supplier for the parts? via the mechanic or the machine shop?

Is this rebuild now a spare or are you going to sell it?

I am in a similar situation, I have a used 4.2 L as a sway and therefore the original engine is up for "re-conditioning" or rebuild if I find that more than a few valves are bent.

Thanks

I have had a quote of approx £23 per valve x 16, £3 approx per seal x 32 from Audi. I have not had it done yet. Still saving up, but have found and independent mechanic to do it. hoping to get it done in the next few weeks.

I intend to fit this AHC into and A8 in place of an ABZ.

Originally Posted by wizzard1222

Looking @ your photo...it appears that the old sprocket has lost it's interior "key lock"? ... & the "gears" appear to be worn down compared to the new sprocket. Would this be the reason for any (your) timing skip?

To me, it appears that it's very possible cause/effect for timing issues on high milage engines.

Thanks

Yep, key-way has gone completely so timing went out and bent all 16 inlet valves!

[Conan_the_Librarian]

Originally Posted by Botang

The heads are ported and polished as standard!

Actually, not true!

We gave the heads a good inspection when I dropped them off and AV Performance and they definately have casting and machining marks on them. So added to the list of work is a polishing.

[ChriS8]

Oh, how I would love to do something like this
But unfortunately my S is the only vehicle I own that has a roof.
So I had to go for weeks by bike again and in these awful winterdays it's not the way to go..
But your pics give me much passion to do this, at a time far far away..

[Conan_the_Librarian]

Pictures to follow


With the heads now with AVP I have started work on the recipient car. A 1997 A8QS i picked up for £500 from North Wales. It had oil in the water and a suspected blown head gasket. As it has turned out it has a blown heat exchanger in the oil cooler. This has turned out to be a 'Part not recognised' by the Audi parts system and is causing a bit of fuss. So out with the ABZ and in with my AHC.

The offending article.....


I started work before I had my camera so here are a few on the phone.

Front end off


Some of the muck that came out as I drained the rad.



Radiator off and the first problem anyone notice anything missing.




Stripping of the plastic I came across a small horror story.......

Going to have to get that welded up!

I think this engine has been out to change the gearbox and has not been put back at all well. Nothing we can't fix.

So after 6 hours today we were at a natural break point so off for a beer.



For those that saw the last one I have a fetish for looking up my tunnel!!!