1988 Scala 1.8t agu conversion

[ant]

Unfortunately after taking it out for a test run with new suspension 2-3 miles up the road engine decided to lose all power and sounded like a scooby, got it dragged home (embaressing lol) and found it was low on compression on 2 (measured 50) and 3 (measured 100), they should have been 150-180... which 1 and 4 where, gutted. Anyway removed the head and have had it skimmed and valves all done, all 8 exhaust valve guides and seals had totally had it so thats probably half the problem, just putting it back together now. Thought i would do the hydro lifters whilst the head was off too following this useful guide: http://www.audi-sport.net/xf/threads/ho ... 8t.118251/

Hopefully will be fitting all new piston rings this weekend and getting the head back on it!

Engine rebuild - head off.jpg

Engine rebuild - bottom end.jpg

[ant]

Silver lining to everything though and thought i would respray the bay again from where i bashed the new paint job when putting the engine in and from where the fuel lines blew and stripped the paint off. Also sprayed the intake manifold and rocker cover with high temp silver spray to tart them up a little..

Primer.jpg

Painted.jpg

Air intake and rocker cover sprayed.jpg

[ant]

Head after being sent off for skimming and valves being re done:

Head refurb 1.jpg

Head refurb 2.jpg

[mark watson]

hi ant
with the skimming of the head before fitting back get an engineering company to check the top of the head where the cams run to make sure they are dead straight , what we have had plenty off with overhead cam motors is the guys are to quick to skim but dont have the correct stuff to reverse clamp the head on guage plates , now the head does warp to a degree when taken of the block , this is why you tighten your bolts in circular motion from inside outwards . ive had this on opels / mazdas / golfs etc , the head gets skimmed but when fitting the cams you put them under a bending load which within 1000km's destroys the head , we have had broken cams / oil pressure problems and always the guys tell me but the head has just been redone so what now ,and i have been through this exercise what happened to my daughters b7 audi was the cams chewed the head up so bad that it dumped all the oil into the head as now the tolerance between the cam and head is way too big and actually scavenged all the oil out the sump that the vvt started chattering and when i took a corner the oil light came on but when i checked the oil level it was spot on , only way to tell was remove the cam cover and run it then i saw i had enough oil in the head to supply 10 heads with oil. if you look at where the exhaust cam seats its not very big so if it is slightly out it does not take much to chew it up.
a trick one the racing engine builders gave me was nip all the head bolts the torque the centre 2 bolts completely through the 3 stages then do the rest after 30 minutes it then gives the head time to stretch itself ( if you want to call it that ) then carry on with the rest.
now some people might disagree but we have had in the family alone 3 20v motors go that somebody has skimmed the head but did not tell me , even the 2.5 mazda diesel wj motor the guys keep skimming heads and voila down the road the flippin cam snaps in 2 , just had my nephews opel sent in for new guides and seals , and straight away they want to skim the head and i told them to stuff off as there is nothing wrong with headgasket etc , just the guide chipped and started smoking on startup

[mark watson]

dont want to be a doom prophet its just the hair stands up on the back of my neck when the engineering guys keep saying they want to skim the head , its easy money for them but it has to be done properly if push comes to shove with a camshaft head then the cams must be linebored again for trueness to the face of the head, i have my own machine shop at the factory and even my guys get it wrong at times by not fastening the job properly ( albeit not car stuff ).
a friend came round the other day and his mazda truck snapped the cam twice on his wl motor , and then he told me he had the head done , when i asked the engineering firm what was done they had skimmed the head , on giving to my guys we clocked the face and then checked the camshaft journals in the head and was out almost 1mm from the middle to the back of the head , and that is why the cam snapped. engineering guys blamed the cam but when 2 cams break in the same place def something wrong , and they just turned their noses up and said not their fault , eventually bought new head and no more problems

[ant]

dont want to be a doom prophet its just the hair stands up on the back of my neck when the engineering guys keep saying they want to skim the head , its easy money for them but it has to be done properly if push comes to shove with a camshaft head then the cams must be linebored again for trueness to the face of the head, i have my own machine shop at the factory and even my guys get it wrong at times by not fastening the job properly ( albeit not car stuff ).
a friend came round the other day and his mazda truck snapped the cam twice on his wl motor , and then he told me he had the head done , when i asked the engineering firm what was done they had skimmed the head , on giving to my guys we clocked the face and then checked the camshaft journals in the head and was out almost 1mm from the middle to the back of the head , and that is why the cam snapped. engineering guys blamed the cam but when 2 cams break in the same place def something wrong , and they just turned their noses up and said not their fault , eventually bought new head and no more problems

Hi mark thanks for the info, the engineering company that skimmed it checked all thoroughly as u mentioned earlier, luckily I know the chap that owns the company and he personally did it for me to ensure it was spot on, they are very good from the previous work I have seen them do.

Your project looks as if it's coming along nicely!

[mark watson]

thats good stuff ant , just ive had my share of horror stories , glad you know and trust the guy , i reckon you have some damn good machinists that side , we have more like monkey see monkey do

project bit on hold , work has me tied up a bit

[ant]

The hydraulic lifters looked in good condition when i took them out so none of them needed replacing. They are an absolute s#!t to take apart, but totally worth doing it as the engine is now very quiet on tick over.

Before:

10) Hydrolic lifters removed.jpg

After cleaning them in petrol for 20 minutes each:

11) Hydrolic lifters after cleaning.jpg

After putting them back together with fresh oil (dont put to much in otherwise you cant compress them back together):

12) Hydrolic lifters finished.jpg

[ant]

While i had a little more room in the engine bay i added an additional small slim line fan in case it needed to flick onto its second stage:

13) Additional slimline fan.jpg

I replaced all 4 piston rings while i was at it, the middle ones only really needed doing but stupid not to do the others for the sake of a few extra ££'s. They did'nt look bad at all when they where removed so must have caught it in time..

14) Piston removal.jpg

They had new bolts put in the bottom when they where dropped back in as they use stretch bolts, top of the block was cleaned up and new gaskets all around:

15) Bottom end finished.jpg

[ant]

Head was put back on and everything else connected back up, timing is always fun as literally no room to alter it but was double and triple checked before firing it up for the first time, engine started on 1st turn of key but still didn't sound right... missing on cylinder one . so tested injector, that was fine, replaced coil and spark plug with a spare and no difference... tested wiring to the ignition amp and from ignition amp to ecu and that was fine... tested current flow through ignition amp and it was faulty through cylinder one... must have gone whilst pulling all the wiring off the head. once replaced fired up lovely and ticked over spot on!!

16) Heah back on and connected up.jpg

Engine back together and looking shinny after re spray

17) Finished re build.jpg

[ant]

Decided to have a tinker with the fuel sender which is built into the swirl pot and pump holder, currently reads the fuel level backwards which is just annoying! Figured out by removing the green wire from next to the black one and touching it at the top the fuel gauge reads correctly.. result! Soldered it to the top and then glued it in place so that it is secure on the board. I know the mk3 golf sender works alternatively but was determined to get the mk4 golf / audi a3 working after modifying the tank to take it! Heard online that you could do this but no pictures or real proof of it. I also shortened the float to the correct length so that it now reads accurately.

Pic of the fuel pump swirl pot with sender and float attached to it:

13) Fuel pump.jpg

Sender mod:

14) Fuel sender fix.jpg

[ant]

Whilst i was under the car making alterations to the exhaust a while back i thought i would take a pic of the gear selector and forgot to put it up, it is the gear selector from the Audi a3, i mounted it under the car, most people put it inside for some reason but seems a lot more work when there is plenty of room underneath.. it also keeps it lower down. All that is needed is drilling a few holes, making some spacers and bolting it up to original holes. Job done.

33. Gear shifter.jpg

[unknownmale]

Nice. Did you hone the cylinders before reinstalling the pistons? I've heard conflicting views regardless of the crosshatching still being visible

[ant]

Nice. Did you hone the cylinders before reinstalling the pistons? I've heard conflicting views regardless of the crosshatching still being visible

I didn't hone them, decided against it in the end as they looked fine. Just cleaned them up and oiled them. Done around 200 miles so far and running sweet.

[Bigmills74]

Hi Ant, I like your idea of modding the scirocco tank to take the Audi in tank pump as I have a new tank waiting to be fitted . Did you upgrade your solid fuel lines to same diameter as the injection type?