a few weeks ago we had another post similar to this, the guy had the ip timing soo far advanced and still had problems with this set-up.
If the seats are worn you don't usually need to replace them, just have them machined. Valves, guides and seals for a mechanical head are only around $100 for all of them new.So $100 plus grind the seats and install the guides. Probably cheaper than a 1.9 head and it'll be fresh, fresh, fresh.
Do you have a block which was originally designed for a hydraulic head, or do you plan to "convert" the AAZ head to mechanical operation?Steve.
iirc the post was by golfmk11dr, currently at the bottom of this page, franken set-up, if i remember he gave up and stuck a 1.6 head back on,,
Ok so I have a 1.6NA and it turns out the valves are pretty worn, which I find out after I have finished porting them however the seats are worn too. So I went to a machine shop and confirmed that basically you need to replace the lot(I'm not daft, but was seeing how much you could get away with), which would be fine if it wasnt so expensive to do compared to the price of a used running engine or some type!So I spotted a 1.9 head on ebay, dont a bit of searching through this and a few other forums and came to the conclusion:-It drops straight on, with stock head bolts-extra oil gallery drain away at the front that needs addressing for use on a 1.6NA block (with a plug of some sort)-cam wheel swaps over-different rocker cover/gasketbut the headgasket?It seems people are using 1.9 ones from what I have seen, I just bought a 1.6 one recently before I'd finished the head, will that be a problem? I'd imagine its more critical the head gasket matches the cylinders so they seal correctly? are all the other holes in the right place (except the one you have to block)I figured a used 1.9 head (with hydro lifters replaced with new ones and I am running a 36mm GTi pump) thats a maximum of 20 years old would be far less worn than an 83 1.6NA head, plus wont need me to re polish and port as naturally the ports are bigger.
Well i checked with seller and the head has about 90k on it. Seems 1.6 diesel parts are not easy or cheap to come by in the uk, 1.9s are much more common although people tend to want a fair price for a complete engine with about 9billion miles on seems more common to get parts like a head.One question is did you use 1.6 or 1.9 injectors?Im surprised that the precups make such a massive difference. I also have the fun of rebuilding a spare ip for this project too.