Did you say your running head studs and a MLS hg on a 1.5l.... Where did you get it i want one!!! (for the 1.5l)
If your useing the 11mm fasteners, just use the 1.9 AAZ metal head gasket and center the bolt holes as best you can befor you lower the head. If you useing the 12mm fasteners, no problem. I got my head studs for the 1.5TD and 1.6TD from Raceware.
I did the 1.5TD thing as an R&D project as I suspected that the shorter stroke, longer rods, and same size bore were indicators that the engine could possibly generate more HP at high RPM than the 1.6. I even had a special 1.5TD pump built by Bosche from a yellow dot 1.5 pump and the LDA top from a 1.6TD pump. From the 100 or so miles that I tested it, it indicated that there were gold in them there hills.
However, it was always pressureizing the cooling system, be it with the original head, studs and fibre gasket, the original head, studs, and metal head gasket, or the last itteration, which was a brand new 1.6 11mm head, studs and metal head gasket. It was always a slight leak, so I suspected the block was cracked, but i haven't tore into it yet.
I was running a k24, and its probably a little big for the 1.5. A VNT would do a better job. The k24 wouldn't build significant boost at lower RPM and the EGT would shoot up, until the rpm climbed up enough to spin the turbo. It did have impressive higher RPM power. Boost would stabilize around 25 PSI, and the EGT would drop down to somewhere around 1100° F or lower, and it would really fly. I don't think high boost is a killer in these engines, but too much fuel (smoke) will do them (and 1.6s) in. An EGT measurement is cheap and very easy to install, especially when you have everything appart, and it really removes all doubt. A VDO vision EGT gauge, coupled with the Aircraft Spruce thermocouple is very effective combination. I think I even have an extra white faced VDO egt gauge laying around somewhere and an extre Spruce thermocouple that I'll let go for cheap if your interested.
I suspect all 1.5 blocks are stressed out right from the factory as the original head bolts don't even use half of the thread depth in the block. So when they torqued them at the factory, the damage was done.
If you can find a good 1.6 block, it would be definatly worthwhile to put the 1.5 guts into it.
I will resurect the 1.5TD project soon. It will use a 1.6 or 1.6td block. I have to see if I can machine the small ends of the 1.5 rods to accept the bigger 1.6TD wrist pin and bushing, as there is no such thing as oversized 1.5 pistons.
