While these pistons are rare, they are probably not quite as rare as the Direct Connection headlight covers (close, though). The engine will essentially be a de-stroked 1.6L turbo diesel, intercooled and mechanically injected. The factory 1.5L diesel engines were never available as factory turbo variants, but the larger 1.6's were, as were the later 1.9L engines. They are all the same family of blocks, along with several of the gasser engines, which range from 1.5L to 2.0 4-bangers, across different generations of the engine. The 1.6 turbo block is considered to be the toughest of the factory blocks, and has the added benefit of oil squirter jets located in the block. The squirters direct oil to the underside of the pistons for the turbo engines, helping to keep the piston temps down.
The neat thing about VW 4 cylinder engines, is that a lot of the parts are interchangeable between engine series and generations. In this way, they are kind of like small block Chevy engines. Heads, cranks, rods, pistons, cams, etc. can all find their way from one engine to another in a lot of occasions. It's possible that I will end up with a 1.5 rotating assembly, a 1.6 block and injection pump, and a 1.9 head.
I currently have 3 different blocks, and I may be in the market for another. The early versions like I have are all mechanical lifter versions. I would like to find a later block, which supports the use of a hydraulic lifter head. There are some later model heads that were only available on the hydraulic engines, and I might like to try one. The later (larger) heads are supposed to flow better than the early ones. 1.5, 1.6, and 1.9 heads will all bolt up. I don't have a finished head yet, but I have a couple that would need to be rebuilt. The hydraulic engines don't like to turn as many rpm's as the mechanical heads, but the later hydraulic heads flow better. It's a trade-off, and I'm not sure which way my engine will be in the end.
Anyway, my plan is a de-stroked 1.6 Turbo Diesel (to get under the displacement limit), running a nice big turbo (probably from a larger Mercedes engine), water-to-air intercooler, a nice big oil cooler, and couple it to a 5-speed VW transmission. The spool-up on the larger turbo will be laggy, but I don't think that will be a problem for this application.
I already have the trans, and it has the ratios I'm looking for. 5th gear in these transaxles is "almost" a quick-change operation, as the 5th gear cluster is housed under a cap at the rear of the transmission. There is a pretty good variety of 5th gear and R&P sets for these trannies as well.
Steve.
