Question about code MF block

[racer_x]

How big can you bore the cylinders in the MF block? I have one here that I'm considering trying to bore to 81.0mm and using some gas pistons for a turbo 16V gas engine. I'm thinking of using this block because it has the oil squirters in it.

Before any one starts yelling "diesel murder," this engine gave it's head to another 1987 Jetta Turbodiesel that broke a timing belt, and the turbo, manifolds and pump were gone before I got it from the parts yard. I just bought the whole long block instead of the head only for the repair on that Jetta. I don't have the parts to return it to being a whole turbodiesel engine.

Sorry if this is too far off topic, but I think there is more expertise here about this particular engine block than in some of the other more general VW forums I frequent.

[vwmike]

How big can you bore the cylinders in the MF block? I have one here that I'm considering trying to bore to 81.0mm and using some gas pistons for a turbo 16V gas engine. I'm thinking of using this block because it has the oil squirters in it.

Before any one starts yelling "diesel murder," this engine gave it's head to another 1987 Jetta Turbodiesel that broke a timing belt, and the turbo, manifolds and pump were gone before I got it from the parts yard. I just bought the whole long block instead of the head only for the repair on that Jetta. I don't have the parts to return it to being a whole turbodiesel engine.

Sorry if this is too far off topic, but I think there is more expertise here about this particular engine block than in some of the other more general VW forums I frequent.

Why don't you just use a 1.8 16v block? It's already 81mm and has oil squirters. The diesel block also has 12mm head bolts, and the gas heads use 11mm bolts so that would present an issue for you.

[racer_x]

Why don't you just use a 1.8 16v block? It's already 81mm and has oil squirters. The diesel block also has 12mm head bolts, and the gas heads use 11mm bolts so that would present an issue for you.

Good point.

I guess the biggest advantage to the MF block is that I have one here. I don't have a PL block (though they aren't that rare, so I could get one). And with the PL block, I'd still have to install the pistons I already have (to lower the compression to around 8:1).

And while the 12mm head bolts will complicate things a little, I'm not sure that 12mm head fasteners are a bad thing for the plans I have for this one. I'm looking for 250whp-300whp for this project, and I know I'll be running significant boost. The larger 12mm studs or bolts will hold things together a little better than the 11mm bolts used on the 1.8L 16V.

[vwmike]

I think a bigger concern is if the head can be properly machined to fit the larger bolts. Also, what bolts would you use? 8 and 16v bolts are different.

This is a little off topic, but what about head studs for a 1.6D? the gas ones are the right length and all, but are 11mm. Does anyone know if there are any head studs out there that will fit?