When rebuilding an M96 or M97 engine, there are many considerations when evaluating your options.
Re-ringing your M96 or M97 engine isn’t even an option for most rebuilds, however most engine builders re-ring engines after only doing a visual inspection of cylinder bores rather than measuring the cylinders for ovality and taper. It is a guarantee if the engine has not been sleeved, the bores are out of spec on even a “fresh” rebuild.
Upon inspection of running engines not already having suffered a failure (even low mileage), the stock engine bores always suffer from excess ovality and taper, which can lead to excessive piston clearances, increased ring land and ring wear, and high oil consumption. Ovality and taper typically is no less than .005″ by 50,000 miles and we have measured engine blocks in excess of .010″, when the factory wear specification for ovality is not to exceed .002″!
Through our exclusive Nickies sleeving process, we have overcome the d-chunk, slipped-sleeve, scoring, as well as taper and ovality issues associated with Porsche 986/996 and later 987/997 models.
We use a proprietary process in which a sleeve comprised of a special aluminum alloy with both high ductility AND strength is fitted to the m96 block. This allows for increased performance while addressing all cylinder issues associated with the M96 engine. Nickies utilize a highly wear resistance cylinder bore plating (NSC – which stands for nickel, silicon, and carbide) for long life, which is very similar to Nikasil™, as used on the Carrera GT, GT2, GT3, and 911 Turbo engines!
Nickies™ feature our superior aluminum alloy up to 66% stronger than than the cast in Lokasil™ bores or MMC sleeves, providing for improved thermal conductivity and reduced wear and friction over original or cast iron sleeves, and allow for larger bores without any loss of strength or longevity. In fact, Our NSC-plated, CNC billet, solid aluminum Nickies™come with a lifetime warranty on cylinder plating.
Nickies™ make the difference!
Ovality and taper aside, applying Nikasil to the stock bores isn’t practical, as the M96 or M97 engine can suffer from numerous cylinder failures the plating process does not fix. Not sleeving an engine leaves it susceptible to cylinder failures such as d-chunk, slipped sleeve, and scoring, all of which are common to all M97 and M97 engines from 1997 through 2008.
We can upgrade your engine to use our Nickies™ as long as there are no cracks in the cylinders that protrude deeper than the bottom of the water jacket, where in that case, the integrity of the whole crankcase has been compromised! (see below). If there is damage on the crankcase side, the damage cannot be repaired economically.
As part of the sleeving process, we machine out almost all of the factory cylinder and leave just a portion of the retaining support structure that was cast in to the case. This allows us to properly support the cylinder while increasing wall thickness of the cylinder up in the water jacket allowing for larger bores, thanks to the thermal and strength properties of our unique alloy.
We retain the preferred original “open deck” configuration, rather than converting the engine to a closed deck which impedes cooling. Due to the high ductility and tensile strength of our alloy, a closed deck is not required. Our unique design retains the proper flow of water through the water jacket and actually improves upon the cooling capabilities of the engine due to over double the thermal conductivity of the alloy used.
Why can’t I install oversize or aftermarket pistons?
There are no oversize pistons available from the factory that are compatible with the Lokasil bores. As such, boring out the stock block and fitting it with new pistons is a recipe for disaster. This engine lasted less than a 1000 miles before the engine failed again.
Why should I use Nickies instead of cheaper cast-iron or steel sleeves?
Closed deck conversions or using cast iron or steel sleeves may appear to be acceptable solutions, but there is a penalty above and beyond incompatibility with the block itself, because cast iron is way less of a heat conductor than the silicone bores, thermal limits are harder to control and can cause hot spotting. As far as power, cast iron has significantly more friction than Lokasil or Nikasil. There is a reason for an all-aluminum block. For example, Toyota with their 1.8 liter four cylinder all-aluminum 2ZZ-GE engine, was able to produce 26.17% more horsepower and 4.65% more torque with the same 1.8 liters of displacement as the 1ZZ-FE that uses cast iron liners.
There are many companies who use sleeving of M96 and M97 blocks with cast iron or steel liners as an economical alternative. Due to weaknesses of the parent block material, thermal expansion differences, and just the fact that cast iron or steel liners are not as ductile, it’s no surprise we see blocks like this one come to us for re-sleeving when the engines fail a second time from blown head gaskets to cracked blocks. Cast iron or steel sleeves don’t work in an M96 engine. The example below is just one of dozens of failed repairs we have fixed.