Engine rebuilder.

deMort · 12 Oct 2017

Some of the very few gen 2 engines with damage have been attributed to thrashing when cold .. the piston heats up faster than the liner causeing patrial seizure due to expansion rates of both piston and liner .

Not going to comment on Gen 1 .

Btw Chris .. not seen you in ages .. hope everything is ok .

bazhart · 15 Oct 2017

In my earlier post I disagreed that "all engine builders are the same".

This season in the top 3 UK racing Championships for road based M96/7 cars those with Hartech engines to our standard specifications and built by us have won all 3.

BRSCC Boxster Championship - Won, PCGB class 1 and 2 Championship - Won, PCGB overall Championship Won, Team event Won.

All engines lasted the whole season with one winter rebuild providing power, performance and reliability and most of the other Podium places were with our engines built by us or built to our specification with our parts built by others.

That is some record - and hopefully fully answers the previous claims - enough said.

To answer a couple of recent comments - Bank 2 has the thrust face of the piston on the top and bank 1 on the bottom. From cold the oil has dripped off the top of both pistons leaving bank 2 more dry on start-up. also the coolant enters both blocks at the bottom. There is limited flow and it flows slowly up the cylinders - so bank 2 always has the top of the piston thrust face hotter than the thrust face of the pistons in bank 1 since the coolest coolant hits the thrust face of bank 1 pistons first and bank 2 pistons last and this is a differential in the oil temperature and the oil film thickness that results that helps prevent loose silicon particles digging into the piston and cylinder bore.

Low revs with high power or torque present the greatest piston face loads on the cylinder bore - higher revs do not so Alex is right -- refrain from high power from cold but when hot use revs and enjoy it.

Gen 1 piston scoring is caused by silicon particles release from the cylinder matrix attacking one side of the piston on the thrust face. Gen 2 scoring is caused by seizures on both sides of the piston because it has expanded more than the bore from cold influenced by tighter build bore clearances and some shrinkage of the cylinder bores in some engines in the thrust direction (where the piston is biggest) over long periods of time

Baz

Engine rebuilder.

deMort

Monaco

bazhart

Barcelona

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