I have just had my mate round asking Rover questions, He has a Twin Turbo 5ltr RV8, the question was how much does a bore expand at normal running temps, the bore is 20+, he has bought some expensive forged turbo pistons from a west london specialist and had the block bored by them to match the pistons, the skirt clearance is between 4 & 5thou,the engine is so slappy he has stripped down the engine to check for damage after less than 1000miles, he described it as sounding like he had left a rod cap loose!!!, Personally I think there is too much clearance and have told him so, He has another 4.6 block with a standard bore which has been pressure tested at 50psi for 3 days without loosing any pressure, this wes done cold, and he is hoping that its ok. what I have suggested to him is get the new block bored and piston matched to 2thou clearance, the company who made the pistons recomend between .0015 and .004 clearance for skirts depending on application, and have said the larger for a turbo race engine, which this engine is not, its a daily driver,
I realise the bigger stroke engines will be prone to slap due to the shorter rods giving greater rod angularity and shorter skirts. any suggestions???
next question??? are RV8 injectors high ot low impedence ?
Ian
![Very Happy :D](./images/smilies/icon_biggrin.gif)