landybehr Posted June 15, 2007 Share Posted June 15, 2007 Hi, I am rebuildung a 4.2V8 at the moment for my RRC. 1) I´ve read that it makes sense to keep the alu engine block at a low temperature - to limit problems that are caused by different expansion of steel and aluminium in the crankshaft and cylinder-liner area. The original 3.9 that powered my RRC should have a 88deg. thermostat. There are also a 82deg and a 74deg available. I will use Megasquirt so there will be no coldstart-enrichment worries with a different coolant temp. Given the above argument it seems logical to use the 74deg thermostat. Will there be any negative effects ??? In which vehicle was that 74deg thermostat used ? I do not use the engine and car to race (the recommendation was from the DesHammill-book which deals about race prep of the RoverV8) Should the 82deg. be the best "allround performer"? I think it was used in the V8 Defender. 2) The standard spark plug for the 4.2 V8 is the RN11YC. This is a Resistor-type, 14mm-thread,car-engine,standard nose, copper core - plug. The "11" reads for a fairly high combustion temperature in the cylinders OR is it the other way round ???. If I used another thermostat, like going from 88deg to 82deg or even 74degrees, would I have to take another spark plug ? Like: the engine block stays cooler then - so I have to use a spark plug which retains more heat or the like? Cheers Hendrik Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.