Supercharged RV8 on flea..

[pwd95]

http://www.ebay.co.uk/itm/Rover-V8-Supercharge-eng...

[chedder]

Interesting specification......skimming the heads increases compression when normally with forced induction you reduce the ratio.
High lift cam??? generally you do the opposite, standard lift cam but much longer exhaust valve duration.

Chedder

[Campbell]

You have to think why he skimed the heads, did the motor over hear and wharp, may be he has deep dish pistons to reduce the compression and isnt the standard compression not some thing like 9.3 to 1.
Im sure if the motor is bolted togeather correctly im sure is will run well.

Cambelt

[Wedg1e]

The Rover V8 heads will take a massive amount of thermal punishment and rarely warp. They pre-date CAD/CAM so there was no scrimping on metal.
Arguably if the heads were otherwise unmodified (I haven't read the ad) there'd be no point in having them skimmed if they were warped, you can pick up spare heads cheaply enough.

[Jammy Dodger]

my engine has been rebuilt for supercharging (chim 5 litre) and the faces were slightly skimmed to ensure "perfect" gasket fit/mating surfaces.

[chedder]

Campbell said:

You have to think why he skimed the heads, did the motor over hear and wharp, may be he has deep dish pistons to reduce the compression and isnt the standard compression not some thing like 9.3 to 1.
Im sure if the motor is bolted togeather correctly im sure is will run well.

Cambelt

Wedges are generally 9.75:1 ratio, lowering the compression ratio helps to stop detonation in forced induction engines, using spacer head gaskets or more commonly composite gaskets these days, helps to bring the ratio down a bit reducing the risk and keep the internal bits.....internal!

Chedder

[vampire222]

Supercharger usually doesn't have to go with lower compression, especially since most are fast response / low boost superchargers.