Compression

[jetpilot]

Guys, i need to call on some knowledge. Is it right that an engine with say street port or some kind of porting will run lower compresson. If so, how can you tell if its about to give up the ghost.

[antnicuk]

Unfortunately compression testing will only give you an indication of engine condition. I had mine comp tested and got 6.3, 6.3, 6.2 on both rotors, I thought great got my self a bargain.......... It popped 700 miles later. Nothing else was wrong, just worn out!!! How gutted was i.

 :mad:

[Glenn Butcher]

Originally posted by jetpilot
Guys, i need to call on some knowledge. Is it right that an engine with say street port or some kind of porting will run lower compresson. If so, how can you tell if its about to give up the ghost.

No - porting doesn\'t change the engine compression.  It is the rotor\'s themselves, and engine condition that changes compression.

The FD engine has a lower compression as it is turbo charged - to say  the RX-8 engine which is naturally aspirated.


As antnicuk has said, you never REALLY know - but you can get an indication from a proper rotary compression tester as to how good the engine is.  But there are warning signs like - always flooding, lots of miles on the engine, hard starting when warm/cold etc.