Originally Posted by
Eivind E
Earlier I was running a 21-4C which after while was so low on compression that it kept going rich and dying all the time. So I swapped it out for a newer one which has very good compression.
However, the old spent one seemed to produce a lot more power. Low down and high speed as well, what could this be down to?
Would it be that the one which had spent all it's compression would be able to rev more? It seems strange to me that the newer engine is so much more of a slouch.
A true comparison between 2 engines that are exactly the same would be most accurate when compression is the same as well.
Also don't forget that the p4c, p4c team, and p4 btt are different engines.