RallyBob's Tricks For More CIH HP
Just looking at all the options to raise compression of my '73 1.9L motor. While plodding through some related Yahoo ClassicOpel keyword searches I came upon some info on using a 1.5L head on a late year engine to bump up compression. I think it was mentioned doing this could get close to the "earlier" high compression ratio engine.
Keeping the work to do this via just head work has it's merrits (like not starting an engine rebuild that I know will take 2X as long and 4X over budget...the story of my life) so I'm curious. My gut tells me I'm going to end up in the long run doing the engine rebuild with the proper piston swap, but I just need to ask about this 1.5L head deal. Questions abound like:
*Is this really as good as it sounds?
*If not, what's the catch?
*Where would one even find a 1.5L head?
*What would be the best guesstimate at the compression ratio doing this?
*Could the compression be bumped a bit more by milling the head? If so, how much milling will yield how many points?
*How will the 1.5L head flow compared to the 1.9L (assuming both are stock) just for a benchmark?
Just tossing some questions out there, any replies will be appreciated.
Just looking at all the options to raise compression of my '73 1.9L motor. While plodding through some related Yahoo ClassicOpel keyword searches I came upon some info on using a 1.5L head on a late year engine to bump up compression. I think it was mentioned doing this could get close to the "earlier" high compression ratio engine.
Keeping the work to do this via just head work has it's merrits (like not starting an engine rebuild that I know will take 2X as long and 4X over budget...the story of my life) so I'm curious. My gut tells me I'm going to end up in the long run doing the engine rebuild with the proper piston swap, but I just need to ask about this 1.5L head deal. Questions abound like:
*Is this really as good as it sounds?
*If not, what's the catch?
*Where would one even find a 1.5L head?
*What would be the best guesstimate at the compression ratio doing this?
*Could the compression be bumped a bit more by milling the head? If so, how much milling will yield how many points?
*How will the 1.5L head flow compared to the 1.9L (assuming both are stock) just for a benchmark?
Just tossing some questions out there, any replies will be appreciated.