13:1 Compression Pistons in 340 Small Block
Hello, let me just start off by saying I’m new here and had some questions regarding engines. I know basics and some advanced terms regarding engine building. My questions today regard more advanced knowledge then what I know and that’s why I am here.
Recently I decided to pull out an old 340 block my old man had sitting in the back and throughout the years he’s acquired tons of parts. One of the pieces he had are .030 13:1 compression pistons (that’s what he was told they are) he pulled out of a 340 motor that he swapped all back to original. This other motor I want to rebuild my goal is to have something street but also build a big block buster with (or at least give them a run for their money).
One essential key that I know makes an enormous difference and I’ve been trying to research on is Camshaft specs and what types you run with performance. I know quite little compared to everything there is to know about camshafts and I rebuilt a couple engines with just mild build but I know with getting into these higher performance pistons you need to run special cams.
This is where the big question come into play, what type of camshaft should I run with this build? I’ve seen lots a people saying 10.5:1 pistons with certain cams run the best but I’d really like to use this 13:1 pistons. I’ve also seen people saying to get them machined down to 12:1 or 11.5:1 but I would also like to not go that route.
If it helps I was thinking about running a Mopar Performance Purple Cam with a Mopar Performance intake manifold and I’m running J heads. I’ve yet to get into Rocker Arm ratios but I’m probably just going to run the stock 1.5 ratio with double spring valves. I’ll probably end up getting some special hardens pushrods and whatever else the cam specs require.
Thank you all!
Recently I decided to pull out an old 340 block my old man had sitting in the back and throughout the years he’s acquired tons of parts. One of the pieces he had are .030 13:1 compression pistons (that’s what he was told they are) he pulled out of a 340 motor that he swapped all back to original. This other motor I want to rebuild my goal is to have something street but also build a big block buster with (or at least give them a run for their money).
One essential key that I know makes an enormous difference and I’ve been trying to research on is Camshaft specs and what types you run with performance. I know quite little compared to everything there is to know about camshafts and I rebuilt a couple engines with just mild build but I know with getting into these higher performance pistons you need to run special cams.
This is where the big question come into play, what type of camshaft should I run with this build? I’ve seen lots a people saying 10.5:1 pistons with certain cams run the best but I’d really like to use this 13:1 pistons. I’ve also seen people saying to get them machined down to 12:1 or 11.5:1 but I would also like to not go that route.
If it helps I was thinking about running a Mopar Performance Purple Cam with a Mopar Performance intake manifold and I’m running J heads. I’ve yet to get into Rocker Arm ratios but I’m probably just going to run the stock 1.5 ratio with double spring valves. I’ll probably end up getting some special hardens pushrods and whatever else the cam specs require.
Thank you all!
