High compression A15's
Posted: Thu Jun 16, 2011 12:44 pm
Hi Guys,
My brother bought a couple of A15 heads a while ago that had been modified including skimming the heads. There were no actual details on the compression ratio that was produced. I am now considering using one of them for a supercharged engine (I was previously going to use a non-modified head). Can someone please let me know roughly what compression ratio A15's with skimmed heads often produce? I know this is a bit of a "how long is a piece of string" question, but I am just looking to understand the range of CR these typically produce when skimmed. I believe that standard CR to be 9.0:1
BTW I am building a fuel injection setup, and if I do this would look to use an after market ECU to provide better control of the timing and prob run a knock sensor where the standard fuel pump usually bolts on.
The information on the trademe auction for the heads is as follows:
This auction is for 2 Nissan Datsun A15 oval port Cylinders heads. One head is extensively modified, high compression, very large valves, ported & polished. New valve guides & double cut valve seats, work was done by Cook Motorsport, Reg Cook.
The second head has big valves & a minor port job, double valve springs. Will be sold together at a fraction of build cost.
Thanks in advance.
My brother bought a couple of A15 heads a while ago that had been modified including skimming the heads. There were no actual details on the compression ratio that was produced. I am now considering using one of them for a supercharged engine (I was previously going to use a non-modified head). Can someone please let me know roughly what compression ratio A15's with skimmed heads often produce? I know this is a bit of a "how long is a piece of string" question, but I am just looking to understand the range of CR these typically produce when skimmed. I believe that standard CR to be 9.0:1
BTW I am building a fuel injection setup, and if I do this would look to use an after market ECU to provide better control of the timing and prob run a knock sensor where the standard fuel pump usually bolts on.
The information on the trademe auction for the heads is as follows:
This auction is for 2 Nissan Datsun A15 oval port Cylinders heads. One head is extensively modified, high compression, very large valves, ported & polished. New valve guides & double cut valve seats, work was done by Cook Motorsport, Reg Cook.
The second head has big valves & a minor port job, double valve springs. Will be sold together at a fraction of build cost.
Thanks in advance.