So I've been lurking here for a while and I read several threads where it was discussed that core shift is an issue in both the N42 and F54 blocks. I then went to Les Collins site where he stated that only 1 in 6 blocks could handle being bored to 89. This came as a surprise to me as I've never seen it discussed on Hybridz or anywhere else. I tried to discuss it over a hybridz and everyone seemed to dismiss the idea. I for one believe someone who has come to a conclusion as a result of testing rather than repeating something that gets said over the internet and is passed on as truth. That being said there are a lot of guys running 89mm pistons that have probably never had the block sonic checked prior to boring it out. Is the .120 minimum mainly for racing or engines that will see extended high rpm's or will a street motor survive with less. Just curious what some of you think. Also did the core shift issue affect all years? I've always read that the Japanese preferred the 75-76 N42 blocks for overboring. Is that a wives tale too? I've been collecting 75-76 N42/N42 motors with the idea of doing the 89mm bore along with the LD28 crank. (been collecting those as well....Collecting this stuff starts getting expensive and hard to explain to my wife as well.
I'd appreciate any thoughts you guys have.
Edited by Chris_Hamilton, 12 September 2016 - 04:06 PM.