jaysVR6 2 Posted January 24, 2006 Report Share Posted January 24, 2006 OK guys, the VR is having a rebore and I am no engineer so before I ask my garage how much I can overbore I'd like to throw the question to the guys who are in the know.I know the R32 lump has not only a larger bore but longer stroke (throw) on the crank to increase the capacity but is this the case with the 2.9 lump? Can I just have my lump bored out to 2.9 and buy bigger pistons (don't know what size) on a my stock crank shaft, will I also need different conrods? If not, how big can I go and retain reliability?There is a nuts ABT crank on ebay at the moment thats worth a fortune, all lightened and stroked but it's silly money and not an option.Advice ASAP please as it's in bits at the moment waiting for parts to be ordered. Link to post Share on other sites
mk3anni 0 Posted January 25, 2006 Report Share Posted January 25, 2006 don't see why an overbore would be effected by your crank or con-rods. Link to post Share on other sites
jaysVR6 2 Posted January 25, 2006 Author Report Share Posted January 25, 2006 I wasn't sure if a larger bore needed a different crank? !dodge Link to post Share on other sites
VRmonster 1 Posted January 25, 2006 Report Share Posted January 25, 2006 id say an 83mm bore (almost 3.0L) is the max to go without changing the stroke, as the sidewalls are getting rather thin by this time. if your after the 2.9, then bore to 82mm, and get the corrado 2.9 pistons n rings. that should be ok. be careful where you have it bored though as theres only a few places capable of it in the uk as it has to be done on a torque plate with a 7.5 degree shaft angle. PM for any more info. Link to post Share on other sites
Recommended Posts