ARP rod bolt specs
04-26-2005, 05:44 PM
#6
Quoting Jason99T/A:
Jarrod, I have checked the housing bore on the rods before and after the rod bolt install (ARP Pro-series bolts). There is some definite deformation after the new bolts are installed. Every motor we build with stock rods has the housing bore re-sized .002" larger than stock to accept a new, oversized bearing from Clevite for this very reason.
You motor is not going to instantly blow up if you don't re-size the rods. Heck, the motor I built that was in my car with the TReX cam/stock heads had the ARP bolts installed without any re-sizing. It is still running just fine after 10k HARD miles and probably over 100 dyno runs and quite a few track passes turning 7200+ rpms. However, it is very important to have to have a housing bore than is within spec, not out-of-round, and free of taper. This is very important for long bearing life.
Another thing to point out is measuring the housing bore with the rods bolts streched to the required amount, not just torqued to spec. Having the ARP pro-series bolts torqued to 45lb-ft very, very rarely gets you within the recommend stretch for this particular bolt. On the motors I have built, this generally takes 55lb-ft or so. This number will vary based on the type/amount of lube used, condition of the threads, and the calibration of the torque wrench.
Jarrod, I have checked the housing bore on the rods before and after the rod bolt install (ARP Pro-series bolts). There is some definite deformation after the new bolts are installed. Every motor we build with stock rods has the housing bore re-sized .002" larger than stock to accept a new, oversized bearing from Clevite for this very reason.
You motor is not going to instantly blow up if you don't re-size the rods. Heck, the motor I built that was in my car with the TReX cam/stock heads had the ARP bolts installed without any re-sizing. It is still running just fine after 10k HARD miles and probably over 100 dyno runs and quite a few track passes turning 7200+ rpms. However, it is very important to have to have a housing bore than is within spec, not out-of-round, and free of taper. This is very important for long bearing life.
Another thing to point out is measuring the housing bore with the rods bolts streched to the required amount, not just torqued to spec. Having the ARP pro-series bolts torqued to 45lb-ft very, very rarely gets you within the recommend stretch for this particular bolt. On the motors I have built, this generally takes 55lb-ft or so. This number will vary based on the type/amount of lube used, condition of the threads, and the calibration of the torque wrench.
