Changed rod bolts on the weekend.
The big moment...
I removed one bolt at a time and replaced it with an ARP bolt. I applied the ARP moly lube to the threads and bolt collar and torqued to 40lb/ft then loosened, then torqued to 40lb/ft again, then loosened, then torqued to 40lb/ft for the 3rd and final time. I repeated this for the rest of the bolts. Then went over the whole assembly a last time. I had to turn the crank for each cylinder pair so I used my torque wrench on the crank bolt. After that was finished I got out the Dremel and lengthened the pickup tube mounting bolt by 1/8". This was done because I am installing a double roller timing chain and when I remounted the tube I had my friend push the tube forward against the bolt after it was mounted and secured into the oil pump. The windage tray mounting bolts were tightened to 18lb/ft. Then I drilled out the oil pan centering rivets. You don't have to re-rivet the new pan gasket when reinstalling. Then I prepped the block to oil pan gasket mounting surface by removing all traces of the old gasket on bolth the block and the oil pan. Next I applied a 5mm by 20mm bead of RTV to the corners of the block where the front and rear covers meet the block. Next we mounted the oil pan as quickly as we could, before the RTV started to skin over. Then I reinserted the oil pan mounting bolts and tightened them to 18lb/ft and the two long rear mounting bolts to 12lb/ft. Then we reinstalled the crossmember and other components, torqueing to spec and using threadlock where required. I then removed the straps from the engine, lowered the car, put 7 qts of Redline, (it took 7 I presume because a lot of oil other than what is removed during a change was lost), and it started right up. I let the car do a heat cycle, then drove it home about 14 miles and kept it under 2k rpms. Tomorrow I'll take it out and kick it in the pants.
One thing I wonder about is I'm sure this torque spec changes when the bolts and rod are at running temp. If the bolts expand at a different rate what does that do to big end concentricity?
Ideally rods should be machined with the bolts on to insure perfect roundness and tolerances.
Nice detailed description (yours)
Might be a "damned if you do, damned if you don't" mod for us high rpm guys. Personally, I'll take my chances doing the ARP bolts than revving over 7k rpm with the stockers. Out of curiousity, what will happen if it becomes out of round? You spin a bearing or anything worse? I know what would happen if a rod bolt(s) gave out.
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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.
I can't remember off the top of my head exactly how much out-of-round the rods went after the new bolts, but I do have it all info written down. I can get this once I'm done with school today.
Jason
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