Quick question, it is possible/advisable to replace the OEM connecting rod bolts in my 350 without having to remove the rotating assembly? As in just replacing them one at a time and then torquing everything afterwards? I've read that the ARP rod bolts require a chamfer (at least on a 455) so I would try and use stock type bolts. My goal is just cheap insurance but I don't plan to rev the motor above 5500 rpm or so. In that same vein, how about the main bolts? This is the same engine as in my twin turbo thread
Hell, no. You would want to have the rod out of the block so that the rod bore can be measured for roundness after the new bolts are installed, and honed as needed to return to roundness as required. As long as the bolts are functionally identical--same diameter, same material, same heat-treatment, same torque, etc--NO PROBLEM. You try to stuff some hot-rod bolts in there (ARP or the like) and you'll again need to verify the roundness of the main journal bores, and align hone/align bore as needed with the new fasteners and new torque spec.
Got it, thanks for clarifying!! I see that TA offers part #1123 for 350 main bolts, similar to 1122 for 455 which is here: http://www.taperformance.com/proddetail.asp?prod=TA_1122 I guess these would be considered hotrod bolts though due to being made of chromoly? If so where should I look for stock type bolts? Rockauto doesn't seem to carry them. Or should I not bother? Another question, should I upgrade to head studs? Planning on 8psi, maybe I'll go 10psi if it lives and I get good at tuning.
At 400 horsepower, and 5000 RPM, I wouldn't bother--especially with "soft" power like a turbo. Nitrous hits harder, faster. I can't help you with that. Probably a good idea with any boosted engine. But then you're torque-plate honing the cylinders due to the different block stresses the studs produce compared to bolts.
Measured cylinders of a sbb 350 with a .0001" increment bore gauge with heads off then measured from the bottom of the empty block with the head torqued on and there was NO difference in measurement. IMHO it is a waste of time and $ to have a sbb 350 torque plate honed. For the non-believers, go ahead and take the same measurements as I did if you don't trust free advice on the internet? If anyone duplicates the measurements I did, feel free to prove or disprove me. Perhaps it has something to do with the head bolt holes in a sbb 350 being blind holes and not through holes like other engines that do need to be torque plate honed? Makes sense to me that a through hole would be able to distort the surrounding structure without the material at the bottom of the hole there to brace/bridge the structure so it can't distort.
Hmmm ok, I'm inclined to leave the bottom end hardware as is and proceed as planned. Seems like I could do more harm than good! Thanks for guising me through this! Interesting! Doea that mean you're advocating the use of head studs since they may not cause a problem in your experience?
The Pontiac V-8 has blind head bolt holes, and the bosses are attached to the water jacket, not to the cylinders. Pontiac bores move like crazy when you torque the head bolts. I can't prove or disprove your measurements on the Buick 350. Doesn't seem likely to me, though.
I can save you a bunch of time here if nothing else! If you replace the rod bolts while in the motor and get that job all done then go out to a hardware store and buy a 10 lb sledge hammer and bust up the block , as this will save you the time involved in putting it back in, getting it running and having it blow up in short order!
