I am racing a cruiser car with a buick 455. The first time it was rebuilt, it lasted 6 races before the #3 rod bearing went out. Had it rebuilt again and got the same result but with a ruined block, pistons, and rods. I have found another block but would like to know why the same rod bearing keeps going out and if there is anything I can do to prevent this from happening again?
Did you plastiguage the journals before assembly? I'm helping a friend with an Olds BB that has been built 4 times due to poor machine shop work and the demons are finally out. He never had rod bearing problems until this last build. He had just freshened the motor again and #4 went out. After disassembly, we found that the rods were resized but none were the same size!!:af: They were close but close is not good enough for an Olds or especially a Buick. Now he needs rods and a steel crank. Do yourself a favor and plastiguage every bearing.
What's wrong with the crank? Did you check your balancer for cracks in the ring? If it's off you were running a very unbalanced rotating assembly. How 'bout the pistons, how are they damaged?
We had the crank turned. It was plastigauged. The rods were resized all the same. The rod hit the bottom of the piston and ruined them. The crank was blued (i assume from getting hot) ruining the crank. Found another 455 and disassembled it and there was evidence of the # 3 rod bearing was starting to spin. Should we have the engine balanced? Is it being starved for oil?
Was your pressure OK? Were the bearings grooved or worn through? Balancing never hurts. How the the rods hit the pistons, on the skirt or the bottom of the dome?
One thing to look at is what type of bearing are you using? If you are using something like a federal mogul AP series bearing, it could fail under higher load conditions. A federal mogul CP series bearing , clevite 77 CP series can handle more power. The CP style of bearing is a trimetal bearing, the Ap series is an aluminum layer bearing. Jim Burek P.A.E. ENTERPRISES
The rods hit the piston skirts, the bearings were wore through. We used clevitte P bearings. This is being used for circle track racing, running higher rpms (3800-4300) constant for 12 laps on a .4 mile dirt track.
I would make a guess that you are starving for oil in the corners. Put an oil baffle in it on the RH side of the pan, or better yet, adapt a pan kit from Speedway Motors or such to your pan. Also, synthetic oil will help, although it's kind of a band-aid to the problem. Buicks DO NOT like more than 0.002" rod and main clearance. You can get away with .0025 but that's pushing it. Run the tighter clearances and 5- W30 Mobil 1. Be careful using heavy weight oils or HV pumps or you'll get the dreaded distributor gear/cam bearing death. Put your oil pressure tap at the back of the block and maybe a low-pressure light on it. If you're losing a rod at those low RPM, it sure seems like an oil starvation problem to me.
# 3 rod bearing is an odd one to loose, I think. I would check those reconditioned rods and make sure the oil holes are lined up on the main bearings where the crank and rods get oil from the block. I had two different machine machine shops ruin a set of rods after they were "reconditioned". They weren't machined correctly. I had better luck with the rods I just stuck ARP bolts in and left them alone (which I had no bearing problem with). I Have little faith in local machine shops to resize a rod end correctly. I feel a stock rod would be closer to "right" if you leave to rod end alone and just put ARP bolts in it. But thats what I'd do if it was my motor.
Folks, Loosing #3 rod bearing is not uncommon. I personaly have lost #3 many times along with Dave Mongeon, Scotty PEEGEE and many others. We hear about #3 going away more than any other bearing. Mike Tomaszewski TA Performance Products Inc.
Mike I'm sure we all appreciate your'e post but what was/is the cause in your educated opinion? I was given a motor that had spun #2 so bad and been driven so long that the rod was worn almost to the rod bolts and I like the rest here thought that it would always be #'s 7 and 8 that would go first because of their position in the oiling system.:Comp:
In my opinion it's a timing issue in the oil delivery to the rod. We have made modifications to the block on many customers engines and also the wagon. At this time the wagons bearings have looked good. The engine has been pulled down every time it came back from the track. We refer to this modification as main bearing oil channels. We had to write a program for our CNC to machine them in properly. Doing it by hand has not proven out so well. We machine these in almost every engine or block that is girdled by TA Performance. Mike Tomaszewski TA Performance Products Inc.
This is being used for circle track racing, running higher rpms (3800-4300) constant A few years ago, I picked up the "circle track mystery Motor" from a young man who had to go to a 350-rule change. It seemed that in three main events, the rest of the drivers didn't like his use of the 455 and the winning of all three. He used a oil pan that had baffels built into it to keep the oil from sloshing to the sides and starving the engine. I still have the oil pan. I can send you a pic of it, (private email) or post, doesn't matter to me. Initially, he said they had a rod bearing failure and then went to the baffeled oil pan. Incidentially, he'd run at a constant 5200 RPM, smoked the tires coming off the turns on a high banked, ashphalt track. ou: This is the motor that I run in my 67 GS, ran low 14s at LACR (5800 feet on this particular day) with virtually no traction and a loose nut behind the wheel. I could have built a house in the 60 foot times.
