When I had my engine done they cross drilled my crank. Don't know if good or bad but must be good since I am still cooking after 30 years.
My machinist was against cross drilling the crank, but it worked out for you. You can ask ten different people and get ten different reasons why it’s good or bad.
Yep, I’ve heard same thing “It weakens the crank” Well SOME cranks it might, but with 3” mains on the Buick 350 crank I’m sure it doesn’t hurt it. My last crank was cross drilled, no issues.
Can't remember if I had my last one cross drilled, but if anything is a structural weakness on these stout little 350's, I've heard a few instances of cranks breaking over the years however I suspect that was due to a casting flaw. I'd love to have a steel crank for my next build but have champagne taste & beer $. Magnaflux/nitriding/x-ray(?)/etc. will have to suffice.
Inadequate rod bearing oiling will end a motors life long before a issue stemming from cross drilling will, especially with a stout 3” main . To just put things in perspective just think of the fact that with a standard half groove main set and a non cross drilled crank the rods only get oiled up during 1% or there rotational time!!!!
If you really want to be proactive, monitor your oil pressure from the rear of the engine. It will be lowest there depending on your bearing clearances. One method, http://www.buickperformanceclub.com/Oilmods.htm
Before I had this motor rebuilt I had broken the crank on the old motor. I was able to drive 30 miles home from the track too, how it managed that I don't know. That one was all stock except for the Comp cam and the headers along with 4 bbl, was running a Thermoquad during that time. Between that carb kinda flooding out and the fact that I had used that Royal Purple crap that gave me a lot lower oil pressure ended its day. I can't remember where crank broke at was thinking towards the middle or lets say a spot where it let me drive it lol.
That's crazy that it still ran. Beats the heck out of my 350 running upside down for a few minutes, lol.
When my last 350 blew up, it broke rods, pistons shattered, put rods out both sides of the block, knocked the starter off and broke it in half, bent all the pushrods, broke the lifter valley and a few bores, cracked the cylinder walls, broke the cam in 3 pieces, shoved it out the back of the cam tunnel, hit the converter and lut a dent in it and bent the flex plate, shot it back into the pan. And THAT engine was still running. I was driving on the highway at 65mph, then oil pressure fluttered, dipped, and I heard a bang, and what sounded like reggae. Binkabonkatinkatonkabink. Must've scared the hell out of that white camry behind me. They definitely got a james bind oil spray. Oil soaked my tires and undercarriage and I did a 360 in the offramp intersection. It was still running when I got out and looked under the car. Starter was sparking everywhere so I decided to shut it off.
On another note, I decided to open up the oil pickup hole from 7/16 to 5/8. I don't trust myself to do the longer feed passage, so I'll just radius what I can and I am going to add a balance line for my own peace of mind.
You don't need to go all the way to 5/8". I drilled mine with a long 1/2" drill bit. That adds a lot of volume potential to the oiling system, 30%. It holds great oil pressure.
I drove a Buick 350 with a rod hanging out of the driver side of the block back to the shop, about 2 miles.
As we'd said in your other thread, at least do something to try and address the issue. This'll actually be an interesting test w/nothing much changed really exc. the balance line. Shame you're not going to be duplicating the driving conditions.
I daily drive the car, I can easily hop on the highway. This engine has 40,000 miles on it, I'll see what the bearings look like in another 40k ha.
Seems like it was harsher driving before but looking forward to the results! I drove my stock bottom end '70 GS 350 4-sp. to the Nationals (700 mi. ea. way) w/3.73 (3500-4k RPM for hours) then raced it extensively for a couple seasons omus was a daily driver. Unfortunately, was young & never looked too closely (or don't recall) @ the bearings upon teardown. Was a missed shift/bent valve that did that engine in.
