Horace, cranks are successfully welded up and reground every day in many countries. A pro inspection by a shop specializing in crank repair may result in saving your beat up crank- stock or aftermarket. Then, a std. overhaul will get you back on the road. You may need a replacement rod, though, depending. Shipping 351-C cranks around is pricey since they weigh 54 lbs!
...Yes, We All make Mistakes! Part of Being Human. Here's what I Know:
After receiving a Set of Clevite 7 Rod Bearings, in the scope of 'Assume Nothing', I Inspected Each and Every Piece. I ordered the set in .010" Over, as the Crank had been Re-Ground/Polished .010 Under.
All Half Bearings were stamped .010, Excepting for ONE Single Half...was Stamped .020, ofcourse I sent the entire set back and then received back a complete and correct set. Is this what happened in Your case, as You pointed out, we'll Never know.
Next, Before Disassembly of the Rotating Assembly, it is Prudent to FIRST, before All, Stamp the Number of the Cylinder on all Rod Caps, Both Halves, Cap and Rod, 1 Thru 8, As they are Viewed When Rotating the Crank to Access. So with the Stamped Numbers, one would have to slip-up on the Details or be Distracted, in Order to Install the Cap Backwards. Without the Numbers on the Rods/Caps it would be Impossible to know Which Cylinder the Rod Goes To!? Unless one was very well organized and did the Rods One at a Time.
I concur with the Boss, Crank Journals are welded and reground Every Day! Just be sure to take it to an 'Experienced' Crank Shop of Experts.
"...When You Pay Peanuts...You End Up Hiring a Bunch of Monkeys!" (George Peppard-The A Team)
P.S. In My Opinion, 4-Bolt Mains with ARP STUDS is the Only way to Go. Maximum Rigidity! That's the Way I built My Shortblock. Even used ARP STUDS on the Heads, Especially.
After receiving a Set of Clevite 7 Rod Bearings, in the scope of 'Assume Nothing', I Inspected Each and Every Piece. I ordered the set in .010" Over, as the Crank had been Re-Ground/Polished .010 Under.
All Half Bearings were stamped .010, Excepting for ONE Single Half...was Stamped .020, ofcourse I sent the entire set back and then received back a complete and correct set. Is this what happened in Your case, as You pointed out, we'll Never know.
Next, Before Disassembly of the Rotating Assembly, it is Prudent to FIRST, before All, Stamp the Number of the Cylinder on all Rod Caps, Both Halves, Cap and Rod, 1 Thru 8, As they are Viewed When Rotating the Crank to Access. So with the Stamped Numbers, one would have to slip-up on the Details or be Distracted, in Order to Install the Cap Backwards. Without the Numbers on the Rods/Caps it would be Impossible to know Which Cylinder the Rod Goes To!? Unless one was very well organized and did the Rods One at a Time.
I concur with the Boss, Crank Journals are welded and reground Every Day! Just be sure to take it to an 'Experienced' Crank Shop of Experts.
"...When You Pay Peanuts...You End Up Hiring a Bunch of Monkeys!" (George Peppard-The A Team)
P.S. In My Opinion, 4-Bolt Mains with ARP STUDS is the Only way to Go. Maximum Rigidity! That's the Way I built My Shortblock. Even used ARP STUDS on the Heads, Especially.
The machine shop say they can save the crank by exactly that, welding up and re grinding back.
All the mains and the other 7 rod journals are fine so no need to weld them all up I feel. The crank was std before all this but with the amount of metal that came from the wiped out bearing/journal I think it wise to maybe do them all to -10 etc. My only concern is that they get it fully straight again and balanced.
First comment from the machine shop which I am not too enamoured with is that the no 3 cylinder must have hydrauliced somehow, the rod is so bent and twisted. Could fuel, water or oil cause a hydraulic lock and twist a rod that badly, I am not too convinced. There is no evidence in that piston or the heads, valves etc that bears this out. They reckon the rod has twisted and loaded and consequently wiped out that bearing and journal ???.
Marlin I agree. My engine has 4 bolt mains, ARP cap studs, ARP head studs and ARP rod bolts all new. The machine shop has the Clevite bearings so I will take a look at what is stamped on them next time I'm there. Unfortunately no chance of checking No 3 as it was thin as paper when we took it off so again we are unlikely to ever know.
Comments please guys on the hydraulicing issue above.
Cheers
All the mains and the other 7 rod journals are fine so no need to weld them all up I feel. The crank was std before all this but with the amount of metal that came from the wiped out bearing/journal I think it wise to maybe do them all to -10 etc. My only concern is that they get it fully straight again and balanced.
First comment from the machine shop which I am not too enamoured with is that the no 3 cylinder must have hydrauliced somehow, the rod is so bent and twisted. Could fuel, water or oil cause a hydraulic lock and twist a rod that badly, I am not too convinced. There is no evidence in that piston or the heads, valves etc that bears this out. They reckon the rod has twisted and loaded and consequently wiped out that bearing and journal ???.
Marlin I agree. My engine has 4 bolt mains, ARP cap studs, ARP head studs and ARP rod bolts all new. The machine shop has the Clevite bearings so I will take a look at what is stamped on them next time I'm there. Unfortunately no chance of checking No 3 as it was thin as paper when we took it off so again we are unlikely to ever know.
Comments please guys on the hydraulicing issue above.
Cheers
quote:hydraulicing issue?
...I Suggest, the Con Rod was already 'Slightly' Bent from the Beginning-Day 1. It was missed during Inspection and Assembly.
The Crank Journal and Wrist Pin Axises NOT Being in the Same PLANE cause a 'Twisting Force' upon every stroke. This Force is what Knocked-Out the Rod Bearing. When the Bearing Failed, the Rod was Twisted Even Further.
It's Called 'Hydraulic LOCK'. But what Fluid would have 'Leaked' into the Cylinder...And NOT leave any evidence?? Instead of Hyd-Lock, I can Imagine a Poorly-Timed 'Miss-Fire', or similar (Crossed Plug Wires Maybe) 'could' have bent a Rod. Do You Remember any such event?
Just Guessing Here, as In My Past, I have found a Bent Rod in a 400 Pontiac Engine I was Re-Building. NO Cause was ever found!
P.S. About those ARP HEAD Studs!! AFTER Installing them, I Blew-Out 2 Different sets of Head Gaskets..Believe it. At higher Revs, a Huge BANG and the Results, Water in the Oil and Oil in the Water, Boiling Over-Steam and Transport Home. The Gaskets Also Failed Between Two Adjacent Cylinders. The Cause...From at least 2 sources, I was advised to Torque the Heads to 90 Ft/Lbs (For a Fine-Thread Nut). Yes, In Levels and in Sequence. Before the Third set of Gaskets went in, I called and talked to a ARP Technician, asked Him for advise and received a Short and Simple answer, 1/2" Studs, IRON Block, 130 Ft/Lbs !! Engine has Run Strong ever since.
I Must Add, for those who will ask. YES! You CAN Pull the Heads Off-Over STUDS, While the Engine is STILL In the Pantera!!! There is Just Enough Room, You have to Remove the Obvious parts and the Pressure Tank. AND Be 6' 6" Tall so You can LEAN WAY In Over the Fender (NO Belt Buckles, Zippers or Gene Rivets Please) and with ALL Your Strength, lift and slide that 75 Pound Iron Head Up and Off. You Have Aluminum Heads!? Your Home Free! But It will Still Take all Your Might to Bring Those Fine Threaded Nuts Up To 130 Ft/Lbs!! Believe it or Don't!
Yes, I knew the 'Book' States the Torque to be 125 Ft/Lbs for the Boss 351, But That Setting is for Factory Course Thread BOLTS, and here we're talking Nuts with Fine Threads. Last, be very careful, 130 Pounds is right On the 'Edge' of Stripping the Threads Out of the Nut And The Block.
Apologies for Hi-Jacking the Thread.
The Crank Journal and Wrist Pin Axises NOT Being in the Same PLANE cause a 'Twisting Force' upon every stroke. This Force is what Knocked-Out the Rod Bearing. When the Bearing Failed, the Rod was Twisted Even Further.
It's Called 'Hydraulic LOCK'. But what Fluid would have 'Leaked' into the Cylinder...And NOT leave any evidence?? Instead of Hyd-Lock, I can Imagine a Poorly-Timed 'Miss-Fire', or similar (Crossed Plug Wires Maybe) 'could' have bent a Rod. Do You Remember any such event?
Just Guessing Here, as In My Past, I have found a Bent Rod in a 400 Pontiac Engine I was Re-Building. NO Cause was ever found!
P.S. About those ARP HEAD Studs!! AFTER Installing them, I Blew-Out 2 Different sets of Head Gaskets..Believe it. At higher Revs, a Huge BANG and the Results, Water in the Oil and Oil in the Water, Boiling Over-Steam and Transport Home. The Gaskets Also Failed Between Two Adjacent Cylinders. The Cause...From at least 2 sources, I was advised to Torque the Heads to 90 Ft/Lbs (For a Fine-Thread Nut). Yes, In Levels and in Sequence. Before the Third set of Gaskets went in, I called and talked to a ARP Technician, asked Him for advise and received a Short and Simple answer, 1/2" Studs, IRON Block, 130 Ft/Lbs !! Engine has Run Strong ever since.
I Must Add, for those who will ask. YES! You CAN Pull the Heads Off-Over STUDS, While the Engine is STILL In the Pantera!!! There is Just Enough Room, You have to Remove the Obvious parts and the Pressure Tank. AND Be 6' 6" Tall so You can LEAN WAY In Over the Fender (NO Belt Buckles, Zippers or Gene Rivets Please) and with ALL Your Strength, lift and slide that 75 Pound Iron Head Up and Off. You Have Aluminum Heads!? Your Home Free! But It will Still Take all Your Might to Bring Those Fine Threaded Nuts Up To 130 Ft/Lbs!! Believe it or Don't!
Yes, I knew the 'Book' States the Torque to be 125 Ft/Lbs for the Boss 351, But That Setting is for Factory Course Thread BOLTS, and here we're talking Nuts with Fine Threads. Last, be very careful, 130 Pounds is right On the 'Edge' of Stripping the Threads Out of the Nut And The Block.
Apologies for Hi-Jacking the Thread.
Hi Guys
Would you believe the same thing has happened again this time on no 2 journal. Same tapping noise around 2000 rpm so engine pulled to take a look.
It was no3 journal that wiped out last time (see pics earlier in this thread) and the crank was welded and new rod purchased. The 3/7 journal is still OK but no 2 is completely wiped out. When the engine was at the machine shop last time all the rods were inspected for straightness and of course no 3 replaced. Crank was ground -10 and all new rod bearings fitted including new mains. Big ends checked for size.
How come this has happened again, any ideas, the engine has done less than 100 miles since the build.
New STD oil pump, lifter bores sleeved, oil restrictor kit fitted. Main bearings are all good so that tells me the oiling is OK so why would it wipe out one half of a rod journal and bearing yet the leave the other intact.
I am at a loss on this one and thinking I should replace with a new crank and rods. However that's easier said than done over here. Before I splash out the money could the same thing happen again, I need to identify whats causing this.
Not going back to the original machine shop, lost complete faith in them.
See pics below on No2 bearing with less than 100 miles. Rod journal exactly as the previous pictures, totally worn with about 40thou wiped off
Cheers
Horace
Would you believe the same thing has happened again this time on no 2 journal. Same tapping noise around 2000 rpm so engine pulled to take a look.
It was no3 journal that wiped out last time (see pics earlier in this thread) and the crank was welded and new rod purchased. The 3/7 journal is still OK but no 2 is completely wiped out. When the engine was at the machine shop last time all the rods were inspected for straightness and of course no 3 replaced. Crank was ground -10 and all new rod bearings fitted including new mains. Big ends checked for size.
How come this has happened again, any ideas, the engine has done less than 100 miles since the build.
New STD oil pump, lifter bores sleeved, oil restrictor kit fitted. Main bearings are all good so that tells me the oiling is OK so why would it wipe out one half of a rod journal and bearing yet the leave the other intact.
I am at a loss on this one and thinking I should replace with a new crank and rods. However that's easier said than done over here. Before I splash out the money could the same thing happen again, I need to identify whats causing this.
Not going back to the original machine shop, lost complete faith in them.
See pics below on No2 bearing with less than 100 miles. Rod journal exactly as the previous pictures, totally worn with about 40thou wiped off
Cheers
Horace
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i'm going with the same thing i said the 1st time, flipped / mixed / mis-aligned rod caps, unfortunately very hard to prove after it's taken apart unless the cap is clearly marked and found to be on the wrong rod