Center main blowout

I’d suggest taking a file to the corners of the cap and block areas , just the ends to take a possible high spot/ burr off. I do it with all my main caps and block, as well as the rods, even after the rods have been resized.

I have to trust the surfaces being flat, no way I have the equipment to check it.

I just use a small fine file, maybe 1/8 inch wide, to put a polish so to speak. It was how I was taught to ensure no cocking of caps when tapped down in place and torqued.

May or may not have caused the issue.
 
The center main bolt holes aren't really blind, there is a window in the block where the bolt ends, and I'll bet that bolt would spin out with a reverse drill. These engines are old and nothing lasts forever so bad things will happen no matter who worked on it. If it went for 15 years it was likely put together right.
 
I lost a center main cap.the crank also broke in half.that gave me a
reason to buy a Merc. crank. For peace of mind I installed a center
main strap.
 
Ol' Ron said:
...I built it for a fellow about 15 years ago... Did I make a mistake?? Not sure. Gramps
Click to expand...

Hehe, this is a very honest perspective from Gramps. I'm pretty darn certain I did stuff 15 years ago that was a mistake. Yup. Pretty certain. I tried hard but ...
 
they make a welding rod called stud rod you can go into a blind hole weld on the bolt it will not stick to the sides we weld on broken bolts all the time with it keep building weld up out of the hole and weld a nut or flat iron on the weld and they turn out has alot of nickel in the rod very strong good luck
 
chain drive said:
they make a welding rod called stud rod you can go into a blind hole weld on the bolt it will not stick to the sides we weld on broken bolts all the time with it keep building weld up out of the hole and weld a nut or flat iron on the weld and they turn out has alot of nickel in the rod very strong good luck
Click to expand...

Basically, this sounds like a good idea and I was thinking of suggesting it myself. I do have a question, though. I have always used "High Nickel" content rod to weld cast iron. This makes me wonder about your statement "it will not stick to the sides". Can you explain this?
 
Ron did not need to step u[ but he did. talk with any engine builder and they have stories about mistakes. Quite a few about the front plug being left out of the oil galley. An old radio guy once told me, the difference between a novice technician and an experienced technician is the experienced one has already burned someone else's equipment. So whether it's engines, radios or marriage there's a lot of mistakes out there. Maybe I should add kids too. :-)
 
tubman said:
Basically, this sounds like a good idea and I was thinking of suggesting it myself. I do have a question, though. I have always used "High Nickel" content rod to weld cast iron. This makes me wonder about your statement "it will not stick to the sides". Can you explain this?
Click to expand...


X-Tractalloy

X-Tractalloy is a special application welding electrode designd for extracting broken bolts, studs and taps from threaded holes.

  • Saves time and money - reduces downtime and labor by getting parts back into service quickly.
  • Versatile - X-Tractalloy will also remove broken screw extractors, taps and broken drill bits.
  • Strong - tensile strength exceeds that of Grade 2, 5, 8, 8.8 and 10.9 bolts and stainless steel.
  • Nonconductive flux - ceramic-like coating insulates threads to prevent damage from welding.
 
Yes - that is really interesting stuff . . . will have to pick some up and give it a whirl. Might help with broken off studs in these dang blocks!
 
First I would use the piece of bolt, put it in hole and try to unscrew by hand, I get 80% of bolts broke like that out that easy
I have also use arc welder rod with some tape to center rod to remove bolt down 6" hole

A left hand drill sized for easy out-- start drilling, most likely it will remove bolt piece before you get it drilled enough to use easy out
 
I don't think a mistake was made. I had the same thing happen to an engine I built. Took two more owners and about 20k miles before the center main cap broke. Notice, it's almost always the center main. These parts are old, and, who mags main caps? Maybe that should be another MUST check to go along with pressure testing.
 
I thought I had an unusual occurrence, but from the posts here, this looks to be more common than I ever thought. Maybe this is why all current V8's use 5 main bearings.
 
Update. I cleaned the pan. Buried in the sludge was a washer. So it did not fail because washers were neglected...and it matches the others. The cap just failed. I think Ron did not do anything wrong. The cap failed! Ron sent me caps and I just returned from Ron SanGiovani's and he lent me some as well. Between them, I hope to find a match and return the others. I need to check the length of the bolts after I pull the broken off bolt remainders from the block. I doubt that the bolts were too long.

Thanks for the help guys.

Dick Listro
 
Thank you for posting your findings .
I think you will find it was just a cap failure,,,,seems it happens more than we realize.

I’m not blaming anyone,,,,but some were quick to blame it on Ron without any real evidence,,,,and sometimes all anyone really has is their reputation !

So glad to see so many stand up guys here,,,,as well as yourself,,,,it makes you have confidence in your fellow hot rodders .

Tommy
 
After that happened to me I installed a speedway main cap support, figured it couldn't hurt, so far so good. Has anyone else used one of these?
 
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