A few more carnage pics of Kelly's boat anchor

Here's a couple more. You'll notice piston #6 is missing....it's permantly stuck in it's cylinder. I could probably get it out with a slegehammer, but why bother.
What I can tell you is that there are a few rings on #6 that are out of place and are wedged between the piston and the cyl. wall. So this piston was moving up, the rings pushed themselves out of their grooves, then bent and likely jammed up the entire motor. One of the oil scrapper rings is down below the piston skirt. It's that far out of place.

But whether or not that's exactly the cause is anybodys guess!

Piston #2 & #5 came out without a BFH. Just pushed them out like a normal engine. No cracks or anything with these two. However as you can tell, both rods are bent. Strangely all pistons move freely with their wrist pin. I guess our corrective action of .0005" additional clearance from the last motor worked on this one.


All of the bearings look fine. A little worn but nothing out of the norm. Definately no spun bearings. The crank looks good other than some UFO bruising on the counter weights.

Bigger pics at http://www.cardomain.com/ride/686815

Oh forgot to add....the cyl wall thickness of the fragments from #6 measured .125". This is after a .040" overbore.
Later,
Will

Certainly some twisted metal.

When a block water jacket is poured , usually the last 3/4 inch is left open for water travel. I wonder if the hard blok stuff would have helped here ?

An eighth of an inch? In general, how much should a moderately modified engine have? Any rule of thumb for that . .?

P.s. Now what you need to do is put up a comical ad in your local Craigslist for a free boat anchor...

From my info from Aussies Phil Irving and Sam Blumenstien, an engine with poorer rod to stroke ratio should have 180 thou at the trust face for an engine with 11:1 compression. Early pre 1969 Ford engines, Chevy small blocks, and 385 and FE Fords don't have the same problem.

A turboed engine with 8:1 compression and 14 pounds boost should probably have that thickness, but straight from the factory, 130 thou was common for all thin wall Fords.

125 thou is pretty good. 90 thou isn't uncommon for a 40 thou over engine which has suffered some corrosion. 351 C 's used to run around with 130 thou at birth, and could hack quite a lot of punishment without breaking, so a 250 won't be at critical with 125 thou.

I emailed a photo of the parts to a friend that does engine machine work... he says it looks like the rods that are still in one piece are all distorted like they were about to fail any way... hard to tell from a photo though.

Crosley":1mmvome2 said:

I emailed a photo of the parts to a friend that does engine machine work... he says it looks like the rods that are still in one piece are all distorted like they were about to fail any way... hard to tell from a photo though.

Click to expand...

Yup....both #2 & #5 are bent. If you go to the CarDomain link and blow up the picture it's pretty obvious.

Later,
Will

Hey Will....time to finish the "ice" motor.

Looks to me like common rod failure.
When the rod broke it broke the cylinder wall and stuck a piston in the hole. The next five firing cycles took out the other rods and stopped the engine.

time to give Cunningham Rods a call

8)

Crosley":mjuwgl32 said:

time to give Cunningham Rods a call

8)

Click to expand...

I tried them....way to expensive!

Off the shelf H-beam Manley's or Scat's are cheaper. All that needs to be done is resize the rod journal.

Looks like we're going with a 271 cid strocker shortblock. Just need to get the math finished so I can order some new pistons.

Later,
Will

any update on cause of failure?

How many rpm's where you at when it let go?

the original thread where he talks about what happened is here
http://fordsix.com/forum/viewtopic.php?t=53990

and you really need to change your signature, that picture is way way over the limits of the allowed size