Technical Engine failure forensics

How else are gonna talk about cousin ****ers and busted timing chains in the same place?
If you didn't, who would ?

 

No, youse are all wrong. Us conspiracy theorists reckon it's the Guvvnment doin it. They have a crack team, probably on crack, that sneak around and secretly dismantle and re***emble your engine trying to work out what we see in old bits. Sometimes they put them back together wrong in the hope it'll get us off the road and into a Prius.
Now, where's my tablets?

 

Well, I'll start taking orders for tin foil hats.
I can do custom aluminum helmets too

 

wish I would have known this when it happened to me several years ago. nobody could touch me during hot laps. when I hit the track for time trials, it was missing terribly. I had advanced the timing a little too much I think. blew the tops off some of the pistons. went fast as hell for about 10 laps.

 

if the chain broke that had to be some force specially if its a link belt type and had to be a interferance in the chain /gear ***y ( dried up chain ( lube port behind gear plugged, run low on oil ) , or the nut or a piece of casting got between the gear and chain , a cheap double roller you look at them funny and they stretch and you can lock up the mess by trying to put the roller on a tooth . another thing is a oil pump thats on the verge of failing and locking up it will pull the woodruff key over on the crank , and cause the whole she bange to be out of time ,them distributor gears are super strong , pull it and look there for bending and the pump gears/lower plate for burning or metal smearing

as for the cousins uncle /aunt thing ... Geneolgy wad never a good thing in my family ...

 

OH and I forgot also to check the lifter and galleries for a cracked, broken one or worn unit and is ****ed in the bore and the very rare occurance of a melted cam bearing ( oil problem) as the La's are known for bad upper end oiling .

 

In the South, if you have a fling with a cousin doesn't your sister get jealous?

 

As Hillary Clinton would say "at this point what does it matter". Enjoy your new wall art and get on with it.

 

Wow ! Lmao

 

I'd just like to know, it's a puzzling thing and it might come in handy one day.
A lot like a smoking hot cousin can be

 

If the rod bolt was on the camshaft side of the rod, I suspect it got into the cam and caught between a lobe and the block, stopping the cam, breaking the gear and chain.

 

I rebuilt a 36 hp VW engine when I was in high school (late 60's). The cases on those engines were magnesium and over time the bearing bores would get beat out of round, so we set the case up in a bridgeport and line bored the block. Then you cut shim stock to go behind the mains, thickness determined by how much you overbored the main bores.

So you have to punch holes in the shim stock to allow for oil p***age. There's a bearing on the nose of the crank that slips on rather than being split shells, and it gets its oil via a p***age in the block that feeds oil to it from the next crank bearing.

Its been so long now I can't remember, but I either missed punching the extra hole in the adjacent bearing shim, or the hole in the shim behind the slip on bearing at the nose. Anyway, when I started it up it ran fine for a few minutes and then locked up dead tight.

The street beside my parents' house is a steep hill. So me and my buddy drug the bug to the top of the hill and let it coast down. Let the clutch out at about 15mph and it slid the rear wheels til the car stopped. Time to pull the motor.

Everything else was fine, but the crank nose bearing was locked up. Had to pull it off with a gear puller. Didn't look bad at all once it was off, so I polished the bore and the crank journal, added the missing hole to the shim, and put it back together. Sold it a couple years later to an older guy who liked the old bugs, and in the late 80's he was still using it to drive back and forth to work every day.

To the point of the story...... I'm wondering if the loose rod cap allowed it to dump most of the oil into the pan to the point where it starved and siezed a cam bearing? Once everything cools down, there's enough clearance that the cam can now turn once its been wiggled around a bit during the dis***embly. Its not unusual for a journal bearing to sieze due to high temps and lack of oil, and still not sustain enough damage to remain locked up once everything is back to normal temperature. Big difference in locking up a rod or main bearing that's still got 8 pistons making it go round and round, versus locking up a cam bearing that's driven by a chain and sprockets about the size required for a go-cart.

I wouldn't buy the premise of some instantaneous stopping of the crank as a cause. When something tries to stop a crank, either the crank breaks or whatever's in its way gets broken. I've dis***embled enough -71 Detroits with multi-piece cranks or multi-piece blocks to be pretty sure of this. And, if such a thing did happen, a camshaft, due to its relatively small diameter, wouldn't have enough rotational inertia to destroy the cam drive.

If something got into the oil pump and locked it up, its unlikely that the pin that locates the drive gear on the distributor shaft could transmit enough torque to lock the cam and break the cam drive. 2 different times during the wretched life of a 351M I had in a pickup, a retaining clip came out of a lifter, managed to find its way from there to the pan, thru the pickup screen, and into the oil pump. Both times, the drive pin in the distributor gear sheared with no damaged to anything else.

 

Was the little triangle oil drip piece in place behind the cam gear?
If not, that could be the start of the problem.
No expert here, just a little experience with 318's

 

As an experienced mechanic (not), all I can add is....its magic, never to be known by mere mortals. By the way....my cousin was pretty hot all those years ago, she was fun, (nudge, nudge, wink, wink) but all these years later........ummmm,

 

Chemtrails?

 

Gremlins!!!!!

 

Maybe you got something wrong... the saying goes like this:
`If you can´t afford a Dodge, dodge a Ford!`
hahaha, I´m not a` to the bone´- MoPar-man myself but I like that...
Just GMify your Mopars and Fords, and you´ll be alright, hahahaha

 

Good buddy of mine is a heavy line mechanic at Dodge, and he'd probably just shrug at you and say "It's a 5.2.....their P.O.S.'s! What did you expect?" ;-) He's not a big fan of them......course he's not a big fan of anything built after about '75!

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****** mentioned in his first post about harmonics....I traded some parts for a garden tractor with a 12hp Te***seh engine with a broken camshaft..I rebuilt the engine used and it mostly for lawn mowing and snow blowing..About every 6 months it would break the cam; I'd replace the cam and all would be fine for 6 months or so..Was getting tired after the 3rd one...By accident I found the flywheel was cracked and even though the nut was tight it was shucking back and forth on the key way..Replaced the flywheel and hand filed a key to fit the slightly damaged crank key way; it then ran for 27 years with out any more cams breaking..Harmonics, no cousins involved..