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Discussion Starter · #1 ·
You never know what you will find when you open up an Opel engine.....

Last weekend I was showing my 9 and 6 year old Grandsons what the inside of my Sportwagons motor looked like. When I pulled the base pan off, something was missing...
 

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Was the bolt in the pan? Just curious. :eek:
 

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Bolts? We don't need no stinkin' bolts.....
 

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can you post a pic of that main bearing shell and the 2 rod bearing shells on both sides of that main sometime? curious to see how they wore.
 

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For me that's one of those 'things that make you go' aaaaaarrrrggggghhhhhhhhh!!!!!!
On the bright side it's nice you found it before there was a serious result ... hopefully. :)
 

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Discussion Starter · #8 ·
netandtim said:
Hey, I just think it's great you were showing your grankids. OPEL, a family sport!!
tim
When we first went into the garage, the 9 year old jumped behind the wheel of the wagon and started "driving".
I asked him where he was going and he said "France".
"So what about the water?"
"I just push this button and it turns into a boat!!"
The 6 year old drove to "Florida".

They did get a kick out of spinning the motor and watching the pistons go up and down.
 

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I saw a Buick Electra with a 455 engine pulled apart back in the 1970's. The engine had 100,000 miles on it and was missing one half of one of the main bearings. The engine had never been apart. Original owner.
 

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Discussion Starter · #10 ·
Another Boat Anchor

I was looking at the wagons motor today and noticed a score mark on #2 cylinder and it looked like there was a little too much of a gap between it and the piston. Popped out the piston and there was a section between the first and second ring lands that was destroyed. Don't know if it was because of detonation, from a broken ring or from the missing main bearing cap bolt. The compression ring on #1 was also broken and had been for a while.

Looks like I have another boat anchor. :(
 

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boat anchor? anything can be rebuilt.
 

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Can you say "Two Litre". With SBC 265 Flat tops, ground and balanced crank, lightened flywheel with S-10 clutch....

Yea, I hadn't planned anything other than a "freshening" when I started on my (formerly Kat's) SportWagon's engine. So far, there's a new head (with exhaust inserts, new cam bearings, two new valves, oil passages drilled and tapped, new studs and rockers, new lifters, new cam, yada yada yada) since the old one was cracked, a ground crank and all new under-size bearings, line bored block, four new rods, Legere-sourced forged 0.040" over JE flat-tops, a new timing chain and gear, new oil pump cover, new pressure plate and disk, new fuel and cold start injectors, new fan clutch, re-cored rad, and so on and so on...

Well, what are you to do?
 

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Discussion Starter · #14 ·
So, any ideas on the cause of the piston damage?

It's interesting how the area from the top of the piston to the 1st compression ring almost looks like a torch hit it. Prime example of detonation damage due to timing being advanced too much? That is the only cylinder that had this issue.

Any thoughts on if the broken main bearing cap bolt could have contributed?
 

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Hot!

Gary, The broken rings and the burnt ring lands are typical examples of detionation and the high local temperatures that result. I would not be surprised if the main cap bolt had been overstressed by the "hammering" of the detionation too. It may have had a flaw or stress riser that made it weaker than the other main cap bolts so that it failed first.
 

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Discussion Starter · #16 ·
- The detonation could have caused the cap bolt to break. Good thought, Jim.

When I got the wagon, I replaced the dizzy because there was a lot of play in the shaft and the dwell kept varing.

Opel detectives at work... Think I'll change the threads title ;)
 

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Discussion Starter · #17 ·
Another 'find' was the cause of the rear main leak. The spring that keeps the seal tight against the crank surface had separated from the seal. My guess is it happened when the rear seal was replaced.

So use care when replacing the rear seal and make sure you lubricate the seal and crank before installing.

That explains the oil puddle under the car each morning.
 

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Just an interesting tidbit. Years ago I got a car dirt cheap knowing it was detonated. It was #1 and broke half the ring land, it too was very scorched. The previous owner had the wastegate doughnut stick and it saw 30 pounds of boost and was designed for 10. No crank or rod damage. He said he was putting down his best ever run at Bandimere when it happened. I was Glad he had the sence to push in the clutch and kill the motor, another few seconds with that busted piece in there and something else would have given up. Makes you wonder about why #1 though?
 

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I've seen a few boat engines that had detonated one cylinder to death, and always wondered why just one cylinder? All I can come up with is that due to variances in such things as combustion chamber volume, crankshaft index, camshaft lobe variations, ignition timing differences, intake manifold flow differences, lots of variables that make one cylinder act differently from another!
Maybe that's why ultra high performance engines are so incredibly blueprinted, everything is checked and double checked and matched up in such anal detail.
And why such details are kind of important even on the poor little "stock" four cylinder engines we throw together in the back yard. Add just a bit too much timing with the wrong gas and sooner or later you're gonna find that overlooked or under-budgeted "weak spot!" Aren't we all guilty of "overtinkering" sometimes to get that extra power out of the engine we didn't build quite tough enough to take it?
That knock indicator I brought up last weak would have told Gary that something was up within his engine long before the damage happened.
Ron (Namba 209) has the knock indicator blueprints, will make the prototype, I hope it works well and is very affordable, as we all should have one!
I think there will be lots more discussion of this in the near future... :)
By the way, I did find a similar knock indicator gauge gadget you can buy for $170 that installs in your car permanently, as opposed to the one Ron is building which I intend to use as more of a diagnostic/tuning tool that can be used on whatever I'm working on at the time. If anybody wants to see it let me know.
 
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