• When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

340 Blew

I will upload some pictures in a couple of hours, I have to head out with family now for dinner. Engine and trans are out, and the block is TOAST.

My numbers matching driveline 73 Road Runner is no more...:(
 
Hi folks.

OK, here are some pictures of the carnage.

$4 rod was broken, and pieces of it were found in the oil pan and embedded in the underside of #3 piston. The nuts were still attached on the remnants of the cap and rod, so I am not yet sure WHY it happened. It wasn't from a nut coming loose. Regardless, the results are sobering. Here are a few pictures:

Here is a pic as we were pulling the assembly out of the car:
20170528_150814.jpg


First indication of major carnage was the windage tray. Note also the nice "dent" in the block along the oil pan mounting flange.
20170528_140925.jpg


Once we got it separated and on an engine stand, the damage was clear. Note again the cracked block in the lower part of the picture where the oil pan mounts to the block. The casting is of course beat up on the inside too.
20170528_174030.jpg


If you look carefully at this picture, you can see a crack that goes vertically up the most of the length of the cylinder #3. #4 let loose but #3 took the brunt of the damage.
20170528_174113.jpg


Here is #4:
20170528_174152.jpg


So unless anyone can tell me different, this block is DONE. It can be a nice boat anchor. My current plans are to strip the block down and toss it in a corner somewhere, in case ever someone wants to spend the time and money to fix it (if it even can be fixed).

Guess I'll be shopping for another small block. When life gives you lemons, make lemonade. I guess a stroker is now in order...

As always, FBBO rocks. Thanks for all the advice and nice comments.

Hawk
 
the only question left to answer is "was he winning when it let go?"

just messin', sorry bout the carnage Hawk
 
the only question left to answer is "was he winning when it let go?"

just messin', sorry bout the carnage Hawk

In his dreams maybe! He was just on the highway on the way to State College when it happened. Sorry, no more exciting than that!
 
Last edited:
In his dreams maybe! He was just on the highway on the way to State College when it happened. Sorry, no more exiting than that!
Like to see picture with it torn down.
can see crack in pan rail.
 
Nothing wrong with that nice 360 magnum motors that summit has good power not alot of coin wham bam thank you mamm quick and easy ! So got a picture of that pan and damage to it? I might be interested if it's not hurt! What pickup does it need ?
 
You can sometimes find 340 blocks around, I have come across a few. And of course, there are still some of the 360 Magnums out there, if you're into re building one.
 
I feel for ya brother...hope you can get it back on the road before too long..
 
To bad your so far away. There is a 69 340 block on craigslist .020 over 400 bucks. I know the guy selling it he usually has nice stuff.
 
Like to see picture with it torn down.
can see crack in pan rail.
We will be tearing it down further today. I am especially interested to see if there is any damage to the heads. Back when I built the engine in 1992, I spent a fair amount of time porting the heads. We also put in larger intakes and exhausts too. Of course, this probably means that they breathe HALF as well as modern day aluminum heads, but hopefully they are still good.

Nothing wrong with that nice 360 magnum motors that summit has good power not alot of coin wham bam thank you mamm quick and easy ! So got a picture of that pan and damage to it? I might be interested if it's not hurt! What pickup does it need ?
I hear ya! We'll see what we can find. A 340 based block will be ideal - then we don't have to change the decals on the hood!
...And sorry, the pan is no good. Pickup is fine though...

To bad your so far away. There is a 69 340 block on craigslist .020 over 400 bucks. I know the guy selling it he usually has nice stuff.
First, this WAS my first car I ever owned, but it is now officially my son's, as I gave it to him so it could also be HIS first car. He just graduated school and got his first job, which means his budget is like the Kink's: "Low budget"! Of course, I will be willing to help him out some. Although the engine was rebuilt in the 90's, it only had 20K miles on it - it should have lasted way longer. I truly appreciate the tip; putting another 340 based block in it is definitely preferable. I guess I have a lot to think about pretty quickly.
 
In his dreams maybe! He was just on the highway on the way to State College when it happened. Sorry, no more exciting than that!

Just sayin'.

We've gotten two blown up engines in the shop just recently that were only going 55-58 mph on the highway. One, a 340, gutted itself. The other a stroker, that was dyno tested to 6,700 rpm, bent a valve @ 55 mph.

Had a guy bring us his Ford head off the 302 in his pickup. Wanted me to find out why the valves kept bending. You Know. What was the other shop doing wrong when they rebuilt his heads? So I asked him, "Who is driving when these valves bend?" "My son."

'Nother guy came in wanting me to weld a piece back on the bellhousing area of his block. There were pieces of clutch on the intake manifold. His son was "just pulling across the intersection" when the clutch let go.

I was 18 when my '56 Dodge with the 413 wedge my Dad helped install didn't want to go to the JC that morning. It spit the u-joint out pulling away from the stop sign. I couldn't see the car behind me from the tire smoke. But I'm sure it was reluctance on the Dodge's part to participate in higher learning.
 
I was heading home after work one night in my '73 road runner. just pulled out from a red light and the driveshaft dropped. Had to call Dad.He knew for sure I was playing around, which I hadn't been. I was the night before.....
 
Just sayin'.

We've gotten two blown up engines in the shop just recently that were only going 55-58 mph on the highway. One, a 340, gutted itself. The other a stroker, that was dyno tested to 6,700 rpm, bent a valve @ 55 mph.

Had a guy bring us his Ford head off the 302 in his pickup. Wanted me to find out why the valves kept bending. You Know. What was the other shop doing wrong when they rebuilt his heads? So I asked him, "Who is driving when these valves bend?" "My son."

'Nother guy came in wanting me to weld a piece back on the bellhousing area of his block. There were pieces of clutch on the intake manifold. His son was "just pulling across the intersection" when the clutch let go.

I was 18 when my '56 Dodge with the 413 wedge my Dad helped install didn't want to go to the JC that morning. It spit the u-joint out pulling away from the stop sign. I couldn't see the car behind me from the tire smoke. But I'm sure it was reluctance on the Dodge's part to participate in higher learning.

:rolleyes:

I hear you - I did my fair share of "testing" with the car when I was younger! As a matter of fact, I remember one time using the Slap Stik at redline and slapped it right into reverse (linkage wasn't adjusted correctly). Luckily the tires just broke loose into reverse and everything survived!

My son hasn't been a hot head driving it in the 6 years he has had it, if for no other reason that he has learned that it costs him lots of extra money in gas! We have had a number of friends see him on the road (our spies - especially when he was 16-17) and he actually tends to drive quite slowly. That being said, I have no doubt he has had his fun with it too.

In this case, the car died while my son was on the way back to college. It was on a stretch of highway that is pretty busy - it would be hard for him to drive excessively fast in the area he was driving just due to congestion. Now he was doing 70 give or take with a 3.55 rear, so the engine was certainly turning some RPMs to keep him at that speed.

So while I am not so naive to think he has never hammered on the car, I really don't think he was in this case. Having said that, there was obviously something that happened to cause the engine to self destruct. As we pull it apart we will see if there are any other signs that will provide a clue...
 
Yeah kids are brutal on cars! I bought my first charger learned this magical thing called power braking and within the day detonated the trans! We don't know any better ! My brother killed a /6 ,my brother in law killed a 98 blazer ,90 firebird trans twice,then the motor a few months later,a 85 trans am motor ,then heads then a fairly new clutch ,79 gmc killed that motor too!
 
OK, my son and I managed to strip the engine down and get the crank and pistons out. It was a bear getting #3 out. Let's just say the #3 cylinder is VERY thin wall now...

Here are a couple of pictures: First, here is a shot of the pan rail crack from inside and outside.
20170529_160238.jpg
20170529_160251.jpg


Here is #3
20170529_160431.jpg


And #4 took a shot too
20170529_160529.jpg


And some chunks out of the block too
20170529_160442.jpg


My best guess is the the bearing for the #4 rod died, and likely sent some parts through the engine. The connecting rod then let go. When it broke, it jammed the #3 piston into the wall of the bore, cracking it.

The bearings did not look good, especially the rod bearings. We had an oil problem a few years ago and the block was sucking oil from underneath the intake manifold and burning it in the cylinder. For one trip, it very nearly sucked the sump dry. I'm wondering if we hurt the bearings then and they have just taken some time to completely fail...

Hawk
 
HEMI BLOCK.jpg
IMO it's fixable, worth fixing now, no. 2 sleeves fix the pan rail and align hone the mains. Honing the main may be necessary because of the whack on pan rail, just my opinion. Put the block in the corner, keep it with the car. I'm in the same boat but I have a little more water in it.
 
Auto Transport Service
Back
Top