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Discussion Starter · #1 ·
well I have been hearing a slight really faint knock on the passenger side of the rear block after the car gets warm at idle. it goes away under any throttle.

SSSOOOOO I went on a witch hunt with the sawed off broom stick. checked the converter bolts and they are all tight.

well the knock can only be heard through the manifold and was worse on the back #4 cylinder. Couldn't hear it through the heads or anywhere else.

Heres the scary part. It stops when I unplug the #4 spark plug.

I am running 10w30 castrol and was told to run rotela T 15w40 today by the engine builder.

The motor was built again 6 months ago because it wore out a cam lobe. he said he went through everything. all push rods are strait and the top of the heads look perfect.

Heres my ideas.

Worn wrist pin
clearance issues with the crank bearings
cam lobe shavings got in the #4 crank bearing
maybe the cam is wearing again, but usually this causes missing. "CAR RUNS LIKE NEW THOUGH".

So what should I do. Run it until it gets worse? try the rotela T 15x40? tear down the top end and check everything I can? I am a little sick about it but I feel like I may have done it being rough on it one day lol. Its already bored 60 over so a new block will prob be needed if I let it go. I think the 60 over bore and 10.1 pistons may be part of my overheating problems also.

As always any thoughts and reply's are high appreciated
 

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arnold I got a question. As you know the number 7 and 8 plug is side by side on a fe engine. I have heard that allowing the 2 olug wires to lay side by side is what causes the skirts to break . As well stated if you run a longer 7 plug wire around fauther so # 7 and 8 wire is issolated from each other that will stop the skirts from breaking . The wires conduct between themselves . That is my question, anything to it ya think?
 

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427 are you saying good plugs wires jump fire between each other?
 

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I know what you're going through.

After we changed the timing chain on my tired 352/250 hp engine, I got the same knock from the back of the block. I bit the bullet and put in a rebuilt 390/300.

Now, the motor has about 1,500 miles, but the body is just about to hit 215,000 miles.
 

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Discussion Starter · #7 ·
I have brand new wires also, Are yall saying plug wires could have done this??? And yall seem pretty sure its a cracked skirt. Can the oil pan on these cars be finiggled off while the engine is still in the car?? so I can eyeball it??
 

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Do the pistons have floating or pressed pins? If pressed could have been cracked when the pins were pressed on if installed that way. If floating then maybe a bushing issue or snap ring has come loose. Usually things with to much clearance don't get better when you rev up. Are the pistons forged or cast? What rpm have you been pushing them to?
 

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Discussion Starter · #9 ·
No idea about the pins, but the pistons look to be forged when looking down the plug hole. Maybe 5500 rpms a time or two. almost felt like it floated the valves then, or either it was the slipping transmission, lol
 

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If it is a skirt broke he stated it was on pass side. No 7 and 8 is on drivers side. In a fe motor those are the 2 that normally breaks a skirt. I have had so many in motors break when tearing apart I lost count. Thats why I asked the question because I wished to have it stop.
 

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Steveo3318,
If you're like me the knock will drive you crazy. I'd have to tear it down to find out what the knock is. If it's a wrist pin it could run 200,000 more miles and not cause any trouble at all. But, if it's something else you've got to find out.
My son lives in Columbia, Ms. by the way.
Depending on the hurry you're in and the availibility of tools and a place to work will determine if you're engine is rebuildable by yourself. Don't ever look at overboring as a gain in cubic inches. Look at it as repairing a screwed up cylinder wall that could lead to other problems if taken too far. If you have to get another block and want to assemble it yourself look for a 360 truck engine. Those have more strength in the bottom end and will take an overbore without creating cooling problems. Good luck, Jim
 

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Discussion Starter · #15 ·
Yep, Its going to drive me crazy. The car is so solid I almost want to throw a nice stroker motor in it, and a monster trans rated up to 800 hp. I am a stickler for knowing what I have and this suck.
 

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Discussion Starter · #16 ·
Also whats the price range I should be looking at for a nice stroker build up. As long as my cylinders are still good???
 

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Discussion Starter · #18 ·
If I could get a stock bore 360 fe and build on it would that be a good idea?? I have heard the 360 blocks are better to bore on and have a stronger bottom end. also my 390 being bore 60 over tends to run a little warm.
 

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I have 2 360s , one I wish to keep, does not matter which both are the same. You need to make up your mind which way or what you wish to do. When you figure that out and what motor you want and if I can help you I donot mind. You can get a cheap 360 block up to any fe you wish. All depends on how much you wish to spend. There is hundreds of ways to go.
 

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If I could get a stock bore 360 fe and build on it would that be a good idea?? I have heard the 360 blocks are better to bore on and have a stronger bottom end. also my 390 being bore 60 over tends to run a little warm.
360 and 390 blocks are functionally identical. The only differences between the two engines are the crank and the rods. They even use the same replacement pistons. (same bore size)

If you build another engine, either block will work equally well. However, do NOT use the 360 crank and rods, as you're giving up 30ci AND the pistons in a 360 come around 1/8" from the top of the deck at TDC. This kills quench and makes it nearly impossible to get a workable compression ratio. A 390 conversion is the big thing when rebuilding a 360, as all it takes are the 390 crank and rods. If building a stroker, either engine is a good starting point, as the blocks are identical, and you're replacing the crank/rods anyway.

Call Barry R at Survival is you're doing the stroker (445). He'll definitely point you in the right direction!

Good Luck!
 
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