360 engine vibration

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Yep I wasn't sure it was the damper either But it has got rid of a bad pulley wobble. So still progress. I've converted ignition to hei. Removed mopar module and ballast resistor. Made no difference Pulling plug leads whilst running drops all cylinders. When running it's a steady 20 on vac gauge. It' reminds me when you have twin carbs and one is being lazy giving less fuel.
 
At about 1500 to 2000 rpm it's ike a thud thud thud Vibration like a plug missing. Quite low frequency. Like when your washing machines is on spin cycle and the load is off balance. I might need to move past this get it road legal and see what it like on a run.
 
Was also wondering about cam timing. Suppose no way to check other than removing cover. Then again what cam is in it?? ? Looking down the dizzy drive hole the cam has a green painted band near the dizzy drive And looks newer Cleaner then rest of engine top of piston are quite carboned up and look original. Because the engine is externally clean I thought it was a recent crate engine but I'm wrong with this. The heads must have been off as the valve springs are clean unlike the rocker shafts. When I replaced the Crank seal the lower cam sprocket is after market. With s359 and the chain is clean. Maybe someone swapped the cam?
 
I like to see these cars set up the way Ma Mopar intended them to run.

You say you put HEI on it, OK now you need to run down this whole thing. Spark Plugs you Selected, Are you Using Platimum Spark Plugs with the HEI, or are you running stock mopar recomended plugs for the mopar brain box gapped at.035" ths. Or are you running a .060 to .080"ths gap on your Platimum Plugs. Got to get all of this stuff mached up right for the technology that you are using. Once you are sure it is right, then move onto the next thing.

Next thing, these carburetors fill up with sediment and corrosion especially after sitting for 4 years, and really especially if you had it stored with ethanol gasoline for that 4 years. Ethanol gas goes bad in 2 months, it draws so much moisture it is crazy. Want some good 90 octane non ethanol gasoline to start with.

I would take that carburetor off, disassemble it, run it through you ultrasonic cleaner with your favorite solution to get all the internal passages cleaned out. Put in the new needle and seats so the rubbers are good, new accelerator pump same, new floats are a good thing too. Just this alone I am sure you will notice it running much better than before.

Keep working through it.
 
Standard plugs I think, I have had 2 different sets in NGK I recall. I do have a 3rd set autolite I'm going to try. Gapped 35 thou.

Also new plugs leads,, dizzy cap, rotor arm, reluctor, coil pickup, coil,

Carb has been stripped rebuilt twice and ultrasonic cleaned

But I will revisit all of above. Thanks for feedback.
 
Your should keep your old spark plugs in order when you take them out, so you know which cylinder they came out of. Then you can read what color the porcelain is at the electrode. Compare all of the spark plugs when you get them out, if one is a different color or has more carbon on it than the others then this is a clue to what is going on with your ignition system. And next step, what is going on inside your engine.

Keep Thinking . . .
 
George Jets said:
Your should keep your old spark plugs in order when you take them out, so you know which cylinder they came out of. Then you can read what color the porcelain is at the electrode. Compare all of the spark plugs when you get them out, if one is a different color or has more carbon on it than the others then this is a clue to what is going on with your ignition system. And next step, what is going on inside your engine.

Keep Thinking . . .
Click to expand...

yep did that numbered them all. All evenly rich, as you would expect for just running in garage off choke
 
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Been to a swap meet this weekend. So no car progress. A plugs numbered and evenly rich. What ohm primary circuit coil with hei 3 or 1.5 ohm. I'm thinking I. 5 ohm ?
Bought this book

IMG_20190317_215049.jpg
 
The 1.5 or 3 ohm question is what is associate with more traditional, non-HEI coils. HEI coils are quite different. I quickly found reference to primary resistance of 0.25 to 0.3 ohms for HEI.
 
OK thanks. Now you mention it my msd 6al on my 58 apache has an msd blaster 2 coil at 0.7 ohm. Think the current coil on the dart is 1.5 ohm.
 
Not much to update as I've been busy on my 58 GMC Apache and changing header tank on my Porsche Boxster. Anyhow I did get a little time on the Dart, it back on all 4 wheels and the bench seat back in place so I could go for a little drive. The short drive confirms it is a vibration but quite low frequency, like 1 cylinder is down or maybe we have an issue with the TC? I have a few other jobs to do on the Apache and Boxster and them I'll come back to this in a week or 2.
On a positive note it drives and runs now.

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I wonder if it was rebuilt and internally balanced with a neutral balanced converter but has the external balanced harmonic balancer on it...
 
I've been busy on other car projects but about to get back on this. I did run it with the front pulley off but made no difference. As the car is still not UK registered I've decided to press ahead with the other jobs so I can get it on the road and give it a good road test to continue fault finding the vibration. So there will be more action on this other thread for a while.
https://www.forabodiesonly.com/mopa...nger-in-england.329728/page-9#post-1972459418
 
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