Off idle BOG at WOT

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78Delta88

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The pistons were flat with the 1 (or 2?) dimple(s) on them. I'm assuming standard pistons.

Car can idle, run fine...revs fine without load. Heck, if I feather it enough, she screams past 100mph. It's just when I come to a stop and punch it...it falls on its face, or stalls.

Going to put a roller cam in, since I don't know what this cam is. Not going to try to figure out what it is.
Ok, so flat tops with 2 relief and 64 CC chamber, your are up somewhere around 10. Could 10.25 to 1... Could be 9.5, just a stab in the dark until you know exact data on the piston and the crush of the head gasket.

What you do know is your timing is going to be around 4 to 8 before TDC as a starting point.

Your description of drivability with the current setup is exactly what you will have with the HEI using no advance.

Until you can properly curve your distributor and tune to your engine, no changes will happen even with perfect fuel quality and delivery.

As far as Cam... If you are high compression and running a Mother Thumper your base line vacuum will be around 12 to 15 inches. And your blow by will most likely be high.


So don't get to concerned on exact cam at this point. It's more important to baseline, and then work from there.

If your base tune is bad, then in reality, not much else matters.
 
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MrSony

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If you have the factory computer controlled hei or any factory components hooked up, it will not run worth a damn. you must have a normal carburetor and non computerized hei.
what carb and distributor are you running now?
 

78Delta88

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If you have the factory computer controlled hei or any factory components hooked up, it will not run worth a damn. you must have a normal carburetor and non computerized hei.
what carb and distributor are you running now?
Yes, that's the major issue. OP is running non-ECM Edelbrock, with original C3 HEI.
 

MonteLS_84

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Jul 28, 2021
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If you have the factory computer controlled hei or any factory components hooked up, it will not run worth a damn. you must have a normal carburetor and non computerized hei.
what carb and distributor are you running now?
Eddy 650, and gm hei with vacuum advance
 

MonteLS_84

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Jul 28, 2021
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Yes, that's the major issue. OP is running non-ECM Edelbrock, with original C3 HEI.
No, currently Eddy 650 and gm hei with vacuum advance. That was previously.
 

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78Delta88

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No, currently Eddy 650 and gm hei with vacuum advance. That was previously.
Ok my bad.... I thought you were still running the original 1984 HEI.

The above pic is of current HEI you are running now?

Is that how that plate looks in its non running state?

If you are running mechanical advance and bogging try the tune up kit lighter springs, heavier weights.

If your plate has the weights like they are in your photo out like that and not freely moving.. That is a major part of your problem. The weights have to move freely and spring back to center when the engine is not running.

If all that is good... Then have your module checked. It's very possible that It's high side is failing.

Also check your coil. As the coil goes bad the engine stumbles, misfires, bogs, poor acceleration, etc...


Just as reference:

Below is 1984 unit.... It has no advance.


Screenshot_20220913-181022.png

Below is the 1974 to 1980 Pre-CCC/EST unit... It has Vacuum & Mechanical Advance.

Screenshot_20220913-181329.png
 
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MonteLS_84

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Jul 28, 2021
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Ok my bad.... I thought you were still running the original 1984 HEI.

The above pic is of current HEI you are running now?

Is that how that plate looks in its non running state?

If you are running mechanical advance and bogging try the tune up kit lighter springs, heavier weights.

If your plate has the weights like they are in your photo out like that and not freely moving.. That is a major part of your problem. The weights have to move freely and spring back to center when the engine is not running.

If all that is good... Then have your module checked. It's very possible that It's high side is failing.

Also check your coil. As the coil goes bad the engine stumbles, misfires, bogs, poor acceleration, etc...


Just as reference:

Below is 1984 unit.... It has no advance.


View attachment 206798

Below is the 1974 to 1980 Pre-CCC/EST unit... It has Vacuum & Mechanical Advance.

View attachment 206800
Funny you mention that. So...I bought a weight and spring kit the other day. It was from Mr. Gasket. I put the lightest springs in, and changed the weights. Common sense told me the weights should move freely, which is why I got the kit. The new weights still seem to hang up. The "new" distributor I'm running is not brand new. It is used...just new to me. There are 2 "bumps" on the base plate that the weights hang up on. Friction is there. For all I know someone could have been messing with it, and put it upside down or something?

The bog is now worse with the lighter springs. I have a hunch that the weights aren't snapping back even more so with the light springs.

I suppose it's possible that both distributors were worn. 🤔

Going to get a new distributor from the store and see if anything changes...
 

78Delta88

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May 23, 2022
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Funny you mention that. So...I bought a weight and spring kit the other day. It was from Mr. Gasket. I put the lightest springs in, and changed the weights. Common sense told me the weights should move freely, which is why I got the kit. The new weights still seem to hang up. The "new" distributor I'm running is not brand new. It is used...just new to me. There are 2 "bumps" on the base plate that the weights hang up on. Friction is there. For all I know someone could have been messing with it, and put it upside down or something?

The bog is now worse with the lighter springs. I have a hunch that the weights aren't snapping back even more so with the light springs.

I suppose it's possible that both distributors were worn. 🤔

Going to get a new distributor from the store and see if anything changes...
It could be that the previous owner of the distributor was trying a self made low dollar method of lock out.

Try to remove the weights and springs and see if you can repair or remove cause of the weights hanging up.
 

MonteLS_84

Apprentice
Jul 28, 2021
63
10
8
Welp, I bought a brand new msd street fire distributor. Still bogged. Put in light springs. Still have the bog. On the bright side, the engine seems to be running smoother and more responsive with the new distributor.

Also, checked for 12v going to distributor - and I have 12v.

Going under now to peak at the tank and fuel pump, and see if I can find anything...
 

MonteLS_84

Apprentice
Jul 28, 2021
63
10
8
Pulled a plug to see what it looks like...

I'm no pro here. Not sure what I'm looking at.
 

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