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Discussion Starter · #21 ·
Ok, I reset initial timing to 12° BTDC... I set the dial on 12° and rotated the distributor until I lined the balancer mark up with 0° on the silver timing tab...

And I set total timing with the engine still running, I turned the dial on 36° and with the engine rpm at 2500 I rotated the distributor to line up the balancer mark up with 0° on the silver timing tab...

Would initial timing still show on 0° after total timing is set ?
 

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Rod...from a Chrysler?
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Would initial timing still show on 0° after total timing is set ?
Nope. (and it's "will it still show 12°?", mark being on 0, dial set at 12) If you moved the distributor, you've changed the initial timing.
I believe you need to set your initial timing and change the distributor springs to change your total timing. I've changed mine once, but now run FI, so I'm not so sure.
 
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Discussion Starter · #23 ·
Nope. (and it's "will it still show 12°?", mark being on 0, dial set at 12) If you moved the distributor, you've changed the initial timing.
I believe you need to set your initial timing and change the distributor springs to change your total timing. I've changed mine once, but now run FI, so I'm not so sure.
I fixed the timing, with the dialer on 12° the balancer mark hits 0° on the timing tab...and 36° @ 2500 rpm total timing.

However, now I can't idle below 1250 rpm and be in gear at 1000 rpm, and give it gas slightly uphill and let off without it stalling.

Think I need to pull the plugs and do a compression test now and see where things stand on that aspect...
 

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Did you hook the vacuum advance back up and then adjust the idle screw?
 
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Race it, Don't rice it!
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35 at 2500 is way too much. Something isn't right.
I feel like you may be confusing yourself on the dial on the timing gun.
When using a dial back gun, you'll set the gun at 12, then point the gun at the damper, pull the trigger on the gun and look for the line on the damper to show up with the flashes and turn the dist until the line on the damper aligns with the 0 on the tab. That lets the gun do the work.
Then set the guns dial to 36 and rack the throttle to 3500 and again, look for the line to be at 0 on the tab. If not, adjust the guns dial you watch the line on the damper either get closer or further away from the 0 on the tab. You need to turn the dial on the gun which ever way gets the line on the damper to 0. Close the throttle and the look at the dial on the gun. The dial indicates the advance at 3500 rpm. Always read the gun.....
To be honest, I hate dial back guns. I don't use them. I have only have two hands and two arms and the dial back guns almost require three.

The amount of advance is built into the dist weight system so it may be anywhere between 30 and 40 depending on the design. You do not MOVE the dist for the all in advance check. Simply rev it up till the advance stops advancing and adjust the gun to get the line on the damper to 0 on the tab and that reading is your total advance.


Things to note...
If you get the idle speed too fast, the dist will start adding advance and mess you up.
Sticking weights that won't return to home every time will mess you up.
Worn timing chains and dist drive gears will make the mark on the damper dance around.
Some guns are bad about not picking the spark and/Or picking sparks from other wires and that will mess you up.
 

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Discussion Starter · #28 ·
Did a compression test last night, (all spark plugs removed), and I'm pleased with the results this time around...

All within the 185-175 psi range, dry test...and the pressure doesn't drop, waited a few minutes in between.
Font Circle Auto part Parallel Number


I wonder what was causing the low readings the first time back in August ? (1 spark plug removed at a time, dry test) 🤨🧐🤷🏾‍♂️...
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Did this test and was going to do a leak down test after, to check for any valve, ring, exhaust, intake, or blown head gasket leaks, but I'm realizing I don't have an air compressor handy to use the double gauges at the moment...

Should I assume there is no such leaks because of the high readings and no pressure drop ?
 

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Discussion Starter · #29 ·
Spark plugs... Number 4 looks oily... But overall, do these look fouled out and in need of replacement ?
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This engine is worn out, the compression test shows that as do the spark plugs, they all are running too cold at best and some show oil fouling. The pressure distributions between cylinders are another sign of this.

At this point you have the answer in hand, leak down tests will only offer confirmation to what is already known.

Time to start saying your money for a fresher engine and if it’s backed by an automatic transmission figure on a replacement for that as well as old automatics behind fresh engines don’t last too long.

So you’re at a decision point where you need to look at your budget and transportation needs and determine what you can afford in finances and down time.

Bogie
 

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Discussion Starter · #31 ·
This engine is worn out, the compression test shows that as do the spark plugs, they all are running too cold at best and some show oil fouling. The pressure distributions between cylinders are another sign of this.

At this point you have the answer in hand, leak down tests will only offer confirmation to what is already known.

Time to start saying your money for a fresher engine and if it’s backed by an automatic transmission figure on a replacement for that as well as old automatics behind fresh engines don’t last too long.

So you’re at a decision point where you need to look at your budget and transportation needs and determine what you can afford in finances and down time.

Bogie
Worn engine ?

Which compression test results are you referring to ?

Current readings are the 175-185 ranges and those ranges are signs of a healthy sbc...
 

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The gauge didn't drop because there is a pressure check valve inside it preventing that.
Compression test, all you have right now, is all you got to go by and it's not a lot. Plugs pictures aren't good enough to tell anything other than you should replace them.
Are they black oily? Black and dry? Either way they are too far gone to reliably re use.
 

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Looking at the August 13th test which is a lot different from the Oct 11th test is this dry to wet or has it healed since August where Cylinder 7 at 105; cylinder 8 at 115?

A chain is only as strong as its weakest link.

You can pump some air in there and listen for where it leaks from. You don’t need a leak down tester to do that. Might be valves or rings. The crank will turn if not either held with a wrench or the stroke on the tested cylinders is a Bottom Center.

If the engine runs you can remove the rocker covers to observe these cylinders rocker motion relative to the others to get a feel for if the valves are being opened evenly compared to others as a way to see if it’s the cam lobes and lifters on these cylinders failing to open the valves very much that is causing the measured compression difference.

Bogie
 

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Discussion Starter · #34 ·
Looking at the August 13th test which is a lot different from the Oct 11th test is this dry to wet or has it healed since August where Cylinder 7 at 105; cylinder 8 at 115?

A chain is only as strong as its weakest link.

You can pump some air in there and listen for where it leaks from. You don’t need a leak down tester to do that. Might be valves or rings. The crank will turn if not either held with a wrench or the stroke on the tested cylinders is a Bottom Center.

If the engine runs you can remove the rocker covers to observe these cylinders rocker motion relative to the others to get a feel for if the valves are being opened evenly compared to others as a way to see if it’s the cam lobes and lifters on these cylinders failing to open the valves very much that is causing the measured compression difference.

Bogie
 

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Those gauges are intended to reference off 100psi of pressure going in the cylinder and the other gauge reads the percentage of leak down. This is with the piston at TDC to 20’ after where the highest ring/bore wear occurs against the highest pressure from the air/fuel.
I doesnt look like the compressor your using is capable of inputting 100psi so a guess is as good as it gets.
I don’t see anything major. Maybe normal wear but nothing sticks out.
with everything you’ve posted so far, I think you have a carb idle mixture problem and the adjustments to make it work even better are removing the compensation of other adjustments.
I’d advise you go back to 12 initial timing, all in at 3500rpm then work in the carb cleaning adjustments.
 
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