Trouble Timing my 340

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Did you have a piece of slag in the plate slot somewhere.

Take the cap off and try to twist the rotor clockwise. If it doesn't move I'll bet there is something in the slot holding up the weight pins. It one of those things you MUST check before putting everything back together.
 
crackedback said:
Did you have a piece of slag in the plate slot somewhere.

Take the cap off and try to twist the rotor clockwise. If it doesn't move I'll bet there is something in the slot holding up the weight pins. It one of those things you MUST check before putting everything back together.
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I checked it when putting the plate back in. I had to touch one slot a bit to get smooth but good point about checking it now that will be easy.
 
If the valve adjustment aren't the problem, I look in to cam timing, like its retarded, you want it 2 - 3 degrees advance. That means pulling the front timing cover and balancer off.

Heck I be swapping cams while in there just so you know what cam it is for sure. No need to pull the intake manifold, lifters can be pulled out with a magnetic rod through the cylinder heads.

Do a cranking compression test on all 8 cylinders and report back. Its really not that big of a deal ,lol and you can see how the plug look. If one or more valves are off the seats, the compression test should show it as being low on compression, then you know which cylinders to back the rocker screws off

On my iron rockers the screws are all about the same height. Look to see if any screws heads seem too far in / low. Hopefully its just an open valve and its not burnt just yet
 
On my old 1973 Duster 340-4spd with 4.10's I ran 22 degrees intial and 36 degrees total all in by 2200 rpm. My 340 had the MP508 cam and 7" vacuum is normal for that cam.
 
dodge freak said:
Good info, maybe nothing is wrong
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I checked the rotor by hand and it does advance and retard smoothly, I just think the springs are soo light and with a high idle, its fully advanced when running. I know the exact cam, the box it came in is in the trunk with the old cam in it. My concern with the valves was the dancing vacuum needle. There is a bit a shake to it. I've been meaning to get compression and that is what I need to do next. I'm all over the place with this thing, thanks for keeping me focused and giving me the right things to check. Its also, nice to hear that 7" of vacuum is OK. What about idle? How low could you get that 340 and .508 cam to idle? 1050 is lowest I got so far and I'm pushing it there.
 
Think whats happening with the weights is once you start it and rev it to get it running smoothly, it hits 2,500 or so and once the weights swing out, they stay out at 1,000 rpm

If the motor starts without kicking back, I would just leave it alone - so long as it doesn't ping under load - the 4.30 gears should help out not lugging the motor down
 
Oh, my crane cam 226 / 230 cam shakes the vacuum needle gauge at idle as well, it pulls around 13 at 900 and idles in gear at 700

The way things are around here - one min red lights and traffic that slows down for green lights so they can stop for each red light, ah how the motor idles and runs at low rpm matters more then anything else.

1,200 idle speed is normal for hot street cars, for me that is too high but again those 4.30 gears will help out. Good mufflers are a must, IMO or everybody is going to looking at your car at each red light wondering why your engine is so loud
 
i just bought lighter advance springs for a buddys 68 barracuda. it comes with 2 springs. replace only the heavier of the 2 factory springs for street use or replace both springs for race use. i think it was around $10. and i get to keep the second spring for myself.
 
dodge freak said:
Do a cranking compression test on all 8 cylinders and report back. Its really not that big of a deal ,lol and you can see how the plug look. If one or more valves are off the seats, the compression test should show it as being low on compression, then you know which cylinders to back the rocker screws off

On my iron rockers the screws are all about the same height. Look to see if any screws heads seem too far in / low. Hopefully its just an open valve and its not burnt just yet
Click to expand...

Finally got the compression test done. Here are the numbers ftom 1 through 8: 129,125,130,149,140,140,150,145. Cylinders 1 & 2 got a spray of PB and a 2nd test. 134 and 141 respectively.
 
seems ok, the number 1 and 3 cylinders you should back off the adjusters a little and see if it brings the compression up, number 2 shot up with oil but number 1 did not and number 3 you did nothing
 
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