Timing Advance Issues

I had the vacuum line disconnected and plugged at idle. This is what I read to do on the forums. At 650 rpms it holds steady at 20 deg. Although like I said I will go home and Mark the timing line with paint so I'm 100% sure
 
Oops, I misunderstood. I'm not sure what the vacuum advace would be reading. In theory it should be zero at idle. I can check when I get home. But the line wasn't connected so it shouldn't have had anything to do with what the timing is reading at idle.
 
Don't worry about the dizzy vacuum advance for now.

Getting a reading on the vacuum the engine is producing. The link I posted on the first page and videos will explain everything.
 
The bottom line on timing is these IH engines like some advance. What I do is advance the spark until it starts to ping on regular under load, then back off a deg or 2. When towing I run premium.

But first things first. Paint the line and tell us what you've got.
 
Is there a chance that if it has an rv cam that might have something to do with it? A friend of mine mentioned that after listening to it and playing with the timing a little bit a couple weeks ago.

I wouldnt know an rv cam if it hit me in the head...
 
A rv cam just means an aftermarket cam designed for a little more low end power. They are barely bigger than factory and don't really sound different.

It is possible the timing gears (cam/crank) are not aligned correctly, but not likely.
 
Getting the vacuum reading at idle is a good idea. What's the elevation where you live? Looking to see what tower location your rotor is under when #8 piston is at the top on the compression stroke is also well worth doing if you still see 20 degs after painting your Mark. Just know that #8 will be at the top twice. Once on intake and once on exhaust/compression. You will be able to discern compression by the air escaping from the vacant #8 spark plug hole as the piston comes up. The timing Mark should also be very close to zero then. Might not be precisely on zero, but close. If the rotor isn't under #8, you could then rotate your plug wires one position to bring your timing in line.
 
heston 79 said:
I was thinking about what you said Scout boy74.

The firing order is 8-4-6-2-3-7-5-1.
Click to expand...

The correct firing order for the IH sv-8 engines is 1-8-4-3-6-5-7-2.
Don't just take my word for it, it is cast into the intake manifold right in front of the carburetor.
Attach your timing light to #8 cylinder.
Distributor rotates clockwise.
Good luck
 
This afternoon I marked my timing line with white paint and confirmed it is still showing 20 deg, just off the edge of the indicator when I'm at idle with the engine warmed up off the number 8 cyl.

Before that I pulled the #8 plug, stuffed a wad of paper towel in there. I confirmed the rotor was pointing at the #8 cylinder wire when it ejected confirming it is hitting on the compression stroke.
 
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So all that being said I still don't know what to make of the timing being 20 btdc... I don't even need to fix it necessarily. I'd just like to know why it is so far from what seems normal with these engines...
 
Scoutboy74

here is a pic of my distributor. It has plenty of room to rotate in either direction...
 

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It looks to me like you have little if any room to rotate the distributor clockwise from the position shown in the pic. That direction would retard the timing from 20 btdc to a lower, more normal number, but only if it can be moved that way. To me it looks like all you can do is advance the timing further by rotating ccw.
 
Many times an engine that is laboring for various reasons will run better will run better with more timing. Lean being most likely.
I guess you have had a vacuum gauge on it at some point? If not, do so and see if it is stable.

A point on plug wire location. #8 can be any cap location you chose so long as the #8 post is inline with the rotor and #8 cylinder is on tdc of it's compression stroke. The dizzy has no preference. From #8 wire tower install the remaining wires in the clock wise direction according to the fifing order.
 
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As I retard the timing it begins to run terrible and starts cutting out. Should I retard the timing all the way to 5 and try to turn up the idle to make up for it?
 
I will test the vacuum later this week. Hopefully tomorrow. I will also take a closer look at how much room is in there to move the distributor. There is definitely room in both directions though, even if the pic doesn't really show it.
 
A drop in engine speed is normal when the timing is retarded, just as the opposite is true when advance is added. Timing adjustments require idle speed adjustments.
 
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