Timing Mark

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69signetv8

69signetv8

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Can't seem to time motor correctly. The damper's timing mark "is" at 0 @ TDC compression stroke however during timing with the light the mark must be 45-50 degrees off. "Connected to #1 plug of course". If I rotate the dist either direction trying to find the mark (of course the motor stalls out). Anyone know why I can't time it with a light?

The motor was rebuilt and I believe this is the correct damper. I have been timing by ear and vaccume getting about 18-19 max then leaving it.
Thanks
 
Longgone said:
Is the timing cover original? 45-50 degrees almost sounds like the timing tab/ scale might be on the wrong side? It`s just a guess, but will it time about right if the timing tab was in a 1:30 reading versus a 10:30 reading?
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Mines opp from what your saying.
It's kinda crazy.. its a 72 motor and I had the rad lower hose swapped to the pass side to match the pump/timing cover, (which means my mark is at 1:30). However I'm not really sure if the cover/damper was changed before I got my hands on it...If it was changed like your saying, wouldn't the 0 mark be @ 10:30 then rather then 1:30 ...otherwise my TDC would be at 10:30 and not 1:30??

Basiclly, Longgone my timing scale and damper line; both line up at TDC about your 1:30 but the light can't find it...unless something else is 180 out. I will find out tomorrow and find out where exactlly it is located......then what? Make a new TDC??
 
Weird. Did you use a piston stop to find/mark TDC?
 
daves66valiant said:
Weird. Did you use a piston stop to find/mark TDC?
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I think I did it right...I went to TDC 0 degree line scale and watched my #1 valves to ensure they were both closed (compression stroke), then put the tip of a screwdriver into #1 sparkplug hole to again ensure it was TDC. I then ensured my distributors drive slot was facing #1 along with the dist rotor itself....does that sound right to you? (what I did)...
 
That's how I usually do it but having the piston stop for a little more accurate measurement should pay off. The are really cheap and since you don't know the history of the dampener I would remark it. Hopefully the rubber on your dampener isn't going bad. Wish I could be more help. I know my old 273 had a timing tab on the passenger side. I put the tab on my 340 just so it looks like the original 273. Have you ever had issues with your timing light before or is it a dial back type? This is peculiar though.
 
daves66valiant said:
That's how I usually do it but having the piston stop for a little more accurate measurement should pay off. The are really cheap and since you don't know the history of the dampener I would remark it. Hopefully the rubber on your dampener isn't going bad. Wish I could be more help. I know my old 273 had a timing tab on the passenger side. I put the tab on my 340 just so it looks like the original 273. Have you ever had issues with your timing light before or is it a dial back type? This is peculiar though.
Click to expand...

I'll check it out. Thanks
 
OldVart said:
Do you have your vacuum advance hose disconnected and plugged Jimmy boy? Also, check to ensure the advance plate in the distributor isn't stuck.
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Hi Sid, I didn't think of that I'll have a look, thanks
 
You havn't got you #1 and #3 wires backwards and thinking you are on number 1. If the mark is at 0 and the piston is all the way up, having the plug wires switched would cause this.

Jack
 
The vaccuum not plugged adds up to about 20* depending on what you have your idle speed (RPM) set at when you're adjusting your timing. Depends on your distributor as well and what springs you have as to when all the timing comes in. I think mine is all in around 3000. Add all your timing events together and you would get 45-50*

Good point Coyote. That would be a simple oversight.

Let us know what happens.
 
Good points...wire "are" correct. I did plug my vaccume. I was wondering, if I have it in the wrong port though. I have a Holley and have the dist vac hooked up to the port above the idle screw (there no vac there until accel). The other for vac guage I have hooked up at the base where there's vac all the time.
My dist is fine...I even sucked on the vac inlet (sick man hay) it works well.

My 0 line on the damper was showing up on the pass side around 10:00, so I measured the damper 23" and div by 4...moved the new line to the right 5.75 inches..it's a little closer but the engine gets really boged tring to time even there.

When the motor was rebuilt, the mach put in a 340 cam, could that screw thing up and I can only time by ear now?

Thanks guys.
 
69signetv8 said:
Mines opp from what your saying.
It's kinda crazy.. its a 72 motor and I had the rad lower hose swapped to the pass side to match the pump/timing cover, (which means my mark is at 1:30). However I'm not really sure if the cover/damper was changed before I got my hands on it...If it was changed like your saying, wouldn't the 0 mark be @ 10:30 then rather then 1:30 ...otherwise my TDC would be at 10:30 and not 1:30??

Basiclly, Longgone my timing scale and damper line; both line up at TDC about your 1:30 but the light can't find it...unless something else is 180 out. I will find out tomorrow and find out where exactlly it is located......then what? Make a new TDC??
Click to expand...

Yeah,if the cover was swapped out the TDC would be at 10:30. I would start with making sure TDC is correct, dist. drive gear is in right, and the rotor points to #1 and plug wire corresponds. If all of those things are right, then create your own timing mark and start from there.
 
Checking the timing mark was one of the 1st things I did on my engine when I got it from the builder because I wanted to switch to the old style milodon hi-flo water pump to fit my radiator.. The engine came from Michigan so I had no way of really of asking the builder about the engine since it was origianlly built for somebody else. It was a well known shop in Michigan and the timing mark was spot on. Get a piston stop...you will not regret it.
Goodluck
 
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