Here's a new one

[LuckyPenny]

after rebuilding my Carb and replacing the points/plugs/wires, I set out to retune and addjust and set up for the coming year of fun on the water. The engine ran so rough and missed so badly that it was impossible to gain much headway. My frustration level was max'ed and I was ready to take a 12ga to it and put it out of its misery. <br /><br />Then as a last resort I started again, tore the carb down and redid the rebuild (no problems found) then I check all the wires (no problems found) then the points, coil and condenser (no problems found) So I went back and tried to static tune the engine. Rotated the engine to TDC, but where was my paint mark on the damper? Then I noticed that the no1 tower on the distr. was pointed the wrong way. So I did a bit of checking. THERE WERE TWO TIMING MARKS ON THE DAMPER 120 DEGREE'S OFF FROM EACH OTHER. During the initial static set up I assumed that the timing mark I had marked was for the No1 cyl.<br /><br />Has anyone else ever run into two timing marks on the damper? What could the possible reason be for them?

 

[Don S]

Re: Here's a new one

What engine???????????

 

[Bondo]

Re: Here's a new one

Has anyone else ever run into two timing marks on the damper? What could the possible reason be for them?

Sure....................<br /><br />The Macks I work on Need 3 marks, 1 every 120*s......<br />They're for Timing the Valves,+ Injection Timing............

 

[achris]

Re: Here's a new one

would it run at all, 120 degrees off?

 

[Laddies]

Re: Here's a new one

the marks could be for a counter rotation engine, but I not seen them except on V/8s

 

[Don S]

Re: Here's a new one

I'm with achris, I doubt the engine would even run 120° out. But I know some Ford V8's had degree marks Before TDC and After TDC on the dampner. But until he lets us in on what engine he has, who knows what the problem is.

 

[LuckyPenny]

Re: Here's a new one

sORRY about the ommision. It is a chevy 350 (1977) Like I said it did start (eventually) but ran so rough with the lowest RPM to keep from stalling at 1700 so I was not able to get a timing light on it.

 

[Don S]

Re: Here's a new one

There is only supposed to be 1 mark (Groove) in the dampner.<br />You need to get #1 piston up on TDC on the compression stroke and see which line lines up with the pointer. If there is more than one line, I'm thinking maybe the dampner is bad and the outer section is slipping which is why the mark may keep getting moving.

 

[LuckyPenny]

Re: Here's a new one

The mark on the damper is not slipping. There are two grooves on the damper. The correct one has been determined and the engines runs very well thank you. My question is why are there two and why exactly 120 degrees apart.

 

[DHPMARINE]

Re: Here's a new one

thats like asking why dwell angle increases as point gap decreases.And the reverse.I don't know why you have 2 marks on your pulley but now you know which one to use.<br /><br />As to running 120 degrees out... <br />3.0 Mercs will try when one off at the cap.All the way around.<br /><br />And that's 4 cylinders.90 degrees.<br /><br />DHP

 

[Don S]

Re: Here's a new one

Since they only come from GM with one timing groove, you are going to have to settle with guesses as to why a previous owner or previos mechanic put a second groove in the dampner. Unless you can find that guy to find out, you will never know for sure.<br />Some possibilities are the dampner is for a different model engine V6, possibly a 327, counter rotating........ I never really set down and compared all of them.

 

[qystan]

Re: Here's a new one

There is a second mark on my 1989 5.7 and its 120 deg ahead. It is only a notch at the edge of the damper. The TDC mark is a groove all the way across the damper.<br /><br />Reason for the second mark.......to mess up Luckypenny and all unsuspecting owners........ <br /><br />Happy new year to all.

 

[trog100]

Re: Here's a new one

"thats like asking why dwell angle increases as point gap decreases.And the reverse."<br /><br />i could tell u in a couple of sentences if u really want to know.. ??<br /><br />trog100

 

[Rick Byers]

Re: Here's a new one

Chevy/ Ford and some European Manufactures put the second notch on the Balancer for timing the engine with a magnetic timing probe used by the dealers and some high tech shops like the one I work at. Usually the first mark to roll up when rotating the motor is the the one that is for magnetic timing. The second one is for timing with a light. Hope this helps clear up the mystery. Rick