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Discussion Starter #1
The trigger wheel for my crankshaft was worn and could turn to and fro a few degrees. I am guessing like 30* It was in the retarded position when I removed it so this could be why my car never has detonation even with a chip and regular gas, lol. I suspect this happened from the time I used that 1 pc underdrive crank damper that wouldnt line up with the rest of the belts. I "shimmed" it and created a gap between the damper and the trigger wheel that would allow it to vibrate. I then went back to a stock damper and I guess it has been sandwiched in place in the retarded position for years. I am glad I went inside the motor to pull the heads for a little "cleaning." The timing components look great. I think I am going to reuse them this go around. Has anyone else ran into problems with trigger wheels, cast or stamped?

I also found a freeze plug rolling around inside the LH head. I think I am going to get the machine shop to remove it in case it is reducing coolant flow. Is there anything I should get the machine shop to do beside check for cracks, flatness, 3 angle valve job and valve seals? Thanks in advance.
 

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Mark motors are notorious for actually cracking or exploding trigger wheels, that's why I was told if I ever go underdrive pulleys to only use a sfi smaller diameter balancer rather than the piggy backs that I had on my 2v due to increased weight and vibrations potentially causing the trigger wheel to detonate or even damage to the oil pump or front main bearing.
 

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Discussion Starter #3
Wow thats crazy. I had never heard that. I got the bowls in the heads cleaned up some and ready to go to the machine shop today.
 

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The newer trigger wheels are stamped, not cast. They are much more reliable, get the newer style stamped one when you rebuild it.

Pete
 

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West Virginia Chapter Director /, MA Drag Race Te
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Yep

I broke one a couple years ago right after running at the track. Came down the entrance ramp on to the highway and it looked like Christmas. Everything shut down and I had enough lights on the dash to look like santa was coming in LOL!

The trigger wheel, once I got it pulled down had broken apart in 3 large pieces and fell in the front of the oil pan. Luckily it shut down quickly. Replaced it and never had anymore problems with that.

Not something that you hear much of for the most part though.
 

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Discussion Starter #7
I am picking up my new trigger wheel today...if I made the order deadline yesterday. The one I damaged was the stamped steel one that came in my PI engine. I cant wait to get my stuff zeroed back out and to try out these "cleaned up" heads. Thanks for the replies. I never realized there were so many problems with the cast ones.
 

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Discussion Starter #9
I already had a stamped gear in my engine stock (its a 02 PI, even though the tags and dates on it show 00). Now that you mention it though, the crank sprocket does look like it has a thicker snout. I never thought about this. I still dont know why that crank damper pulls down so far though. I am going to stay stock this time. Also on a side note...I didnt make the deadline yesterday so 1 more day and I'll have a new trigger wheel. I also dropped the heads off today.

Does anyone know how a freeze plug would be rolling around in my head if I have never messed with the freeze plugs on that side before? Did this happen at the factory? They said they would do their best to get it out of there, lol.
 
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