Lazeum Posted July 22, 2012 Share Posted July 22, 2012 (edited) Something is not working as it should on my car. Measuring ignition at idle gives me nearly 40° where the engine runs best. Anything below 30° and the engine runs really bad. The setup: - bottom end rebuilt by myself, F54 with flat tops, new pistons, new rings, new haed gasket (Felpro), etc. Quench gap is set at 0.8mm (0.032") - head is P79 done by Braap with Rebello cam & surrounding components - 3x 40DCOE tuned with a wideband - Ignition is done with Accel coil + Mallory Unilite (I just fried my Hyfire CDI 6AL box which is now out of the car - could it be related?) - The car runs great, pulls great, idle is solid, acceleration is smooth with no misfire or what so ever . Timing advance is set to 16-18° which should give me advance at idle around 14-16° & total timing around 34°. Before the rebuild, the engine was also set this way, measurement with timing light at that time was providing me expected results at idle around 16°, now it does not. - When I did install the part, I wasn't able to get the 11:45 position on the squill shaft the way it should work according to the FSM. So I set it up randomly, I just made sure cable for spark plug #1 was right in front of dizzy finger at TDC on compression stroke. So I should be good with timing. When Cyl #1 is in compression at TDC, I've got a good spark (which I have since engine runs good). - Chain install was done while engine was on the stand with the 2 bright marks installed the way they should. So I should be ok as well regarding this point. - Cam timing hasn't been done super precisely, so far it is set at hole #2 on cam sprocket (with notches exactly in front of each other). Bottom line: nothing is really wrong with my engine but measurements done with several timing lights (static & with advance knob) are all giving me irrelevant data so it is difficult to know where I am with timing. How can the engine runs good with 40° at idle at total timing around 56°? Something does not make sense to me and don't understand why! Please help!  Edited July 22, 2012 by Lazeum Quote Link to comment Share on other sites More sharing options...
Lazeum Posted July 22, 2012 Author Share Posted July 22, 2012 (edited) Thinking twice about my issue. I'm wondering if it isn't my crank damper going bad that would have slipped getting an wrong offset. Each time I start the engine, I've got a serious squeal noise coming from the alternator belt, could it be the damper? I've always though it was the alternator, maybe it isn't. The best way to check while everything still on the engine would be to check 0° mark at TDC by measuring piston position directly. I'll do it next weekend. It might be time to dump stock damper & get a new one (why not going with fluid damper then?) Edited July 22, 2012 by Lazeum Quote Link to comment Share on other sites More sharing options...
didier Posted July 22, 2012 Share Posted July 22, 2012 Yes, you should go to fluid damper, it's a safe solution for high revs, but even if your actual damper slipped, your timing with the crank gear is still in place, with 56° your engine would knock or stop ! Quote Link to comment Share on other sites More sharing options...
Lazeum Posted July 29, 2012 Author Share Posted July 29, 2012 (edited) I just came back from my investigations for timing. 1- the TDC is not where the 0° mark is which makes total sense. I stuck a rod in spark plug hole #1, when 0° mark is in front of indicator, piston is not at TDC. It happens before which makes sense since idle timing is measure at 45°. So TDC is most likely 30° before 0° mark. 2- Pulley is in good shape. No sign of rubber being torn apart. I put it in a vice, locked the hub with 2 bolts and I wasn't able to make the pulley move. I've tried as strong as I could. 3- 0° mark seems actually in front of the cover indicator when the notch for pulley cotter pin in vertical. It is a very gross adjustment since I haven't measure precisely. I've always though TCD on piston #1 = Vertical cotter pin groove. So I don't understand what is happening. I just know the engine is running great and I can't measure timing properly. So I guess I'll leave it alone for now (I'm going to Megajolt anyway by the end of the year) It could be wrong pulley vs. indicator, damaged pulley (I've put paint marks on the pulley to control if hub rotates back to the outer piece). It is a crazy idea but I'm wondering if my top end wouldn't be out vs. bottom end. I can't see however how the engine would run that good with such deviation. I would need to check cam timing but I first need to get exact TDC position. Edited July 29, 2012 by Lazeum Quote Link to comment Share on other sites More sharing options...
Lazeum Posted August 19, 2012 Author Share Posted August 19, 2012 (edited) issue is still there... I've made a tool to get accurate TDC position. It is an old spark plug, destroyed, drilled, tapped with M8 rod inserted with locknut milled at the end. I found out TDC is actually exactly at the mark on my damper. So the damper is fine. I've also disassembled it, it is also fine, there no rotation motion or what so ever between the hub and the outer pulley. I went back for a trip yesterday with the Z. it is running strong but timing is still at 40°- 45° at idle. It makes no sense!!!!!!! I've checked it with 2 different timing lights; one with an advance knob & one without adjustment. Both give the same result! What can cause such results???? bad timing between bottom end & cam? compatibility issue between spark cables & timing lights? The way dizzy handle sparks? bad timing lights? bad handling from my side (how can I mess up with timing lights measurements? - I've tried induction pick up both ways also)? Bad reading from me (but indicator is 2 inches away for TDC mark)? I've tried to reduce timing, it isn't possible; Anything below 35° makes the engine runs really bad. So I'm at the sweet spot for idle & total advance is ok since I've got plenty of power & smooth engine operation at high rpm. Something is not right, I'd like to find out what... I would be the first one to run a L6 with 40° at idle & 58-60° total??? I'll drop the current setup for Megajolt in the near future, I need to make sure everything is right before changing everything for a new setup that would need some debugging. ========================= on a side note, I've also tried for what is worth to measure timing at idle while engine is not running. I've setup engine at TDC on cyl #1 on compression. Then, I've measured angle on dizzy cap & dizzy position back to a common mark. I come to the same conclusion as timing lights, I'm way out.... I've measured arc length & radii to come up with angle: -10° at cap & +17° at dizzy. It makes a total angle of 27°. Timing is then around 54° since dizzy is twice slower than crank. There're errors in my measurement for sure but I'm nowhere near 15° timing at idle... Edited August 19, 2012 by Lazeum Quote Link to comment Share on other sites More sharing options...
madkaw Posted August 19, 2012 Share Posted August 19, 2012 (edited) Are you sure #1 plug wire is lined up with the dizzy cap number 1? Does the rotor line up with number 1 at tdc? It almost sounds like you are one tooth off, but compensated by having your wires one plug off! Weird all the same! Looking at your picture- if that rotor is sitting where it is at 1 TDC, then it is wrong. The rotor should between the 9&10 oclock Edited August 19, 2012 by madkaw Quote Link to comment Share on other sites More sharing options...
Lazeum Posted August 19, 2012 Author Share Posted August 19, 2012 (edited) I set up rotor to be close to whatever wire I could. I then plug the first wire to be #1, the remaining wires are set according to firing order. The picture you see of the rotor is as it is at TDC. It is not as the book says but engine runs well. I think you're pointing toward something good; I should set everything up perfectly. It would remove one unknown item from my issue list... Edited August 19, 2012 by Lazeum Quote Link to comment Share on other sites More sharing options...
madkaw Posted August 19, 2012 Share Posted August 19, 2012 Your dizzy cap should have a mark next to number 1 cylinder so you know where to set up rotor . Your almost 180 degrees out by that pic. Sure you were on compression stroke of number 1? Quote Link to comment Share on other sites More sharing options...
Lazeum Posted August 19, 2012 Author Share Posted August 19, 2012 My dizzy is not a stock unit so there's no mark on it. It is a Mallory Unilite. Ive moved the squill shaft since our last post but I did not have the chance to start the car. We'll see if that changes anything. The offset between the rotor & the cap seems to be similar compared to previous setup. Unfortunately, I will be able to try it only next weekend... Regarding compression stroke, I'm 100% positive that bottom end is correctly located. For the head & cam timing, it is only visual but cam lobes position on cylinder #1 are almost symmetrical. if it would be off because of the chain, it would be visible I believe so I discarded this hypothesis. and for rotor orientation, I don't think it should be a factor. What should matter is timing between rotor and sparks/cylinders. The location of the rotor at TDC should not matter as long as spark plug wire #1 is at the correct position. I believe FSM only states squill shaft position to make sure timing would not be one tooth off. My engine is running strong & I have lot of room to play with timing, it would not be the case if I was way off. Since I don't get what is happening I might not think right. I'll report back my findings. if there's anything I should consider, I'll be happy to try Thanks! Quote Link to comment Share on other sites More sharing options...
NewZed Posted August 19, 2012 Share Posted August 19, 2012 Maybe your timing light is triggering off of a different plug wire. You might line up the light and sensor on the Unilite for sparking cylinder #1 and see where the timing mark is, engine not turning, just to feel comfortable that the engine is not really firing the #1 plug 50 degrees before TDC. You should be able to get within a few degrees I would think, if you know when the Unilite breaks the coil circuit (trailing or leading, etc.). If you do that and things are close, then you can focus on getting the timing light to read the right wire. If you do that and things are still way off then you can continue being confused. Quote Link to comment Share on other sites More sharing options...
Lazeum Posted August 20, 2012 Author Share Posted August 20, 2012 That's a good idea I did not think about. I'll give it a shot Quote Link to comment Share on other sites More sharing options...
2eighTZ4me Posted July 1, 2013 Share Posted July 1, 2013 Holy crap!! I thought I was the only one with this problem. I just stumbled across this looking for something else. When my MSD 6AL box took a dirt nap (for the 2nd time...doggone POS) - I removed it and ran straight coil. 50 degrees timing was what I was seeing as well. Got the MSD box back and put it all back the way it was - timing right back down to normal. Everyone I have asked has been speechless at this oddity. So - tomorrow, I plan to pull the MSD box out of the loop again and run straight coil and see what the timing does. I see this thread is nearly a year old - so - were you able to find any closure to your situation? I'll let you know what my test results are. Quote Link to comment Share on other sites More sharing options...
Lazeum Posted July 1, 2013 Author Share Posted July 1, 2013 (edited) I have never been able to prove for sure what went wrong on my setup... MSD or Mallory box, with or without, did not change anything for me. Most likely the root cause was spark plug wire style. I've tried many timing lights with & without advance adjustment, brands, they came out with same results. In the manual of my timing light (Gunson brand) that say wires could cause false reading. Since, I've switched my dizzy for a distributorless ignition system and I cannot be happier: torque, emissions, power, engine smoothness. Everything is now better. I've changed spark plug wires in the process and my timing light works now as it should. Edited July 1, 2013 by Lazeum Quote Link to comment Share on other sites More sharing options...
SlowRob Posted July 17, 2013 Share Posted July 17, 2013 I had the same issue, running an old Allison optical trigger in the distributor. It turned out the trigger wheel had mis-located, throwing the timing out of whack. Curiously, mine ran fine with 50 degrees advance, and also fine when set properly. Quote Link to comment Share on other sites More sharing options...
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