The Stovebolt Site Forums The Shop Area The Electrical Bay Engine timing 180 degrees out and it runs

I have purchased a 1969 C10 and have started restoration. The latest problem I have found is the timing mark is 180 out. The truck starts, idles and accelerates pretty good so I am confused on how the timing mark can be so far off and still run. Will the truck run with timing 180 out? Can the pulley be mounted wrong. Any help on what do I need to do to fix this would be appreciated.
Pete

OK- - - -how about a few more details? For starters, which engine are you working on? A 69 C-10 can have at least three V8's and a couple of 6 cylinders as original equipment. Six or V8? Since all of those engines have timing marks on the front of the engine, the most obvious guess would be a slipped outer ring on the harmonic balancer. If the timing marks on a good-condition damper ring are 180 degrees away from the mark on the timing cover when the #1 cylinder fires, there's no way the engine can run. On either a Chevy six or a V8, regardless of displacement, it might be possible to make an engine run with the timing marks 20 or 30 degrees of crankshaft rotation out of place, advanced or retarded, but that's about the maximum "out of time" the engine will tolerate.

There is a precise way to determine if the timing marks and the pistons are in synch, but very few, if any people on the Stovebolt forum are willing to follow the steps necessary to get an accurate check. Drop me a PM if you want some details.
Jerry

Pete, you better rethink this. You better be more clear as to what you are telling us. What timing mark? How is this timing mark 180 out? Jerry is assuming you mean the balancer marks and pointer, and I would assume that also........... but I have learned that nothing can be assumed on an initial posters post.

NO, the balancer can not be put on wrong, it's keyed to the crank.

SO:
1. What motor?
2. What "timing marks"? Make sure you are not talking about home made marks or the distributor rotor or some other thing.
3. How are you interpreting 180 out?

It is a 230 or 250 6 cylinder still haven't narrowed it down to which one. My bore scope is not working so can't look at the top of the pistons. I was of the same opinion Jerry, I have had 8 cylinder engines sputter but not run when they were 180 out but don't have any experience with a 6 cylinder 180 out. The item with the timing mark does not look like a typical harmonic balancer It is a heavy duty two belt pulley with a grove cut in the edge of the pulley. Could I be mistaken on this mark as TDC I know how to find TDC on the Engine but haven't gone down that path yet.

I am using a timing light and the slot on the pulley is 180 degrees out when number one fires. I don't see any other marks on the pulley.

Funny stuff. I had a 318 in an old truck jump time. I pulled out the distributor and turned it 180 dropped it in and got it started. But what i think you have is that the distributor is not installed right, for what ever reason? And that the wire order on the cap was arranged to compensate for the wrongly inserted distributor. Probably easily fixed? At least i would think if you know how to set it up correctly..if not, ask.

You would have a 250 if stock. The stock harmonic balancer does have a factory groove cut on the edge. That is to align with a saw tooth "pointer plate" attached to the timing cover. If the pointer plate it mounted correctly.
I think Glenn has it figured out. Balancer 180 out, dizzy 180 out and wired per firing order.

Get your engine to TDC on compression stroke and remove the distributor cap. See where the rotor is pointing. Either wire from there or lift distributor and turn the rotor to line up where it should.🛠

That will be my next step. I will do that and see where the balancer is at. I feel the balancer has spun and the key way is no longer where it should be. Who knows what has happened in the last 51 years.

It can't slip with a keyway. It can't have slipped exactly 180 with no key. The Dizzy is screwed up. I don't know what putting the timing gear on wrong would do or if it could be done and compensated for. You will figure it out by removing dizzy and set it back in with no.1 at TDC on compression.

Keys and woodruffs can shear and do, now and then.

Try your timing light on each wire and see where it flashes on the marks.

Dumb question, but you are putting the timing light on #1 plug wire? Right?

Actually, that is a very good question. Holy Guacamole!!!!!!!!!

One more time: GET A TOP DEAD CENTER WHISTLE. Very cheap and goof proof for the hobbiest or ones without a lot tools/experience. Do a "tdc whistle" search and watch the video on how easy and accurate one is.

Your thumb is always with you. May the "Force" be with your no. 1 cylinder.

Yes I am putting the timing light on plug wire #1. Not my first rodeo. Will do more research next weekend. after I find TDC and position of distributor will know more. May have to pull harmonic balancer and re-key to align timing mark to TDC.

The comments and suggestions are not meant to disrespect. A thorough diagnosis always starts with the basics. We don't know what anyone has missed. Experienced or not. It should be fairly easy to see if keyway in balancer is matched with keyway on crank. flashlight, mirror, whatever. As I said before if it slipped or sheared key, it would not slip exactly 180 deg. The odds are 360 to 1. Not counting the "minutes". That would be 21,600 to 1. Good luck next weekend.
Be sure and come back and tell us what you find is wrong.

You are not 180 degrees out, your marks are off. Rotate engine with plugs out, when number one pushes out air, that is TDC for number one.

Ed

I believe some of the vans had the timing index plate located in a different location on the front cover and you connected your timing light to the # 2 plug wire. At least that is what the 63 service manual says. Could you have one of those engines or at least the front cover?

250's have the fan belt grooves machined into the outer ring of the balancer. The load of driving accessories such as the water pump, alternator, power steering, air conditioner, etc. can cause the rubber bonding between the hub and the balance ring to slip. Pull the valve cover, watch the #6 cylinder valves as you turn the engine until they're "rocking" (exhaust closing and intake opening) and see where the timing mark and the distributor rotor is pointing. The dizzy should be pointing at the #1 plug wire (not #6) and the timing mark should be somewhere close to zero. If the timing marks don't align with the rotor pointing to the #1 plug wire, change the balancer.
Jerry

I chased down the timing and it appears the harmonic balancer has spun on the rubber bonding and the balancer will need to be changed. The key way is still in the correct position but the timing mark on the outside of the pulley is way off from where it should be.
Pete

Good Job Pete.