The Stovebolt Site Forums The Shop Area Engine Shop Possible Harmonic Balancer Problem

Message board members,

Has anyone heard of a harmonic balancer looking normal, but having the outer ring shifted on the rubber damper? I have a 73 model 250 inline 6 and after I bought it, it ran well, but could not be timed with the light. It actually appeared to be timed on cylinder 5 instead of cylinder 1.

I immediately looked for the hard solution. After making sure the distributer was in properly (using the timing mark on the damper on the compression stroke of cylinder 1), I pulled the front cover and looked for the timing gears to be a tooth off. The gears were fine, and even though the job was a pain, the new gaskets will probably help the engine stop leaking oil like a seive.

After putting everything back together, I got the engine to run well, but the timing mark still seems to be about 90 degrees off when checked with a light. I think the balancer must be out of whack, and that would account for the rotor not lining up where I expected. I had to stab the distributer a few times, moving the gear a tooth at a time until I got the engine to start.

Is this possible for the balance to be out of whack, or am I barking up the wrong tree?

Thanks for your help.

Yes, it is possible for the ballancer to have moved. An easy way to still use the harmonic ballancer is as follows; Remove all the spark plugs and break all of the insulation out of one and weld a bolt or anything that will stick out of the sparkplug down into the cylinder. Now screw this into the hole where the spark plug used to be [make sure the piston is at the bottom or close to it, now turn the engine over slowly in a clockwise direction till the piston contacts the bolt, make a mark on the harmonic ballancer where the TDC of the timing mark is, now turn the engine over slowly in a counter clockwise direction till the piston contacts the bolt and make a mark like you just did on the harmonic ballancer, now take a steel tape or some other way of measuring the distance between the marks, divide this distance in half and that is true TDC of the engine. Make this a heavy mark so you can see it with a timing light and time the engine accordingly. [I'm sure you will remove the bolt after the 2nd mark was made on the harmonic ballancer]
This will work if some one has installed the wrong front cover and the timing marks are not where they should be in relation to the crankshaft.
I hope this will be of some help.

Thanks for the info. I understood your response, but it seems to be more about a different pointer on the front cover instead of a messed up balancer. However, the cure given will certainly isolate the problem. Is it possible for a stock balancer to have the outer ring shift on the rubber damper?

Additionally, I'm thinking about building a custom ignition and fuel injection system for this engine. Does anyone know about harmonic balancers with magnetic triggers built into them? Will after market V8 units fit on the 6?

Thanks...

Yes, they do slip. No, you can't keep using it. Unless you have an outer pulley bolted onto the front it will fly off. I have lost two on my 292. I lost one, when I started it up and it just dropped on the ground. I lost another while I was driving along at about 65.
I have a half dozen from other vehicles laying around that have slipped. Sometimes they come in handy such as on the press.

I agree that if it has slipped, junk it. A good way to detect when this happens is to first paint a stripe across the front so you can see if it shifts.

Richard,
Thanks. I'll go find a new one before my new front seal becomes too used to the old one.