Bendix kicking out prematurely?

Topics Last Day Last Week Tree View    Getting Started Formatting Troubleshooting Program Credits    New Messages Keyword Search Contact Moderators Edit Profile Administration
Model T Ford Forum: Forum 2016: Bendix kicking out prematurely?
Top of pagePrevious messageNext messageBottom of page Link to this message  By Tom Melham on Saturday, July 02, 2016 - 12:22 pm:

Greetings all from a new user. I'm commissioning a fully rebuilt engine in my 1926 Coupe, and having lots of trouble getting it started. I believe the electrical system and fuel lines are okay. The engine is tight, so I have to use the starter. The starter turns the motor over okay, but on the very first "chuff" of a cylinder firing the bendix disengages and winds down with a loud whine. (It's not backfiring - the spark is fully retarded and the timing is correctly set, I believe.) I feel that if I could somehow sustain the cranking action, I'd get the thing going.

Is this just par for the course with a new engine? Has anyone got experience with this kind of problem?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ted Dumas on Saturday, July 02, 2016 - 12:31 pm:

It sounds to me like either the spark is advanced or the cylinders are miswired or maybe both. Take a fresh look at your timing and wiring.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Fred Miller, Sequim WA on Saturday, July 02, 2016 - 01:51 pm:

Ted is right about the timing and wiring diagnosis. I personally have experienced this with lots of engines over the years. The key here is that it only seems to happen after there has been work on the engines. I also had the same issue that has only happened one time with the bendix that went bad.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Dan Treace, North FL on Saturday, July 02, 2016 - 02:02 pm:

Tom

That is normal action and sounds of the Bendix gear spinning back from the flywheel gear. The starter motor Bendix turns the engine at 150 rpm's when engaged.

When the engine fires, even briefly, the engine is then turning faster than the Bendix gear, and its then disengaged from the flywheel gear, and whinning its backward action as it free wheels.

Typical famous Model T electric starting try sounds :-)


Top of pagePrevious messageNext messageBottom of page Link to this message  By Norman T. Kling on Saturday, July 02, 2016 - 03:30 pm:

Try pulling the T to start it. If the engine runs smoothly, there is something wrong with the starter, but I don't think it's the starter. I think something else is causing the engine to misfire. So it just hits on one cylinder and the starter disengages, which is the way it should. Then the engine stops running. Perhaps give it some more throttle and a little richer fuel mixture. However, if it is an ignition problem it still might misfire.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Charlie B actually in Toms River N.J. on Saturday, July 02, 2016 - 03:46 pm:

Dan sounds closest to correct by me. Providing the timing/spark settings are OK. If it doesn't run try enriching the carb needle a bit. The loud whine is an indication the bendix is being spun out of the flywheel.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Harold Schwendeman - Sumner,WA on Saturday, July 02, 2016 - 05:59 pm:

Dan & Norm - Pure "conjecture" on my part, but I'm wondering,...

Because Fred mentioned that he has also had this happen, but only on engines that have been "worked on", and because Tom Melham said that the engine is "tight" because it's just been rebuilt, I'm thinking that the "tight engine" thing is sort of the "common denominator" here:

My "theory" is that there is really nothing wrong with your engine, starter, bendix or anything Tom. I think what might be happening is that when your "tight" engine first fires, it fires hard enough to kick the bendix out, but not quite hard enough to start. I think if it were me, I'd tow the car to get the engine started, and after it runs long enough to loosen up a bit, the starter will hopefully thereafter, crank the engine hard enough (fast enough) to not only kick the bendix out and get the first cylinder to fire, but also to get the second, third, etc to fire and the engine to start.

Dan Trace,....you being our club's "tech advisor", what do you think,....does this make sense? FWIW,......harold

P.S. Also wouldn't hurt to check battery condition (charge) tight and clean terminals, good ground, etc, to be sure starter is cranking as fast as possible.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Tom Melham on Saturday, July 02, 2016 - 07:44 pm:

Thank you all so much for your advice. The consensus was to look again at the electrical system, and so I did - sure enough, coil number 1 wasn't operating well at all. The top (bass) piece of the points seemed a little bent and twisted - after bending this back in to approximately the right shape, and establishing the correct gap, we managed to get the engine running. The starter is much more persistent now. Interesting how these things are connected.

My newly rebuilt engine (I mean completely rebuilt) has now run for 7 minutes - for the first time in 30+ years. And I am very happy to mark my return to active T ownership.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mark Strange - Hillsboro, MO on Saturday, July 02, 2016 - 08:12 pm:

Glad you were able to fix it, congratulations and welcome! :-)


Top of pagePrevious messageNext messageBottom of page Link to this message  By Doug Wilson - Omaha NE on Saturday, July 02, 2016 - 08:32 pm:

I had a blown head gasket and did not know it. Check the compression. The Bendix getting kicked out all of the time was the major indicator I had a problem.


Add a Message


This is a private posting area. Only registered users and moderators may post messages here.
Username:  
Password:

Topics Last Day Last Week Tree View    Getting Started Formatting Troubleshooting Program Credits    New Messages Keyword Search Contact Moderators Edit Profile Administration