Hi All,

I've just done an engine swap on a 24 chummy (both engines correct numbers for the mid-1924).

All went smoothly until I tried to start it. Its 12v and always has been in my ownership. With the new engine in, there is a horrible graunching/metallic grating noise unlike anything I've ever heard. The engine is sort of turning over but not well.

Before fitting the starter motor I took the cover off the back and cleaned everything up, and the aluminium cover over the bendix spring. I didn't take apart any of the mechanical parts, only cleaning.

Has anyone had this before or think of any reason this is happening? Standard engine swapped for standard engine should just work... I've done three engine swaps in as many days on three different cars, the only one of which hasn't worked is mine!

Many thanks,

Will

My car outside the Rising Sun pub on Cleeve Hill overlooking Bishops Cleeve and the Malvern Hills.


Borrowed engine in my car while mine undergoes maintenance.


Top Hat Saloon trials car and the Purple People Eater also undergoing engine swaps with Barry Clarke and Martin Eyre

Location: Bishops Cleeve

Is one of the starter motor housing fixing bolts touching the flywheel?

Good suggestion, I've checked it and it doesn't seem to be the problem. Thanks!

Location: Bishops Cleeve

I've just taken apart the bendix assembly and found that the rear most dog gear has snapped in half.



The break however doesn't look new and has been burred over over what I can only assume has been much use which it certainly hasn't had in the last three days.

Could this be the cause of the noise?

Cheers!

Location: Bishops Cleeve

Wil start it on the handle without the BS fitted and see if you still have the noise. Another thought when changing a BS starter, need to watch the location dowel doesn't drop into the bell housing that can make a noise if caught beneath the flywheel. Cheers Ian

Location: Bristol

The engine turns over normally on the handle with no hideous noises, I haven't tried to start it on the handle yet but will give it a go, the magneto sparks at ridiculously low revs - gave me a nip when I was cleaning it up!

Location dowel is still located. Good suggestion though, thanks Ian!

Location: Bishops Cleeve

It's not something simple like a worn ring gear on the flywheel of the new engine is it?

Location: NZ

Its not making any noises running without the starter attached, maybe a little rough but thats just a timing issue easily sorted. It therefore has to be the starter motor and the broken dog gear sounds like the obvious thing that is wrong.

The starter ring isn't new but its also not knackered. Did Austin have different flywheels with different numbers of teeth at any point?

Thanks!

Location: Bishops Cleeve

Hello Will,

It shouldn't be possible to have an odd toothed ring gear.
The gear should be on the clutch cover for all forward facing starter and the part number seems to have stayed unchanged until the rearward facing starter was fitted. With this change the ring moved onto the flywheel to suit the change of starter location. I think I'm right in saying for all of 24-32 the gear was actually machined into the clutch cover plate rather than a separate ring shrunk on, and fitting a new one means machining the cover to accept it. When I was looking at replacing a badly chewed gear it seemed very close to the mounting bolts, and I found a good S/H one instead. If the gear has been replaced before it could be possible that this has not ended up quite right and is causing a mesh problem, but i'd consider this very unlikely.

1924-1932 Gear machined on clutch cover Part BJ24 Herehttp://archive.a7ca.org/wp-content/uploads/PL_353D.pdf

Hope that helps.

Location: New Forest

Thank for all the suggestions,

I've now tried a "known to be working" starter motor, fitted as normal, and that is also making a horrendous grinding noise like a bad gear change.

I know how a BS starter should sound running on 12V and its nothing like this!

The engagement gear on the starter is not hitting the six mounting bolts holding the starter ring (clutch cover plate) to the flywheel.

The two mounting bolts holding the starter motor to the bell housing are not too long and therefore not touching the flywheel/starter ring.

The position of the spacing lug hole for locating the starter, along with the mounting hole positions are the same as the previous engine.

The mounting surface on the bell housing doesn't look as though its been machined at all in its life.

I can't see any newly graunched metal surfaces or any swarf anywhere, all looks normal.

I've tried looking into the motor as its fitted without the cover plate on the forward face of it to see if I can see whats going on, the gear looks as though its engaging and disengaging as normal.

The car push starts and drives as normal, so theres nothing fallen down into the bell housing causing the grinding noise.

I've tried raising the starter motor up with a piece of cardboard on each side to see if that helped, no difference.

I'm now going to try using a forward facing starter as fitted to the later 20s cars.

Does any one have any different suggestions?! Losing my mind a bit over this...

Cheers!

Location: Bishops Cleeve

Will, looks like you have covered most things so a last suggestion, the two bolts that hold the big rebound spring only just miss the starter casing, if you don't have the correct narrow head bolts or some slack in the bendix bushes it's very easy for contact to occur when you operate the starter. This can make the noise you describe. Ian M

I am still convinced your problem relates to the ring gear either being locally worn or the wrong type. Another thought have you checked the flywheel position relative to the crankcase i.e too far forward or back?

If you put the starter on another engine and it functions correctly the issue has to be with the flywheel.

Location: NZ

The replacement starter was fitted to my 1929 car and worked a treat, so I know the starter works, unless it broke like first one, the first time I put it on this engine. I've taken the starter off and spun it up on the battery and it doesn't make any terrible noises.

The bolts holding the bendix spring are the correct type with machined heads - good idea though!

The position of the flywheel relative to the holes on the crank case is the same as the first engine, so can't be a problem, the only thing I haven't done is to measure the diameter of the clutch cover plate and starter ring

Has anyone ever heard of a duff batch of clutch cover plates being made?

The engine was completely rebuilt by a reputable austin engine company several years ago and hasn't yet been run enough to have run in.

Thanks again!

Location: Bishops Cleeve

You could have the wrong starter ring fitted to the flywheel, the problem has to be related to the ring in some way, either worn, the wrong type, or fitted round the wrong way.

Location: NZ