1927/8 Chassis Rail Tweak - Is this common?

[Hedd_Jones]

Having been messing with the chassis of what was a GE cup recently, I discovered that the offside chassis rail, bottom inner flange has been kinked in the vicinity of the oil filler (mag engine).

If this kink wasnt there, the engine wouldnt sit properly on the chassis as the underside of the crankcase would foul, stopping the engine mounts touch.

Ive ever noticed this on vintage chassis before, but I dont have a lot of Mag engine knowledge. Is this a common?.

This chassis is late 27, early 1928 according to the chassis number, and has the longer rails that oversail the springs, which are not on the later short chassis.

Links to photos

http://www.steamscenes.org.uk/tti/20/008_1878.jpg

http://www.steamscenes.org.uk/tti/20/008_1879.jpg

[Parazine]

Yep, this is common. My '27 chummy had the kink to allow the crankcase to sit properly and I think my '28 chummy from 30 years ago also had it. When I adapted the later chassis rails to fit my '26 Top Hat project, I had to add the kink as the rails came from a thirties car and didn't have it. Without the kink, the mag crankcase won't bolt down. I think the factory had a tool to add the right shape - I did it with some heat and a big hammer and dolly....

[Ruairidh Dunford]

I am changing gearboxes today and checked, my 1928 Chummy (original chassis and crankcase), does not have this.

This car is one of the last magneto engined Sevens, Chassis 60***.



   

   

[Reckless Rat]

Perhaps it's one of those "only if it needs it modifications? There does appear to be evidence of some fretting on both those crankcase photos.

[Hedd_Jones]

with sand castings, it is possible that dimentions are not always 100% consistent. So perhaps

[Parazine]

My later crankcases have the step, like yours, but the earlier ones may be different - I don't have one to hand to look at. It maybe that they "bashed" the chassis on the production line if it was needed.

But, there is also the difference between the Austin cast crankcases and the Birmal produced ones, maybe one touched and the other didn't?

I think one type has "Austin" cast on the side of the case and the other has it cast into the web but I can't remember off-hand which was which....

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The cases I've just looked at, Birmal on the web, Austin on the side. I'm not even sure if this was consistent though...

[Dave Mann]

    Wouldn't it be easier to fit packing washers under the crankcase feet. I had a similar problem on an RN which made fitting the front suspension difficult. Then during it's last rebuild I spied a slight bend in the OS chassis rail easily corrected with a Jim Crow borrowed from a local railway preservation group.