Dating and Engine

[Mike Costigan]

Simon, AVJ vans continued well into 1937 on the high frame, but with Girling brakes and 3-bearing crank ... but what I don't know is if the engine used a special crankcase to realign the drive height.

["Slack Alice" Simon]

Thanks Mike.

The way Austin varied its castings, it would be sensible to check three bearing 'cases for mounting height, and not assume that they are automatically low frame.

I was going to suggest you could tell by the position of the "stop" on the starter bulge, but this may not apply to later castings.

Cheers

Simon

[Jamie]

Showing my ignorance, how do the high and low frame engines differ in the way in which they fit into the car?

["Slack Alice" Simon]

Apologies, Jamie

I thought someone with better knowledge would come back on this, but you are stuck with me.

This is what I think I know, but it may be wrong.

When they changed to low frame the engine was mounted lower down in the chassis, so the feet of the crankcase were moved up to make this happen.

Which means a high frame engine in a low frame sits a bit high.

And a low frame engine in a high frame will be too low, by my logic - but I am sure I have read somewhere on the forum that you can't put a low frame engine in successfully but surely it just needs jacking up a bit?

So, as you can see, I am confused.

Also, as they changed from three speed to four speed and from short chassis to long chassis the engine moved forwards a bit - again done by re-positioning the foot mountings.

I think.


  highframestop.jpg (Size: 18.03 KB / Downloads: 229)

I have not put a picture in before, if this has worked you will see a pic of the "stop" on a high frame crankcase - the noggin sitting on top of the starter bulge, which in a high frame is hard up against the back of the starter mounting flange.

I can't find my pic of the low frame 'case - but the "stop" is a much more obvious squarish lump about 1" back, away from the mounting flange.

Clear as mud?

Cheers

Simon

[Bryan]

Below is the image of the low frame stop. There was a discussion on the old forum that can be found by searching ‘high frame ‘
Bryan

[Bob Culver]

Although it is far from ideal a lot of standard  non special cars contrive to run wiht the wrong crankcase. The Williams special book, amongst a myriad other questionable statements, claims them to be interchangeable. The late case in early chassis raises the projection thru radiator cowl etc.

[Reckless Rat]

If that's the two "official" differences between a High frame and a Low frame rubber mounted crankcase, then what's this one?... The engine number places it in 1933 , so high frame - there is no stop/noggin and it looks original:

[Bryan]

I’ve also got a ‘33 engine (M181165) in the shed without the stop on the starter housing.
Bryan

[Jamie]

Thank you all for the information and advice. I had a quick look and there is no lump of the starter housing.

Onwards, now, with cleaning it up, finding a few missing parts and reassembling it all.

Jamie.

["Slack Alice" Simon]

So now we have 2 bearing (Hedd) and three bearing (Jamie) with no noggin on the starter housing.

So how now do we tell if Jamies engine is high or low frame?

It is down to measuring the distance of the feet below the top?

And I was so pleased to be able to tell the difference just by looking!

Simon