1936 7 hp chassis in Australia

[Tony Fearn]

004.jpg

Andrew, I have spent the afternoon looking at a DK2A-0 dizzy and have uploaded photos to my 'personal album' in the Gallery for future reference.
You'll have to log on to the Gallery as well as JowettTalk to see them, and then use the link below.

DKY2A

[Andrew Henshall]

Tony, you have solved my problem! Thanks for all the photos. Just so you understand why I couldn't work out which way my DK2A-0 distributor rotates, here is a photo of its body plate: the important arrow is missing!

DSC05511_s.jpg

I had worked out that the rotor arm was wrong for my DK2A-0 (because of the misalignment to the cap), and assumed that I needed a different rotor arm to suit a distributor that rotates clockwise. You have confirmed this, and so I now know that I need to find a Lucas 405469 (same as 400052) rotor arm.

What you have shown is that the cam is also wrong for my DK2A-0 (the advance mechanism is correct however), and so this is in fact the root cause of the misalignment in the cap at points opening. It appears that I have a cam from a DKY2A distributor based on your photos of that unit. Hence I need to find the correct cam for my DK2A-0 distributor.

You have also highlighted the fact that I also have the wrong points in my DK2A-0 distributor; I appear to have the points out of an earlier DJ type. Maybe the whole top plate is out of a DJ type; who knows? Given that when the DK2A-0 distributor I purchased arrived here it was actually fitted with the cam out of a DJ type distributor, you can understand that it was clearly put together from a box of bits that didn't match.

Thanks for co-ordinating things with Ian R for me; he has not yet replied to any of my emails for some reason.

[ian Howell]

Andrew (and Tony): -

Ian R is not a regular user of the Internet so you may have to wait some time for an Email reply. I am sure a telephone call would not be considered intrusive (maybe not from Oz though! A%A%A%!)

Ian lives fairly close to me, so if I can help - just ask (as long as I am 'At Home!'.

Which said, I expect to be back in Sussex next weekend as I have a rally to attend (If it isn't raining).

[Tony Fearn]

Thanks Ian.
I spoke to IR on the phone yesterday on behalf of Andrew's search for Luvax Type AR shock absorbers.
He said he wasn't internet savvy, so I undertook to relate to Andrew what the situation was.
IR went into the barn with the phone, and rummaged around quite a bit, and found four matching shocks, but when we discussed details it appears that they are not Luvax type AR (Andrew please note - I will email shortly).
I append a photo of what I think Ian has in the barn.

Rotoflow Model A1.jpg

Tony.

[Andrew Henshall]

Thanks for your fantastic help Tony. After looking though the whole collection Ian H was hopeful that the shock absorbers might be Luvax Type AR units, but wasn't sure at the time.

For those members who are following this subject (i.e. Lucas Type AR shock absorbers, arms, & links for a 1936 7 hp Jowett pass car), here is a summary of my findings to date:

There are many different configurations of Luvax Type AR shock absorbers, but all use a Mazac main body casting, with a pressed steel cover. The Mazac casting tends to fracture internally during use, and this makes the unit non-repairable. New fully machined Type AR steel bodies are available (from VCSA in the UK), but at a high cost.

Type AR units come in at least two different mounting orientations: 4" centre-distance mounting holes oriented vertically, and 4" centre-distance mounting holes oriented horizontally (as per the 1936 7 hp Jowett cars). In each case, the filler plug is located at the top (naturally). The cover can not be simply rotated through 90 degrees to convert one type to the other; they are different internally, and the valve screw in the body has to be under the filler plug anyway. Also, the flats for the cotter pin on the shaft will be 90 degrees out of position and the recuperating valves will also be out of position.

Type AR units come in at least two different output shaft configurations: a splined shaft (which needs a splined arm to suit), and a plain shaft with flats for the cotter pin (which needs an arm with a cotter pin). I am told that no Jowett used Luvax shock absorbers with splined output shafts, hence my 1936 7 hp car must have had cotter pinned arms. See below:

Luvax Type AR 006_s.jpg

Type AR units come in at least two different damping arrangements: early units were double acting single rate shocks; they provide the same damping rate for both bump and rebound. These early Type AR units have "RESISTANCE" pressed into the cover above a double ended arrow. See below:

Luvax Type AR 006_ss.jpg

Later Type AR units were double acting dual rate shocks; they provide a softer "bump" rate and a stiffer "rebound" rate in order to improve ride and handling. This allows the suspension to rise easily without upsetting the chassis/body and provides good control of the suspension on the rebound. These later Type AR units have "MAIN RESISTANCE" pressed into the cover above a single ended arrow to signify which rotation direction provides the stiffer rate for rebound. These units have to be fitted in handed pairs, so you need to have two units with arrows pointing in opposite directions, and fit the correct unit to the correct side of the car. See below:

Luvax Type AR003_ss.jpg

I understand that it is possible to adapt modern telescopic shock absorbers to your pre-war Jowett, but if you want it to look original, and also achieve the benefit of having dual rate shock absorbers, you now know what to look for.

Many thanks to Graham at VCSA and Tony Fearn for assistance with all the info above.

Regards,

Andrew

[ian Howell]

Andrew, Tony, et al: -

I'm sorry to have raised Andrew's hopes only to be dashed by reality. I can only plead that the shock absorbers on my 1930 Long Four are of the Smiths type, which consist of a small drum and a spring loaded friction band tensioned by means of a bolt and wing nut, rather like an external contracting brake.

So I was not familiar with the various permutations for the Luvax series, which brings me to an important point: -

WHICH CAR DID IAN R's SHOCK ABSORBERS COME FROM? I think the answer is probably an Eight, as they were part of Alan Benewith's collection and he had an (or possibly more than one?) Eight, which I believe is now in the Bradford Museum.

This still leaves the intriguing possibility that, in light of Andrew's tribulations, there may be a number of variations here too!

The plot thickens!