Front Uprights

[notacarguy]

Here's an interesting development. As I've been reassembling the front suspension I've discovered that my car has two right front uprights. Both have 3 degrees of caster. So when assembled the right side would have +3 degrees and the left side would have -3 degrees. Clearly not normal. What do you think, was this a purposeful set up, for oval racing perhaps? I don't know all of the history, but the car shows other signs of being raced. Or did at some point someone just grab a similar-looking part and throw in on?

And finally, I understand there were 3-degree and 5-degree options for those uprights. I believe the original Ace spec is 5 degrees. Would I be better off sourcing (or making, it's starting to look like) one 3-degree left or a pair of 5-degrees?

[B.P.Bird]

Tom,
Well spotted - the combination of opposite caster angles side to side would make for a very dangerous ride (don't ask how I know.) Cannot imagine it was done deliberately. As to your question I have never been able to feel any difference between 3° and 5° caster therefore I would try and find either one 3° port or a pair of 5°. I rather suspect that early customers found the steering heavy at slow speeds (parking for instance) leading to a reduction in caster angle and a trap for the unwary for the rest of time....
For what it's worth I don't think the cause of the heavy slow speed steering is anything to do with caster angle, it is simply a combination of very high geared steering and the Michelin X tyres which were fitted to almost all Aces in period. Nowadays the 5.50 x 16" Blockleys seem to work just like Dunlop R5 cross ply competition tyres in that there is plenty of grip, but being cross ply the steering is much lighter. However perhaps Thomas Maitre, who uses them on '1192 might advise you here - or indeed any other user. In any event first things first you need to find or make an upright. Perhaps having a word with Charlie Gray at A.C. Heritage would help, at least they should have the drawings

Barrie

[notacarguy]

Thanks for the information, Barrie. That's very helpful.

I've started to draw the components it would take to build an upright. And I 3d-printed a model of the kingpin mount to make sure I got all the dimensions correct. I'd still prefer to buy one, but it would be feasible to have the pieces made and weld it up.

-Tom

[B.P.Bird]

Tom,
Do let us know how you get on. It might well be that there are other owners who need upright replacements
Barrie