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Messages - B.P.Bird

#31
Jonas,
Apart from being RHD the battery tray in AE22 is almost identical to your AEX 31. Like all these differences on the early cars one would love to have a changeover car number or date, but it seems A.C. didn't bother to record these running changes in production. Keith Lessiter might have an idea though
Barrie
#32
Be careful, the early Ace has a different battery tray and fixing. The early battery is aligned fore and aft - I think '31 would have been like the other early cars ?
Barrie
#33
Gary,
An interesting and challenging project. I'm sure, with your customary determination, you will succeed; but here's a question. Imagine the scene:
It is a wet and cold night. The rain has been coming down steadily all evening. A dithering O.A.P., just like me, approaches a Zebra Crossing intent on reaching the Fish & Chip shop on the other side of the road. Meanwhile a young, lithe driver in a 2 Litre Saloon, just like you, has been driving across town, adhering strictly to the speed limits. As the 2 Litre approaches the Zebra Crossing the O.A.P steps out, concerned only that the Chipper might be closed. Now the question - would the O.A.P sooner the approaching A.C. had drum or disc brakes fitted ?
Barrie
#34
Sorry Gentlemen 'The Club' has no entity of itself - we The Members are the club. Accordingly I applaud your pointing out of these anniversaries, but if you had done it ahead of the date then perhaps they could have been marked in a satisfactory fashion - at the very least a note or an article in ACtion would have been great. Not too late though, if you think your A.C. is under represented get writing: I look forward to pages of interest appearing in ACtion authored by your good selves on that brilliant A.C. the 2 Litre Saloon and its wonderful Weller engine
Barrie
#35
Set up properly the Bishop Cam system is very effective and very quick. Going to a rack loses the quick ratio and originality: The former loses a great part of the car's character and the latter will decrease the car's value.
Barrie
#36
Greg,
Looking at your photographs and reading about your steering woes I am left wondering what exactly the 'TR Revington' steering box top cover is ?
If, as I suspect, it is some kind of modification to introduce spring loading to the peg engagement with the cam then my view would be that your steering will never be right til you return the steering box to original Bishop Cam specification. If Bishop had wanted compliance in their system they would have included it: It would seem to me that their whole purpose was to eliminate compliance. Introducing any kind of compliance will appear at the steering wheel as excessive play.
Incidentally I should observe that when checking and setting play at the steering wheel rim only light force should be applied - the front wheels should not move nor the tyre sidewalls flex.
I find the steering system on the Ace, Aceca and Mk. I Cobra quick and accurate - threading the A.C. through a series of corners on a quite country road is a joy.
Barrie
#37
Jonas,
Who knows what was in the author's mind when the original 1/16" was specified ? In any event I think Michael has a very persuasive argument that A.C. meant total total toe in. In addition that dimension is not a critical, engineering law of physics: It is really an arbitrary guess - if manufacturing teams thought that their suspensions would drag back to the tune of 1/16" toe out then best start off with 1/16" toe in. I doubt there was much calibrated testing carried out in the early days, but by experiment and experience manufacturers came to recommend a static toe in figure. There is no reason why you and your highly accurate Trackace cannot do the same thing, coupled with your assessment as a driver and an observation of tyre wear patterns. So I would start off at 1/16" total toe in and then see how she drives and how the tyres wear.
The nice thing about having the Trackace is knowing exactly where you are with these adjustments - once you have got a satisfactory setting of toe in you can return to it with great accuracy.
Do let us know what you discover, I will need to set the toe in on '22 shortly
Barrie
#38
Michael and Jonas,
My apologies for a long pause in contributing to this essential topic. My poor defence being the hours I am wasting on setting up a new lap top, demonstrating my ignorance of all things digital.
To begin with, when reading Michael Trotter's posts, I realise what a chasm exists between a proper engineer, like Michael and an amateur fitter, like me. Thus I have no doubt that my opinion on the clearance of cam to peg is quite wrong and the cam is machined with more clearance on lock as compared to straight ahead. Which being the case I am now puzzled by the too often observed, incorrectly adjusted Bishop Cam steering box, binding as lock is applied. In my experience there is a tendency, during adjustment, to reduce straight ahead free play too much and this seems always to result in the peg binding in the cam as the rocker arm travels from the straight ahead position. This prevents the self centering action of the caster angle operating and makes your Ace or Aceca an absolute pig to drive....
To address the specific problem described by Jonas, one of the symptoms of excessive toe in is poor straight line stability. If, as Michael suggests, this is the situation with AEX 31 then it will be interesting to hear the results of a revision to the toe in adjustment.
Turning to the general question of toe in I used a tracking pad for many years, such as Michael describes, but eventually concluded that the drag due to tyre rolling resistance probably varied as the square of speed and any slip angle detected at walking pace might be misleading at sixty or seventy miles an hour. The other doubt in my mind was repeatability, or rather the lack of it: Slip angles measured on each run seemed to have quite a large scatter. I now use the 'Trackace' system mentioned by Jonas. The other thing about the effects of drag on front wheel alignment concerns the early versus the later Ace chassis: The early cars, including '31, have hard mounts for the inner wishbone whilst the later car uses rubber bushes which one might suppose give  greater compliance. As far as I am aware the toe in setting remained the same for both when you might expect the early 'solid' wishbone to require less toe in angle ?
Jonas mentions choice of steering box oil and I don't believe that this will have any effect on straight line stability. In the interests of longevity I use a synthetic gear oil - Mobil SHC 75W - 90, but I'm sure his Penrite is satisfactory.
Steering box brace: It was not me that was involved in a batch, but I have made a couple for myself. I remember David Sanderson telling me that the LHD Ace steering box mount is far less rigid than the RHD mount and I think the steering brace requirement could have come from SCCA racing. Whatever the instigation you can't have too much of a good thing so braces all round - RHD and LHD. However I doubt that the brace would affect straight line stability as any flexing would be more likely during brisk cornering.
Finally (sigh of relief) I am wondering about some of the calculations shewn in this thread. Mixing fractions of a degree with decimal points is not a good idea. It does seem to be the modern way, but 2.5° is not 2° 50' it is 2° 30' . On this basis '31 with 40' of toe in (0.66°) then it is over 3/16 of an inch
Barrie
#39
Jonas,
Do bear in mind that the cam is machined to give more clearance to the peg in the straight head area. This is the reason why the peg must not be set too close - it will bind as lock is applied
Barrie
#40
Jonas,
The Ace is not prone to tracking or tramlining, neither are Michelin X tyres.
I wonder if you have lost the caster self centering action by over tightening the adjustment  on the peg ? There should be some play at the steering wheel rim.
The cam doesn't wear like the peg and I would fit just a new peg and adjust the clearance to allow the wheel to self centre as soon as you relax your grip on the steering wheel whilst turning.
Fitting the front uprights on the wrong side gives you reverse caster angle and some epic directional excursions - I hope '31 has not suffered this insult.
Barrie
#41
Wonderful photo's and an intriguing story. I too speculated that the hood arrangement looked Heath Robinson. Thank you for sharing with us
Barrie
#42
Great looking machine, she will be loads of fun
Barrie
#43
Jonas,
Would there be a special reason why you want the hydraulic damper ?
Barrie
#44
Jonas,
I am sure your carburetter specification is correct: AE 22 came with original carburetters and they do not have the hydraulic dampers. I wonder if there was a change later with the CL, CLB & CLBN sixes ? For that matter I wonder why SU introduced the hydraulic dampers. I could speculate that it was more about comfort than performance - you can see the dashpots responding to the inlet duct pulsations and this does make a characteristic noise as the dashpot pistons and springs dance merrily up and down. Perhaps the addition of oil damping to air damping was  simply to introduce a bit more civilisation ?
Anyone out there know their S.U. history and can educate us ?
Barrie
#45
Gentlemen,
This has confused me a little as I thought there was only one size of budget latch, as originally supplied by Wilmot Breeden and have fitted one to an Ace or Cobra on several occasions. However going back to source and looking at the WB brochure I see that there is indeed a choice:

3/16200-1 Hooked Bolt. This has 3.68" mounting centres or
3/10844-4 Bridge Type. This has 3.0" mounting centres

It is this last 'Bridge Type' that is correct for our cars. The problem being that non original suppliers may now be making copies and you need to check which one is being offered. Visually the two are very different, but only when viewed from the side; the 'Hooked Bolt' type is flat whilst the 'Bridge Type' is stepped up and mounts clear of the the sheet metal bracket on little folded legs There is also the complication that there is another part which is identical except it is left hand. We need the right hand one as above.
Barrie