invacar LightBulbFun's Invacar & general ramble thread, index on page 1, survivors lists on Pages 24/134 & AdgeCutler's Invacar Mk12 Restoration from Page 186 onwards, still harping on...

[warren t claim]

1 hour ago, Sheefag said:

Worse than that, you have to put it together with just one hand.

I'd be leaving a pice missing. 

[Mr Pastry]

19 minutes ago, LightBulbFun said:

and in general I have been told and heard plenty of stories of Model 70's doing 70+ miles an hour, so I dont think its un reasonable to think a Model 70 could exceed the NSL at least

I'd be surprised if it is any faster than a Fiat 126, which has almost the same frontal area and a bit more power.  Seriously, how well is it going to stop from 70+ with one SLS front brake?  I think that is a cause for concern.

[Jim Bergerac]

1 hour ago, chadders said:

 I still think a true 80 or 82mph is rubbish as even invacares can't break the laws of physics. 

[treehugger]

3 hours ago, RoverFolkUs said:

Has the rent gone up in the politics section? Everyone seems to have moved to this thread to argue about things 🤣

Yes, the EVIL TORIES put it up. 

[Sheefag]

Quote

Just Rejoice At That News

[treehugger]

She wouldn't have allowed any invacares to remain. 

[RayMK]

True,  anecdotal claims of reaching or exceeding 70mph in an Invacar have to be taken with a pinch of salt,  but the effects of conditions can enable unlikely speeds to be achieved in low powered vehicles while being entirely within the laws of physics e.g. a following wind, slight downhill gradient typically found on sections of a motorway or just slipstreaming a slightly faster vehicle.  These are not official two way speeds recorded under scientific conditions but can still be actual speeds achieved.  My Reliant Regal had 17.5bhp when new in 1961 but will cruise at 55mph for extended periods on the A5 according to my son who sometimes follows in his car (BMW 5 series or previously a Volvo V70, in either case using his phone for GPS speeds).  Reliant advertised the car as being capable of 62mph flat out.  A  2cv6 will easily maintain 65-69mph on its 28bhp despite poor aerodynamics and my Mitsubishi i would easily cruise at 70mph on its 57bhp, topping out at an indicated 91mph, so probably over 85mph.  Add favourable conditions to any  of these and unlikely speeds can be achieved before exceeding maximum rpm.  Three wheels and low frontal area will give a slight advantage to the Invacar in terms of drag but a Reliant with its non-independent rear end has no toe-in or out to fight, unlike the Fiat 500 (front and rear) or the Invacar if it is not a pure trailing arm independent set up (I cant remember whether its rear is semi trailing or not).  However, the joy of driving low powered cars is not so much to do with speed, more to do with learning how to drive efficiently and with three wheelers doing this without causing them to fall over - none of my Reliants have ever lifted a rear wheel.  Know  your car's limits, anticipate road conditions, load the vehicle sensibly and great fun can be had. 

[LightBulbFun]

7 hours ago, Mr Pastry said:

Btw did you manage to source a kingpin kit?

yeah, my contact just confirmed they have 45 kits in their stash, so ill see about purchasing 2 or 3 having a couple spare in this case cant hurt  

[LightBulbFun]

28 minutes ago, RayMK said:

but the effects of conditions can enable unlikely speeds to be achieved in low powered vehicles while being entirely within the laws of physics e.g. a following wind, slight downhill gradient typically found on sections of a motorway or just slipstreaming a slightly faster vehicle.

what something like this?

https://www.flickr.com/photos/28083135@N06/8558460260/

 

[RayMK]

5 minutes ago, LightBulbFun said:

what something like this?

https://www.flickr.com/photos/28083135@N06/8558460260/

 

Laws of the Fuzz may overrule speed record attempts there, but the Atkinson could probably be overtaken by the Invacar if it could power* through its bow wave on a non restricted road.  There's a wonderful you tube video of an Atkinson circus lorry towing several trailers and driven by a lady, highly unusual back in the day.

 

[High Jetter]

3 hours ago, warren t claim said:

I'd be leaving a pice missing. 

I see what you did there

[Zelandeth]

I've definitely had an indicated 70 out of TPA coming down the A5, though the important word there is indicated as I didn't have the satnav on at the time.  The error at 50-55 though is only a couple of MPH though so I've no reason to believe that it's a wildly inaccurate figure.  Wait till she emerges in the spring and I'll try to get some video showing some real world examples.  It's definitely a case of she *can* do 70 rather than she's *happy* to do 70 as you're really pushing the top end of the rev band at that point.  60 really is the highest I'd be comfortable cruising at for any length of time.  If the situation allows, just like the Trabant she's happiest between 50-55.  Cruising in that range doesn't really feel perilous at all unless it's windy.

When I've gone on the motorway my strategy has always just been to slot myself in behind a lorry sitting on the 56mph limiter and bumble along behind them.  That way also helps avoid having to contend with the aerodynamic bow wave when overtaking them which is by far the most unnerving part of being on the motorway.

I do suspect that the carb jetting is tuned heavily to optimise mid range torque, and it feels to me that if you could get more air and fuel into there than it's got quite a bit more grunt available. 

I reckon the really long intake tract can't help throttle response either, and the heavy flywheel absolutely does definitely impact things there - though with it being hooked to a CVT thst really doesn't make any odds when driving.  It is a swine if you accidentally rev the engine up in neutral though as it takes an absolute bloody age to spin down again before you can actually engage a gear.

Have to admit I'd love to try attaching a pair of Mikuni carbs and seeing what that did...

[LightBulbFun]

10 minutes ago, Zelandeth said:

Have to admit I'd love to try attaching a pair of Mikuni carbs and seeing what that did...

the thing that tickles me the most is, as per my comment, that *is* an engine that was once in a Model 70  

now its making nearly 100 horsepower   stick that back in a Model 70 why dont yah!

[Zelandeth]

8 minutes ago, LightBulbFun said:

the thing that tickles me the most is, as per my comment, that *is* an engine that was once in a Model 70  

now its making nearly 100 horsepower   stick that back in a Model 70 why dont yah!

Interesting, yes.  As for putting that in a Model 70: Hell no.  

I think about 30bhp would be the real world sweet spot, accounting for the losses in the CVT.

[Christine]

Back in the day , many invalids tuned up their chariots,  some had body kits and spoilers too . Villiers / Upton 210cc  engines  from go karts that  put out some 20bhp , where a popular upgrade, if the ministry wouldn't give you a free 500cc  model 70 ...

6.7  to 1 compression is rubbish   .. skim the heads or barrels

[LightBulbFun]

18 minutes ago, Zelandeth said:

Interesting, yes.  As for putting that in a Model 70: Hell no.  

I think about 30bhp would be the real world sweet spot, accounting for the losses in the CVT.

Yeah its just when you get the inevitable "stick a Hyabusa lump in it" comments, I always think to myself, nah! theres no need the standard engine is more then capable of aching silly figures if thats the sort of stuff your looking for  but im happy with my ~20Hp, well as long as she can cruise at 60Mph like TPA can then Iill be happy, I mean even on the former motorways here, its all 50Mph limits if your lucky LOL

this talk of top speed is something I just want to find out for information sake so I have that datapoint for the datasheet so to speak , and so I have a proper answer to give people, because when you tell someone about an Invacar/that you have one, one of the inevitable questions is always "how fast does it go" or "what its top speed"

 

16 minutes ago, Christine said:

Back in the day , many invalids tuned up their chariots,  some had body kits and spoilers too . Villiers / Upton 210cc  engines  from go karts that  put out some 20bhp , where a popular upgrade, if the ministry wouldn't give you a free 500cc  model 70 ...

6.7  to 1 compression is rubbish   .. skim the heads or barrels

hah, one tyre fire/torque steer yo! 

(for those who dont know, Villiers machines are 1 wheel drive  )

I know an Invacar Mk12E is primarily actually gearing limited when it comes to its top speed of 50Mph, I asked if you got a suitably sized sprocket could it go even faster, the answer I got was "yeah but you wouldn't want to!"  

[High Jetter]

I guess, like most motability situations, it's a stability issue. 

[R Lutz]

Is somebody implying these Sp***a Chariots have CVT?

[wuvvum]

The Model 70s do, yep.

[LightBulbFun]

25 minutes ago, wuvvum said:

The Model 70s do, yep.

and so does the Harpermatic    

 

[LightBulbFun]

Also funnily enough while digging up that piece on the Automatic Harper Mk6  I came across this, from October 1968 detailing a Prototype Model 70

"it will do 70 Mph" aint that topical! 

[warren t claim]

BUMP 5 A REEL THREAD

[LightBulbFun]

16 minutes ago, warren t claim said:

BUMP 5 A REEL THREAD

hah  , but im not sure the thread is not really applicable here, since its already been fairly reliably established that a Model 70 and even Invacar Mk12's speedometers dont lie  

however there was another thread along similar lines of most optimistic speedo, but in the sense of, the scale of the speedo vs the actual vehicles top speed

which I of course had to leave a comment on  

https://autoshite.com/topic/50156-speedometers/#comment-2568032

 

both the AC Electric Invalid Tricycle and Tippen Delta Electric which clock up to 60Mph!

but only a 12-ish MPH actual top speed  

 

[chadders]

1 hour ago, LightBulbFun said:

Also funnily enough while digging up that piece on the Automatic Harper Mk6  I came across this, from October 1968 detailing a Prototype Model 70

"it will do 70 Mph" aint that topical! 

Not 82mph I note.

Just out of curiosity "since its already been fairly reliably established that a Model 70 and even Invacar Mk12's speedometers dont lie" how and by who? The same 'enthusiasts' that quoted the 82mph?

"Thou doth protest too much" springs to mind.

 

 

 

[LightBulbFun]

27 minutes ago, chadders said:

just out of curiosity "since its already been fairly reliably established that a Model 70 and even Invacar Mk12's speedometers dont lie" how and by who? The same 'enthusiasts' that quoted the 82mph?

"Thou doth protest too much" springs to mind.

actual users of machines who verified the accuracy of the speedometer by GPS or other such means, 

I mean common now, literally on the previous page I quoted such a verification  LOL 

On 10/09/2020 at 02:21, Zelandeth said:

On 09/09/2020 at 23:14, LightBulbFun said:

Woo Go TPA  

im curious do you know how accurate the speedo is against GPS or such?

Astonishingly accurate.  According to the GPS speedometer app on my phone, 60mph is an indicated 61mph on the dash.

Far more accurate than anything else in the fleet!

and for completeness sake heres the Mk12 verification also  

On 18/05/2023 at 17:14, egg said:

On 13/05/2023 at 18:13, AdgeCutler said:

Brian had reached the dizzying heights of 51mph,

Blimey, maybe a new land speed record for a Villiers powered invalid carriage (accuracy of Smiths dials not withstanding), that took some guts!

 

On 19/05/2023 at 21:05, AdgeCutler said:

On 18/05/2023 at 17:14, egg said:

Blimey, maybe a new land speed record for a Villiers powered invalid carriage (accuracy of Smiths dials not withstanding), that took some guts!

The speedo seems to be accurate, at least it reads the same as the speed check signs locally. I’ve checked it against them on numerous occasions at various speeds and the readings always match.

and another for the Model 70, this time from Dollywobbler's TWC

On 26/12/2021 at 20:55, dollywobbler said:

I managed 70mph downhill on the A23 once, sat nav confirmed. Also confirmed that the speedometer is remarkably accurate. That was while TWC wasn't in the finest fettle. She hit 65mph on the Shrewsbury bypass more recently, without the need for gravity.

 

certainly no one here is quoting the 82Mph top speed as hard fact, or at least I hope not! as I have said also just on the previous page (and plenty of times previously), no one knows where that comes from, hence why I am eager to find out what the actual vMax figure is  

[plasticvandan]

The theoretical max figure is surely dictated by gearing and maximum revs?

All fairly irrelevant as road conditions,weather and laws of physics play their part.i have traversed in a Reliant at an indicated 97-so perhaps 90 but I never liked to take them much above 65,cross winds or rough roads make keeping them in a straight line difficult. Air gathering under the front end tends to start lifting them up resulting in ever lightening steering.During the aftermath of a named storm I was driving a regal along the M5 and actually had to leave it asap,as I had had to drop my speed to 25mph as I was needing 2 lanes to keep it going forwards,due to wind blowing me around.

[Mr Pastry]

46 minutes ago, plasticvandan said:

The theoretical max figure is surely dictated by gearing and maximum revs?

Yes quite right, but you also need to know the frontal area and the drag coefficient as it is all about air resistance.

Horsepower & Aerodynamic Drag Calculator (stealthmotorsport.co.uk)

 

[mk2_craig]

Doesn’t look like anybody has carried out anything approaching a proper scientific, peer-reviewed, industry-standard study. 
 

None of which matters really, as most sane people wouldn’t wish to propel themselves at such speeds with so little in the way of safety features. (and I’m speaking as someone with a full motorcycle licence)

[Christine]

1 hour ago, plasticvandan said:

The theoretical max figure is surely dictated by gearing and maximum revs?

All fairly irrelevant as road conditions,weather and laws of physics play their part.i have traversed in a Reliant at an indicated 97-so perhaps 90 but I never liked to take them much above 65,cross winds or rough roads make keeping them in a straight line difficult. Air gathering under the front end tends to start lifting them up resulting in ever lightening steering.During the aftermath of a named storm I was driving a regal along the M5 and actually had to leave it asap,as I had had to drop my speed to 25mph as I was needing 2 lanes to keep it going forwards,due to wind blowing me around.

Bugger that..

[Mr Pastry]

To give credit where due, I am sure that AC designed the model 70 responsibly and knew what they were doing, and they would have tested the maximum speed.  And they would probably have geared it so that it ran out of steam before it became uncontrollable.