Problem with the throttle linkages due hing external temperature

[andrea]

I am just returned from my holiday, and beginning to first test drives my AH following the 5-50-500 miles program
apparisched on Austin Healey Magazine page 29 September October 2011
All is good -
Start is OK Car start immediately at the first turn, when hot some little dieseling at the cut off
Oil pressure at 60/2000rpm decrease when thermostat open the way to Oil radiator
Water temperature (with auxiliary 12"electric fan ON) not exceed 212°F see my Digital Cooking instrument application
https://picasaweb.google.com/112770...&authkey=Gv1sRgCM70ivTIpL2oaw&feat=directlink
Electrical I have find one bad screw on a new fuse box and have added one easy connect Digital voltmeter
Brakes some problem with the Hand brake regulation are on the way to be solved

Now the Speedometer mark a little more than 50 Miles
and due the hot temperature of the August in Italy one great BUG appear:
at the cold start all works normaly, after 5- 10 mile trip, 15 min from home, throttle linkages appear very hard to move, I have found that the TWO teflon bush on the command bar are warm sensible,or dilatation of the bar is so great, that the system stop to work correctly
I am seriously oriented to jump the linkage system, with a
cable wire command- the others solution are or drive the caron winter only, or dismantle the interiors for change or modification of the two bushes .
I haven't see anyone that have the same problem on BCF
especially TEXAS and CALIFORNIAN drivers
Cheers

PS I have jumped the BATTERY SWITCH as programed

 

[Randy Forbes]

Andrea, I never liked the original design, and on more than one occasion, managed to get the accelerator pedal over center, trapping it at full throttle.

My recommendation is to poop-can it, and devise a more positive__and safer__direct link (it's not as though you'll be converting your car back and forth from RH to LH drive, nor have you shown to be a slave to originality).

I repurposed some of the original components, putting the pedal/pivot mechanism at the floor level; from the bell-crank now located at the bottom of the transmission aperature, it was a straight shot up to the crossbar that actuates the three (3) Weber 45 DCOEs. I left some provision for adjustment, and because of the (then) purpose of the car, designed the new linkage to have a fairly long pedal travel, to easily modulate throttle openings.

I'll see what I can turn up for pictures of the linkages, if you choose to go that route. If I remember correcetly, aren't you running a trio of Webers too? If so, that's a lot of (throttle return spring) tension to rely on a cable end...

 

[Randy Forbes]

Pieceing together some pictures__I don't know of any series that illustrates the entire assembly, so we'll see what I can turn up...

 

[Randy Forbes]

Not sure how those got posted before I was finished with the compilation, but there's more...

A bit of a dodge to fit the carpets (and any future floormats) but a much more positive and comfortable arrangement:

 

[DerekJ]

Andrea, I think I remember you saying you are fitting triple Webers. You might want to try the Dennis Welch cable throttle arrangement for them. This results in much smoother and more direct throttle response.

 

[andrea]

Hi Randy
Tanks fro reply, your solution is easy and handy, and I understand how it works from the photos.
Actually I have on the car the two SU solution, I agree with you and I also never liked the original linkages system, I have tested the 3 WEBERs solution with the incomplete car (no body panels on)and valued that the system don't work with
the Weber. and this solution can be refused by ASI (veteran car homologation)
So I have prefered to have the original system- and Webers (ready to go ON)when I am ready for
cable (or other direct link solutions),my premonition is confirmed.
When I made my first test was the middle of June and temperature aren't so hot
and NO problem was evidenced in the my 7 road test, 5-10 km from home each,
on road with limited traffic, now I have attempted a more long trip of 50 km. and
I am stopped after only 30'-
Efforts on the warm hardened bush are so hard that the throttle bracket turned on the steel bar, so I have a limited rpm excursion, my speed was ridiculous, early evening,but luckily I find a solution to recover the car for the night , touch warm pieces of linkage was impossible also with gloves, I solved the situation the next morning with engine cold.
I have ordered this cable kit for the immediate SU solution
and for webers I will value your solution or a double cable solution, hoping that
some pieces of the single cable can be reused.
Cheers

 

[British_Recovery]

Just a thought. Check your engine grounding strap as it might not be doing it's job, resulting in current having to find a ground any where it can. This can heat up the linkage.

Bob ( and Dennis )

 

[CanberraBJ8]

Great idea Randy - I really don't like my standard throttle (though up at the carbies it is roller bearing guided). I am thinking a version of what you've done there would be a good addition to my car - though right hand drive will need a little variation.

 

[andrea]

Hi Derek
I know D Welch cable system, it is very strong and affordable, probably make from aluminum billet with CNMachine,
design is the same for 2xSU actually on the car-but prices are different GBP 85 for the steel kit and more than GBP 230 for the aluminum kit.
the 2xSU is a temporary solution on my car, 3xWeber will be the definitive
-so I have prefered the economic solution for the 2xSU and reserve the better alluminium for the 3xWeber definitive with a strong monney supreme sacrifice.

I am valuing also Randy solution, the pedal can be the same BN1-BN2 LHDwith the same bush and coup,and bracket and the rigid connection - only few holes on the down of car, easy accessible under, but the movement of the engine should be transmitted to the link- and carbs throttle .
The next, cable Kit experience, can help me to decide the final 3xWeber link solution.
Cheers

 

[steveg]

See also the DMD linkage at 260 Australian dollars:

https://www.dmdaustralia.com.au/components.html

Scroll to bottom of page.

 

[andrea]

See also the DMD linkage

As usual DMD make a good piece, I have appreciated the double articulation joint on brackets.
View attachment 28474Steve
I remember that you have make this reinforcement on linkages, have you experienced some hard movements on it as me?

 

[andrea]

If someone is interested on cable solution I have find one hand made very professional system, only traces of the author is Greg W.-View attachment 28483View attachment 28485View attachment 28486
unusual cable position- Note the round command brachet
I have find the photos on one old site of Lin Rose
Look also this site https://www.lokar.com/product-pgs/throttlecables-kickdowns/tc-kd-pgs/throttle-cables.html
and instructions https://www.lokar.com/instruction-sheets.html
Cheers

 

[steveg]

View attachment 28474Steve
I remember that you have make this reinforcement on linkages, have you experienced some hard movements on it as me?

Andrea,
I have had no movement problems with the brace in the picture. Part of this may be due to clamping the arms on bare metal then painting assembly afterward. Clamping on pre-painted rod is a bad idea.

 

[GregW]

If someone is interested on cable solution I have find one hand made very professional system, only traces of the author is Greg W.-View attachment 28487View attachment 28488

Those are my photos originally from a thread here called 1500 CFM. Through various forum upgrades, the pictures were deleted. The good news is the latest forum software allows us to edit old posts, so I will add those photos back in when I get the time. Hopefully this week.

 

[John Turney]

Just a thought. Check your engine grounding strap as it might not be doing it's job, resulting in current having to find a ground any where it can. This can heat up the linkage.

Bob ( and Dennis )

Yes, check that. I sometimes drive mine in >105F heat (40.5C) with no problem to the car.

 

[tonyhosk]

Andrea

I'm intrigued by the 5-50-500 mile programme for a rebuilt engine. Would you mind explaining it.

tony

 

[andrea]

Hi Tony
I have Find it on https://healey.org-- article "On approach to restoration" Part 37-page 29
Very interesting guideline to how beginning the road Tests
if you have diff. to download thi article pls. sent me a PM with your e mail addr. and I sent the PDF
Cheers

 

[tonyhosk]

Thanks Andrea - I've just gone on the healey.org website and joined. I should therefore be able to access the info, but if you don't mind sending me the pdf, my email is th@endo.co.uk

 

[andrea]

Yes, check that. I sometimes drive mine in >105F heat (40.5C) with no problem to the car.

Hi Bob and John
I have appreciated your suggestion, I have measured with the Ohmmeter the resistance from the grounding point just near the battery and the most far site of the car I have added to the probes one wire extension with clamps, I have make more measurement in the same sites. this is a pondered media:
Engine- Upper part 00.4 lower 00.4
Starter-Upper Bolt 00.4-00.6 Lower Ground Strap 00.4-00.5
Fire wall Various grounding points 00.4 -00.5
Carbs 03.4-02.5
Linkage Bracket Bar 01.2-00.8
Carbs Linkages 00.4 - 00-5
Radiator cap 00.5
Thays seems good to me, I am right??
I also find one other TWO hours experiment. with my pump cut off and coil disconnected, KEY on ON position, no warming on the link bar
Also the battery dispersion in a week (normally my battery is disconnected) appear normal
Comments are welcome
Cheers

 

[andrea]

Sometime I complete a reply, then I lost all when I will add some photos to the tread. this is happened few minutes ago!!GRRR!!
This is no due at BCFsite program, that works well for me, but at my limited ability and writing system.

I have worked again on the Cable throttle system (Kit, not yet arrived) following this project photo's (GregW.??)
My version is a little different on material used, but the rudiments are the same, I have fastened a steel piece on the rear of the Air Filters
Cheers