mk1-forum.net

Having just got my Arden on Amals in and running, the throttle linkage is really a piss poor design, has anyone redone it so it actually works in a nice and progressive manner, it just seems a bodge the way it has been done.
Just thinking maybe something TIG'd up to go on the exhaust manifold studs with cable then another bracket TIG'd onto the bar with the cables attached mid way along so the throttle cable is just above the centre of the rocker cover.
Just interested if anyone else has done something that actually works??
Only managed to set fire to it twice but got the fuel pressure sorted and all ok, bit of crud in one carb where the float needle sits didn't help with stopping fuel gushing down the front of the engine mind!

May not a big help, but i gave up with those Amals after 1 year or so of trying to make them work.

Sold them and fitted Weber's wich now run fine and are quite reasonable concerned the fuel consumption...

linkage worked fine for me, it was heavy but thats about it?, you need to worry more about the limitations of the amals rather than the linkage!

Does the setup on OBL45F help?

http://mk1-forum.net/viewtopic.php?p=315080#p315080

Fanfaniracing wrote: ↑Tue Jan 31, 2023 8:43 pm May not a big help, but i gave up with those Amals after 1 year or so of trying to make them work.

Sold them and fitted Weber's wich now run fine and are quite reasonable concerned the fuel consumption...

It runs nicely, what set up did you put on re Webers? twin 40's or 45's? and I'm guessing the 600mm manifold?

Richspec wrote: ↑Tue Jan 31, 2023 11:54 pm linkage worked fine for me, it was heavy but thats about it?, you need to worry more about the limitations of the amals rather than the linkage!

Yes it works ok, heavy as you say but do have big feet!! Just seems a bit of an afterthought!! I'm guessing limitations you mean the cold starting and tending to set fire to themselves??

MrNoo wrote: ↑Wed Feb 01, 2023 8:07 am

Fanfaniracing wrote: ↑Tue Jan 31, 2023 8:43 pm May not a big help, but i gave up with those Amals after 1 year or so of trying to make them work.

Sold them and fitted Weber's wich now run fine and are quite reasonable concerned the fuel consumption...

It runs nicely, what set up did you put on re Webers? twin 40's or 45's? and I'm guessing the 600mm manifold?

I made a Manifold myself, so the Webers just fit under the Bonnet with the Airbox

i have replied for part of your questions on linkages, but i have put it in the story on OBL45F restoration in australia. They are poor by todays expectations, but there is much more.
cheers Lindsay

MrNoo wrote: ↑Wed Feb 01, 2023 8:09 am

Richspec wrote: ↑Tue Jan 31, 2023 11:54 pm linkage worked fine for me, it was heavy but thats about it?, you need to worry more about the limitations of the amals rather than the linkage!

Yes it works ok, heavy as you say but do have big feet!! Just seems a bit of an afterthought!! I'm guessing limitations you mean the cold starting and tending to set fire to themselves??

Yeah big feet here too
Yes those exactly, it does tend to get old real quick..! But it does depend on how much use it gets?
Finding someone to set them up properly isnt easy either, you can get them 'pretty' good yourself but thats about it.

lomin wrote: ↑Wed Feb 01, 2023 10:23 am i have replied for part of your questions on linkages, but i have put it in the story on OBL45F restoration in australia. They are poor by todays expectations, but there is much more.
cheers Lindsay

Yes many thanks, your linkage set up and positioning of the various levers/bellcranks is the same as mine.

Richspec wrote: ↑Wed Feb 01, 2023 11:07 am

MrNoo wrote: ↑Wed Feb 01, 2023 8:09 am

Richspec wrote: ↑Tue Jan 31, 2023 11:54 pm linkage worked fine for me, it was heavy but thats about it?, you need to worry more about the limitations of the amals rather than the linkage!

Yes it works ok, heavy as you say but do have big feet!! Just seems a bit of an afterthought!! I'm guessing limitations you mean the cold starting and tending to set fire to themselves??

Yeah big feet here too
Yes those exactly, it does tend to get old real quick..! But it does depend on how much use it gets?
Finding someone to set them up properly isnt easy either, you can get them 'pretty' good yourself but thats about it.

Yes I imagine! Well, it will be a high day and holiday soon around machine so will be used as much as that! Slark's have had it on the rollers so its been set up, they had 135 @8,000 out of it but not got a race cam in it. I think I will see how I get on with it, may engineer another linkage or if they are a real pain swap to webers.

Re the heaviness of the peddle, you can get reduced pressure springs for Amals which will help this to some extent.

Amals on 8 ports were always a bit of a compromise.

I had amals on my Commandos. Never understood them - in theory or practice! Most Norton Commando owners like me replace them with an easily understood SU

I have rallied my 8 port on Amals for a couple of years now.
I've tuned and modified the cards to reduce throttle pedal effort and achieve better AFR over all throttle/RPM combinations. It's still not perfect but very driveable.
Biggest gains were redesigning the throttle linkage and reducing the float levels and fuel pressure. All of my testing was done using a Stack Lambda gauge with the sensor inserted at the end of the Y part of the exhaust. Access made via a 25mm hole where the floor starter would be.
Very time consuming and laborious process of changing jets, needle height and slide cutouts, running the same test route and noting the AFR at various conditions.
Image below of my set-up.

This has always been one of my favourite setups! Yours looks great.

Getting this setup tuned is one of the hardest things to do on a Mini. I am really pleased that you have found a way of getting them running much better. Have you thought about moving the throttle linkage lever point to the middle, this should reduce "lag" caused by twisting of the shaft. Just a very minor thought, but I thought it was worth mentioning.

Looks a nice set up!! I took the Amals off and fabricated a pair of short inlets and used a pair of Weber 40's, seems to go very well indeed but always wonder how much the short inlet is holding it back. Managed to get them all under the standard round nose bonnet. Ended up at 137@7,500 with the rally cam in it. Drives very nicely indeed, bit of an animal.

MrNoo wrote: ↑Tue Feb 13, 2024 5:30 pm Looks a nice set up!! I took the Amals off and fabricated a pair of short inlets and used a pair of Weber 40's, seems to go very well indeed but always wonder how much the short inlet is holding it back. Managed to get them all under the standard round nose bonnet. Ended up at 137@7,500 with the rally cam in it. Drives very nicely indeed, bit of an animal.

How is the low RPM response with the short inlet manifold and Webbers?

Croz wrote: ↑Tue Feb 13, 2024 8:57 am I have rallied my 8 port on Amals for a couple of years now.
I've tuned and modified the cards to reduce throttle pedal effort and achieve better AFR over all throttle/RPM combinations. It's still not perfect but very driveable.
Biggest gains were redesigning the throttle linkage and reducing the float levels and fuel pressure. All of my testing was done using a Stack Lambda gauge with the sensor inserted at the end of the Y part of the exhaust. Access made via a 25mm hole where the floor starter would be.
Very time consuming and laborious process of changing jets, needle height and slide cutouts, running the same test route and noting the AFR at various conditions.
Image below of my set-up.

Paul at last your here.
I thought most of the test miles were just because you love driving the mini and my coffee
This car is excellent that’s down to Paul’s engineering and enthusiasm and probably the most miles covered by an 8 port ever..
Dave..

Croz wrote: ↑Tue Feb 13, 2024 5:34 pm How is the low RPM response with the short inlet manifold and Webbers?

If you bury the throttle at low rpm it seems cammy, but if you're gentle it's fine and really pulls hard. I suspect it's a combination of the cam, large valve head and short (they are stupidly short) inlets. Once you're over 1500 you can bury the throttle and it's fine. But it certainly loves to rev, torque curve is pretty much flat from around 3k to 7k, it does have a 3.4 final drive which makes it nice to drive on the road.

Any chance getting a picture of your setup?