Timed on #1 or #4 cyl?

[keith m 131]

Theo,

I have just been out to the car and the freeplay in the pedal is basically zilch. I think you have come up with the answer. I dont think I have enough clutch pedal travel and that is why I have to adjust the clutch tighter to be able to select gears. So if the cable is adjusted tightly then it wont be able to completely disengage.
Now that would explian the car struggling to achieve a higher speed and the drone because the engine is over revving in relation to the speed the car is doing.

I reused the fiat pedal box and servo unit but I guess the pedal is either the wrong shape (too near the floor) or the cable is too short or both.
I have a spare cable so I could weld a threaded rod to the end of the cable to extend the travel. But I think your right about the pedal travel, the pedal is most likely hitting the floor before full travel is achieved hence I have had to adjust the cable to suit.

Boy do I feel good right now.

Keith

[131 Lover]

Hi Keith !
If i was you i would put 13" tires on it and try again,if you have any!
 i used to have 132, 14" winter tires on my 131 special when i was in my younger age, i can remerber that it was struggling to make up to the toppspeed but always failed!

Also the speedometer showed wrong because the different ratio of the 14" winter tires,it felt ok at lower speeds but was struggling att higher!

What tires are you using with the 15"wheels?
Find a tire calculator and do the math..

Slipping clutch, even at high speed should not last very long time without slipping all the time..
Just my point of wiew,
Regards
Alf

[Thotos]

I dont think I have enough clutch pedal travel and that is why I have to adjust the clutch tighter to be able to select gears.

So the reason for your problem is what I said right at the beginning You've put the engine and gearbox in the wrong car 

[keith m 131]

Thanks Alf,

I will keep what you say in mind but I think Theo has uncovered the problem in the clutch.

Keith

[keith m 131]

You did indeed,

but maybe if I fix the problem then it may forgive me. But as I said I could have been ruthless and sent it to the big scrap yard in the sky.

Gloating rights are all yours.

Keith

[Thotos]

Gloating rights are all yours.

  Seriously though, no need for gloating; I'm glad to have been of help if I was 
Changing the cable is not going to do it I'm afraid. You need to increase pedal travel or you can change the pedal pivot point (fulcrum) or you can extend the pedal above the pivot point so the point where the cable is attached to the pedal travels more (but that will give you a heavier clutch pedal).  Or you can shorten the clutch actuating arm (drill a new cable hole nearer the gearbox) but once again that will make the clutch heavier.

[keith m 131]

I was planning on cutting the pedal shaft itself and weld it back at a different angle so it wont hit the floor so soon. It wil bring the pedal higher so more travel, what do you think?

keith

[Thotos]

I was planning on cutting the pedal shaft itself and weld it back at a different angle so it wont hit the floor so soon. It wil bring the pedal higher so more travel, what do you think?

That would work provided there's enough room for the other end of the pedal (where the cable connects) to travel the distance without hitting anything. But you don't want the clutch pedal to be higher than the brake pedal. I like the brake and clutch pedals to be at the same height as not only it looks better but makes it easier and quicker to move from one pedal to the other without hitting the side of the pedal. Can you not reposition the complete pedal box to allow for more clutch pedal travel?

[david]

Right I've got it clock the car with a friends car and see if the speedometer reading is roughly the same although you should be able to judge 80mph.
I did look at a morris minor years ago that had a 2000 t/c fitted and he was complaining about lack of performance but he had a right mix of parts in it ie a mk3 supermirafiori 2000 engine a 124 gearbox that was notchy and horrible and a rear axle from an 1800 morris marina and it was sluggish and the old gent who was 82 was well impressed with my 131 sport as I took him down the road and lit it up but he was going to come back so I could try and sort it out but I never saw him again ! maybe he popped his clogs ? hope it wasn't my driving 

[keith m 131]

There is not a lot of room in the footwell so moving the pedal box would probably be do-able but very difficult, as the servo is bolted through the pedal box aswell, and if I was to space it off the bulkhead then the servo piston might not be long enough to reach the brake pedal. I will explore the option of changing the angle of the pedal first.
I agree about the pedals being the same height but my installation may not allow that.

Tomorrow I will do some measureing and see what I can do to get more pedal travel.

keith

[keith m 131]

Hi David,

I have tried it with the sat nav and that was pretty close.

When building the car I was very conscious of keeping all the running gear the same, I was aware of the problems that mismatching parts can bring.

I really think that the lack of clutch pedal travel is the problem, it is now obvious that if I have no freeplay then the clutch cant be engageing fully hence the high rpm and reduced drive.

Keith

[keith m 131]

Theo,

in your post you say about changing the pivot point, extending the pedal above the pivot or shorten the clutch actuating arm.

Can you upload some basic hand sketches showing what you mean then I will have all the possible options whilst trying to work out the best option, just so I fully understand what you mean. It may also help me come up with another idea.

Keith

[keith m 131]

Can anybody tell me the relaxed length of the clutch return at the gearbox, mine doesnt have one fitted so I need to find a similar replacement.

regards

keith

[Thotos]

Can anybody tell me the relaxed length of the clutch return at the gearbox, mine doesnt have one fitted so I need to find a similar replacement.

Do you mean the return spring on the actuator arm? While I wouldn't say "you don't need one" (as you should really have one) my car's never had one and I also removed it from my previous Sport and never had problems. The 131 clutch pedal has a strong return spring on it.

in your post you say about changing the pivot point, extending the pedal above the pivot or shorten the clutch actuating arm.

Changing the pivot point won't be easy. You'll probably need to modify the complete pedal box for that so I wouldn't even try. I think your best bet is to extend the pedal at the top so the cable connects higher up and will have longer travel. But you might need to drill a new hole in the bulkhead for the cable to go through higher than before.

A clutch pedal is a first order lever where the fulcrum or pivot point is between the effort point and the load point.



In the clutch pedal, the effort point is the pad where you press with your foot and apply effort and the load point is where the cable is connected. If you increase the pedal at the top making the resistance arm longer, the tip of the extended pedal (where the cable is connected) will move a longer distance when the clutch is pressed.

The clutch actuating arm is a second order lever with the fulcrum or pivot point at one end.



The effort point is where the cable is connected and the load point is the clutch bearing. If you move the effort point nearer the load point, that is drill a new hole for the clutch cable nearer the gearbox, then for the same movement of the cable you'll get increased movement at the load point. Disadvantage of this is that more effort is required so the clutch will be heavier.

Depending on the amount of extra travel you need to get, you might have to use both the above options or just one of them.

[keith m 131]

Thanks Theo,

very informative, are you by any chance a physics teacher? The idea of drilling a new hole nearer to the gearbox sounds like the easiest option and hopefully I will get the extra travel I need. Even though I may end up with my left leg looking like Arnold shwartseniger right arm but if it works and my car runs as it should then I can live with that. I am not even bothered if the pedal gets so high that I knee myself in the chin when changing gear, on second thoughts that maybe going a bit too far.

Yes I was asking about the return spring fitted to the actuator arm, I measured the location and picked up one 150mm long to day and will make up a extension hook to achieve a pedal that is not too heavy.

Keith