Butterfly Springs
Discussion
Hi All
Just noticed that both my springs that sit at the back of each butterfly spindle (the ones with a loop in the one end and a 90 degree bend in the other wrapped around each spindle) are broken.
Are these just throttle return springs or are they to prevent backlash?
I also have 2 springs attached to the passenger side rear airbox bracket and throttle linkage to return the butterflies to the closed position when the pedal is released.
Are the 2 broken springs easy to replace and where can I get them from as they look quite specialist?
Kind regards
Simon
Just noticed that both my springs that sit at the back of each butterfly spindle (the ones with a loop in the one end and a 90 degree bend in the other wrapped around each spindle) are broken.
Are these just throttle return springs or are they to prevent backlash?
I also have 2 springs attached to the passenger side rear airbox bracket and throttle linkage to return the butterflies to the closed position when the pedal is released.
Are the 2 broken springs easy to replace and where can I get them from as they look quite specialist?
Kind regards
Simon
The first ones mentioned are to keep the rod that the butterflies are attached to in place, the rods only come out once the butterfly plates are removed, but best replace them.
The springs on the passenger side air box are, as you stated to keep the butterflies in a closed position when not on the throttle.
The springs on the passenger side air box are, as you stated to keep the butterflies in a closed position when not on the throttle.
Nickccc said:
The first ones mentioned are to keep the rod that the butterflies are attached to in place, the rods only come out once the butterfly plates are removed, but best replace them.
The springs on the passenger side air box are, as you stated to keep the butterflies in a closed position when not on the throttle.
Thanks NickThe springs on the passenger side air box are, as you stated to keep the butterflies in a closed position when not on the throttle.
That's what I thought, not a 2 minute job then mate!
Regards
Simon
Nickccc said:
One as standard, though two on some cars as a fail safe.
^^^^^^^^^^wot he said
^^^^^^^^^^A few people have had the single spring snap and the throttle butterflies stick wide open
In this case 2 springs are better than 1
Regards
Simon
Edited by SimonKD on Sunday 30th October 20:24
pmessling said:
might add another then, safety first
Not sure if anyone else has noticed this, but the problem I see with the return spring is that with the angle it pulls on the arm. When the throttles are closed it pulls pretty much along the length of the arm, so all it does is wear the bodies. I'd like to fit some new torsion springs too, but I probably won't get round to finding a supplier for a bit. How many would be interested? - we should probably do this as a group buy.
Steve.
I would repectfully say that if you remove the large spring connected to your airbox and the throttles don't close you have a problem.
The two springs on the end of each butterfly rod should be more than enough to close your throttles. The spring on the airbox IS THE FAILSAFE. Two springs on the airbox is plastering over the problem, and if I see this on a car I ask them where they got their last service from.
.
People whos butterfly springs are busted and use the spring on the airbox to close the throttle will alway fall into the trap of having high engine tickover, and will likely blame the joints that connect the two throttles together. This is why there are so many threads on upgrading these linkages. In reality this isn't necessary.
IMHO no matter how you mess with the throttle linkages there will always be a little 'play', and if the throttles are being kept shut with the airbox spring this 'play' becomes improtant with keeping the butterflies closed. Hence the problem starts.
The butterfly springs often have a problem keeping the throttles closed because either the way the head has been bolted down, or the way the butterflies have been set up, or your rods are just bent.
It was poor initial manufacture that should have had ballraces along each butterfly rather than rely on metal to metal.
I hope that lot all makes sense. In short, setup your engine with NO failsafe spring attached to the airbox, and only put the spring back on as a failsafe once the car is operating with no need for it. Your car will work much better this way
The two springs on the end of each butterfly rod should be more than enough to close your throttles. The spring on the airbox IS THE FAILSAFE. Two springs on the airbox is plastering over the problem, and if I see this on a car I ask them where they got their last service from.
.People whos butterfly springs are busted and use the spring on the airbox to close the throttle will alway fall into the trap of having high engine tickover, and will likely blame the joints that connect the two throttles together. This is why there are so many threads on upgrading these linkages. In reality this isn't necessary.
IMHO no matter how you mess with the throttle linkages there will always be a little 'play', and if the throttles are being kept shut with the airbox spring this 'play' becomes improtant with keeping the butterflies closed. Hence the problem starts.
The butterfly springs often have a problem keeping the throttles closed because either the way the head has been bolted down, or the way the butterflies have been set up, or your rods are just bent.
It was poor initial manufacture that should have had ballraces along each butterfly rather than rely on metal to metal.
I hope that lot all makes sense. In short, setup your engine with NO failsafe spring attached to the airbox, and only put the spring back on as a failsafe once the car is operating with no need for it. Your car will work much better this way
Steve_T said:
Have you got them - don't see anything on the RG site and on the Power site the only option is add to wish list - although it doesn't specifically say out of stock.
Give them a call, they aren't listed E3635. I may have had the last 2 from RG but Power should still have some.FarmyardPants said:
^ makes sense. I suppose the big spring will keep one bank of throttles closed, and the balance bar (with associated slop) keeps the other closed, if the torsional springs aren't working 
Well exactly. If you've busted both your butterfly springs cos noones checked and to be honest they aren't exactly battleship material. Then the airbox spring slams one side shut and the other side is at the mercy of the play in the throttle linkages.julian64 said:
FarmyardPants said:
^ makes sense. I suppose the big spring will keep one bank of throttles closed, and the balance bar (with associated slop) keeps the other closed, if the torsional springs aren't working
Well exactly. If you've busted both your butterfly springs cos noones checked and to be honest they aren't exactly battleship material. Then the airbox spring slams one side shut and the other side is at the mercy of the play in the throttle linkages.Because the cable operates one side and the other (with the idle stop) is pulled by the linkage, I was getting a significant lag on the drivers bank due to a sloppy linkage. Both side were closing fine on their springs, but eliminating play in the linkage made a noticeable improvement in smoothness by bringing them into sync.
If you have a slopply throttle linkage though, and they pretty much all are. Then you can still adjust even a sloppy linkage to both open at the same time.
Not ideal but it'll still work fine.
However if the throttle linkage is responsible for opening and closing it shut then you can't get away with anything but a perfect 'no play' linkage. Pretty much asking for the earth there with the original setup, unless the butterfly springs are working.
I could well be wrong and I often am, but this was my take on it. I had to make a new butterfly rod for mine as the old one was actually bent, by the end on the bench the butterfly springs were snapping the butterflies back into place just fine.
Then I put the inlets back on the car and bolted them down, only to find the straight butterfly rod I'd made then also seized in the hole as the holes were now effectively bent out of shape.
Eventually after a lot of faffing I got them working properly.
Not ideal but it'll still work fine.
However if the throttle linkage is responsible for opening and closing it shut then you can't get away with anything but a perfect 'no play' linkage. Pretty much asking for the earth there with the original setup, unless the butterfly springs are working.
I could well be wrong and I often am, but this was my take on it. I had to make a new butterfly rod for mine as the old one was actually bent, by the end on the bench the butterfly springs were snapping the butterflies back into place just fine.
Then I put the inlets back on the car and bolted them down, only to find the straight butterfly rod I'd made then also seized in the hole as the holes were now effectively bent out of shape.
Eventually after a lot of faffing I got them working properly.Gassing Station | Cerbera | Top of Page | What's New | My Stuff