Accelerator Cable for Dual Carbs ? Options

[cary]

In putting Mark's engine back in and replacing the broken accelerator cable. It seems the cable isn't quite long enough to work/fit correctly. In the FI arrangement the cable crosses the engine at 45 degrees. In dual carbs it needs to come at the bar at 90 degrees. Which pulls the bowden out of the firewall. Which will allow water down the cable tube.

What have others done to work around this ?

[Darren C]

Exactly Rhodyguy, thanks.(Is that you cutting your line on this fish?)

So this morning I took a walk down to my garage and took off a few dust covers to carry on with the evolution of the humble throttle cable story.
I pondered a while on which cars to show you that would illustrate changes, and settled on jumping 40 years forwards into the 1960’s.
Solid rod linkages were common on all makes of pre-war cars as I’ve commented on already.
This is ok when your engine is low power and hard mounted in the chassis. Just think of the old vintage car movies where the engine shakes the car and its occupants roughly when idling along.
As things progressed the high end manufacturers did much modification to dynamically balance their engines and included torsional dampers and such like before they conceded to flexible mounting their motors and accepting at idle and on acceleration they’ll move.
This was the Eureka moment that threw the solid throttle linkage from pedals to carburettors into depths of history and the age of the Bowden cable throttle was born.
But just before we make the jump, I’ll show you an example of how engineers who knew the deficiencies of the cables dug their heels in to overcome rocking engines with solid rod throttles.
In this example a Cardan shaft is used with a solid flexible plate coupling at the end it leaves the bulkhead, and a sliding rose ball joint at the end it mounts to the bellhousing.

(IMG:http://www.914world.com/bbs2/uploads_offsite/i265.photobucket.com-18255-1463227831.1.jpg)

This allows for a solid accelerator mechanical link to be achieved between the fixed body of the car (and gas pedal mount) and the motor which very cleverly doesn’t pull or push on the throttle itself as the engine is free to rock.
This is then linked in the traditional way with rods and ball joints to another interesting mechanical transition bell crank that incorporates a kick down device in this automatic transmission version.

(IMG:http://www.914world.com/bbs2/uploads_offsite/i265.photobucket.com-18255-1463227831.2.jpg)

Finally linking multiple carburettors with finite adjustments. Note the manufacturers choice in weighted self lubricating brass connection blocks that build in a pendulum safety factory to compliment the return springs in a failure mode. Not infallible (nothing is) but boy if you can see and understand the detail and reasoning behind the design you have to admire it.

(IMG:http://www.914world.com/bbs2/uploads_offsite/i265.photobucket.com-18255-1463227831.3.jpg)

Obviously this was high end market when it was built and budgets were a little different to the FMCG marketplace of today where even the motorcar is becoming a disposable asset instead of a keeper.
In the mainstream however at this time (I’m still talking 60’s) the norm was a Bowden cable throttle. Cheap and easy solution, and perfectly good when kept in good condition and run & operated correctly. As I’ve commented in previous quotes, KISS, (keep it simple stupid) the cable ticks all these boxes in the right application.

So jumping forward again to the 1970’s where our 914’s live, I chose another of my cars to show a little further throttle evolution relevant to the aftermarket carb conversion of a 914 where this thread has its origin. Having opened a few hoods, this car has a Bowden cable from gas pedal to engine and then the linkage is split to service two sides of the motor.

(IMG:http://www.914world.com/bbs2/uploads_offsite/i265.photobucket.com-18255-1463227832.4.jpg)

Again the design of choice is cable to main engine link, then solid link bars & rods to the destination. In this picture it’s worthy to note that the pivot points of the linkage rods are run in ball bearing races, and the tie rod ends have wire locked ball and socket ends to combine and reduce any play in the system between the banks.
All in all it provides as best it can an intrinsically safe and adjustable linkage with devices to remove mechanical wear and friction. I’ve rebuilt this twin cam & the previous V8 and I can tell you again, that they have taught me a great deal.

So why am I rambling on 914 world about my own indulgences?
Sure I’ve owned, built & restored 20+ VW bugs from 1952 thru 78.
8 or 9 VW busses (I loose track)
Numerous Ghia’s, Type III Variants, notchbacks, 412 etc.
Lots of Porsche from 356, 911, 924, 944, 928, 968, 986 (all versions) to Cayenne Turbo and now my first 914 in the Build-Off Challenge.
As much as I love them all, I’m not a one stable guy, I have god knows how many other brand cars, and had so many cars in total over the years I do genuinely have no idea on the figure.
One thing is for sure it’s opened my eyes to how many ways there are (and have been in the past) for an infinite number of manufacturers to re-invent the wheel.

Racer Chris, you wrote…”You're just too smart for the rest of us Darren”

Well; I’ll let others be the judge of that, being smart is a genetic thing (like Rhodyguy being 50% banana) man is only just on the verge of being able to manipulate genetics. In the meantime we are stuck with the cards we’re dealt.
There’s always a yin and yang Chris. My ex-wife would say I could tell her pi to 50 decimal places but I was shit in bed. (Still have kids though, yep someone was foolish enough to let me breed)
Maybe you’re one of those guy’s who’s better in bed than me Chris, who knows, none of us has it both ways and does it really matter anyway when all we end up wanting in life is comfortable shoes and absorbent underwear.

So, the point of this rabble is?

Look at ALL (not just one suppliers) 914 carb linkage kits, cable routes and general engineering quality and decide which one is for you.
I’ve made my opinions (very strongly it seems) known, and out of frustration I made my own linkage (only because I was fortunate enough to be able to do so)

And maybe, just maybe, some of you who’ve walked into this minefield here may have the balls to say “hey I think this product could be better too”