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914World.com _ 914World Garage _ twin throttle linkage...
Posted by: crash914 Mar 22 2005, 07:11 PM
ok, for all you twin carb/throttle body experts out there....
I have a redline weber twin throttle body set up....got the linkage cross bar etc. from the same place...
I can't get this stupid thing to work correctly 
I can get the right side to open and close fully and the other won't open all the way...I have switched everything around many different ways...even changed out the linkage cams...???
The linkages rotate into the center of the motor...flip the carbs around? so they rotate out?
the ball for the cross bar is down...if I flip it over, it will interfer with the air cleaner?? THis is driving me crazy!!! the only thing that I can figure out is that the holes are drilled off. one must be out further than the other..or the carbs need to rotate different amounts...???
I also can't figure out how to mount the crossbar to the front of the motor...I guess I could make up another cable stop...but???
I guess I can shoot some pics when I cool down...now for 
thanks!
Posted by: MecGen Mar 22 2005, 07:24 PM
I think you would need to see a pic,
someone here will show you one for sure and if not,
tomorow I'll snap a pic. Maybe run a search in old posts.
Good luck
cheers
Joe
Posted by: john rogers Mar 22 2005, 07:26 PM
Couple of things to check. Does each one open fully if the cross linkage is disconnected? They have to work that way since when setting them the linkage is disconnected. If you hook one side up will it open fully? How about just the other side will it open fully? If the problem is when both are hooked up then the linkage is flexing due to some misalignment. The drop shafts should be as close to vertical as possible and make sure the carb cams or what ever they are called are on the throttle shafts fully and tight. I've had them come loose and rotate some on their own. Finally make sure the arms on the cross shaft are tight and not slipping when you work the throttle. Grab'm and see it they move on the shaft. Good luck.
Posted by: crash914 Mar 23 2005, 06:30 AM
Thanks for the insite....
yes, the throttles open fully when disconnected.
Yes the cams and levers are tight..
It looks like the cams (throttle levers) should be mirror image. They are not...looks close, but they are not exact mirrors.
Anyone using a easy to set up linkage? whos? this one looks good but is a POS...
I also think that I need shorter drop links..hmmm...got a couple of places to look for those...
ready to can the whole thing.... 
Posted by: Tom Perso Mar 23 2005, 06:56 AM
Get the CB Performance linkage setup. I think it's $100 or so from them. It's way better than the redline one.
My friend has a Redline one on his 912 motor, it works fine... But, it does look cheesy.
Later,
Tom
Posted by: Joe Sharp Mar 23 2005, 08:13 AM
If you have a center piviot linkage it is a POS. Won't stay tuned as the motor changes temp and hard to get right in the first place. I have the Hex Bar linkage on 2 sand rails and one of the 914s. Esay to adjust and once adjusted, if you are careful about how you treat them they will stay in tune for you.
I did these in '92.
Joe
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Posted by: Aaron Cox Mar 23 2005, 08:42 AM
never had a problem with my CB linkage....
miles ahead of bugpack, redline etc....
Posted by: rhodyguy Mar 23 2005, 09:26 AM
i don't know the dial in for the center pull linkage. i presume there is one rod for each side. if the rod length run is shorter on one side there may not be enough travel to fully open the butterflies on the that side. the triad pictured is far and above the best linkage i've EVER dealt with. it DOES cost more than other, imho, inferior products, but you get what you pay for. btw, the thottle cable holder comes WITH the linkage. it may seem insignificant, but when the linkage from cb shows up without one you'll be cobbing something together.
k
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Posted by: GBallantine Mar 23 2005, 09:54 AM
I use the CB Performance Hex Bar Linkage setup on my twin Weber IDF 44 race car . In order to have the carbs in sync on opening and closing the drop shaft linkage must be in a 90 degree vertical position to the carb cam. If you look at the left and right side of the air cleaner base plates the attachment arms where the hex bar connects are not a mirror image, they are offset. What I did was cut off and reweld the arm to create a mirror image on each base plate allowing the drop shaft linkage to connect in a straight line to the carb. Problem solved, carbs in sync.
GB
Posted by: rhodyguy Mar 23 2005, 10:09 AM
staying in the verticle plane absolutely, is hard to achieve with regards to the down rods. use of hiem joints, like the triad, helps avoid the binding. i was pissed off enough when the cb one arrived without a t.c. holder. having to cut and weld a brand new item to optimise it's operation? the triad is a plug and play. powder coated out of the box.
k
Posted by: Aaron Cox Mar 23 2005, 10:12 AM
kevin,
it took me 5 minutes tops to make a good throttle cable holder for my CB setup.
i like it alot.... the triad looks great too.
(Skline - post my engine picture)
Posted by: rhodyguy Mar 23 2005, 10:17 AM
i just bolted mine on after i opened the box. 
does the powder coating on yours match the cross bar? bottom line...use what works for ya. another thing i didn't like on the cb, was the goofy little springs that ride against the ball ends of the rods. the rod will travel a bit as the springs compress, imho. get the engine good and warm, and set the travel on the cross bar with the end bolts and jam nuts. done deal.
k
Posted by: Aaron Cox Mar 23 2005, 10:20 AM
aluminum has no need to be powdercoated
i agree....both work...... both look great....
use what works for ya...
Posted by: rhodyguy Mar 23 2005, 10:24 AM
you got me there!!! it does like to be polished after it dulls a bit. 
k
Posted by: crash914 Mar 23 2005, 07:27 PM
some pics of the set up...
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Posted by: Aaron Cox Mar 23 2005, 07:29 PM
| QUOTE (crash914 @ Mar 23 2005, 06:27 PM) |
| some pics of the set up... |
there is your problem! links need to be vertical! that pivot needs to be 4" higher!
Posted by: Aaron Cox Mar 23 2005, 07:30 PM
not sure if you can see... but the pivot onb this is higher...and the links are vertical
my motor 
Posted by: Series9 Mar 23 2005, 07:49 PM
You've got things backwards and upside-down. Turn the large gold piece on the end over so the pivot is above the top of the TB. I believe you will also have to flip the linkage end-to-end after doing this so it will fit.
Posted by: Series9 Mar 23 2005, 07:53 PM
After looking at it some more, I think you can just turn over the gold pieces on the end w/o flipping.
Posted by: crash914 Mar 24 2005, 06:04 AM
I need to get some more pictures...
When I flip over the gold plates...I can't install the air cleaners!!
Thats what got me thinking that my adjustable linkage is too long..
Stoooopid computer locked up last night and so I could not send any more...I will send some more later...thanks for the insite...
Posted by: Joe Sharp Mar 24 2005, 08:43 AM
That linkage should work out just like the picture of the Candy Apple Red Mid-engine sand rail above.
Joe
Posted by: Joe Sharp Mar 24 2005, 08:52 AM
I thought I had that bracket. Sorry about the sand, its off my othe sand rail. I like the background of this pic.
Joe
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Posted by: rhodyguy Mar 24 2005, 09:03 AM
are the arms movable on the rod? if so, you need to slide them out to the point where they are just clear of the filters. that may help with the shallow down angle. when you go to dial them in try this. filters off, engine warm. back one idle screw off. use the other one to raise the idle to the point when the pulses don't effect the sycronometer ( i use 2700 rpm). adjust one of the rods to match the flow, or the ammount the throttle plates are open. turn the idle back down and turn the idle screw not making touching back in to just enough to make contact without affecting the idle. shut the engine down, have someone depress the gas pedal and look to make sure the throttle plates are fully opening. i have huge k&n filters, i had to use the "off road" variety of cb's base plates. the cross bar was too wide and i had to trim the length and redrill the ends. then i got rid of the pos and put on the triad.
k
Posted by: Aaron Cox Mar 24 2005, 10:05 AM
| QUOTE (rhodyguy @ Mar 24 2005, 08:03 AM) |
| are the arms movable on the rod? if so, you need to slide them out to the point where they are just clear of the filters. that may help with the shallow down angle. when you go to dial them in try this. filters off, engine warm. back one idle screw off. use the other one to raise the idle to the point when the pulses don't effect the sycronometer ( i use 2700 rpm). adjust one of the rods to match the flow, or the ammount the throttle plates are open. turn the idle back down and turn the idle screw not making touching back in to just enough to make contact without affecting the idle. shut the engine down, have someone depress the gas pedal and look to make sure the throttle plates are fully opening. i have huge k&n filters, i had to use the "off road" variety of cb's base plates. the cross bar was too wide and i had to trim the length and redrill the ends. then i got rid of the pos and put on the triad. k |
how tall are your filters kevin?
Posted by: rhodyguy Mar 24 2005, 10:25 AM
i bet his arms bang on the fliter bases now that i think about it and that's why his arms are angled that way. mine measure 3 1/4"t x 5 1/4"w x 8 1/3"l. os measurements. how much $ was that redline linkage?
k
Posted by: Travis Neff Mar 24 2005, 10:42 AM
I'd add that your droplinks - are they right and left hand thread? meaning if you loosen the jam nuts can you spin the link and adjust the size, or do you have to remove the heim joint and spin it around?
If you have the right/left threads you can make minute adjustments to get the links on either side exactly the same, plus it is a helluva lot quicker and easier to make adjustments - move your slider arms closer to the carbs too.
Posted by: Aaron Cox Mar 24 2005, 11:07 AM
not worth fuching with it...
buy a Triad or a CB linkage
Posted by: rhodyguy Mar 24 2005, 11:32 AM
-1. get the triad. oh, too much money 
. as compared to a set of auto cross only tires? in herb's picture the base plate for the filter is not installed.
k
Posted by: Joe Sharp Mar 24 2005, 01:20 PM
This the way that I approch it. (---- Levers work best in the middle of thier arch.
Bring the rods to the middle of thier adjustment.
Make them the SAME length.
At half throttel the cam on the throttel shaft should be at 90 to the linkage rod
and the lever on the hex bar should be at 90 to the rod
the throttel lever to the cable should be at 90
and the cable should be pointing at the hex bar lever cable piviot point.
Every thing working in the middel of its arch, as close to 90 deg. as you can get it.
I have some extra al Hex-Bar stock, If you PM me with the length of yours I'll send you some, but you'll have to drill it yourself.
Posted by: crash914 Mar 24 2005, 05:46 PM
All good ideas guys, keep them comming....
The cost of this linkage was about $120.00 I think....getting old sucks...
you are also correct that I have to angle down the aluminum arm so the arm and linkage doesn't hit the air cleaner base.??/
here are some more pics..
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Posted by: crash914 Mar 24 2005, 05:50 PM
nother.
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Posted by: rhodyguy Mar 24 2005, 05:54 PM
other agreeing that it's not working for you i can't help with the linkage fix for that one. is that a cb f.i. set up?
k
Posted by: crash914 Mar 24 2005, 05:57 PM
as you can see from the picture above, the angle is to clear the air cleaner...
I keep comming back to the links are too long..
they are the right/left thread type...10/32 sized. I am thinking about re-threading the right hand part, then cutting them down so they are less than the 3 9/16 I now get...
Also the throttle butterfly linkage is not a perfect mirror image..that is off by I am guessing 1/8 inch or so...
What else do you guys need to see??
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Posted by: Joe Sharp Mar 24 2005, 06:03 PM
Sorry Herb But it looks like there is no room for the air cleaner. Duh!!! I don't know if you could shorten that much.
WTF was the manufacture thinking.
Joe
Posted by: crash914 Mar 24 2005, 06:06 PM
Joe, you mean swap the throttle bodies? So the butterflies swing out?
or the big aluminum arms??
or the cross bar socket??
Posted by: Joe Sharp Mar 24 2005, 06:18 PM
The Socket goes up. Can you show me a pic of you air cleaner? I'm going to clean this before i post another picture of it.
Joe
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Posted by: Joe Sharp Mar 24 2005, 06:21 PM
Then I have a problem with the return spring.
Joe
Posted by: crash914 Mar 24 2005, 06:30 PM
problem with the air cleaner...
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Posted by: Aaron Cox Mar 24 2005, 06:37 PM
Flip the pivot....
needs to be above the carb body
Posted by: crash914 Mar 24 2005, 06:45 PM
O-tay did the flip...
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Posted by: Joe Sharp Mar 24 2005, 07:10 PM
And the return spring clip is pointing up.
Joe
Posted by: skline Mar 24 2005, 07:24 PM
last call
get a better linkage - CB
Posted by: bperry Mar 24 2005, 10:22 PM
Not sure I'd toss in the towel just yet.
I do agree with you that the drop shaft arms look a bit too long in your setup.
One thing that I notice immediately is that you are using FI bodies
and not IDF carbs. It also appears that your distance from the center
of the butterfly shafts to the linkage plate is much smaller than on
IDFs. On 40 IDFs it is about 3.5" from the center of the shaft to where
the plate mounts. Your distance looks much less which may be
what is causing all the fitment issues. It might work just fine on real IDFs.
The CB one would at least give you more room since
it is flipped from yours and offers 2 height options; however,
before giving up you could go get/make some shorter heim joint arms/shafts and
some standoffs and see if you can get it to align with enough
clearance to miss the air cleaners. (See photo for using standoffs).
Lowe's around here has both heim joints stuff and standoffs.
Shorter shafts may actually make adjustment more difficult thought.
BTW, you can get it work properly without having your down shafts
at 90 degrees. (Mine aren't and both open together and fully at the same time)
What is VERY important is that if they are not at 90,
that their angle is exactly the same. If they aren't, the rotation rate on each
side will be uneaven and one will move faster/slower further/less than the other.
The easiest way to ensure this is to make sure that the linkage arms
are mounted on the cross bar at the same distance from each end.
I noticed in one of your pictures the linkage arm on the cyl 3/4 side
looked quite a bit further from the end than the other side.
When trying to adjust sides to match, if one butterfly isn't opening all the way,
simply slide one arm closer/further from the end of the hex bar.
One direction will give more rotation on the butterfly and the other
will give less.
You will have to adjust the downshaft as you slide it, but usually it isn't too bad.
Just keep slowly sliding and adjusting until both butterflies open
fully together and both fully close together.
As a starting point, I'd set both down shafts to EXACTLY the same lengh
and then you should be close and adjust arms on cross bar from there.
Hope that helps.
--- bill
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Posted by: Kargeek Mar 25 2005, 01:07 AM
Here is my CB unit...arms pointed to the rear of the car, simple bracket for the accelerator cable. My cross shaft is set in the lower holes of the cross bar mounts and the excess trimmed off. I agree that your fitment problems are due to the lower height of the throttle bodies. Return it and get a CB unit. DH
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Posted by: crash914 Mar 25 2005, 07:36 AM
Wow...this thread is a great help to me...keep it going!!
Bill, the picture of the weber set up is exactly what view I needed....
I can see that there is an extension from the throttle arm to the drop link..this would be different on each side to allow the drop link to be exactly vertical.
The problem that I have ( I measured this morning) is that the pivot point for the hex shaft is off set one side is back 3" the other is forward by 1/2"????
I think that the problem is that the gold plates aren't made correctly...as was said, this is throttle body not IDF's
Thanks! all
Posted by: Joe Sharp Mar 25 2005, 07:53 AM
I forgot about these, PM me your address and I'll send them along with some Hex-Bar stock. I hope you can use them.
Joe
Opps, forgot the pic
Posted by: Joe Sharp Mar 25 2005, 07:54 AM
Pic
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Posted by: rhodyguy Mar 25 2005, 08:08 AM
the last 2 pictures of yours nailed it herb. most kits come with the t.b shaft extensions, which will help. shorter drop rods and repositioning the arms one face forward on the hex rod should get you where you want to be. don't run the brackets upside down like in the one picture.
k
Posted by: crash914 Mar 25 2005, 08:11 AM
Yea, I am trying to get ahold of the vendor on the extensions...
Joe, thanks for the offer..If I can't get this figured out, I will take you up on it...
I just want the vendor to make it right first...
Posted by: Joe Sharp Mar 25 2005, 08:20 AM
KOOL!!!
Joe
Posted by: crash914 Mar 26 2005, 07:21 PM
THANKS GUYS!!!!
Follow up....
I found the extension for the connection on the butterfly linkage, installed it.
Then I shorteded up the drop links by 3/4 inches.
Low and behold IT WORKS!!!
I just finished installing the motor and re-connecting the Mega-squirt....
Of course I just had to fire it up...with no exhaust!
ha ha...everyone in my house was right up above the garage watching TV...then they all had to change their pants!!
I rocked the house!! 
I also woke up all the dogs in the neighborhood..
All I have to do is throw the tires back on, drop it down and go for a spin...tomorrow...
So far, no sign of any oil leaks!!! I might be back on the road Monday!!
Oh yea..this is one bad ass motor...I got to be over 150 hp.....when is the next dyno day????
Thanks again for all the support from the board...Thanks Brad for making this happen!
later...
Posted by: Joe Sharp Mar 26 2005, 07:50 PM
Kewl 
Posted by: Joe Sharp Mar 27 2005, 07:47 AM
Herb: Check out the linkage on Chris Foley's engine bay on Jakes thread about Chris's new engine.
Joe
Posted by: rhodyguy Mar 27 2005, 09:37 AM
motorvating!! happy easter! your neighbors will have liked it better when the car was on jackstands. 150 
, should be quite zoomy.
k
Posted by: crash914 Mar 27 2005, 12:33 PM
Yea, I just went around the block a few times...I think I pissed off the neighborhood....at least I waited until noon....
There is something about breaking the tires loose in 2nd gear...I haven't done that before....
before I pulled the engine, I was reading 77HP with my G-tech...got to try it again...
I have some rough spots in acceleration, but I have not tuned the Ms yet...I have got to get some real gas too....a little pinging...8 to 28 deg. of advance...
The idle is good.
got to fix a wire on my Wide band O2 readout...then I can tune...still it was a rush just going around the block. It is supposed to rain tomorrow, so I won't drive to work..that will make sure that I tune it in better before driving...
man this thing is quick...can't wait until Memorial day at the track!!!
Posted by: Joe Sharp Mar 27 2005, 01:06 PM
I say again!!
Joe
Posted by: crash914 Mar 28 2005, 06:51 AM
I knew that it was comming......now where did I put that camera.....
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