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Steve Arndt Samba Member
Joined: August 01, 2005 Posts: 1780 Location: Boise, Idaho
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Posted: Tue Dec 13, 2011 9:52 am Post subject: Does CSP center linkage clear with tall manifolds? |
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I'm thinking of trying CSP center pull instead of CB linkage. With the non offset big beef IDF tall manifolds the hex bar linkage needs a long spacer on the 3/4 carb to line up and it isn't the best. Will the CSP linkage clear the alternator and line up with the tall manifolds? |
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wildman1 Samba Member
Joined: December 30, 2003 Posts: 674
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Posted: Tue Dec 13, 2011 12:12 pm Post subject: |
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Steve, the CSP bellcrank linakge does clear with plenty of room on my narrow built 2387cc, with CB BB manifolds. However, the standard IDF/DRLA kit rods were not long enough for the CB manifolds. I purchased the CSP IDA linkage kit and used the appropriate length rods from that package to make it work. I am not sure if the IDA kit is all you need, but since owning and working with both, looks like it could work.
Although, the IDA kit has different arms at the throttle shaft and if I recall, they weren't proper for my engine. In the end I used two rods from the IDA kit, throttle arms from the IDF kit and one of the center pulls, either one. As luck would have it, the IDA center pull had a lower cable mount and was offset just enough to correct both issues with an aftermarket shroud.
After all that was sorted out I was happy with it. The rod angles could be better, but it worked smooth and once dialed never fell out of sync.
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Steve Arndt Samba Member
Joined: August 01, 2005 Posts: 1780 Location: Boise, Idaho
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Posted: Tue Dec 13, 2011 1:13 pm Post subject: |
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I already ordered the IDF kit so I'll have to make it work. Thanks for posting your experience installing it. I want to build a cable linkage system in the future but this was an easy temp upgrade for now.
I'm switching from CB tall IDF intakes and CB 48mm throttle bodies with their linkage, to Redline 45mm TBs and the CSP linkage. I hope for a bit smoother tip in, and easier throttle control. |
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mharney Samba Member
Joined: June 01, 2002 Posts: 8353
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Posted: Tue Dec 13, 2011 6:23 pm Post subject: |
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Steve, using them with the CSP linkage in my 2332 in my bus with doghouse shroud. The right side heater outlet had to be flattened on the underside for the rod to clear it but it was doable. The highest point is when the throttle is closed. The geometry effects are also much smaller with the long throttle linkage rods. Another reason I like the CSP linkage. |
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wildman1 Samba Member
Joined: December 30, 2003 Posts: 674
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Posted: Tue Dec 13, 2011 11:50 pm Post subject: |
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Here is the IDF/DRLA CSP linkage kit on shorter 4.75" non-offset manifolds. This set up would clear factory heat outlets on a German shroud. Picture is before the CB Performance CNC Big Beef manifolds. 7" tall, non-offset.
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mharney Samba Member
Joined: June 01, 2002 Posts: 8353
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Posted: Wed Dec 14, 2011 1:12 am Post subject: |
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Wildman, this is what I was referring to, but as I said, they didn't clear completely. The right hand heater outlet was fouling the rod. |
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wildman1 Samba Member
Joined: December 30, 2003 Posts: 674
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Posted: Wed Dec 14, 2011 8:35 am Post subject: |
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Mark, it cleared this set up when I had the factory shroud in place, it was about 1/16" gap at closed throttle. I guess I got lucky? I have read of others clearencing as you did, and read of some that didn't have to.
Same with the center pull clearing the lower left backingplate bolt head/tin. One center pull cleared with no issues, the second kit I bought was different all around, in little ways, but non the less, clearencing was needed there.
Steve, modulation is superior with the CSP linkage and it seems to have a decent ratio even with severe angles. Full throttle was equal to within an acceptable amount. The hardest part is adjusting the rod ends behind the distributor, "if" you have one.
I like the cable/pulley ideas floating around, but they too have cons. Good Luck. |
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Steve Arndt Samba Member
Joined: August 01, 2005 Posts: 1780 Location: Boise, Idaho
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Posted: Wed Dec 14, 2011 9:48 am Post subject: |
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No distributor here, running direct fire! I also have a Puma non heat shroud.
The CB throttle bodies don't have bypass ports for syncing the barrels on the same side. The Redline have IDF style bypass screws. This will be nice. |
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youngstah Samba Member
Joined: December 28, 2008 Posts: 89 Location: california
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Posted: Sun Mar 25, 2012 9:18 am Post subject: CSP linkage mod, out of sync mid range. |
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I was looking for more info here earlier too.
As there are multiple variables in the "clearance" issue I thought I'd post more pictures as some may be running similar problems as I try and resolve mine. Pita, after forkin out for a csp and these manifolds.
The solution I've come up with has revealed to me I obviously know little about the science and math of linkages. Maybe someone would care to explain or school us all in what we'd need to understand to resolve the prob I'm having?
2276 CB Big Beef Manifolds (offset manifolds) 44idf + csp idf kit + doghouse shroud.
1. Rods provided don't reach right carb.
2. Heater duct in the path of rod. (wrench holds rod at closest point to avoid shroud contact)...my attempt at figuring a diff solution.
Above shows the problem and below is what I thought the solution would be:
Problem is this:
The throttle opens in sync now, yay! It also stops in sync! Yay. But crap! It's not in sync in between. The left carb butterfly opens at a rate much quicker than the right. ? Wtheck!? ........WHY?
With the mod and offset manifolds here's a top down of the csp bellcrank w closed and open throttle.
Any input appreciated. |
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youngstah Samba Member
Joined: December 28, 2008 Posts: 89 Location: california
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Posted: Sat Mar 31, 2012 11:44 am Post subject: |
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Anyone? |
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Steve Arndt Samba Member
Joined: August 01, 2005 Posts: 1780 Location: Boise, Idaho
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Posted: Sat Mar 31, 2012 12:33 pm Post subject: |
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I added 1 inch to the link rods (braised). That made it work with Redline throttle bodies and CB tall IDF manifolds.
Kind of a bad pic here, but you get the idea.
Steve |
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gprudenciop Samba Member
Joined: July 06, 2008 Posts: 606 Location: portland or
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Posted: Sat Mar 31, 2012 12:49 pm Post subject: |
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Looks like you changed the geometry of the linkage since the manifolds and other parts are the same you could try adding that same mod to the 3/4 side? |
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youngstah Samba Member
Joined: December 28, 2008 Posts: 89 Location: california
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Posted: Sat Mar 31, 2012 6:24 pm Post subject: |
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I guess that's where Im confused, the change in geometry.
Is it the angle in the top down shots that matters or is it the angle and length of the rods from the bellcrank to manifolds? (facing the engine from the rear)
The rod still moves the same amount as before, right?...or do I have that entirely wrong? What puzzles me is that at idle it matches and at full throttle it matches, just not in-between. What angle or logic affects that? |
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modok Samba Member
Joined: October 30, 2009 Posts: 26781 Location: Colorado Springs
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Posted: Sat Mar 31, 2012 8:02 pm Post subject: |
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Look at what angle the rod is compared to the pivots at half open. Should all be 90 degree angle, or all the same at least, if not you have a progressive linkage, it may be good idea or bad, I donno.
You bent rod you'll have to imagine it straight, or as a kangaroo |
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youngstah Samba Member
Joined: December 28, 2008 Posts: 89 Location: california
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Posted: Sat Mar 31, 2012 9:08 pm Post subject: |
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Thanks Modok.
What I think you're saying is, with the butterfly at 50% the goal is to have the rod perpendicular to the throttle arm. Point one being the pivot (ballend) at the bellcrank and point 2 being the ballend on the carb linkage...draw a straight line between these two and thats the line to use?
What exactly contributes to a "progressive linkage"? |
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modok Samba Member
Joined: October 30, 2009 Posts: 26781 Location: Colorado Springs
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Posted: Sun Apr 01, 2012 1:22 am Post subject: |
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yes, that is right
So at both ends we have a pivot point(carb shaft, bellcrank shaft), and the "line" between the ball ends of the links.
If it is at 90 degrees, the actual leverage is the distance from the line to the pivot.
Here's the cool part, when it is NOT at 90 degrees, the instantaneous leverage at whatever position is pretty much the distance from the line to the pivot.
I hope that makes sense, maybe a diagram is required?
Having different length levers at different angles, the action will not be linear.
Linear would be 1 degree at the bellcrank moves the carb 2 degree, that is a rate. You will see the rate changes though the travel, sometimes this can be taken advantage of so you have a slower rate near idle for more precise throttle control at part throttle, and a faster rate near full throttle.
Sometimes called a progressive linkage
By moving the carbs up, it appears this will make it somewhat the opposite way, and to fix that you would need to change the position of the little arms on the carbs. |
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Steve Arndt Samba Member
Joined: August 01, 2005 Posts: 1780 Location: Boise, Idaho
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Posted: Sun Apr 01, 2012 7:13 am Post subject: |
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If you look at my pic of the Redline throttle bodies compared to IDFs, it is even more difficult. The throttle shaft is moved up close to 1 inch compared to IDFs. That is why I had to lengthen the link rods. Mine are synced nice at idle and WFO, but still not perfect at 20 to 50% open (same as with the old CB linkage). It is a smoother feeling linkage than CB but still not ideal.
Also, if I had heater ducts on my shroud the rods wouldn't clear. |
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youngstah Samba Member
Joined: December 28, 2008 Posts: 89 Location: california
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Posted: Sun Apr 01, 2012 1:31 pm Post subject: |
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modok wrote: |
If it is at 90 degrees, the actual leverage is the distance from the line to the pivot.
Here's the cool part, when it is NOT at 90 degrees, the instantaneous leverage at whatever position is pretty much the distance from the line to the pivot.
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Ok, the straight line distance (rod length) represents the affects of instantaneous leverage off idle? Or are you saying literally the distance between the line and the linkage pivot = leverage value. A drawing of this might be helpful.
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I hope that makes sense, maybe a diagram is required?
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Would love one. I'm trying to understand right now how my current setup created the problem in the first place. Much appreciated.
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Having different length levers at different angles, the action will not be linear. |
Ok, since the mani's raise the throttleshaft (not 90deg in angle between points) I need to make sure the lengths between each ball end are equal and that the angles are the same. Does this include angles In the top down view i posted or only facing from the pulley?
What's confusing is that the linkage provided by CSP has different length rods one long and one short. They provided a linkage arm that fits on at a particular angle.
So based on the other extended arm example do I need to lengthen the arm to get closer to 90 deg...(minimizing leverage differences between carbs) and then tweak the angle of the arm to account for the leverage amnt?
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Linear would be 1 degree at the bellcrank moves the carb 2 degree, that is a rate. You will see the rate changes though the travel, sometimes this can be taken advantage of so you have a slower rate near idle for more precise throttle control at part throttle, and a faster rate near full throttle.
Sometimes called a progressive linkage
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I hear what you're sayin. The goal is to match the rates between 2 carbs. Rate is a product of leverage. Leverage is affected by distance and angle.
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By moving the carbs up, it appears this will make it somewhat the opposite way, and to fix that you would need to change the position of the little arms on the carbs. |
Each arm should still be the same angle right?
Man my head hurts. Why don't they design it correctly in the first place?
Thanks for the help. |
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modok Samba Member
Joined: October 30, 2009 Posts: 26781 Location: Colorado Springs
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Posted: Sun Apr 01, 2012 1:42 pm Post subject: |
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I'll make a drawing, after dark tho if ya don't mind. Nice day today |
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youngstah Samba Member
Joined: December 28, 2008 Posts: 89 Location: california
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Posted: Sun Apr 01, 2012 7:43 pm Post subject: |
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At your convenience. Much appreciated. Yes, nice day. |
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