$&%&*% carb linkage, does it ever stop needing? Options

[tat2dphreak]

OT but applies: Hurry up Jake and get the new linkage perfected.

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I was thinking the same thing last night, in between cussing at trying to work on a hot engine because of yet another linkage issue...

this isn't the first linkage issue... the first day I drove the car home after installing the new engine(and linkage) the throttle ear broke (IMG:style_emoticons/default/WTF.gif) then it had been idling high until 2 weeks ago, when Wes and I finally figured out that tie angle of the springs was not letting my wron carbs close all the way, we used stronger springs, and changed the angle, and all was well for a few weeks, until this...

at this point if I knew (another) new linkage would really fix it(I.E. Jake's linkage) I'd pony up the $ ASAP.

my worry is hurting something else, of course after everything else that has gone on... I mean when one carb is running at part throttle and the other is closed, it CAN'T be good... essentially running WAY out of sync. I'm just glad I only had to go a little ways with the issue....

I had the tools in my car, but there was no where to pull off in that last little bit...

[yeahmag]

Shoot some pictures of your linkage: overall, left, right, throttle bracket

I bet you have something goofy in your geometry if you are having all of these problems. The linkage should work smooth and even.

[Root_Werks]

Don't know who makes this style, but I do like it. Every adjustement is a threaded rod with lock nut. Very precise and sturdy.

[flipb]

Here's my solution.

(IMG:http://www.914world.com/bbs2/uploads_offsite/lh3.ggpht.com-10752-1271179155.1.JPG)

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[SUNAB914]

FI,
Blah, blah, blah

[McMark]

Don't waste your money on a VDO CHT setup. Read this thread.

[tat2dphreak]

Don't waste your money on a VDO CHT setup. Read this thread.

yea, I read that yesterday, I'll buy one of those and toss this VDO POS.

the spruce setup looks quite reliable and is even cheaper than a vdo kit (IMG:style_emoticons/default/smile.gif)

[yeahmag]

I use one too... Love it.

[VaccaRabite]

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I have one in my 914.
Mike saw it and liked it so much he bought one for the bus. The Dakota Digital CHT is the bomb.

Oops. Mine is different from the one in Marks thread. Mine is the digital gauge.
(IMG:http://www.914world.com/bbs2/uploads_offsite/www.dakotadigital.com-1435-1271207870.1.jpg)

It does not look very 1970, but it is very easy to read. A trade off I was willing to make. If mine ever says 485, my engine is in trouble....

Zach

[FourBlades]

You probably know this, but just in case: your engine expands up to a half inch
in width as it gets hot, which can cause your cross bar to pop off. I think the
solution is to crank the bolts with the balls on the ends into the ends of the rods
until the springs in there are compressed completely, then tighten the nuts so
they don't gradually back off as the bar rotates.

You probably knew this already, but it was news to me lately.

John

[tat2dphreak]

no, I did not know the expansion was that great. I will check the spring tension when cold.

I'm getting a late start tonight, decided to drink a few beers with a buddy instead of wrenching :beer:

[FourBlades]

Nothing wrong with a few (IMG:style_emoticons/default/beerchug.gif) (IMG:style_emoticons/default/beerchug.gif) (IMG:style_emoticons/default/beerchug.gif)

I'd say tighten the ends into the cross bar with the engine stone cold until the
springs are just fully compressed but no more.

I think putting extra tension on it may fatigue and break off the arms on the carb
plates that the cross bar mounts on. You don't want to create a force trying
to spread the carbs apart by over tightening.

John

[Mark Henry]

If your engine expanded 1/2" that would be .250 per jug and your lets say 9.5Cr would now become about 5.5Cr...unless your saying that your rods also grow 1/4" at 200*F

6061 aluminum @600 degrees expands .010 (that's 10/1000 of an inch) per inch.
So the most expansion you would see is about .040 (.080 for both sides) and at 600 degrees you have way bigger problems to worry about.

And just in case someone wants to figure it out the math is 13 x 10^-6 inch per inch per degree.

Bottom line is it only grows by about .040-.050

[Chris Hamilton]

If you cant keep the arms from slipping put a couple hose clamps on the bar to keep it in place. It isn't perfect but at least it'll keep your throttle from sticking open until you can get some screws to stay.

[VaccaRabite]

mark is right. The engine expands when warms, but not 1/2 inch. A few Hundredths of an inch, sure. But 1/2 an inch expansion would lead to the engine eating itself for oil starvation at every bearing point. Folks using bell crank style synchros would have 3000 RPM idles when warm. Its crazy talk!

[Jake Raby]

I've found that TIV engines expand roughly 1/8" at 350F head temp with cast iron cylinders, a tad more with Nickies. The hotter the engine runs the more the engine expands.

I've had some second thoughts about bringing the Accu-Link system to the market. With all the horror stories of stuck throttles and etc I'd hate to end up in a big mess because someone didn't install the system correctly. I've been trying to reduce the amount of support that we have to offer with products by getting rid of the majority of our components that require extensive installations, set up and tuning. I could see hours being spent on the phone with installers of a system like this because they can't make it run perfectly.

Lots of people that currently have issues will buy a set up like this, because it is the best thing since sliced bread, they'll then find that their issues remain with this system just like the old system. That'll be because their issues weren't related to the linkage in the first place, they just didn't know that or believe that.

I may use the system on my turnkey engines that we can set up ourselves and then sell the idea and patent/ etc to someone else in the industry thats willing to deal with the support that I am not willing to.

[DRPHIL914]

chris-
I know you really hate the FI ?!?!?
I have had my share of carb problems too- 69 austin healy with dual webbers(back in h.s.-25 yrs ago+) i date myself. - but after struggling to return my 75 2.0 to good function f.i., i am ready to try the carbs!!!!
too.- i think it is the old ECU and vaccuum that cause most problems- the injectors etc are not the culprit, - but each to his own i guess!

[biosurfer1]

I've had some second thoughts about bringing the Accu-Link system to the market.

Well that's not good news...I've been waiting months for this product. Guess I should have just gone with something else.

[Jake Raby]

I've had some second thoughts about bringing the Accu-Link system to the market.

Well that's not good news...I've been waiting months for this product. Guess I should have just gone with something else.

Thats why I never recommend people waiting on a development, we may have issues making it work sufficiently or for some other reason it may not go to market.

The Accu-Link is a great product, but unfortunately it requires unconventional installation compared to other systems and the learning curves related to installation would surely create issues for us.

..and my insurance company flipped out when they caught wind that we were developing a throttle related product. Thanks Toyota, you bastards.

[bandjoey]

If it's that good, shoot a quick DVD of the install, and include that and then sell the linkage with a No Support clause in the legal paper we have to sign before shipping. (IMG:style_emoticons/default/idea.gif)

If this isn't going to happen Jake, what's the alternative to hex bar that works and is easy for us nubes to adjust? Thanks for the help and info. (IMG:style_emoticons/default/biggrin.gif)