Triple Webber's installed..

[phantaz]

Started Wednesday morning and idling, runing and driving friday morning..

 

Pulled the Fuel injection off and installed the 45DCOE Webber's.

 

took a few hours of tinkering with the idle jets but it idles and doesnt backfire or jump. blipping the throttle screams it up to 5k rmp easy and idles back down most of the time =) some times have to quick blip it.

 

not bad since the carbs have been sitting in a box for 8 years. checked it all out and went through every screw out piece we could find and cleaned and sprayed any material out of of it would could.

 

Couple of questions though.

 

1. Rough idea of what the timing should be set on?

2. Should this be able to run without the vacumn advance being attached to the intake?? we did all this and forgot it was unattached..

3. had to put 3 really tight springs on it to keep the idle down.. extremely hard to get a steady acceleration.

4. has a N42 head, competion springs, newer "Fuel Injection" cam. Rough idea of the Idle RPM? we can get it to idle around 900rpm but it has flat spots.. up the timing a little and it idles around 1000-1200 rmp and has one slight flat spot around 2800rpm. 3000rpm and it takes off like a rocket.

 

i will post some pics as soon as we get it cleaned up a little. No filters on it right now.. the rubber ends had hardened so much that trying to stretch them on cause them to crumble.

[Leon]

I just installed my 40DCOE carbs on my Z so I'll put in my 2 cents...

 

#1 & #2 Set your timing for about 34* with mechanical all in. I am not using vac advance, it is likely dead anyway. This means that you are probably around 15-20* initial depending on dizzy and rpm.

 

#3 You need to use as little return spring as possible. Stiff springs will wear your bearings quicker. Make sure there is no binding in your linkage and that it moves freely. Then set up your linkage so that it is self returning. I am still in the process of doing this and has been my biggest challenge. The car starts and runs great but getting the throttle to return to idle without heavy springs has been taking some time and tinkering.

 

#4 Set your idle rpm after you set dizzy advance and then make sure that no progression ports are uncovered. After that set the mixture. Once that is set you can play a little with the speed screws to balance the carbs and get the idle down. Make sure the progression ports remain covered! Mine can idle as low as 500-600 rpm if I want them to (and if I can get the linkage to return).

 

#5 I thought I'd bring up the PCV system as well. I got a K&N filter for the valve cover breather, but I'm still figuring out how I want to do the rest of the system. The simple solution would be do route the lower hose to a catch can and vent to atmosphere or to a PCV valve connected to one of the ports in the intake. The elegant solution that I found while searching is what stonehenge69 did on his stroker. He utilized a PCV valve threaded into the block and a hole threaded in each runner so that the crankcase vapors get equally distributed and the carbs are easier to tune, while keeping the PCV system intact.

 

I've been scouring the net for linkage and PCV solutions and I'll post results when I get that stuff figured out.

[cygnusx1]

You need to spend quiet time with your linkage.  Be methodical.  Disconnect one carb at a time until you find where it binds.  Don't be afraid to up/down your timing to get the idle where you want it.  It's better to raise the idle speed by increasing timing than to expose the progression ports!!!

[phantaz]

Leon, Thnx for info and PCV rerouting is also something we were looking into..

 

Ill have to run this by ny Dad though.. he has trips on his and waayyy more experience playing with them.. im not sure what the progression ports are but i bet he does..

 

something else onthe linkage.. it has what i call turnbuckle type links instead of rods. My Dad says they are the short versions.. he has the long versions.. quicker throttle response i guess. longer one are for slower throttle response.. .

 

Cygnusx1... once again.. progression ports..i need to find some info on this quickly i guess =)

 

thanks for the replies and comments.. should have some pics up by mid week.

[cygnusx1]

Take a look at this diagram.  Part number 48 is the progression port cover.  Take off the covers and shine a light down in there.  Look at the little pinholes.  Move the throttle plates and you can see them through the little holes.  The top edge of the throttle plate should be blocking the pinholes from engine vacuum at idle.  If it's not, you need to adjust your linkage or throttle stop screw to allow the position to be correct.  This is one of the first critical steps to tuning a weber.  Once you are there with the throttle plate you NO LONGER MESS WITH THE stop screws.  You can turn it +/- 1/4 turn to stabilize the idle, but no more than that.  

 

Those little pinholes are there to piss fuel into the engine when you begin to crack the throttle.  They make the engine transition, from idle to about half throttle+, smoothly.  If you tune idle, with the progression ports pissing into the engine (exposed to engine idle vacuum), you will get a flat spot off idle.  

 

BTW, you can use those holes to perform a "VISUAL carb synch".  Make all the butterflies cover the same pinhole! 

 

 

 

 

Back to my timing talk.  If you find that the engine idles too slow after you do this, play with the IDLE VOLUME SCREWS (#56) up and down to get best idle.  THEN you can add timing or take timing away to get the idle where you want it.

Edited December 13, 2010 by cygnusx1

[cygnusx1]

A pic is worth a thousand words.  Thanks to google sketchup.

 

 

 

 

[phantaz]

My new hero.... thanks for the pics!!!

 

didnt go tinker with it today.. low last nite was 6.... yes.. single digit.. 6. that just sounds so damn cold when you say it outloud lol

 

high windchill today sooooo will wait for a slightly warmer day =)

[phantaz]

Another question popped up the day before and i forgot to ask..

 

when looking at the intake side of the Carbs... the left side intake as a large hole just above it... when we rev it up.. we get gas coming out of that hole every now and then.. we pulled the top plate off and the gasket looks good. My Dad says his triples have never done that and not sure what it is.

 

and ideas?? i still think the gasket is not good.

[Leon]

Another question popped up the day before and i forgot to ask..

 

when looking at the intake side of the Carbs... the left side intake as a large hole just above it... when we rev it up.. we get gas coming out of that hole every now and then.. we pulled the top plate off and the gasket looks good. My Dad says his triples have never done that and not sure what it is.

 

and ideas?? i still think the gasket is not good.

 

That's the intake for the air correctors. Check your float levels, I bet they're too high.

 

I don't have my Weber book with me to see what 45DCOE float height should be. Float specs vary depending on carb model. What does the top of your carb say, is it 45DCOE9 or another model? Setting the floats correctly is essential for proper carb operation.

 

If you are interested in tuning triples and how they work, I recommend getting Braden's book. It's a great resource to have on hand and the price is nothing to complain about!

 

Otherwise, both this site and google have tons of info. Hey, there's even a sticky!

[phantaz]

That's the intake for the air correctors. Check your float levels, I bet they're too high.

 

I don't have my Weber book with me to see what 45DCOE float height should be. Float specs vary depending on carb model. What does the top of your carb say, is it 45DCOE9 or another model? Setting the floats correctly is essential for proper carb operation.

 

If you are interested in tuning triples and how they work, I recommend getting Braden's book. It's a great resource to have on hand and the price is nothing to complain about!

 

Otherwise, both this site and google have tons of info. Hey, there's even a sticky!

 

awesome.. awesome.. and even more awesome...

 

headed out tonite to tinker while my Dads bluegrass band practices in the garage... music from both worlds..

[phantaz]

well..... its running and not stumbling at idle or revving up... runs while under a load.. idle from a stop pretty good up to around 2800 rpm.. try to gas it and it just kind loads up slightly but at 3000rpm it pulls like a freight train.

 

2 major problems to overcome though.

 

1. idle still wants to hang around 1300.. can blip the throttle sometimes and it will drop to 950. the solution so for is med throttle return springs.

its smoothed it out but you have to have a muscled up leg to push the throttle down which cant be good on the linkage.

 

2. with one of the springs off its easier to operate the gas but the idle will stay up at 1300 or so and it has a lurch in it just off throttle. you start easing the throttle and bam its taking off like you you floored it.. it feels like its hanging and then something lets go.. kinda.

its really hard to explain.

 

still tinkering but damn is it smooth and no backfires anywhere in the rpm range. just the idle problem which probebly has something to do with the second problem also.

 

i have some video but my computer is arguing with me about format and cant seem to link it or play it other than on my T-mobile site.. grrrrrr

[phantaz]

Oh yea... drove it to the nearest town for gas.. about 15 mins away..and when i popped the gascap it had a huge vacumn on it!!! i kept the hose to the surge tank in the engine bay so im not sure what that was about.

[cygnusx1]

Got a pic of the linkage?  Almost all Weber installs run an auxiliary return spring.   The abrupt change in pedal pressure could be due to linkage geometry/angles that bind up.  Pics would help.

[Konish]

well..... its running and not stumbling at idle or revving up... runs while under a load.. idle from a stop pretty good up to around 2800 rpm.. try to gas it and it just kind loads up slightly but at 3000rpm it pulls like a freight train.

 

2 major problems to overcome though.

 

1. idle still wants to hang around 1300.. can blip the throttle sometimes and it will drop to 950. the solution so for is med throttle return springs.

its smoothed it out but you have to have a muscled up leg to push the throttle down which cant be good on the linkage.

 

2. with one of the springs off its easier to operate the gas but the idle will stay up at 1300 or so and it has a lurch in it just off throttle. you start easing the throttle and bam its taking off like you you floored it.. it feels like its hanging and then something lets go.. kinda.

its really hard to explain.

 

still tinkering but damn is it smooth and no backfires anywhere in the rpm range. just the idle problem which probebly has something to do with the second problem also.

 

i have some video but my computer is arguing with me about format and cant seem to link it or play it other than on my T-mobile site.. grrrrrr

 

I went through three sets of webers and *all* of them had them same issue...the butterflies simply will not close when the motor was running. Of course, I could either pull the throttle linkages shut or put a HUGE spring to help close them (but still had to blip). You've already observed/felt what that's like trying to drive around town with a screen door spring. With the car running, I would have to pull the throttles closed about 1/32" of an inch to fully seat them. However, with the car off, the throttles would shut all the way with no movement. Sure enough, fire the car up and it would idle a lot lower...say 1000 rpm-ish. Roll the throttle open the carbs would hang at high idle. If I killed the car without pulling the throttles shut or blipping, the carbs would close all the way once the car was stopped.

 

Also, the bores were simply horrible in those things. I had light leaks all the way around each set of butterflies and I even had a custom set of butterflies made to no avail. Even with the throttle stop screw completely backed out, the butterflies could not seal against the bores. Mind you 2 of the three sets were brand-new out of the box. This made synching impossible because even when fully "closed" the leaks all metered a different amount of air. As a result I had to synch to the highest flow rate which caused my idle to be something like 2000 rpm or higher. Do get anything in the realm of 1200-1400 rpm, I had to manually shut them all and compensate with the idle air screw...but then they were flowing different rates of air. LOTS of people suspected binding and while some of the concern was valid, they did the same exact thing disconnected form the main throttle shaft.

 

On odd thing I noted when my car was running and the linkages were disconnected. One of my linkages was still connected to the carb butterfly lever and the upper end was disconnected and was resting freely against the common shaft. In messing with the throttle the linkage rotated away from the common shaft (as it was dosconnected) and fell forward leaving it hanging by the butterfly lever. Just the weight of the linkage itself pulled the throttle almost 1/3 open (which instanly killed the car). I tried this a few more times and it was repeatable. As you well know, even using your fingers, it's hard to crack the throttles open on the Webers, and yet the linkage was heavy enough to pull the throttle open while the car was running (?) When off, the linkage would simply hang there and was certinaly not heavy enough to even budge the throttle lever. Try it, you'll see that light finger pressure when the car is running will be enough to open the throttle with ease.

 

I suspected (and still do) that some fluid dynamic forces (just guessing, I'm no engineer) make it easier to open the throttles under load which conversely makes it harder to close and almost beyond the mechanical spring pressure at the very end of the sweep.

 

Also on the newer DCOEs, the first transition port was way too far back which made the car run really, really lean when the throttle is cracked open (which is why I had the custom butterflies made with an altered angle). Essentially, IMHO Webers are the biggest pieces of crap in the carb world...again my opinion and some people swear by them.

 

I finally bought an old set of Solex/Mikunis, had them rebuilt and installed them on my car. The butterflies seal light-tight and will hold fluid indefinitely. Synching was spot on, idles at 900 rpm, no nose-dive on acceleration with a seamless transition from the idles to the mains. Car runs like it's fuel injected; I love these carbs. Understand that I did nothing differently in terms of tuning the Solex carbs IRT my Webers (as they use the same tuning procedures), but everything on the Solex carbs was text-book in terms of how they responded to changes/tuning. Another thing, the Solex carbs were no easier to open or close with the car running or not and it uses really light assist springs on each throttle lever which makes driving the car a breeze.

 

I hope you get them to run right...

 

R/

Dustin

[cygnusx1]

 I go out to my car that sits for days in 15-30 degree temps, pull the choke and they fire right up.  After about 2 minutes of warmup with me holding the revs at around 1500, I let off the throttle, and it purrs at 900rpms.  Every time.

 

I think that the only way engine vacuum could pull open the butterflies was if there was more vacuum on the bottom half of the butterfly than the top.  Otherwise, vacuum pulls on the top and the bottom equally, canceling the moment out.  Could a bad seal/fit at the top edge of the butterfly cause this problem...I suppose it could?  It sounds as if your cabs have all had bad bores or bad plates.  Tough to imagine, but possible.

Edited December 17, 2010 by cygnusx1

[phantaz]

someone asked what model carbs these are....

 

 

they are 45DCOE9 Number series 7E

 

 

I am trying to get pics up but having issues with loading them.. i should have some up this weekend after i steal my gf's camera.