HELP: Getting it going. Timing, Weber DCOE

[zinz]

Boy and girls, pay attention. Steve knows his way around Webers...

 

Toby is no slouch, either ?

 

I'm glad we have these guys on FAQ. Not sure what we'd do without so many good folks. 

 

 

[Stevenola]

1 hour ago, zinz said:

Boy and girls, pay attention. Steve knows his way around Webers...

 

Thanks but there are many here with far more knowledge than I, I am just trying to save anyone the pain, suffering, and $$$ I've been through to get them right   Worth it in the end, but am always learning about these supposedly "simple" devices!

Edited September 21, 2016 by Stevenola

[TobyB]

Quote

set it at 36 btdc with

no vacuum, 

...and yeah, if you don't have a vacuum advance distributor, you're done!  Sorry, I could have left that out, as very few use vac advance distributors with sidedrafts...

 

As to float level, it may vary with car due to some engines being inclined, like the M10. If the carb's not level, they changed

the float level to compensate...  Alfa tipped its engines differently in different cars, and thus some were, and some were not, level.  Depended on the manifold

and the car!  I suspect not all 2002 manifolds get the carbs level either.

 

You can always experiment.  As you lower fuel level, you'll get different transition and 'moderate high power' characteristics because

the fuel takes more vacuuum -'depression' and also more holes on the emulsion tubes are uncovered.  Below a certain level, the E tubes will leak 

too much air, and you'll go stupid- lean when you try to accelerate.  But above that level, you can experiment.

 

And yes, if the engine is vibrating, fuel gets everywhere, including into the air correctors, making you go richer...

 

With a wideband, you'll get there.

 

t

 

[MildSeven]

22 hours ago, zinz said:

I use UNI filters with these Solexes... airbox won't clear the standard booster. 

 

I believe I have a standard (non-tii) brake booster but custom brackets for the airbox which is what raises it a little.

 

16 hours ago, Stevenola said:

-Unscrew the progression hole covers and verify that the holes are the same pattern and size as mentioned by Simeon.

-Verify your cold start piston(s) are not stuck open.

-Verify choke #2 is same 34mm.

-Get a matching accel pump discharge valve.

-Are there differences in airflow between the 2 barrels of one or both carbs?  Both throttle valves are shaved?

-Sync the carbs, set timing (make sure you are timing to the correct ball). 

-Check airflow at idle and at 2500-3k rpm for any differences between carbs which could indicate poor linkage.

-Set idle speed at 1000rpm, set mixture screws for best idle, repeat until stays at 1000rpm.

-Measure float level in place by making a mini dipstick and set floats so the level of fuel is 25mm from the deck of the main jet stack hole.  This is more accurate than the book method.  Activate the fuel pump so the bowls fill up before measuring.

 

Thank you for the response! Looks like I have a lot of homework to do this weekend.

 

to answer the question:

- Are there differences in airflow between the 2 barrels of one or both carbs? Both throttle valves are shaved?

 

I believe there were differences between the barrels on a single carb, if memory serves me correct there were differences on both carbs. I will post the numbers after sync'ing them.

For the throttle valves being shaved, if memory serves me right each valve (4x) of 1 carburetor had 2 notches shaved out of it.

 

Thanks again!

Anthony

 

 

EDIT: any advice on the spark plug gap, I couldn't find anything (especially 2002 related).

 

 

 

 

Edited September 21, 2016 by MildSeven
too soon

[zinz]

I Googled around Crane XR700 plug gap and read a few hits...  My take away is that your 0.037 is probably too wide.  Generally speaking, minimum stock gap is 0.024, using an electronic ignitor can allow an increase of 0.01, or 0.034.  You induce a lot of resistance with such a wide gap, so any worn/weak link in the ignition (wires, cap, rotor, plugs, etc...) can cause a misfire.  My advice would be to reduce the gap to something more moderate, say 0.030. That should certainly give you good running, provided the rest of the ignition is in top-shape. After you've gotten the timing and carbs sorted out, you go twiddling with spark gap.  

 

I bet you'll get it running nicely once it's properly timed.

Ed

[TobyB]

Yeah, I agree with Ed- nothing wrong with .030" to start off.   You may lose some ability to blast through a rich mixture-

but then, your goal now is to not have a rich mixture.

 

Can you post a pic of what's been done to the throttle butterflies?  It could be an attempt to balance their transition- or 

the result of getting 2 carbs from 2 different places.

Machining the butterflies is one way to adjust what the transition ports do.

 

Do flow each barrel- if you find they're different, that can point to either a very different idle mixture, or a bent throttle shaft.

Both of which should be fixed, and neither is hard to fix...

 

t

 

[MildSeven]

On 9/21/2016 at 0:29 PM, TobyB said:

Yeah, I agree with Ed- nothing wrong with .030" to start off.   You may lose some ability to blast through a rich mixture-

but then, your goal now is to not have a rich mixture.

 

Can you post a pic of what's been done to the throttle butterflies?  It could be an attempt to balance their transition- or 

the result of getting 2 carbs from 2 different places.

Machining the butterflies is one way to adjust what the transition ports do.

 

Do flow each barrel- if you find they're different, that can point to either a very different idle mixture, or a bent throttle shaft.

Both of which should be fixed, and neither is hard to fix...

 

t

 

I went with .032 to start finally.

 

for the throttle butterflies. turns out I didn't take a photo when dissembling them but I tracked down a photo of what they look like on the net.

 

I did the flow of all 4 barrels, slight differences

 

 

 

 

 

 

Edited September 26, 2016 by MildSeven

[MildSeven]

ok so, I generally work on the car in the garage on Saturday/Sunday when the kids are napping so I have limited time, sometimes I'll work on the car on weeknights but recent;y I've been tired an unmotivated given these issues which are over my head in terms of knowledge.

 

To help me be more productive during my sat/sun afternoons I listed everything down and printed it out. Here's my list with some comments added.

 

I've never really heard what pinging/knocking sound like, this 2002 was my first dive in to this stuff.... so I really value everything I read on here.

 

Here's my list with comments in blue. Your feedback is welcome towards the end of Sunday I discovered my throttle pedal lever was spinning on the spline, so that's where it ended with more frustration and no drive.

Edited September 26, 2016 by MildSeven

[MildSeven]

sorry about the multiple posts for some reason I was having issues editing the previous post and this one is missing most of the formatting.

 

here's teh list I put together from everyone's comments, and the stuff I did over the weekend in blue

 

1.    Float level check/Set
•    Measure float level in place by making a mini dipstick and set floats so the level of fuel is 25mm from the deck of the main jet stack hole.  This is more accurate than the book method.  Activate the fuel pump so the bowls fill up before measuring.

-    I tried with paper, the paper would absorb the fuel and throw off the reading…  So, I a tie wrap, I put some tape around it and lowered it down until the tape was level with the deck.
a.    DCOE 16 7E (Cyl 1&2), looked like 24mm
b.    DCOE 9 8C (Cyl 3&4), looked like 25mm
-    
•    Float Settings
o     7mm & 13.5mm (8C)  
o    7.5mm & 14mm (7E)

-    Untouched for now

 

2.    Set Fuel Pressure Regulator: 2.5-3psi

-    Lowered to 3psi

 

3.    Spark plug gap
-    Gap changed to .032
-    Appearance Spark plugs prior to change
-    
-    In jan 2015 when I pulled the car apart, they we’re all carbone’d up.
 

4.    Carburetor  Checks:
•    Unscrew the progression hole covers and verify that the holes are the same pattern and size.
-    Hole Size and count are different
DCOE 16 7E:

DCOE 9 8C:

•    Verify your cold start piston(s) are not stuck open.
-    They Look fine

•    Verify choke #2 is same 34mm
-    Untested yet
•    Are there differences in airflow between the 2 barrels of one or both carbs?  Both throttle valves are shaved?
-    Yes slight difference, figures below
-    I believe these photos are at 3000 RPM but the differences were about the same at 1000rpm
-    

•    Get a matching accel pump discharge valve.

-    Should I get a 40 or a 70?

 

5.    Set all screws to initial start setting

 

6.    Synchronize Carbs
•    Synchronize the carbs at idle

•    Rev to 2500-3000rpm for any differences between carbs which could indicate poor linkage.

-    

7.    Timing
•    First set the distributor by ear
-    I think I suck at this

•    timing light

•    Timing specs

o    Haynes TI specs, avoid higher number) :
-    1000rpm 18 – 22
-    1500rpm 23 – 27
-    2000rpm 28 – 32
-    2500rpm 33 – 37
-    2700rpm 35 – 39
o    Read on forum
-    3000rpm 32

a.    Rev’ed engine to 3000, set timing light to 32, pointed down bell housing hole.
b.    When adjusting the timing, the RPMs would fluctuate based on my twisting of the distributor. I think in the end I did 32’ at 3000rpm… but even though I painted the OT line on the flywheel, it’s super difficult to read.
c.    I think I will put that timing strip I saw on this forum on the pulley, much easier to see. I will set to TDC on oil rail then stick it.

o    Toby
-    If distributor is in poor shape  rev the engine up over 4500, set it at 36 btdc with no vacuum, and see what happens when you let it drop to idle.  And be ready to have to fuss with it a bit...

 

8.    Adjust air by bass screws & adjust idle speed
•    Toby: Then you fuss with the idle mix screws.  They will NOT all be identically screwed in or out for best idle, but for starters, they should be. Once you've gone around 2 or 3 times, then try adjusting each one separately by 1/8th

•    Stevenola: Set idle speed at 1000rpm, set mixture screws for best idle, repeat until stays at 1000rpm.
-    I just started to try to do this before time ran out (kids waking up, starting BBQ.. etc) but I don’t find any changes occur really when adjusting them

 

Edited September 26, 2016 by MildSeven

[TobyB]

Quote

throttle butterflies

That looks like the right/factory way of adjusting where the progression drillings open. 

 

Your synchrometer readings look good, too- that amount of variation's not perfect, but it's in the 'good enough for now' range.

 

Good plug pic- suggestion, tho- next time, use a tungsten light, and a white piece of paper behind.  Then the camera will do a better job of getting color.  (that's extra credit, though)

From your plugs, your back carb looks pretty good- it might be a tad rich, but it looks healthy.

The front carb, not so much.  Hard to tell, but if you haven't done something mechanically to chip off the carbon, it looks lean to the point of detonation (which shattered the carbon off).

And the black carbon looks like it also runs (or has run) rich, OR been misfiring, which it can do if it's way lean.

Take a look down the progression holes (good pic there, too) when the carbs are sitting at idle.  Ideally (hah) you see the throttle plate covering them all, just

about to uncover the first, and as you move the throttle off idle, they uncover... progressively.  The cutaway part of the edge of the one pair should push that opening point  just a little

earlier, which (hopefully) keeps the two closed to matched.  I fear that they aren't- those progressions are pretty different, especially at '1/2 progression' and more. 

 

Your float settings make sense.  If nothing else helps balance front- to- rear, you can start lowering the fuel level in the rear carb.  But you'll also need to do something to

enrich the front carb...

Once it's running well enough to drive, you can do a 10 minute drive at the speeds you want to fix, then switch off and read the plugs.  Ideally, you then clean them,

but I've found, especially if I do a bit of hard acceleration at first, that I can get a pretty decent read after about 10 minutes.

The wbo2 helps a lot here, too.  On the race car, I ran 4 pyrometers to look at each cylinder.  That helped a lot with balance and troubleshooting.... often, troubleshooting the pyrometers!

 

You're doing fine.  This is not easy at first.

 

t

 

[MildSeven]

19 hours ago, TobyB said:

That looks like the right/factory way of adjusting where the progression drillings open. 

 

Your synchrometer readings look good, too- that amount of variation's not perfect, but it's in the 'good enough for now' range.

 

Good plug pic- suggestion, tho- next time, use a tungsten light, and a white piece of paper behind.  Then the camera will do a better job of getting color.  (that's extra credit, though)

From your plugs, your back carb looks pretty good- it might be a tad rich, but it looks healthy.

The front carb, not so much.  Hard to tell, but if you haven't done something mechanically to chip off the carbon, it looks lean to the point of detonation (which shattered the carbon off).

And the black carbon looks like it also runs (or has run) rich, OR been misfiring, which it can do if it's way lean.

Take a look down the progression holes (good pic there, too) when the carbs are sitting at idle.  Ideally (hah) you see the throttle plate covering them all, just

about to uncover the first, and as you move the throttle off idle, they uncover... progressively.  The cutaway part of the edge of the one pair should push that opening point  just a little

earlier, which (hopefully) keeps the two closed to matched.  I fear that they aren't- those progressions are pretty different, especially at '1/2 progression' and more. 

 

Your float settings make sense.  If nothing else helps balance front- to- rear, you can start lowering the fuel level in the rear carb.  But you'll also need to do something to

enrich the front carb...

Once it's running well enough to drive, you can do a 10 minute drive at the speeds you want to fix, then switch off and read the plugs.  Ideally, you then clean them,

but I've found, especially if I do a bit of hard acceleration at first, that I can get a pretty decent read after about 10 minutes.

The wbo2 helps a lot here, too.  On the race car, I ran 4 pyrometers to look at each cylinder.  That helped a lot with balance and troubleshooting.... often, troubleshooting the pyrometers!

 

You're doing fine.  This is not easy at first.

 

t

 

 

thanks for the advice Toby...

 

At first when I was trying to get it running (first start since Jan 2015) the timing was off and I hadn't done my homework with the distributor yet, it ran pretty crappy, backfiring, frontfiring, sidefiring...etc

 

Today, I'm not feeling super confident about the timing...I mean the motor sounds much better but that flywheel mark is so hard to see and I can't stick my face in any closer.

At what point can I make the call to drive it around the block or something...without breaking anything because I'm dying to do this!

 

I think I should take a video so that you guys can help me gauge if things sound/look alright.

 

[Stevenola]

I am not sure that with different progression hole patterns for each carb that you will ever get them to run correctly.  I think they would require different idle jets at the very minimum and determining this could be an exercise in frustration trying to match each carb's transition from off-idle to main circuit and in between.  

[MildSeven]

25 minutes ago, Stevenola said:

I am not sure that with different progression hole patterns for each carb that you will ever get them to run correctly.  I think they would require different idle jets at the very minimum and determining this could be an exercise in frustration trying to match each carb's transition from off-idle to main circuit and in between.  

 

have i told you guys I hate this car?

 

so I should be looking in to getting a 45DCOE 9 8C or a 45DCOE16 7E or 2x 45DCOE...

 

edit. on fist look, I couldn't find an Italian dcoe 9 8C but i found this ugly 16 7E: http://www.ebay.ca/itm/Weber-45mm-DCOE-16-7E-Bologna-Lotus-Cosworth-TC-Toyota-4AGE-BDA-Formula-Atlantic-/322273006158?

 

 

Edited September 27, 2016 by MildSeven

[Simeon]

Now you said early on that these same carbs had been running well on this very car?  Certainly it is a massive challenge to try and get them to run the same but perhaps someone has?  Is there any filing on the leading edge of the throttle plates?  Any holes in the plates?

 

Conventional wisdom is definitely that unless the carbs are a matched set, that you can get to flow a similar amount of air through at idle, with the throttle plates in the same relative place to the progression holes (and are jetted exactly the same) you are really going to struggle but there are definitely some talented people in the world.  If you are not so sure as to how well the carbs ran before, then yes, seek either a new matching carb or a pair.  If they definitely worked well then play for a while but be aware that this is likely to end up frustrating.

[MildSeven]

2 hours ago, Simeon said:

Now you said early on that these same carbs had been running well on this very car?  Certainly it is a massive challenge to try and get them to run the same but perhaps someone has?  Is there any filing on the leading edge of the throttle plates?  Any holes in the plates?

 

Conventional wisdom is definitely that unless the carbs are a matched set, that you can get to flow a similar amount of air through at idle, with the throttle plates in the same relative place to the progression holes (and are jetted exactly the same) you are really going to struggle but there are definitely some talented people in the world.  If you are not so sure as to how well the carbs ran before, then yes, seek either a new matching carb or a pair.  If they definitely worked well then play for a while but be aware that this is likely to end up frustrating.

 

These carbs ran on this car before, how well they ran is another story, I can't say I noticed any issues but the car felt under powered (possibly because i wasn't used to it), it's my first carbureted car and first dive in to mechanics (aside from non-motor related stuff).

 

EDIT: actually I just looked up the old videos the previous owner took for me before the sale:

 

https://youtu.be/t8ymVU0iKzw?t=2m15s

https://youtu.be/kaP1VNREzEk

 

 

Yes there are 2 notches cut out of the throttle plates, similar to the random image I posted above. I'm wondering if I could put around with it, then over the winter try to find a match to either of these. am I crazy?

Edited September 27, 2016 by MildSeven
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