engine and drivetrain No money to tune, Going it my own. Weber DCOE40-32's Schrick 292

[2002Scoob]

Before someone pulls out the flame torch, yep, I've done a fair bit of reading on the subject, searched, read many a post of jetting suggestions, etc. A few of you know I'm in the midst of a top-end rebuild of my 02. For my reference having a topic thread is helpful. I've done a fair bit of reading, and continue to do so on the theory and practice of setting up and tuning, so I'm hoping I can get it right. 

Due to a rather heady and over-budget build, I might just go it alone to setup, jet, and tune the DCOE 40's. It's the curse of having tight budgets and fixed income, so it’s either pay more now and get the car running and not make it to one of my best friend’s wedding… Or keep her in the garage for another winter… Which really sucks because I had some trips planned with the car that I can no longer afford. (goodbye Tuscany, goodbye Bordeau). L

I've got a few previous posts along the way where I've asked and received some great suggestions from forum members, but now that I'm in the home stretch of the project, and have my cam/filtration setup decided, I would love to tap the brain-trust that is the FAQ on starting Jetting Sizes.

 

Here's a link to a previous thread where you guys helped out in figuring out my initial setup. 

 

Carburetors were rebuilt with the following-

32mm Chokes. Debating maybe going to 34's in the future but I have 32's now, and their paid for so I'll run em.

F16 Emulsion Tubes

50F9 Idle Jet

2.00 Needle valves

I also installed a Cold-start elimination kit from EuroCarb

25mm trumpets

will be running a modified large Single-element foam filter from RamAir.

 

From before rebuilding- I have the following jets left over.

Main Jet-132

Air Correction Jet- 195

 

Head is an E12, original head with original bottom end/Pistons. I'm guessing this will be the 2nd time it has been decked. How much, I have no idea.

Before, I was on the fence with using the Alpina 272 cam I had lying around, but I've now decided on the Schrick 292. (Alpina cam is up for sale if anyone wants it. I'll make a deal.) With the 272 there were  a few that recommended going with 125-130 for mains, and 195-200 for correctors as a start, but no bigger than 130’s

My thought is to buy conservatively sizes jets to get into the ballpark, and a jet drilling set to adjust AFR and tune on my own. 

BUT…. I have the old 132 mains and 195 correctors, should I just give those a shot and could they work well enough?

 

The next question is what tools/setup do I need, or does the Braintrust recommend?

I will be purchasing an AEM wideband AFR gauge.

If I buy undersized Jets, I will purchase a Jet drilling set to modify them

What do yall recommend for an effective, but semi cost sensitive solution for metering/synchronizing the carbs? I’ve seen several different gauges from the hand-held meter that you hold up to the Trumpets, to the 4 gauge syncronometer setups.

What do you guys think?? Any additional tips and tricks?  Thanks!

-J

 

[2002Scoob]

For Syncing, there's these two options-

 

https://www.dellorto.co.uk/shop/dellorto-motorcycle-carburettors-parts/trumpets-manifolds/accessories/4-column-manometer/

 

 

https://www.dellorto.co.uk/shop/car-accessories/balancing-tools/synchrometer-airflow-meter-for-dhladcoes/

 

for 20 pounds more than 4 column manometer seems like a decent option, but then do I also need a set of these?? at 22 pounds each they definitely increase the cost... 

https://www.dellorto.co.uk/shop/weber-carburettors-parts/carburettor-parts-weber-carburettors-parts/dcoe-dcosp-parts/dcoe-vacuum-adaptor/

 

EDIT- It appears I don't need the adapters. However, I need to check that my carbs have vacuum ports that they can connect to. If not, it's the single unit for me.

Edited July 13, 2016 by 2002Scoob

[2002Scoob]

Aaannnnd... It does not appear that I have the needed ports to run a manometer. :/ bummer because that would have made things easier for sure.

Sent from my iPhone using Tapatalk

[zinz]

Nope... it's something I'll never understand why Weber quit the vacuum ports on the DCOE... using a manometer is much more precise, and doesn't interfere with airflow as you take readings and keeps both hands free while balancing the sync.  The DCOM Webers have these ports as do later Solexes, Mikunis, and Dels... I believe.

 

Either way... if the boys at Scuderia can sync 6 Webers on a V12 with a squirrel cage, then you won't have any troubles with two sidedrafts.  It's pretty easy 

  

 

 

Ed Z

[KFunk]

Ahhhh, you're making this real complicated.  I've been running 40DCOEs for around 9 years of daily use, and have never re-jetted or truly 'tuned' them.  Getting linkage reliable and fuel level perfect are the essential things.  Synching with the little squirrel cage looking synch tool is a nice luxury for smoother response, but not that required.  Good spark? Meh, points work ok and electronic is fun. 

 

If you bug me enough, I'll finally go out and take out my jets and write down the sizes.  I haven't changed them ever, worked fine with both stock cam/engine and current 292/9.5:1.  It's just how they came with a kit sold through an 02 catalog in the 70s or 80s that said they'd pick the right jets for you.  I can get around 30 MPG on the highway for long trips (5-speed/3.91), or 24 to 25 in daily use.  I'm probably not making max hp, but it sure is fun, so I'm not concerned.

[2002Scoob]

2 hours ago, zinz said:

 

 

Either way... if the boys at Scuderia can sync 6 Webers on a V12 with a squirrel cage, then you won't have any troubles with two sidedrafts.  It's pretty easy 

  

 

Ed Z

 

Yah, I'm feeling rather confident in the syncing part. I'm leaning towards getting a pair of the squirrel cages (I like this term), as mentally it makes sense to me that I would sync the front carburetor first, then sync the front barrel of the 2nd carb, with the rear barrel of the 1st, followed by syncing the final rear barrel of the 2nd with the 1st of the 2nd. 

 

Logical??

 

I'm more concerned with the jetting, and if the jets I have could work with my setup, but I guess I won't know till It's all together with the AFR gauge. But does the 132 mains with 195 correctors seem plausible? 

 

Also, (and I know i'm in Germany, so price/hours don't seem to line up for anything) but what would anyone guess for a reasonable estimate on basic setup/tuning? That would include setting the timing/advance, syncing, and jetting?

 

It's looking like a set of squirrel cages are around 100 euro (110 bucks)

 

AEM AFR wideband gauge is about 250 euro (275 bucks)

 

And timing lights are all over the map. anywhere for 50 euro cheapos to 200. Not sure which or what would be best, I've never dealt with setting timing before, so if anyone has a recommendation of a 'good enough' setup. Chime in please!

 

So, all in, to do it myself, if I don't have to buy additional jets, i'm looking at around 4-500 euro to self-tune, and I have tools to fiddle in the future

Edited July 13, 2016 by 2002Scoob

[zinz]

Overthinking it... relaxxxxxxx.

 

Only need one squirrel cage.  Absolutely don't need two.

 

Did you read this thread and Chris' jetting Rx ? Similar build...

 

Innova advancing timing light with tachometer should be about $75-$140 USD... available online lots of places.

 

What ignition set up are you going with, again?

[2002Scoob]

For ignition I've got a Bosch blue coil and IE mechanical distributor. I had dreams of a 123, but it's out of my budget for now.

[TobyB]

Quote

Only need one squirrel cage.  Absolutely don't need two.

Yup, just get one, use it and be done.

 

The wideband is the other part.  I like the logging one I have, just because I can also get it to read throttle 

position and revs, and that tells me a LOT about which circuit's doing what, when...  But you certainly don't NEED

to log, just be able to watch the meter a bit more carefully than you can on the track.

 

Then you drive it.

 

Then you see what happens.

 

Don't drill jets.  Tune what you have (you will be close) and keep notes.  Then change jets, try again, compare notes.

You MAY end up needing a 127 or a 122 or something like that- but heck, those jets were once made, and they do

sometimes show up on ePay for less than the drill set costs.  What you will probably find is that you end up with 3 sets of jets,

6 sets of air correctors, and a ton of emulsion tubes.  Because the real dark art in these things is the E-tubes... and making

THOSE on your own requires a pointy hat and a big, billowing cloak... and probably a cutaway carb and a flowbench....

 

If you absolutely can't find the 118 main you need, in 6 months or a year, then yeah, you get to drill it.  But you get 

way close enough on stock sizes for almost any purpose.

 

Just bolt it together and drive it.  You'll have such a big grin on that you won't even think about tuning for a coupla months.

 

The other thing- your carbs don't have air bypasses.  You will probably want to read up on how to adjust where the throttle plate lands

across your transition drillings, and be ready to drill holes/file/bend/modify the throttle plates to tune how the transitions feed in fuel as the

throttles open.  This is a bit scary, but once you get to work on getting a nice easy tip- in and good metering at 40km/hr in town, you find

that this was not the strong suit of the Weber.

 

Ditch the blue coil- use a pertronix and a Flamethrower coil, or something better than the blue.  It's weenie with a 32/36 (relatively)

and for everything you have, you want an electronic trigger, a relatively healthy coil, and good wires and NGK plugs.  Use the money

you save on the second synchrometer and jet drills to get this stuff.  Then you don't have to worry.  Well, I carry a second ignitor, because I do worry...

 

One last thing- that linkage will probably give you headaches.  After wrestling with that style, I gave up and fitted the cross-

shaft

style, and stopped having problems.  That douple- push system assumes the carbs don't move- and they do.  On the soft mounts, from

vibrations, from sagging rubber, from cornering forces.  And the 2 carbs move separately.  If you use a plate- style air filter, it's not so bad,

but when the carbs can move separately, you'll be re- synching pretty regularly.  I know others live with it, but it drove me nuts...

 

hth,

 

t

 

[zinz]

4 minutes ago, TobyB said:

the real dark art in these things is the E-tubes... and making

THOSE on your own requires a pointy hat and a big, billowing cloak... and probably a cutaway carb and a flowbench....

 

so funny, but so true...  for those of us who subscribe to SideDraft Central and read Keith Franck's fluid and gas dynamics dissertations as he experiments with e-tubes and jetting.... it'll soon make you feel like you're just a monkey banging two rocks together.  ...or maybe that's just me?

 

carry on...

 

Ed 

[JerryC]

Squirrel cage is new to me. Is this one?:

 

http://www.ebay.com/itm/AirCooled-VW-Dual-Carburetor-Synchronizer-Synchrometer-AC000120-Carb-Sync-/172232797605?hash=item2819dfeda5:g:E2UAAOSwLmVXD9bE&item=172232797605&vxp=mtr

 

$38 buy-it-now, "over 10 left"...

[zinz]

That be the one... here's the pic, sans rodentia

 

 

So simple, even a two-rock monkey can use it.

 

 

Edited July 13, 2016 by zinz

[KFunk]

You only need one, as you can just adjust the front carb until its a reasonable amount, then pop it onto the back one and adjust until its close to the front one, then pop it back on the front and see if its still the same, and adjust, and go back and forth all you want until both give you the same reading.  You don't need to compare the two barrels on the same carb, because they're both adjusted by the same adjuster.  You can check for fun if you want by moving it back and forth, but unless something is seriously twisted inside the carb, itll be the same.

 

Just bolt 'em on and see what happens.  I've never used any kind of wideband or oxygen sensor of any sort, and I'm not dead yet.  

[2002Scoob]

Guys, thanks so much for all the feedback!

 

I'm feeling pretty confident in moving forward with tuning. 

 

I went ahead and pulled the trigger on the AEM wideband AFR gauge and the single squirrel cage. I'll do some more research into timing lights and purchase within the next few days. 

 

1 hour ago, zinz said:

So simple, even a two-rock monkey can use it.

Zinz, I'll have you know, this Monkey just learned how to use his 2nd rock not long ago, so things are looking good

 

1 hour ago, TobyB said:

One last thing- that linkage will probably give you headaches.  After wrestling with that style, I gave up and fitted the cross-

shaft

style, and stopped having problems.  That douple- push system assumes the carbs don't move- and they do.  On the soft mounts, from

vibrations, from sagging rubber, from cornering forces.  And the 2 carbs move separately.  If you use a plate- style air filter, it's not so bad,

but when the carbs can move separately, you'll be re- synching pretty regularly.  I know others live with it, but it drove me nuts...

 

 

Toby, as always, excellent insight. I only quoted your last bit, as everything else seems gold. The car came with a Bosch Blue, so I was just going to run it as-is, but I'll look into the Petronix coil. I found a distributor here in Germany that sells them and I'm awaiting a quote.

 

The carbs have the 3 progression holes, and I'm hoping the throttle plates are pretty close to dialed. Those are the one area of the carb i didn't touch when I rebuilt. The bearings seemed A-ok, and the plates fit their bores nice and tight. I figured it best not to much with what works. Time will tell i guess. I just packed some grease in there and hope it keeps on keepin' on.

 

But, back to your quote, I decided to rigid mount the carbs vs. soft-mounting. It seems theres equal amount of people who say its necessary vs. those who say it's not needed, so hopefully that helps mitigate synchronizing issues of the double-push. If, for some reason I run into trouble, I do have a soft-mount kit as well I can give a shot. What's your take? for, or against? 

[TobyB]

I dunno.  I always ran soft mounts.  Never tried rigid, but other engines do that...

The danger is fuel foaming in the float bowls, and... well, heck, try it your way first!

 

Quote

You don't need to compare the two barrels on the same carb, because they're both adjusted by the same adjuster.  

 

bwahahahahaahahah!  This SHOULD be true!  But as you futz with each barrel, you find you have a bent throttle shaft, #3's idle screw

is somehow different than the other 3, and #1's valves are tight, so it's drawing more....  

 

Yes, to start, just look at #1 and #3.  But pretty early on, you want to then confirm that #2 and #4 match 1 and 3.  And figure out why not.

When you get to transition angle opening/uncovering, the flowmeter tells a useful tale for each bore.  It's surprisingly sensitive.

Also good for making sure your linkage is synched once the carbs come off the idle stops.

 

t