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Getting ready. B20 Dual DCOE Swap Check list

Dawson

Yes?
Joined
Jun 25, 2007
Location
Hartford, CT
So I believe I've sourced all my parts. Just want to make sure I'm not leaving anything out here.

1) Lynx manifold from Eric @ Hi Performance
2) Weber 45mm DCOE (x2) from Carbs Unlimited
3) Redline "soft mount" kit (x2) also from Carbs Unlimited
4) Redline Linkage bar kit for dual DCOE From Carbs Unlimited
5) Longer Choke cable
6) New Intake/Exhaust gasket
7) New fuel line

Sound like I'm forgetting anything? Or does anyone with more experience know how much tweaking its going to take to make this all work?

To be clear the car already has the Redline 32/36 DGV conversion and a 4-1 Tubular exhaust manifold among other mods. This is all for the '66 in sig.
 
Air filters?

Don't see them on your list. The long weber manifolds will put the carbs too close to the fender to get air filters on.
 
Probably just gonna run the stacks with screens. Plus the Lynx manifold is a real shorty that'll let almost any filter option fit later on down the road.
 
You'll probably need a fuel pressure regulator that can drop the pressures down to 2.5, 3 psi. DCOE's have these big firehose float valves, it's easy for a fuel pump to overpower and flood them.

On my car, the choke cables that went to the SU's fit perfectly fine on the DCOE's. Just make sure you don't overtighten the little retaining bolts on the cable housings.
 
Fuel tee and some tuning bits.

45Webers1.jpg


45Webers4.jpg


45Webers6.jpg
 
Very good point, how are the carbs set up? There are thousands of tuning combinations. Idle jets, main jets, air corrector jets, emulsion tubes, accel pump inlet and outlet jets, venturi sizes.

Getting it to run at all is easy. Getting it to run well is hard. Getting it to run perfectly is a true artform.
 
That's going to be epic! Nothing is sexier the dual or triple web's.

In the late 80's I had a Camaro with a straight 6. Sucked all the way up until I got a 73 head, Clifford triple side draft and three Mikuni's. Crap did that thing sound amazing!
 
Very good point, how are the carbs set up? There are thousands of tuning combinations. Idle jets, main jets, air corrector jets, emulsion tubes, accel pump inlet and outlet jets, venturi sizes.

Getting it to run at all is easy. Getting it to run well is hard. Getting it to run perfectly is a true artform.

Getting it to run is one thing. I'm pretty confident in my abilities to build/fab/swap stuff around. But when it comes to that finite tuning stuff, there's an old school Volvo shop a couple towns over and I plan on leaving the car in that guys care for a couple days to get her all dialed in.

Edit: The car has a wideband already, so theoretically it should make the tuning process go a bit smoother...
 
Little possible thing: I've seen some kits where on the shaft for the levers the actual levers are aluminum, and are postiotied then the pinch screws are cranked down.. The ones I've seen have the aluminum tapped and a short screw going in...I have seen several times friends go savage and somewhat strip the threads , then the arms go out of sync..
They were all whaaaa! waaaaaaaa!.. solution: longer screws and a nut. Now you can crank it down..

Also, the fuel pressure thing.. Don't know the cam you have but I can show you where Ford motorsport says regarding fuel pressure that they run it 5-6 psi, and I have moved mine up just as insurance against full load lean out...

I really have no idea what Amazon has for fuel pipe size but my same generation Saab had 6mm OD so maybe 5mm ID...and a bad case of the ol' vapor lock when running hard, then puttering or shut down then run hard..
Changed to bigger---I used 3/8s pipe, but 5/16 would have been fine and easier to deal with....and vapor lock issue went away...

Din't see "Electric Fuel Pump(s)" on your list....You pump is made by same folks that made my pump and I suffered from block heating the pump..till I went to two Facet pumps in the trunk.

It could be that I had a somewhat hotter motor....

Do you have any ideas what you're going jet it???
Want some ideas?
 
Getting it to run is one thing. I'm pretty confident in my abilities to build/fab/swap stuff around. But when it comes to that finite tuning stuff, there's an old school Volvo shop a couple towns over and I plan on leaving the car in that guys care for a couple days to get her all dialed in.

Edit: The car has a wideband already, so theoretically it should make the tuning process go a bit smoother...

Unless the guys have set up jetting from zero, they may not be a help, see above.^
Get it correct from beginning, and you can almost certainly get it fine tuned..
Its when people "get creative" that people have jetting nightmares.
 
Little possible thing: I've seen some kits where on the shaft for the levers the actual levers are aluminum, and are postiotied then the pinch screws are cranked down.. The ones I've seen have the aluminum tapped and a short screw going in...I have seen several times friends go savage and somewhat strip the threads , then the arms go out of sync..
They were all whaaaa! waaaaaaaa!.. solution: longer screws and a nut. Now you can crank it down..

Also, the fuel pressure thing.. Don't know the cam you have but I can show you where Ford motorsport says regarding fuel pressure that they run it 5-6 psi, and I have moved mine up just as insurance against full load lean out...

I really have no idea what Amazon has for fuel pipe size but my same generation Saab had 6mm OD so maybe 5mm ID...and a bad case of the ol' vapor lock when running hard, then puttering or shut down then run hard..
Changed to bigger---I used 3/8s pipe, but 5/16 would have been fine and easier to deal with....and vapor lock issue went away...

Din't see "Electric Fuel Pump(s)" on your list....You pump is made by same folks that made my pump and I suffered from block heating the pump..till I went to two Facet pumps in the trunk.

It could be that I had a somewhat hotter motor....

Do you have any ideas what you're going jet it???
Want some ideas?

It is a "universal" kit so I'm a little weary of it already. But regardless, I plan on taking my time and studying it well before slapping it on at the risk of mucking something up.

I have the Isky vv71. And Based on what I've been reading, 4psi ?1 is the ballpark I should shoot for.

Don't know about fuel lines either, at best guess I'd have to say 1/4 or 6mm. Haven't had any issues yet, but i really cant compare the DGV to these cannons.

I'm keeping the stock mechanical pump for now at least. Never had a lick of trouble out of it. Even running all day in 90+ temps.

YES! I would gladly take any tips and tricks for some base settings on these puppies.
 
jetting

i think if you post more of the specifics of your engine we can help you get closer. do you know your head flow? how big an overbore? here a a few notes i have from similar engines. they are only a ballpark but should get you running****no warranty expressed or implied!
#1 choke-36mm main jet -145 air corrector -155 emulsion F-16 idle-55f8 needle jet-200

#2 choke-36 main-150 air corrector-170 emulsion-f2 idle 55f8 needle jet-225

webers are very precise and once you understand what all of the tuning bits do your wideband and some tweaking can make them work quite well. k
 
It is a "universal" kit so I'm a little weary of it already. But regardless, I plan on taking my time and studying it well before slapping it on at the risk of mucking something up.

I have the Isky vv71. And Based on what I've been reading, 4psi ?1 is the ballpark I should shoot for.

Don't know about fuel lines either, at best guess I'd have to say 1/4 or 6mm. Haven't had any issues yet, but i really cant compare the DGV to these cannons.

I'm keeping the stock mechanical pump for now at least. Never had a lick of trouble out of it. Even running all day in 90+ temps.

YES! I would gladly take any tips and tricks for some base settings on these puppies.

OK , probably the fomatting will suck since I hain't a typist of computer nerd, lets see:
Model F?rgasare Halsring Spridare Huvud-munstycke E-r?r Luft-
munstycke L?gfarts-
munstycke Acc.mun-stycke Pump-ventil N?l-ven

Motor--cam----carbies-- venturi--aux vent--main--E-tube--air corr-idle acc.--needle-pump
B20 D/K-Kam 2 x 45DCOE 36 4.5 135 F2 175 55F8 40 70 175 6
B20 R-Kam 2 x 40DCOE 36 4.5 135 F2 150 60F8 45 40 200 6
B20 F/R-Kam 2 x 45DCOE 38 4.5 145 F2 170 60F8 45 40 200 6
B20 R-Kam ....2 x 45DCOE 40 4.5 155 F2 130 60F8 45 40 200

Emulsion tube F9 and F16 will work on nearly anything, and is very common on all the OHC cars when hotter cams and comp is used..

Big thing I see everybody do--even alleged heroes---is they always have the throttles closed too much so the progression bleeds aren't able to pee in some fuel..There were--are on my old 45s--don't know if still on latest---a brass plug you could pull on top and see if the throttle plates were uncovering the first of the progression holes...

T'other thing is nobody bothers with the "cold start mechanism", which is like a good Mikuni VM bike carbie in that its an enrichment cicuit, not a "choke" per se..

Make the Cold Start" thang work.. I use bicycle brake cable.

Hate to say it but unless the "guys" are over 55 they probably don't have tons of time working on any carb much less DCOE...
You on the opther hand are motivated..
Set the throttles so the plates are crack open, "volume" control (it ain't idle jet) 1.5+ a smidge turns open

Shoot there's another reason I like electric pumps..In cold weather I run the pumps until I hear the floats are full, then I give it a couple of stomps on the gas, THEN hit starter and it catches, back off as fast as possible holding it around 1000....then easy tip in little bit , little bit as it warms just a bit---2 minutes-and its starting to warm up..

Then at some point if it doesn't idle you'll need an assistant to hold the throttles so you can jump out and start twisting the screws..
A Remote starter is nice..
 
Depending on the manifold you may need a taller RH engine mount or a spacer under it to just tip the engine a smidgin.

Have you got the Thackeray washers, I don't see them on your list.
 
Wow thanks for all the info John! I just ordered the carbs so I'll see what's inside 'em once they come in. Then order jets, tubes, needles, etc... from there.

I'll figure out the enrichment circuit linkage as I go. I was actually thinking something along the lines of a bike cable as well.

Even if I can't get it all dialed in, I know this guy with the Volvo shop will take care of it. He's in his 60's, has multiple "round fender" bricks, and will chase you out of the shop if you try to get him to work on anything newer than a 940. Haha!!

I guess I should look into the whole electric pump thing. It's slowly starting to make more sense to me now.

Thanks again for the advice man!
 
Depending on the manifold you may need a taller RH engine mount or a spacer under it to just tip the engine a smidgin.

Have you got the Thackeray washers, I don't see them on your list.

It's a shorty manifold. It's going to clear with plenty of room to spare.

What is a Thackeray washer??
 
What kind of choke cables are on the car now? My PV had the dual SU's with choke cables going to both - the worked as is on the cold start valves on the DCOE's. Maybe I slid some extra cable back through the firewall behind the dash, maybe not. But either way I didn't trim the cables or the housing, just hooked them right up as is.
 
And PS:
B20 R-Kam 2 x 40DCOE 36 4.5 135 F2 150 60F8 45 40 200 6
I'm a bit curious what my carbs have in them now. I have 40's (probably a little too small), 36mm chokes. I utterly forget all the other jets.

Mine's a 2.1L bottom end, R-Sport head, W-81 cam, 4:1 header.
 
It's a shorty manifold. It's going to clear with plenty of room to spare.

What is a Thackeray washer??

They're short flat wound springs, like maybe a coil and three quarters...
thackeray_washer1.jpg


Go on the mounting studs..

Post piccies of your "soft mount kit"

If its a flat thing with rings of rubber bonded both sides, you should imagine cranking down the nuts for the carbies and the raised rubber being a nice fulcrum.. BE CAREFUL....very easy to snap a corner off...

Oh and this is the desired pump, or one of them, I always mount 2 pumps.
pump4.jpg


Just for when the time comes.
 
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