Jump to content
nbristow01

scored some dual 40 webers

20 posts / 974 viewsLast Reply

Recommended Posts

The history is these weber 40 carbs have.... been on a car that has been in the club for several years. After a few years the car started to run bad so he figured it was carbs and did not know how to set duals or work on then. So he put a lynx 45 setup on the car and lost cylinder 4 a few weeks later.

SO he offered these to me for 250 bucks..linkages and all..can't pass that up!! I plan on putting these on my car in late Jan so have time to rebuild them etc.

I run a 9.5 1mm over motor with 284 cam..motor has maybe 50k miles on it. Crane fireball ignitiion that is set dead on right now. I never rev over 5500. I usually stay at 45-5000 on shifts.

I noticed the carbs have different covers but otherwise look identical..here are the specs on them: 125 Main, F16 air correct, 50FB (F8?) idle ,

Is this a good baseline for startup? Also I think it was Toby that said for better torque the carbs should run about a 32 choke?...so where is this located on the carb?

Also on the intakes...any idea what brand they are? No markings on them just some numbers 121 141 and 125..also brake vacuum is on cylinder 2

post-17424-13667667220262_thumb.jpg

post-17424-13667667221248_thumb.jpg

post-17424-13667667222106_thumb.jpg

Share this post


Link to post
Share on other sites
Guest Anonymous

Those are certainly not matching pairs. I would surely not spend any money on those and sell the carbs. Get something else.

Dual webers may look and sound cool but a 38/38 or even a 40/40 is just as good a carb.

Share this post


Link to post
Share on other sites

I don't any obvious problems with these as a pair to tune. If they're both 40 DCOEs, and both look to be older models, you should be fine with finding a matching calibration set-up. (your PO likely obviously took one of a prior pair for his Lynx carb, and found a single to make this set).

Properly tuned, a set of DCOEs will kick-ass on any single carb set-up. No contest. One direct straight-thru tunable inlet per cylinder beats ALL.

Good luck.

Tom

Share this post


Link to post
Share on other sites

they are both 40's, but non-matching. that means some of the internal passages may be different making them a nightmare to tune together.

standard advice found in every one of the many threads on installing dcoe's

1/ buy a book on these. read it.

2/ realize that dcoe's are NOT a "bolt on" mod. they require an understanding of how they work and all the many variables to tuning and synching.

3/ completely disassemble and rehab any used set before install

4/ count on hours of tuning after installation to get them right. there is no "standard' setup that works on all cars. see note "2".

5/ regular attention will be required to keep the in top tune.

if you love doing this stuff, dual sidedrafts are a hoot.

if your car is a DD and you like simple and reliable, run away.

Share this post


Link to post
Share on other sites

Ordering a book today. The PO bought a new 45 for the lynx. I sent the carb pics to my friend that wonder the car before this guy. He confirmed that the carbs are the ones he had. He said they tune the same just the top covers are different. My car is a DD so I will hang on to my 38/38 setup in the event these duals become to much for me to deal with. I have a friend that has a wideband and a big bag of weber parts. He spent about ten years as a weber tuner for a race shop. SO he has offered to help me out.

Wish me luck fellas...I am going in

Marshall you are most likely right. But at least this way after I jack around with these things I will better understand what you are all talking about with these duals. They may come up for sale later LOL

Share this post


Link to post
Share on other sites

The manifolds look similar to the factory ti ones. Check the openings to ensure they match the 2.0 litre engine (not from 1600ti). Cannot be sure without looking at both sides for the proper markings. If they are stamped "Cannon", well then you know what brand they are.

Share this post


Link to post
Share on other sites

They came off of a M10...2.0 motor. E12 head etcetc so I should be good on that part. I have looed at this setup a while. I would love a Lynx setup but never can track one down.

Share this post


Link to post
Share on other sites

TEP is selling a single side draft crossover manifold. $500 (cough cough)

If the carbs came off a runnng local car why be concerned wifh the jetting. As stated the PO was wrong in his diagnosis of his engines problem. Throw a "rebuild" kit in and run ( $25/ unit)

Share this post


Link to post
Share on other sites

Nick,

Take a look at the progression holes. If they match for pattern and size, you should be good to go. I wouldn't be worried about the non-matching covers, as one or both may have been replaced in the past. The keys are to ensure the jetting is the same, and the progression holes are the same.

If you're unfamiliar with DCOEs, the progression holes are located just above the butterfly. Generally speaking, when the carbs are tuned, the butterfly in its resting position will just cover the first progression hole. As the butterfly opens, it reveals additional progression holes. Some DCOEs have two, some have three, and some have four. A quick visual inspection should reveal whether you're likely to have fun or heartache.

Share this post


Link to post
Share on other sites

My Car is a daily driver with twin 45 Dellorts , get your friend to show you how to use a wide band 02 sensor , buy your own , weld the bung in your down pipe & tune away . Once done they stay in tune , just the balance can vary , easy re set up with an air flow meter.

Great price , you will have fun with that set up .

Share this post


Link to post
Share on other sites

Thanks guys..I really want to have duals if I can since I have always loved the sound and guys with duals are always faster than me. So here are the settings I have now:

Both carbs have 3 progression holes

main jets:125

Idle jets: 50F8

Etube: F16

air correct: 170

main venturi: 28mm (is this to small? Or good for use under 5500RPM)

Pump jet:40

I have ordered rebuild kits since all the rubber o rings are brittle and crumbling.

This setup came off of a stock motor. I have 9.5 and 284 cam. So is this a good start baseline? I will be putting a wideband on before the install to help take out guess work

Share this post


Link to post
Share on other sites

The 28mm chokes will be a bit restrictive, but as this is your daily, you'll get great low-end torque. Try them as they are (after replacing the gaskets, of course), and see what you think. You can always replace the 28s with 30's, 32's or 34's. I suspect you'll eventually move to 32's as they'll strike a very nice balance of low end torque and higher rev power.

The rest of the jetting sounds pretty straight forward.

Share this post


Link to post
Share on other sites
The 28mm chokes will be a bit restrictive, but as this is your daily, you'll get great low-end torque. Try them as they are (after replacing the gaskets, of course), and see what you think. You can always replace the 28s with 30's, 32's or 34's. I suspect you'll eventually move to 32's as they'll strike a very nice balance of low end torque and higher rev power.

The rest of the jetting sounds pretty straight forward.

Thank you very much!!

Share this post


Link to post
Share on other sites

What everyone's talking about is the pattern of drilling under the

red- circled brass plugs.

It takes 30 seconds to pull these on both carbs and confirm that they're

the same, or similar.

If they are, then you're good to proceed. If they're way different,

you'll probably be fighting an unevenness at light throttle cruising.

But they MIGHT work ok. Just not exactly the same.

The other thing to look at is to make sure the threads on the yellow

circled idle screws is the same thread on all 4 barrels. If you have

2 fine thread and 2 coarser thread, you'll have to compensate when setting

the idle. Not a problem- IF you spot it beforehand!

Nice score.

t

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.




×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.