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Discussion Starter · #1 ·
Bill,

are you still looking


Bill,

are you still looking for a linkage arm?

If so I found one upstairs in the secret stash of stuff I know I'll need someday before I die (I hope, otherwise I've simply amassed a bunch of junk {
})

Ball Linkage LF carb...is that it?

If so and you still need it em your address to [email protected] and I'll put it in the mail to you.

Regards, JRV
 
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Discussion Starter · #2 ·
Thanks JRV. Close but unfortun

Thanks JRV. Close but unfortunately the wrong one. I need the one for the LR (3-4 cylinder) carb.

The LF lever on my car has a tab to connect with the RF carb yoke. The LR carb that I need (3-4 cylinder), has a yoke to connect with a tab on the RR (1-2 cylinder) carb.

Yup, I still need one or I have to retrofit a used one. I have a free used one but the ball stud has seen better days and the lever was bent at one time.

Thank you very much though.
 
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Discussion Starter · #4 ·
Bill,

yes that's the on


Bill,

yes that's the one I found, #44. I mistakenly thought it was the 7-8 Carb, but turns out it's a 3-4 Carb.

It's used if that matters.

Regards, JRV
 
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Discussion Starter · #5 ·
JRV,
If it's in good/exce


JRV,
If it's in good/excellent shape, I'd love to have it and would be happy to pay for it. I'll email you my address. Thanks again JRV.
bill
 
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Discussion Starter · #6 ·
I'll post a pic later and

I'll post a pic later and you can be the judge of whether it's what you're looking for.

Regards, JRV
 
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Discussion Starter · #7 ·
JRV,

The mailman delivered


JRV,

The mailman delivered the lever arm today and I think it will work fine. This is the last piece I need to replace my carbs with the new GT-4 ones I recently purchased.

I'm going to deal with sloppiness in the push rod linkage next and then fit hose barbs into the intake maniflods to facilitate carb balancing by direct measurent of intake manifold vacuum with a bank of 8-fluid filled manometers.
 
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Discussion Starter · #8 ·
Hey Bill, hope the arm works o

Hey Bill, hope the arm works out.

Keep us updated on the carb tuning/balance proceedures you're developing as others might find it helpful.

Regards, JRV
 
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Discussion Starter · #9 ·
I have a couple of BK Synchrom

I have a couple of BK Synchrometers for measuring air flow for balancing carbs. I find their accuracy barely sufficient. Maybe the SK versions are better for idle conditions but I don't know for sure. The problem is one can only look at 1 or 2-cylinders at a time. What to do?

I removed the hard plumbing for evacuating the charcoal canister and tapped the resulting holes in the intake manifolds for 1/8 inch pipe taps, right angle barbs. Flexible hoses were connected between the barbs on each intake manifold and 2-carb tuner manometers, like the motor cycle guys use. Balancing becomes really easy with this instrumentation. It measures the intake manifold vacuum in all cylinders simultaneously and is exquisitively sensitive. One merely equalizes the vacuum between cylinders at a given rpm and you are done.
 
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Discussion Starter · #10 ·
Cool , I like it.So just what

Cool , I like it.So just what is the procedure. How do you start and what do you adjust. Can you please give us a blow by blow approach here. Thanks
 
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Discussion Starter · #11 ·
Who carries manometers for pur

Who carries manometers for purchase?
Inquiring minds want to know.

Looking at my DCOE's I found areas with a flat boss downstream of the throttle plates that look like perfect canidates for hose barbs. I would love to make the modifications and REALLY dial these carbs in.

Thanks, DJ
 
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Discussion Starter · #12 ·
DJ,

Being “cheep” I tend to


DJ,

Being “cheep” I tend to look for inexpensive solutions – for a manometer –
I purchased 2 mercury column sets from the Honda Motorcycle shop- $40.00 each about. Sets of 4 columns have been available to dial in the multi-cylinder rice rockets for a long time. I attached them to a board with a hook such that I could hang them from the hood latches (this is for a C4 which has 6 mm holes in the manifolds down stream from the carbs.)

I retrospect, I should have bought 3 sets, not that I do this very often, but it would have been cleaner to do both barrel sync and carb sync simultaneously.

Aaron
 
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Discussion Starter · #13 ·
Steve,

The procedure is to


Steve,

The procedure is to merely adjust the carb air flows, or more precisely, the intake manifold vacuum for each cylinder, until the mercury columns are equal in height. This is obviously done by adjusting one of the air balance screws to equalize vacuum within a carb and adjusting the linkages as necessary to obtain equal vacuum between carbs.

Note that vacuum decreases for a cylinder when the airflow increases and conversely vacuum increases as air flow is decreases. This opposite to the effect one would see with an air flow meter measuring air entering a carb.

One thing you will notice is when you increase the airflow to a relatively high vacuum cylinder, the manometer column in that cylinder will droop, yet vacuum in the other cylinders will increase slightly as the engine speeds up. This is an effect you normally would not notice with an air flow meter that is not as sensitive and is only looking at one cylinder at a time. The effect of an adjustment can be evaluated immediately. This procedure works especially well when checking off idle balance, say up to 2500 rpm. It's quite easy to observe the relative positions of the multiple columns as they dynamically change.

There is something you have to be careful about though. It's not a good idea to rev the engine and suddenly close the throttle. Under this very high vacuum, long duration condition, there is a danger some of the mercury could be sucked into the intake manifold. The manufacturer claims that a small ingestion of mercury will not harm the motor but it's pretty toxic stuff and expensive to replace.

I removed the hard plumbing on my 308 that evacuates fuel vapor from the charcoal cansiter and replaced it with soft, silicone vacuum tubing for heat resistance and hopefully long life. The remaining holes in the intake manifolds were tapped with a 1/8 NPT thread to accept my barbs of choice. Measuring vacuum here has proven to be a near ideal solution because the orifice connection to the tapped hole to the interior of the intake manifold is quite small in diameter. This small diameter orifice helps to dampen the vacuum signal. It may also be cosmetically reversable.

I'm not sure I'd tap the carbs to obtain a vacuum signal but theoretically, any port down stream of the throttle plate could work. I use a similar method on my S2 Elan with a pair of DCOE's, with excellent results.

The manometer system I selected is the Carb Tuner Deluxe made by MotionPro. It has a plastic high visibility body that won't corrode. They also make a less expensive model, the Economy Carb Tuner. Their online link is:

http://www.motionpro.com/Docs/servicetools.html

I think they will sell direct but I bought mine by comparison shopping online by searching on "carb +tuner +deluxe". A good motorcycle shop may stock it or should be able to order it for you. Prices vary a good bit.
 
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Discussion Starter · #14 ·
EXCELLENT Stuff !!!

The abo


EXCELLENT Stuff !!!

The above mentioned sets can also be used to set throttles on F40's and 355's.

Thanks for the tips and links. Good Stuff.

Regards, JRV
 
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Discussion Starter · #15 ·
Man, how about THAT, JRV!!

Man, how about THAT, JRV!!

That's cool jus' cuz you can see that whole carb set up at one time. We should build one.
 
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Discussion Starter · #16 ·
This is just excellent! Just w

This is just excellent! Just what I needed. I am hoping next winter to rebuild the carbs on my 308 and the task of synchronizing doesn't seem quite as daunting.

Thanks for the great info everybody.

DJ
 
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