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Re: Holley carburetor [Re: Coke] #2556057
09/28/18 05:35 PM
09/28/18 05:35 PM
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That particular one is made or distributed by Scott Drake.
https://www.summitracing.com/search/brand/scott-drake/department/engines-components/product-line/scott-drake-valve-cover-oil-caps?N=401272%2B4294949512&SortBy=Default&SortOrder=Ascending&autoview=SKU&ar=1

And there are cheaper ones like these:
https://www.summitracing.com/parts/snn-10071
and
https://www.summitracing.com/parts/trd-4999

Since you have to ship, lets make sure we can match a PCV Valve for it.
Most likely something for a Ford 'CJ' Cobra Jet or such. But most important will be that its the correct size for the grommet or hose. I collected some information about sizes but wont be able to look for it until tonight.

Re: Holley carburetor [Re: Coke] #2556145
09/28/18 11:51 PM
09/28/18 11:51 PM
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Its hard to find dimensions on-line. The Ford Cobra Jet used a threaded PCV valve so that's not a match.

A review for the Stant 10071 states it comes with two grommets. If so, then its more likely for a common PCV valve will fit.

Re: Holley carburetor [Re: Coke] #2556231
09/29/18 12:06 PM
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Ok don,t worry.They are not expensive parts,so i can order a couple of pcv valves and use the most aproppiate.The stant cap you posted looks good to start.What i don,t know is why all these breathers-pcv caps do throw vapors to the atmosphere instead to have a connection tube for the air filter.




Last edited by Coke; 09/29/18 12:16 PM.
Re: Holley carburetor [Re: Coke] #2556273
09/29/18 02:03 PM
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If the PCV doesn't fix it for you, I would suggest checking everything that would make it run rich. Make sure the air bleeds are not blocked (they are the 4 very small passages on the front, just under the choke plate). I think the idle air bleeds are the outer 2. Make sure the floats don't have any gas in them, and are adjusted right. Make sure you have the correct gasket between the carb body and the metering block. Not a likely cause, but make sure it doesn't have some crazy sized jets in the front, (should be around a 76) because that could make it idle a little rich. I would definitely put another PV in it too, just to completely rule that out.

Re: Holley carburetor [Re: Coke] #2556281
09/29/18 02:29 PM
09/29/18 02:29 PM
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Originally Posted By Coke
Ok don,t worry.They are not expensive parts,so i can order a couple of pcv valves and use the most aproppiate.The stant cap you posted looks good to start.What i don,t know is why all these breathers-pcv caps do throw vapors to the atmosphere instead to have a connection tube for the air filter.

OK.
You can try one for a Chrysler v-8 and if you want to experiment,
ACDelco CV736c has is reported to be good for engines with lower manifold vac, and has 3/8" connection (suction side). I don't have the other diameter.

As to why so many open breathers? That might be a sociology question as much as a technical one. laugh2

On a good running engine, the most of the vapors will to through the PCV valve and the breather is just air in. Before 1960 or so, cars here used draft tubes to evacuate the crankcase. The low pressure under the moving car sucked the vapors out. Probably the same in Europe.
To address the greater blow at high rpm, wide open throttle, some racers use vacuum pumps or evacuation tubes in the exhaust.

One problem with PCV valves is with engines that have poor manifold vacuum at idle. There has to be enough vacuum at idle for the valve to be in the most restrictive position. I *think* if your engine can get 11 - 12"Hg at idle, it should be OK with a stock PCV Valve. This why some people experiment with different valves like that CV736. I had plans to test the flow of PCV valves but that's been sidetracked.


Re: Holley carburetor [Re: Coke] #2556294
09/29/18 03:20 PM
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IMO, Isolate the intake tract from everything else, booster, PCV, all of it. Plug that stuff at the intake. Cars run without those emission/accessories all the time. It's not those items causing the bad idle situation.

Figure out why the engine won't run without a gaping vacuum leak.

That camshaft should not require any type of "drilling" anything on the carb to run properly.

Re: Holley carburetor [Re: BLACKHEMIRR] #2556322
09/29/18 04:52 PM
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Originally Posted By BLACKHEMIRR
If the PCV doesn't fix it for you, I would suggest checking everything that would make it run rich. Make sure the air bleeds are not blocked (they are the 4 very small passages on the front, just under the choke plate). I think the idle air bleeds are the outer 2. Make sure the floats don't have any gas in them, and are adjusted right. Make sure you have the correct gasket between the carb body and the metering block. Not a likely cause, but make sure it doesn't have some crazy sized jets in the front, (should be around a 76) because that could make it idle a little rich. I would definitely put another PV in it too, just to completely rule that out.


Hello,i blew all the cicuits with air pressure when i removed the carb a couple of days ago and i didn,t find a blocked passage.I removed the primaries metering plate to check the PV valve.
Fuel bowls level ok,in the botton of the window,drip a bit of fuel if i shake
the car.
I put a new body gasket that i had stored from a Holley trick kit i bought several years ago.All the holes match.I just had to make another hole for a center pin,cause the body has two and the gasket only had for one.
I found that the throttle body has threads
for eight bolts and i only had six.
I started to imagine horrible things about where the two screws could have gone until i read in the Urich,s book that even having 8 threads,only the earlier models came with 8 screws.
However the two center bolts were in the wrong threads.I put them where it should to go(Taking the book pictures as a guide)and tightened them a bit using an impact screw driver.That solved the vac.leak i had between the plate and the body at the front of the carb.The right side continues leaking a bit(Tested with that smoke machine that Mattax likes whistling)

Both main Jets are 70s.
I know you can change air bleeds in the latest carbs.That is a good improvement.

Re: Holley carburetor [Re: Mattax] #2556331
09/29/18 05:52 PM
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Originally Posted By Mattax

OK.
You can try one for a Chrysler v-8 and if you want to experiment,
ACDelco CV736c has is reported to be good for engines with lower manifold vac, and has 3/8" connection (suction side). I don't have the other diameter.

As to why so many open breathers? That might be a sociology question as much as a technical one. laugh2

On a good running engine, the most of the vapors will to through the PCV valve and the breather is just air in. Before 1960 or so, cars here used draft tubes to evacuate the crankcase. The low pressure under the moving car sucked the vapors out. Probably the same in Europe.
To address the greater blow at high rpm, wide open throttle, some racers use vacuum pumps or evacuation tubes in the exhaust.

One problem with PCV valves is with engines that have poor manifold vacuum at idle. There has to be enough vacuum at idle for the valve to be in the most restrictive position. I *think* if your engine can get 11 - 12"Hg at idle, it should be OK with a stock PCV Valve. This why some people experiment with different valves like that CV736. I had plans to test the flow of PCV valves but that's been sidetracked.



Interisting. i have seen that Moroso sells a system wich threads a tube in the header close to the out for this purpouse.

Also ,i have done a new test today.
I have stolen the pcv valve from my Jeep 5.2 magnum wich has a 3/8 nipple and i have connected to the 3/8 port in the rear of the carb.






The idle is erratic and low rpms when the pcv valve is connected.Rightnow ,this thing needs an open 6-7mm
(Sorry for the metric,1/4"?) hole for a decent idling .
When that port is open it idles around 750-800 and seems to throw less smoke and fuel smell.However the engine was still cold and i haven,t had the time for warming it up.

Regards,

Re: Holley carburetor [Re: crackedback] #2556382
09/29/18 08:31 PM
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Originally Posted By crackedback


That camshaft should not require any type of "drilling" anything on the carb to run properly.


That,s what i think.This cam is more mild than wild.
The trouble has to be in the carb.I think that it creates a rich condition and needs that air for compensating it or something.
In the end a fixed leak is a temporary solution..

Re: Holley carburetor [Re: Coke] #2556387
09/29/18 08:42 PM
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Turn the idle UP using the adjustment screw on the carb. 800 rpm in park/neutral.

Where are the idle mixture screws set? Most of the time if you leave them at 1 1/2 turns out, it's going to be rich.

Is fuel dripping in from the boosters?

The issue IS NOT anything related to the PCV or booster. Isolate the intake and solve the carb/timing issue and worry about the other stuff later.


Re: Holley carburetor [Re: crackedback] #2556395
09/29/18 09:01 PM
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Originally Posted By crackedback
Turn the idle UP using the adjustment screw on the carb. 800 rpm in park/neutral.

Where are the idle mixture screws set? Most of the time if you leave them at 1 1/2 turns out, it's going to be rich.

Is fuel dripping in from the boosters?

The issue IS NOT anything related to the PCV or booster. Isolate the intake and solve the carb/timing issue and worry about the other stuff later.




The car has manual gearbox,are not 800 rpm are a bit high?
If i use the idle screw i loss the transfer slots adjustment.Don,t understand the Holley design,why that screw is so accessible.
The mixture idles are 1&1/2 or 1&1/4 (i don,t remember how i set them last time)turns out.
Tomorrow i will check if i see fuel dripping from the boosters.
Also it has manual brakes,the only thing connected to manifold are the headlights covers.The vacuum advance does not work so i have plugged the port.

Thanks

Re: Holley carburetor [Re: Coke] #2556427
09/29/18 10:29 PM
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Manual trans run it at 800 rpm. It's fine. This is NOT a factory cam with 200* of duration, it's in the mid high 220's and needs more RPM to run right. Additionally, run it lower and the splash to oil the cam is minimized at idle which is BAD!

Turn the mix screws to about 3/4-1 turn out.

Lose transfer slot? If the mix screws don't do anything, it's likely dropping fuel in from somewhere else (ruptured PV diaphram) or dripping boosters is likely. At least you don't have the in gear issue that an auto trans would have. If need be open the secondaries slightly. Use a .015 feeler gauge or some paper layered up between the set screw and arm on pass side to hold it open as a test.

The inside of the carb looks black which usually means it's really rich with inadequate initial timing. Now that the timing is about right, the rich side needs to be solved.

Re: Holley carburetor [Re: Coke] #2556478
09/30/18 12:33 AM
09/30/18 12:33 AM
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Not much to add here. Hard to imagine this is going to come from me, but don't wory so much about the instruments and measurements. Just spend the time fiddling until it starts running good. See what I posted on the 18th - pretty similar to what Crackedback wrote. Open up the throttles for more rpm. As it warms up and you start to tune it in, you can lower it.

The engine is cold. Either hold the throttle open on the fast idle step, or just screw the idle stop in until its warm. Stock '69 440 fast idle speed was 1700 rpm! I'm too lazy to pull my '67 book off the shelf, but I'm sure even pre-smog, it was at least 1400 rpm. After a minute or two you can reduce it 3 or 400 rpm to something around 1000. Then when its warmer, a little less. Once your closer 800-900, then fiddle with idle mix and see what does.

7 mm hole is out line. Half that diameter - which is roughly 1/4 of the area is all that a PCV valve would be. So it doesn't seem like you have a vacuum leak at all.

Re: Holley carburetor [Re: crackedback] #2556702
09/30/18 05:26 PM
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Originally Posted By crackedback


Lose transfer slot? If the mix screws don't do anything, it's likely dropping fuel in from somewhere else (ruptured PV diaphram) or dripping boosters is likely.





Oh,they do.Very strange things but they do laugh2 The pcv diaphragm is ok and i haven,t seen the boosters dripping at idle.
I have done several tests today ,engine at 170 celsius and every time a diffent thing occurs here,very confusing.
Let me repeat the tests again,to see if i,m
able to get a better conclusion.I will record another video to show you how this is going on.

Meanwhile a bit offtopic,but i need to order some parts,a vacuum canister for example.The broke unit i got is the part 3656766.I have seen it on the web listed as a part for small block dist.There is another part number for BB i think.
Do you know if this part is correct for this distributor (MP electronic ign)or maybe a previous owner made it to fit ?

Thanks

Re: Holley carburetor [Re: Coke] #2556806
09/30/18 10:43 PM
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170* C!?? What is ? Coolant? Oil?
Coolant should be 180* F, or roughly 90*C when the engine is warmed up.
Oil temperatures in the sump will be similar when just idling.

Well I'm tired after a day playing in a parking lot. So maybe more in the morning. Don't worry about the vacuum advance for now. What's wrong with it anyway?

Re: Holley carburetor [Re: Coke] #2557123
10/01/18 04:46 PM
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170*Farenheit ,coolant.
The vac advance stopped working few days ago.Just wander if this unit is correct for the BB dist.I have found that all the MP dists have the same body and only the shaft lenght changes,and due these canister are adjustable ,i suppouse that i can mount the same part number.

Reply wen you can or you want,of course.No hurry.

Re: Holley carburetor [Re: Coke] #2557337
10/01/18 11:52 PM
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Broken? Difficult item to break. Did you put a vacuum pump on it? Could it be the ported vacuum is blocked by the substitute gasket? No rush to test. Work on getting the engine running nice at idle. It will be itererative. Which is another way of saying the process is repeated several times as you closer.

When you order more bowl and block gaskets, order a 10 pack. Its much cheaper.

Re: Holley carburetor [Re: Mattax] #2560308
10/07/18 12:27 PM
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Originally Posted By Mattax
Broken? Difficult item to break. Did you put a vacuum pump on it?

Yes, i did:

https://youtu.be/WvjHgs5YX8c


I continue studying the carb,just to become familiar with the circuits.

Just one question:Wich holley carburetors had auxiliary idle air bleeds?
Had that circuit The 4160 factory installed on latest 60s Chryslers ?
I did notice that the gasket does not have a hole for the ports marked with the yellow circle:




I have a set of spare gaskets and neither have them.
On the orher hand ,there is a picture in the Urich&Fisher book wich shows a correct gasket for the 4160 that came in the 68-up Chryslers, and it has the hole for those ports.

Last edited by Coke; 10/07/18 12:28 PM.
Re: Holley carburetor [Re: Coke] #2560509
10/07/18 08:58 PM
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The additional idle air bleeds came on carbs as part of a package to meet then new exhaust emmissions requirements. Many had an adjustable air bleed and sealed idle fuel mixture screws.

The passage for the timed vacuum port is at the bottom.

If the canister isn't holding vacuum, the diaphram must be damaged. Replacement of the diaphram is possible but not usually worth the cost unless its an unusual cannister. (about 75 USD).

You mentioned its a Mopar performance distributor. It will either have been made by Chrysler or Mallory. The main difference is the advance mechanism. The vacuum advances are probably the same. Any vacuum advance for a Chrysler built B/RB magnetic pickup distributor should physically fit and work. The differences will be the internal spring, and the notch which limits the maximum degrees, and the preload adjustment on the spring.

R3918A-IMG_1975.JPG
Re: Holley carburetor [Re: Mattax] #2562592
10/11/18 09:00 PM
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Originally Posted By Mattax


You mentioned its a M[i][/i]opar performance distributor. It will either have been made by Chrysler or Mallory. The main difference is the advance mechanism. The vacuum advances are probably the same. Any vacuum advance for a Chrysler built B/RB magnetic pickup distributor should physically fit and work. The differences will be the internal spring, and the notch which limits the maximum degrees, and the preload adjustment on the spring.


Beware of that.
I just have received the new part that i had ordered.It was listed as a direct replacement part for my canister ,but it is not.
As you can see,they are symmetric,it means the lever and the bracket are inverted.
Here are a couple of pictures,just in case it can helps to someone else:

https://ibb.co/eO2sG9
https://ibb.co/bS6Kw9

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