Later distributor and a Holley 4000 - aka teapot

[fiddy6]

Hi All,

I thought I'd post my results of using a Holley 4000 Teapot with a 60's y block distributor.

Using a 3/8 UNF block off I have plugged the front vacuum port.
I have removed the spark valve and fitted a standard Holley power valve block off in its place.
I have supplied vacuum to the distributor from the manifold right next to the vacuum port for the wipers. The wiper port is blocked in the pictures.

I had to up the idle valves a bit but that was expected.
There are no vacuum leaks that I can detect.
I'm yet to get a timing light on it to check it.
It runs and drives nice. off idle response seems better.

The original setup had the vacuum line from the front of the carb attached to the distributor, it worked but timing was all over the place and it idled hot in my opinion.

Feedback welcome.

Cheers

Geoff

[Hot Rod Reverend]

I have used this procedure on a number of Holley 4000s with good success...
http://www.eatonbalancing.com/2013/0...-distributors/

[dmsfrr]

Originally Posted by fiddy6

I thought I'd post my results of using a Holley 4000 Teapot with a 60's y block distributor.
...

The original setup had the vacuum line from the front of the carb attached to the distributor, it worked but timing was all over the place and it idled hot in my opinion.

The 60's distributors were designed for a 5 to 20 inches of vacuum signal from the carb, not the intake manifold.
The (unmodified) teapot carbs create a vacuum signal of 0 to 5 inches.

The modification procedure from Eaton Balancing noted above by HRR is the way to go.


.

[fiddy6]

HRR. Thanks. this is where I got the idea for the spark valve plug. I liked the method but didn't want to cut things I had no way to replace or plug easily.

Dmsfrr. Thanks I'll get a vacuum guage and test from the various sources. I'll try and post the results.

[dmsfrr]

Originally Posted by fiddy6

...
Dmsfrr. Thanks I'll get a vacuum guage and test from the various sources. I'll try and post the results.

just fyi, the position of the throttle plate inside the carb changes the vacuum signal for the distributor. So a vacuum signal from someplace else isn't what the distributor vacuum canister mechanism was designed for.
.

[scicala]

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Having straight manifold vacuum at idle will cause the idle speed to increase (because of lots of spark advance), and makes you back off on the speed screw. This changes the relationship between the throttle plates and the idle transfer holes. That's not how the carb was calibrated to work. Do the "Eaton" method that HRR supplied. That way you don't get vacuum to the distributor until you open the throttle slightly.

Sal

[cvicky]

just the mechanical advance on my 60's distributor with vacuum on stock Holley 4000 plugged my Y block runs great I'll try the eatons conversion later

[fiddy6]

Okay. I've finally gotten back to this. There is more to the saga. I found a fuel leak from the fuel inlet plug. The plug you remove to get to the back of the needle and seat. It was leaking down the back and into the secondaries. This was causing all sorts of madness when trying to tune and road test. With the help of a mate, made a tool to thread in the plug and act as a guide to cut the seat for the plug flat. Someone had dropped this carb on its head at some point causing the plug to not seat properly.

On to the timing. The distributor was stuck in the block... So a few soaks in wd40 and some runs to heat up and cool down, I managed to free it up. I've abandoned vacuum advance for now. I found what's left of the factory timing marks and dialed in 16 degrees. That seems to be where it is happy with just mechanical advance. It drives great and pulls as much as I want from it up the hill to home.

The choke was also way out. It was what was causing the idle to be so high or nothing. I followed the shop manual instructions to set the choke... Hot and cold. Hot starts are great. No need to touch the gas and just a flick of the key is all that's required. Cold starts require a fair crank with the throttle slightly cracked, then it wants a minute to run nice... It feels too rich. Any adjustments ruin the hot start behavior. I'll live with it for now.

I feel like I've got her to a good place right here. I've solved my vacuum leaks. The heater and wipers.

I'd like to tidy up my fuel lines and get back on to sorting out vacuum advance.

Does anyone know the thread size or fitting name needed to fit into the brass inlet fitting on the back of the teapot? A previous owner had obviously had fuel quality problems which I've solved with a new fuel tank. There is a glass bowl on the bottom of the pump and another glass bowl followed by an inline filter before the carb.

I'd also like to know if I cut the screw on the carb for the Eaton method, is it a one way trip?

I really want to keep this carb as most aftermarket carbs seem way too big for this motor. With the exception of a 390 Holley 4160 which is quite expensive.

[fiddy6]

Photo of the tool made to fix the plug surface

[fiddy6]

Photo of the filter arrangement

[fiddy6]

Another update.

I found and fixed more vacuum leaks. Several inlet manifold bolts were basically finger tight.

I managed to get to the point where I could Idle the engine right down with the throttle plates closed. It now has a lovely smooth idle and starts easily hot or cold.

I've rebuilt the rest of the fuel line from the pump which has removed several leaks.

I've completed the Eaton method vacuum modification to the carb. After this I timed it at idle with a vacuum gauge and it came out to 16 ish degrees with very stable vacuum and a smooth idle. The ported vacuum method works as there is no vacuum on the port at idle and there is a nice smooth vacuum signal when the throttle plates open.

The throttle linkage was a mess too. The linkage to the pedal was all bent outta shape, the linkage to the arm to the carb was wound out way to far to the point where full throttle was never going to happen. All sorted now, I went through the shop manual and adjusted it as close as I could to spec.

I've attached pics of my fuel line and new vacuum line.

I'm really happy how things have turned out... I also found out that this motor is a 312 (refer to my crank flange post). Thanks for the advice.