MTFCA Forum

Could some kind soul please post a picture or two of a properly restored 1926-27 Holley Vaporizer? We are attempting to detail such a unit on a car my friend bought and we are unsure of the intake manifold color. The exhaust manifold will go cast iron grey high heat spray, right? But what color is the goofy-looking intake manifold - Ford Engine Green or black? And is the whole thing painted one color?

Also, we are having a HECK of time starting this beast. The coils are buzzing and when in a blue moon the engine does catch and starts, it runs fine. So, I'm ruling out ignition problems. But getting it to the point of starting is an exercise in frustration. There is fresh gas and it is reaching the carburetor. I disassembled the carb portion and cleaned the plate and innards of the intake manifold to remove built-up carbon. Is there supposed to be a gasket on both sides of that plate or only one side? The blown-up drawing showing a Vaporizer does not show a plate gasket at all. But I would assume there must be at least one? This is my first contact with a Holley Hot Snot system and I'm not impressed by the starting or power (lack of).
Can you guys with oodles of Holley Vaporizer experience possibly suggest why we're having such difficulty starting the engine in a warm garage? Lord only knows how difficult it will be to start in the real world outside of a warm garage or in colder weather!

Thanks in advance.

Marshall, the Clueless One

The car will start easily and run well with a vaporizer if the vaporizer is working correctly.

Lots of info & pictures on the vaporizer in t his link https://www.mtfca.com/discus/messages/4 ... 16013.html
This is a picture of the engine in Henry Ford's personnel car see this link
https://www.thehenryford.org/collection ... =gs-559395

Re: Hard Starting:

"Most of the problems with this (Vaporizer) type carburetor are caused by leakage in the Primary Air tube upper/lower seals and Outlet Tube Nut seal or the seal between the carburetor base and exhaust manifold with the Vaporizer Plate sandwiched in between. When it is not leaking and working correctly it is a great carburetor, but if it is leaking air or the Vaporizer Plate is rusted through I is a boatload of trouble."
Ron the Coilman


The Vaporizer will not tolerate any air leaks. Even a small air leak in certain critical areas would likely cause hard starting with a cold engine.

Put a very thin amount of black RTV on the primary air tube at both ends and on both sides of the heater plate around the edges. I bet it will work properly after the RTV application.

Yes, thank you all for your input. I had viewed the suggested thread many times and studied the drawings, as well as other past threads posted on this website. Once again I ask, should there be a gasket on the plate? I don't see such a gasket on the drawing, but there were remains of one in our carb. Maybe there is one (or two?) in the rebuild/gasket kit? If only one gasket, on which side of the plate does it go?

Because the pictured carb system was not a Holley Vaporizer, but a Simmons, I wasn't sure if the intake on the Holley should be green or black. I have seen photos both ways. True, this car we're working on is no Rosenthal Trophy contender, but we'd like to at least get the colors right.

I put a bead of sealant on both side of the plate. The tube inside had had a horrible repair with all kinds of goop at the base. I wonder if there is a leak there? Maybe I should also remove the bulb portion and check the gasket there, too?

Marshall

No gasket on the plate ! There used to be the short tube & knurled nut available - yes, that can be a potential leak.

Thanks, RajoRacer. Did I screw up by placing a bead of sealant on either side of the plate? I wonder why there had been a form-fitted gasket there when I disassembled the carb last night? It didn't look homemade. The edges were too precisely cut or stamped to have been made with scissors on the kitchen table.
Marshall

You are most welcome. When I inherited my Gramps' TT, I recall my Dad having problems with the Vaporizer quite often - he didn't understand the concept & my Gramps was a bit thrifty like most T owners so he had the Vaporizer install when it became available. I rebuilt it & it ran quite well after that.

One other thing to comment on: Fuel would drip out of the bowl when the sediment bulb lever was opened. Upon disassembly to clean the plate and inner surfaces last night, I noticed that the float was set for a low level - yet fuel ran past the bowl gasket and down the sides of the bowl. The bowl was filling up. and the bowl gasket couldn't contain that much fuel. I cleaned the needle and blew out the passageway and seat after removing it for cleaning. I set the float level to be almost parallel with the casting top, as is done with the Holley NH carb (and Model A carbs). It leaked worse than before! Removing the carb AGAIN, I reset the float to where it had been and installed a new bowl gasket from an NH gasket kit. I THINK that has stopped the leaking, but I am unsure how the engine will perform with such a low level in the bowl. Where should the float be set on this Vaporizer set compared to an NH?
Marshall

You want the float to be "level" when the float valve closes, and you want the "B" (thicker) float. See: http://www.mtfca.com/discus/messages/70 ... 1509971387

The flooding you are experiencing is due to a leaking float valve, and nothing else.

Yes, it has the thicker float. I'll keep fiddling around with the float height. For starters, should it be close to parallel with the upper casting when inverted?
M.

...should it be close to parallel with the upper casting when inverted?

yes

and there is very little fiddling required; it's either parallel or you adjust it to be parallel by bending the tab at the hinge...by eye is fine and if you're worried enough to make a gauge, it will run the same as if set by eye anyway...it simply isn't as critical as people will have you believe...any flooding/overflow after that is a failure of the float valve.

Thanks, Scott. I'll adjust the tang tomorrow and hope the leaking stops. Maybe I should tap the needle to "seat" it?
Marshall

Be sure your fuel system is free from any kind of debris. No carburetor will work properly with foreign matter in the fuel.

Update: I replaced the needle and seat, which seems to have stopped the overflowing bowl. But this engine is still a hard-starter, even with the coils buzzing away merrily and the spark plugs cleaned and gapped at 0.025". I'm sure it's fuel-related, because the engine will catch and run for a second, then die. It does this numerous times before it will stay running. Adjusting the GAV makes no difference, nor does holding the choke rod back longer than usual. 'Just kind of frustrating, although when the engine does stay running, it sounds good. My friend may just end up living with this hard-starting situation.
Thanks to everyone for their input and suggestions.
Marshall

Remove your spark plugs and check for continuity between the terminal and the center electrode. If there is not 100% continuity there's a break in the connection possibly from not using your fingers to put the terminal screw on that spark plug, over tightening with a wrench will cause spark plug failure.

I would sure be looking for a vacuum leak on that thing at this point. Lots of opportunity for one on a vaporizer. Glad you got the overflowing issue under control...that's one variable put to bed...

"When the engine is cold, it is advisable to turn the vaporizer adjusting rod (located on the instrument board and also referred to as priming rod) a quarter turn to the left (anti-clockwise) ** ** A quarter turn or more beyond its normal setting of about one full turn open** and pull out on this rod to prime the engine. In order to avoid flooding the engine with an over-rich mixture of gas, the priming rod should only be held out for a few seconds at a time **while cranking the engine**. As soon as the engine warms up turn adjusting rod back to the right."
(Ford Owner's Manual)

I suspect an air leak either within the vaporizer itself, or the manifold to block interface. Another possibility is that the choke is not closing fully when the choke rod is pulled out. The mixture adjustment is normally set at about one full turn off the seat, and opened a little more when starting a cold engine, as outlined above. Your particular vaporizer may need the initial mixture setting somewhat richer. Another possibility is that your throttle shaft is worn, allowing excess air to leak in. Try starting the car following the above procedure EXACTLY.

Moxie26 wrote: ↑

Wed Oct 19, 2022 9:33 pm

Remove your spark plugs and check for continuity between the terminal and the center electrode. If there is not 100% continuity there's a break in the connection possibly from not using your fingers to put the terminal screw on that spark plug, over tightening with a wrench will cause spark plug failure.

Coils will buzz no matter what they are electrically set at, and if the spark plugs are defective chances are you'll never get it to fire correctly. Wouldn't hurt to have your coils checked and also check your spark plugs for continuity

Though it would be quite a bit of work replace the vaporizer with a good know intake manifold and Holley NH and see if the problem goes away….

As mentioned above, coils buzzing does not take ignition problems off the table. Coils can buzz and still produce a very weak output. Even with coils buzzing, you can have weak spark output, timing issues, timer issues, spark plug issues or wiring issues. Hard starting can also be caused by valve issues, valve guide issues, compression issues, and more. If the engine really runs well once started and warmed up, it points to an air leak in the vaporizer/intake manifold assembly. Overchoking the engine when starting and holding the choke part way out for some time after starting will often overcome an air leak. Opening the adjustment knob more than recommended may help. An air leak at the manifold to block gaskets may diminish once the engine warms up, and return when it cools off. Assume nothing. Check all the systems. Find the problem and fix it. The car will start easily and run well with the vaporizer if everything is working as it should. Under some conditions, the vaporizer will outperform the regular intake and NH carburetor.

Marshall..... Have you had a chance to use any of our suggestions for your friends Model T problem?

The best way to deal with vaporizer problems is to put on an NH Holley from Russ Potter.

Erik Barrett wrote: ↑

Thu Oct 20, 2022 1:53 pm

The best way to deal with vaporizer problems is to put on an NH Holley from Russ Potter.

I’m running one of Russ Potters rebuilt Vaporizers on my 27 coupe. Looks brand new and runs like a dream. Probably one of the few with no issues.

Brad

Brad,
I guess I have the other good running vaporizer carburetor! It always seems to go 8-10 years before you need to fuss with it. The most sketchy part is the thin heat exchanger plate. Mine finally failed after about 20 years of use. Whenever you take one off and mess with it you may have to fiddle with it a bit to get it set right. Then it can be dead reliable for at least a decade!

IMHO, TH

p.s. Yes Erik often tells me his stock "get an NH" jest!

FROM 20 YEARS OF VAPORIZER DRIVING:

If you pull the choke and turn over 4 compressions, ignition off.
Then push the choke back, turn the ignition on and press the starter, mine starts every time.

If I don't do the first part, it will never start.
I richen about 1/6 turn for starting too.