Too hot to keep fuel in liquid form!

[Byron Warwick]

I've read all the posts about running hot flatheads. My problem is getting vapour locks at about 180 to 190 deg F.
I'm running a '54 Mercury flathead with the glass bowl fuel pump, in my '34 pickup. It wasn't this bad last year. I've talked to Ken CT, about replacing my fuel pump, which I rebuilt before 2009. I know there are opinions about installing an in-line fuel pump along the frame. What is a good pump to use, at what pressure? Using a 2-4 lb pump, do I need a regulator? I guess I can only use it to start up after sitting , or to get the fuel pumping, and then shut off.
Ken mentioned a bad coil, how do I check that on the side of the road? That's a lot of questions, answer what you wish. Byron
PS: I'm also busy replacing a BROKEN crankshaft in my '54 MG TF at this time!

[Old Henry]

For 6 volt it's AirTex 8902 available here: http://motors.shop.ebay.com/eBay-Mot...0.l1313&_rdc=1

For 12 volt it's AirTex E8016S available here: http://www.ebay.com/itm/AIRTEX-E8016...880d0d&vxp=mtr

You don't need a regulator and you can run the pump continuously or just when you need it which is what I do.

Here's my installation:

[Old Henry]

Here's how I check my coil on the side of the road:

Disconnect the low tension wire from the coil to the distributor and clamp a jumper wire onto that coil terminal. Unplug the high tension wire from the coil and plug in a spare spark plug wire. Now turn on the ignition to power to coil. Hold the end of the spark plug wire near a head bolt to check for spark as you tap the end of the jumper on a head bolt to simulate the action of the points. If you get spark when tapping the coil it's good. If not, could be a problem.

[JM 35 Sedan]

I'm having the same problem with gas boiling/bubbling on my '35 when using a '47-'48 glass bowl fuel pump. A fix for this was discussed in a post made be G.M. a couple months back. I'm designing a 1" spacer for my FP that also has a heat shield that fits in between the glass bowl and the intake/deck area of the engine. This change will also require a 1" longer FP push rod.

[Walt Dupont--Me.]

Originally Posted by Old Henry

Here's how I check my coil on the side of the road:

Disconnect the low tension wire from the coil to the distributor and clamp a jumper wire onto that coil terminal. Unplug the high tension wire from the coil and plug in a spare spark plug wire. Now turn on the ignition to power to coil. Hold the end of the spark plug wire near a head bolt to check for spark as you tap the end of the jumper on a head bolt to simulate the action of the points. If you get spark when tapping the coil it's good. If not, could be a problem.

Henry, do you need a condenser in the circet to make this work? I have never tried that. Walt

[G.M.]

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ALL,ALL,ALL old coils will look almost like a new one cold. You have to heat the coil up over it's operating temperature and 99% of ALL old Ford Coils will produce a very small yellow spark. This applies to NOS Ford coils as well. I built a machine 15 years ago for skip to test old coils as well as after he rebuilds them. He don't bother testing the old ones any more, it's just a waste of time. It takes 15 to 20 minutes to test an old coil. G.M.

[Byron Warwick]

Thanks 'Old Henry' , (or the professor, as your usually hit it right). I had always wanted to know the coil solution. Your pump installation also looks very neat. Byron.

[Old Henry]

Originally Posted by Walt Dupont--Me.

Henry, do you need a condenser in the circet to make this work? I have never tried that. Walt

No. You're removing every part of the circuit except the coil to isolate it for testing. Don't know why this works without a condenser, maybe don't fully understand all that the condenser is needed for, but it does work this way for testing.

[Old Henry]

With regard to suspicion of bad coil or some other ignition part, there is an even easier way to test for spark without dismantling anything. I carry my timing light (12 volt one works fine on 6 volt) and any time I suspect ignition problem rather than fuel problem I just hook it up and start clamping the pickup around various wires that are supposed to be carrying spark to see if they all are properly. That's the high tension coil wire and each spark plug wire. You can pretty quickly see if you really have a spark problem and, if so, where it is. If spark is in all wires that are supposed to have it I turn my suspicion to the fuel system.

Before I finally installed my electric back up fuel pump I cured vapor lock whenever I had it by pouring cold water on the fuel pump. That cooled it down, condensed the vaporized gas, and I was on my way. Anyone plagued with vapor lock can do this until you're tired enough of it to install the backup electric pump.

[Old Henry]

Originally Posted by Byron Warwick

Your pump installation also looks very neat. Byron.

That installation didn't even require drilling a hole to mount the pump. I used a hole that was already in the frame at just the right spot.

Was in a car show Saturday and was glad I had not altered the engine compartment to fix my vapor lock problem as some have done in a major way. Engine compartment is still totally stock without the accompanying chronic vapor lock problem.

[FlatheadTed]

If you bump the starter with key on ,you can get a spark of the ht coil lead pulled from the distributor ,or if the points are closed you can touch the hot side of the coil with the ignition wire or a jumerwire you will also get a spark also of the HT lead .

[gmc1941]

Champion produces a spark tester. This has neon light which reacts to the spark by just touching the spark wire. By checking one against the other you can detect a wek spark. Uses less space if your carting around a timing light