BA: no idle, dies after ½min

[truck]

Hi all,

You might remember Finn Flatty and his '29 with BA. The same that had exhaust water leak some weeks ago.

Now we'd be almost ready to hit the road, however we have a major tuning issue with the engine.

The original carb, Holley 2100, was running bad and super rich. I rebuilt it with a carb-kit. Next the engine would not run below approx 2000rpm. By ear it runs good above 2000. Then dies suddenly after 15-60 secs. Needs some cranking to fire up again.

We considered the carb was still bad, so Finn Flatty brought in a brand new Holley 94. Still the same problem with the new carb: no idle, runs pretty well above 2000 and then dies suddenly. The nose indicator says the mixture is pretty good.

So, we have here a fresh rebuild BA, new carb, new Bubba Chevy distributor, new Blaster2 coil, new spark wires, champion #H10 plugs.

My best guesses

1) fuel pressure. universal electric pump puts out too much pressure the needle can't hold -> floods. We tried with another el pump and also with a regulator found at the garage shelf, but no change in engine behaviour (however i am not sure about the condition of the regulator)... two pumps and one regulator did not solve it. Yet i might need to check the pressure with a gauge. what fuel pressure would you run?

2) vacuum leak. low vacuum pulls open the carb power valve -> stumbles to rich mix. The missing idle speaks to vacuum leak too. But there is no visible vacuum openings intake nor carb. Is there some Flathead common vacuum leak points? At intake?

3) coil. maybe the new coil is bad. the coil does not heat up though. The connected timing strobe blinks all the way until engine dies.

4) distributor? simple mechanic device, hard to believe.

5) Cam dialed incorrectly

This drives me nuts, since it is hard to find a simpler engine than this, and i can't get it rock Ideas and help are greatly appreciated.

Thanks.

[George/Maine]

Do you know if there is a special cam shaft in there.
Hot cams have idle problems.

[Binx]

Remove the fuel line and pump fuel into a jar to see if there is enough flow and clean. Also make sure the distributor vacuum line is connected to the intake manifold and not the carb.

Lonnie

[54vicky]

get rid of the champion plugs to begin with

[Scott H in Wheaton]

Originally Posted by 54vicky

get rid of the champion plugs to begin with

That won't have any affect on the fuel delivery problem.

[34PKUP]

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Originally Posted by 54vicky

get rid of the champion plugs to begin with

As stated, what has the brand of spark plugs got to do with any of the symptoms described ?

[glennsanders]

I have ran champion plugs in almost all my cars and bike old and new and never had a problem s .Still waiting on answer on what they have to do with the problem he is having?

[flatjack9]

There must be an uncontrolled leak somewhere to let enough air in to run at 2000 rpm and no idle. Cracked manifold? Also might want to check that the gas tank is vented properly. This could cause the engine to stop after a short run period.

[Finn Flatty]

The cam shaft is stock, condition inspected by the machinist and the gas tank is in original position with the factory cap, worked well with the the previous banger motor.

[Mart]

Sounds like massive air leak.

Without the parts in front of me I can't even guess what may be causing it.

Mart.

[BUBBAS IGNITION]

note::

THE MSD BLASTER 2 COIL IS THE WRONG APPLICATION FOR SURE !! ITS RATED AT .7 OHMS AND WILL DRAW WAY TOO MANY AMPS!!! USE 1.5 OHM COIL WITH ALL OUR DISTRIBUTORS INCLUDING POINTS AND ELECTRONIC VERSION.......

[my4dv8]

Ok thanks bubba , our mallory spark box died on the chev converted 8ba dist. so we swapped back to points and MSD blaster coil . Wouldn't run worth a darn with the blaster coil. Put a simple old coil back on , perfect.
Not trying to hijack here ,but what application is the Blaster designed for?

[flatheadmurre]

To little valve clearance ??

Bad seal when engine heats up...

[oj]

You have an electric fuel pump? then turn it on long enough to fill the bowl, shut it off and start the engine. That will give you insight to fuel delivery.
Low vacuum not closing power valve has no effect on the idle ckts.
Kinda sounds like you have a huge vacuum leak, if left to itself does the rpm spiral down until the engine just dies? If yes, then look for vacuum leak - you should be able to hear it. If no, then have a look at your throttle blades, they must not be closing.

[George/Maine]

The cool kids used dialed in.
Simple Did you every hear it run with that camshaft. Yes or no
BA I guess that's 8 BA remove intake.

[BUBBAS IGNITION]

Originally Posted by my4dv8

Ok thanks bubba , our mallory spark box died on the chev converted 8ba dist. so we swapped back to points and MSD blaster coil . Wouldn't run worth a darn with the blaster coil. Put a simple old coil back on , perfect.
Not trying to hijack here ,but what application is the Blaster designed for?

Blaster 2 is designed for extreme high amps drivers and electroinc current control. Should us a high end msd box....