Started with a BANG . . .

av8 · February 05, 2005, 10:31:02 PM

. . . followed by a major miss and great clouds of smoke!

The heretofore trouble-free stock 8BA in my '48 F-1 seems to have a problem, and since I have no serious tools at home and won't be able to tow it to the shop until Wednesday I thought I'd toss out a request for ideas rather than just fret it about it for the next few days.

It's clearly got a dead hole, and a compression test will likely give me a clue about the seriousness of the situation. But I thought I'd get a jump on it today and ask if there might be some classic condition that the very-old hands here might recognize from their own experiences.

It's been running strong -- cool, excellent oil pressure, usually starts on the first cylinder. Drove it to breakfast this morning, thought I detected a bit of a miss on the way home. The miss persisted later when I drove to the gas station to fill up. I restarted the motor, got that big BANG as it started to crank, paused, hit it again at which point it started with a serious miss now and the smoke. Nursed it the few blocks home -- still running cool with good oil pressure, parked it, noticed nothing out of order in the engine compartment. I should add that the exhaust note is considerably louder, as in a holed muffler.

I was hoping that this motor would take me well into Summer or longer, but I might be building that new stroker before I'd planned to.

TIA for any bits of wisdom or words of consolation.

Mike

1FATGMC · February 05, 2005, 10:36:57 PM

Quote from: "av8". . . followed by a major miss and great clouds of smoke!

The heretofore trouble-free stock 8BA in my '48 F-1 seems to have a problem, and since I have no serious tools at home and won't be able to tow it to the shop until Wednesday I thought I'd toss out a request for ideas rather than just fret it about it for the next few days.

It's clearly got a dead hole, and a compression test will likely give me a clue about the seriousness of the situation. But I thought I'd get a jump on it today and ask if there might be some classic condition that the very-old hands here might recognize from their own experiences.

It's been running strong -- cool, excellent oil pressure, usually starts on the first cylinder. Drove it to breakfast this morning, thought I detected a bit of a miss on the way home. The miss persisted later when I drove to the gas station to fill up. I restarted the motor, got that big BANG as it started to crank, paused, hit it again at which point it started with a serious miss now and the smoke. Nursed it the few blocks home -- still running cool with good oil pressure, parked it, noticed nothing out of order in the engine compartment. I should add that the exhaust note is considerably louder, as in a holed muffler.

I was hoping that this motor would take me well into Summer or longer, but I might be building that new stroker before I'd planned to.

TIA for any bits of wisdom or words of consolation.

Mike

This probably isn't it, but I hope it is.

Is there any chance that the miss means not firing in one or two cylinders. If they aren't firing you might of pumped raw gas past them and into the muffler. Start it up and the gas in the muffler explodes. I know all about that (Right Jim-River1).

Now hopefully it is still pumping gas and giving you smoke as it burns in the exhaust. What color is the smoke.

I hope it is something simple like this.

c ya, Sum

av8 · February 05, 2005, 10:50:04 PM

Quote from: "1FATGMC"
This probably isn't it, but I hope it is.

Is there any chance that the miss means not firing in one or two cylinders. If they aren't firing you might of pumped raw gas past them and into the muffler. Start it up and the gas in the muffler explodes. I know all about that (Right Jim-River1).

Now hopefully it is still pumping gas and giving you smoke as it burns in the exhaust. What color is the smoke.

I hope it is something simple like this.

c ya, Sum

It's certainly a possibility, Sum. The smoke is white and dissipates quickly, almost as though it were water vapor, although it was difficult to tell very much from watching my rearview mirror on the few blocks I drove to get home. We had heavy fog last night which was just starting to burn off this morning, so that confused the visual clues.

Aisle 7 is coming over for coffee in the morning and will bring a compression gauge to help us get a bit closer to an answer. Someone on Fordbarn suggested a stuck valve, as did one of my old school pals who built and raced a ton of flatheads in his teens and has spent much of his adult life as a pro technician.

Thanks for suggestion, Sum.

Bruce Dorsi · February 05, 2005, 11:35:41 PM

Mike, was that "BANG," as in backfire, or "BANG," as in a mechanical noise?

What about the possibilty of a valveguide retainer, valve spring, or valve (hope not!) breaking, allowing an exhaust valve to hang open?
....Not sure though how that would cause white smoke, unless a water jacket got cracked.

enjenjo · February 06, 2005, 08:32:21 AM

A stuck or bent valve was my first thought. Exhaust valve from the sound of it. I never had one on a V8, but I had one on a straight 8 Pontiac that had similar conditions, including the loud exhaust, that had a bent valve in it.

My other thought was a head gasket, between two cylinders.

Of course it could be a fouled plug and a blown muffler too.

Bib_Overalls · February 06, 2005, 10:47:56 AM

Well, if it is a valve, you don't have to worry about it taking out the piston and head! Hopefully it is something you can fix in the truck.

Sean · February 06, 2005, 10:54:18 AM

I don't know anything about Flatheads, but here's what my Dad would have blamed it on--
"Well, if you weren't out Hot Rodding it that wouldn't have happened. What were you doing, smokin' the tires off, or racing somebody?..."

enjenjo · February 06, 2005, 11:48:00 AM

Quote from: "Sean"I don't know anything about Flatheads, but here's what my Dad would have blamed it on--
"Well, if you weren't out Hot Rodding it that wouldn't have happened. What were you doing, smokin' the tires off, or racing somebody?..."

Boy, do I remember hearing that!!!

av8 · February 06, 2005, 01:51:34 PM

Quote from: "enjenjo"
Quote from: "Sean"I don't know anything about Flatheads, but here's what my Dad would have blamed it on--
"Well, if you weren't out Hot Rodding it that wouldn't have happened. What were you doing, smokin' the tires off, or racing somebody?..."

Boy, do I remember hearing that!!!

I turned the tables on my dad with just such a line -- like the one I'd heard countless times -- when he earned himself a speeding ticket with a stern warning about "exhibition of speed" with my Chevy-powered '39 Ford coupe in 1960. He was so embarrassed he wasn't going to say anything, but my mom ratted him out at the dinner table that evening. It seems that an LAPD motorcycle cop nailed him and a young guy in a '55 Olds 88 when they engaged in an impromptu stoplight contest. All my dad could say was "Well, I shut him down."

Sean · February 06, 2005, 02:51:38 PM

My dad is a hypocrite too.

When I was 17 and still living at home, I bought a Mustang GT. The next morning, a Saturday, I jumped out of bed so I could go drive my new Car, but when I looked out the window it was gone.

About 15 minutes later, here comes Dad in my Car. He got out and said "Man, that thing runs pretty good, don't be going out tearing it up."

A few minutes later, as I pulled off our gravel road onto the blacktop, I saw the first set of twin black stripes, with a short space, followed by a shorter set of stripes. OK, I thought, Dad smoked 'em through 1st and grabbed 2nd, no big deal. A mile or so later, I saw another set. Then I got to the first intersection and saw where he slid it around to head back to the house....

av8 · February 06, 2005, 05:37:15 PM

Compression test shows the F-1 has a dead -- and wet -- No. 1 hole. All the rest are fine, 90 pounds cold and with good plug color.

I'm hoping and praying for a blown head gasket and will know what I'm up against when I pull the right head tomorrow.

1FATGMC · February 06, 2005, 05:45:47 PM

Quote from: "av8"Compression test shows the F-1 has a dead -- and wet -- No. 1 hole. All the rest are fine, 90 pounds cold and with good plug color.

I'm hoping and praying for a blown head gasket and will know what I'm up against when I pull the right head tomorrow.

Sorry I was wrong :cry: . We'll keep our fingers crossed that it still isn't something big.

c ya, Sum

av8 · February 06, 2005, 07:20:58 PM

Quote from: "1FATGMC"
Quote from: "av8"Compression test shows the F-1 has a dead -- and wet -- No. 1 hole. All the rest are fine, 90 pounds cold and with good plug color.

I'm hoping and praying for a blown head gasket and will know what I'm up against when I pull the right head tomorrow.

Sorry I was wrong :cry: . We'll keep our fingers crossed that it still isn't something big.

c ya, Sum

Nothing to be sorry for, Sum. All guesses gladly accepted!

Look for more news tomorrow.

CalifCarl · February 07, 2005, 05:02:22 PM

I know I have only lurked here for the most part and haven't done a life history acceptable to the poser crowd.

I will if needed!

But I broke a rod in my flathead back in the late seventies which acted simular. Didn't have the big bang or anything, just loss of power and excessive pinging. It must have broke just at the most ideal spot, because no major damage caused by the broken parts. Pulled the pan and head and replaced the rod with the engine still in the car.

Not saying this is the same thing, but it could be. I drove the car home for a couple of miles and you never would have thought it had a broken rod.

GPster · February 08, 2005, 11:59:09 AM

Haven't you got that head off yet? I'm sitting here wailing for "The Rest of the Story". I'm trying to learn something here. I bombed out with the oven cleaner on undercoating, GPster