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Need HELP Engine Back Fired Blow off oil Fill cap and More

Started by Bill Balkie 24172, June 24, 2012, 07:16:56 AM

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Bill Balkie 24172

Hello ,
    I am really concerned. I took my car for a 20 mile ride yesterday with no problems what so ever . Went to start it today and with a single crank of the engine i heard a pop , lots of smoke and went for the fire extinguisher . Good new was it was not on fire , waited for the smoke  to cleared i restarted it and pulled the car out of the garage . I then noticed the Oil fill was Gone , but it did find it laying in the engine compartment with a huge dent in it , then i noticed the Valve covers both side were way out of shap and the gaskets were  actually blown out of the covers .   Where do i go from here ?  i am now taking off the bent valve covers . Could this be that the oil fill cap was clogged and not allowing the engine to breath ? Very very concerned .

  Bill
Bill Balkie
1970 Coupe DeVille
2009 CTS

The Tassie Devil(le)

Sounds to me like there was a build-up of Gasoline vapours in the sump, and the ignition firing simply ignited it, and the only place the resultant explosion could go was to the softest, and weakest places.

I would also be checking the sides of the Sump as well.

You could have a leaking mechanical Fuel Pump diaphragm, which could have led to the gasoline in the sump.

Bruce. >:D
'72 Eldorado Convertible (LHD)
'70 Ranchero Squire (RHD)
'74 Chris Craft Gull Wing (SH)
'02 VX Series II Holden Commodore SS Sedan
(Past President Modified Chapter)

Past Cars of significance - to me
1935 Ford 3 Window Coupe
1936 Ford 5 Window Coupe
1937 Chevrolet Sports Coupe
1955 Chevrolet Convertible
1959 Ford Fairlane Ranch Wagon
1960 Cadillac CDV
1972 Cadillac Eldorado Coupe

Jeff Wilk

 Bill,  been there before.  Most certainly an excess gas issue. Question is from what/where.   Mine was a freshly rebuilt engine for my 58 fleetwood sixty special 35 years ago.  I had no hood on the car and was attempting to start for first time.  Kept dripping (well i was 18 so it was more like pouring) gas down the carb.   And using a remote start button to crank it.  Cinally got some ignition and BAMB!!!!!  Explosion of all that extra gas internally.  Oil filler was honestly found 5 houses Away.  Valve covers both bulged as did oil pan.  Also blew out carb gasket.   Oh yes i was also deaf for two full days.

So.......as Brian states,  find the source of a gas leak or overflow and you will have your root cause diagnosed.  Do check all the gaskets carefully though and check oil condition. 

Good luck

Jeff
"Impossible Only Describes The Degree Of Difficulty" 

Southern New Jersey

1959 Cadillac Fleetwood Sixty Special
1975 Eldorado Convertible (#12 made)
1933 Phaeton Chevrolet - "Baby Cadillac"
1933 Master Sedan Chevrolet - "Baby Cadillac"

SOLD
1976 Cadillac Mirage (factory authorized Pick-Up)
1958 Cadillac Sixty-Special
1958 Cadillac Sixty-Special
1958 Cadillac Sedan
1958 Cadillac Coupe Deville

Bill Balkie 24172

Jeff and Bruce ,
      my car was at a shop getting some body work for the last couple of months . i do have an electric fuel pump hooked up to a on off switch . I have a feeling that they had the ignition on with the pump on the on position and must of dumped some gas into the carb with out the engine running . This is just a thought , anything is possible at this point . I always thought the car run to rich anyway . i have to put the car back into the garage but now i am a little shy about starting it . and my driveway is on a pretty steep incline .

    Bill
Bill Balkie
1970 Coupe DeVille
2009 CTS

TJ Hopland

Ahhh electric fuel pump with a manual switch.....   I think you found your problem especially since others were around the car.   Its such an easy mistake to make even yourself and then to expect others deal with it correctly?   I have seen and heard about many similar incidents including a neighbor that lost his whole house, cars, and dog to a fire.   If its just for priming it should have a momentary push button switch.  If its for more than that it should be set up like the earlier factory ones were running through a oil pressure switch so it can't run except during cranking if there is no oil pressure which is a pretty good indicator whether or not the engine is running.  Places like Jegs and Summit sell kits pretty cheap.   
StPaul/Mpls, MN USA

73 Eldo convert w/FiTech EFI
80 Eldo Diesel
90 CDV
And other assorted stuff I keep buying for some reason

Tito Sobrinho

Bill:
By the explosion magnitude, I would think, it was due to an incorrect ignition timing =incorrect valve timing= broken timing chain.
But I hope it will be a simple matter as suggested by our fellow members above.
Tito S.

1949 CCP 6267X  (First Series)

Thanks to Frank Hershey for its design and thanks to Harry Barr, Ed Cole, John Gordon and Byron Ellis for its engine.

Bill Balkie 24172

Toto ,
   Thanks for your response , the car drove very well the day before . and after the explosion my main objective was to get the car out of the garage . It did start right back up and i pulled the car out . then shut it off ,that is when i noticed the damage to the valve covers and the oil fill  blown off the car . i changed the oil and i did not smell any gas in the oil. so i have to think the timing chain is OK .
   going back to the original Manuel fuel pump .  sooner or later today i have to start this car back up today . and put it back in the garage . i had an extra set of valve covers that i just installed . i will let you know what happens .

  Thanks,
       Bill
Bill Balkie
1970 Coupe DeVille
2009 CTS

gary griffin

Bill,

    My first inclination is that the electric fuel pump is delivering fuel at a higher pressure than your carb can handle.

   Carbs are simple and have needle valves to stop fuel delivery when the float bowl is full. We are quick to add electric fuel pumps when we have fuel delivery problems.  The original mechanical fuel pumps delivery is automatically regulated by engine speed, but the electric fuel pump is always on full speed tring to deliver enough fuel to go hundreds of miles per hour. As wear occurs in the needle valves regulating float levels the fuel pump continues to delever fuel which passes through the needle valves and down into the engine. First thing to do when installing an electric fuel pump is to check fuel delivery pressure (Don't count on rating on the box) and check the pressure your carb needs to operate correctly. Useually about 2 PSI and most electric pumps put uot more pressure than that. A PRV  (Pressure Reducing Valve) can be installed to regulate the pressure.

   I would only use an elecric pump for priming when the car has been sitting a long time and in case of failure of the mechanical pump.   


   
Gary Griffin

1940 LaSalle 5029 4 door convertible sedan
1942 Cadillac 6719 restoration almost complete?
1957 Cadillac 60-special (Needs a little TLC)
2013 Cadillac XTS daily driver

Bill Balkie 24172

Gary ,
  Thanks so much for your input .I had a 1957 Seville that always used the Mechanical pump , and i also had the electric for priming . I never had a problem . I purchased this  new 1957 car in October and it only had the Electric pump the mechanical pump was removed . I had  a few extra mechanical pumps  I sent those  mechanical pumps to Gould re builders with all in tensions to install a fresh mechanical pump. Want to set this car up the same way to run on the Mechanical pump . I am not sure what happened yesterday but i was going to have my car flat bedded home from a body shop in Philadelphia to my home in Mount laurel NJ about 20 miles . the truck was not available , so i decided to drive the car home . I was glad i did because the car drove very nice . Parked it in the garage , then went to My Grand Daughters Birthday Party . Life was Good . Until i started the car this morning . I thought i was going to call the fire dept.  Since then , i changed the oil, But it did not have a gassy smell  , replaced what looked to be some dry vacuum lineplugs in the carb. . By the way my car is running dual Edelbrocks 1406 carbs . My original carbs are out being rebuilt .   .... After about 5 hours 1:00pm eastern time , about 1/2 hour ago I started the car and it fired right up and ran smooth and quiet . Went around the block and parked it back in the garage . the next time i start this car it will be running on a mechanical pump . The good news is i did not blow apart the sump  like i did the valve covers and the car does run smooth ,So the timing chain must be OK  I have noticed the car is running rich , black smoke around the exhaust pipes .   Thanks Again Gary ,Tito , Bruce , TJ , Jeff ,
Bill Balkie
1970 Coupe DeVille
2009 CTS

62droptop

not sure why everyone is so quick to fault   electric fuel pumps
i use a electric pump on my  62 390 and never had an issue
in fact ,it has never ran so good or strong

from june 2 to june 16, my car covered 4700 plus miles , a lot of that over 80 mph down the highway
in that time ,the car was run down the dragstrip,a lap on a oval race track and did some serious carving down some canyon roads

it however has the proper pressure rating and my carb is in good shape
i use a pump with a stated pressure rating of 5psi
if you are worried about too much pressure ,a inline regulator is a simple addition

if you have the proper rating pump and a carb that is working good, you can leave the pump on all day and never have fuel in the oil
if you have a float issue,nedle and seat issue or leakage , the fuel pump will keep pumping and fill the oil with gas

first thing to do is pull the dipstick and smell the oil
does it smell like fuel??
if so ,get it out of there right away
gas washed out the oils ability to lubricate properly and will waste an engine in short time

as a good measure ,specially for cars that dont get  regular excersize, when you check the oil, smell it also
a lot of times ,if the carb leaks down over time, it goes into the oil
even though you may only have a few hundred miles on you  oil, it still can be full of gas
i would also find out why your car is running rich, probably why there is gas in the oil


gary griffin

   I don't disagree that a proper installation of an electric pump with the proper regulater can make a car run well for extended periods of time but I also agree with the engineers that designed the original system with mechanical fuel pumps.

   Obviously I prefer to have the electric pump only for a back up and priming after extended periods of non use.

   A mechanical pump is designed to deliver approximatly the proper quantity of gas for the RPM's being driven while the electric is designed to deliver approximatly the maximum amount of gas you could burn under the most extreme conditions such as accelerating up a steep hill under full load.

    Either system will function properly most of the time but when things start to wear like the needle valves in the carbuerator the electric pump is more prone to over delivery of fuel and the associated problems associated with that situation.

   Tossing the mechanical pump and going all elecrtic has too many potential risks associated with it as far as I am concerned. Last sumer I had to have a car towed in during a club drive because of over delivery of gas from an electrc fuel pump that a previous owned had installed on my Triumph Stag. The car was designed for a 2 PSI fuel delivery and the pump was putting out 6 PSI. A regulator valve solved the immediate problem but I will be installing a mechanical primary pump and the electric pump will have a shut off switch installed.  From now on electric back up pumps with original equipment pumps as primary will be in my cars. To each his own of course.
Gary Griffin

1940 LaSalle 5029 4 door convertible sedan
1942 Cadillac 6719 restoration almost complete?
1957 Cadillac 60-special (Needs a little TLC)
2013 Cadillac XTS daily driver

Dave Shepherd

Carter AFB's/Edelbrocks are not happy over 7psi. at the needle and seat. Sounds like there was fuel in the intake manifold and off it went and pressure blew back down into the crankcase thru open intakes when it lit up.

The Tassie Devil(le)

Reminds me of an incident at the Drag Strip, where my mate was about to fire up his car, and a sudden rain squall stopped him.

Rain stopped, and he proceeded to crank it over and all of a sudden, there was an explosion, and the insides of the carby was completely blown out.

He had forgotten to turn off the Nitrous Oxide when it rained, and somehow, the engine filled with the explosive compound, and as soon as the ignition fired, whammo.

Too much explosive stuff where it isn't supposed to be is a recipe for disaster.

Bruce. >:D
'72 Eldorado Convertible (LHD)
'70 Ranchero Squire (RHD)
'74 Chris Craft Gull Wing (SH)
'02 VX Series II Holden Commodore SS Sedan
(Past President Modified Chapter)

Past Cars of significance - to me
1935 Ford 3 Window Coupe
1936 Ford 5 Window Coupe
1937 Chevrolet Sports Coupe
1955 Chevrolet Convertible
1959 Ford Fairlane Ranch Wagon
1960 Cadillac CDV
1972 Cadillac Eldorado Coupe

62droptop

Quote from: gary griffin on June 24, 2012, 04:10:23 PM
   I don't disagree that a proper installation of an electric pump with the proper regulater can make a car run well for extended periods of time but I also agree with the engineers that designed the original system with mechanical fuel pumps.

   Obviously I prefer to have the electric pump only for a back up and priming after extended periods of non use.

   A mechanical pump is designed to deliver approximatly the proper quantity of gas for the RPM's being driven while the electric is designed to deliver approximatly the maximum amount of gas you could burn under the most extreme conditions such as accelerating up a steep hill under full load.

    Either system will function properly most of the time but when things start to wear like the needle valves in the carbuerator the electric pump is more prone to over delivery of fuel and the associated problems associated with that situation.

   Tossing the mechanical pump and going all elecrtic has too many potential risks associated with it as far as I am concerned. Last sumer I had to have a car towed in during a club drive because of over delivery of gas from an electrc fuel pump that a previous owned had installed on my Triumph Stag. The car was designed for a 2 PSI fuel delivery and the pump was putting out 6 PSI. A regulator valve solved the immediate problem but I will be installing a mechanical primary pump and the electric pump will have a shut off switch installed.  From now on electric back up pumps with original equipment pumps as primary will be in my cars. To each his own of course.

Gary, you have a stag
you are a brave man
i too run in a truimph circle also, 71 gt6 convertable not net finished,
have quite a few buddies with stags in the detroit area

i have also found that issue on english cars over the years
people dont know that the little stuff only need 3 psi or so max pressure and stick some big ol v8 spec pump on their LBC and wonder why it doesnt work well

Bill Balkie 24172

Hello,
I consider myself lucky that it did not distroy more then my valve covers and oil fill cap . As for now . I will be running on  the Mechanical pump all the time,  Electric just for prime in the future . ordered a new carb. edelbrock 1406 until i can get my original system rebuilt . I have always been very careful with the electric fuel pump .  Although i instructed the shop even using tags on the pull switch so they would understand how it works you never know what happened . I may never hook it up the electric one  again after this experience .  I am going to bed

  Bill
Bill Balkie
1970 Coupe DeVille
2009 CTS

TJ Hopland

Good to hear that its apparently running fine and there is apparently no major damage.


Here is one of many oil pressure switches that are available.
http://www.jegs.com/p/Holley/Holley-Fuel-Pump-Safety-Switch/743663/10002/-1

also the instructions that show how to wire it into any car.  Their method the pump runs during cranking and when the oil pressure is above 5 psi. 
http://www.jegs.com/InstallationInstructions/500/510/510-12-810.pdf

you could still put a switch in to keep it from running but the oil switch would keep it from accidentally running when the engine was not running. 
StPaul/Mpls, MN USA

73 Eldo convert w/FiTech EFI
80 Eldo Diesel
90 CDV
And other assorted stuff I keep buying for some reason

Bill Balkie 24172

TJ ,
  That is the best 26.00 I will ever spend .  The diagram is a great tool as well .

Thanks,
    Bill
Bill Balkie
1970 Coupe DeVille
2009 CTS

TJ Hopland

That setup is basically how GM did it the first few generations of EFI.  By the time of OBD2 (1996) I think the computers just handle it because they obviously know if the engine is running or not and by that time were capable enough to handle extra functions like that. 
StPaul/Mpls, MN USA

73 Eldo convert w/FiTech EFI
80 Eldo Diesel
90 CDV
And other assorted stuff I keep buying for some reason

gary griffin

W. Lee,

    I cheat on LBC's my Stag has a TR6 engine and a Toyota 5 speed transmission. My 1948 Triumph 1800 roadster will have a Tr 4 engine along with a Toyota 5 speed. The 5th gear in the Toyota is is about 1.2 to 1 which makes Triumph,s O K on the freeways.  My 1937 Lanchester is stock and not liking to go down the road much faster than 40 MPH in fact it probably likes 35 better. My Cadillac will be a freeway cruiser even though it origially had a 4:11 rear end I am trying a 3:26? . I expect it to be  a dog in town but a very comfortable cruiser which is what I expect to be doing with it
Gary Griffin

1940 LaSalle 5029 4 door convertible sedan
1942 Cadillac 6719 restoration almost complete?
1957 Cadillac 60-special (Needs a little TLC)
2013 Cadillac XTS daily driver

pauldridge

I personally think all the cautions about electric fuel pumps is without merit.  There are literally hundreds of models of carbureted cars that use on electric pumps, including most all British and Italian makes.  And, again, not a single one that I can think of utilizes any sort of separate switch for the electric pump other than the ignition switch itself, with no issues.

If anything, in my opinion, the mechanical pump poses a greater hazard when the rubber diaphragm finally deteriorates and allows raw fuel into the crankcase, which is truly the only logical cause of the incident which spawned this thread.

I'd bet good money that there's not a 346 flathead Caddy made with mechanical pump  that can operate without vapor lock in 110 degree Texas summer heat.

On my '40 Sixty Special, I've bypassed the fuel delivery section of my mechanical fuel pump altogether (leaving the pump installed to provide the vacuum boost), in favor of an inexpensive Airtex electric unit calibrated expressly for low pressure carb delivery.  Yes, as a precaution, I do have a good quality Holley pressure regulator and gauge so I can insure I'm getting about 3 PSI pressure.  I ran the fuel line up the firewall and straight over to the carburetor, rather than the original configuration of having the line pass directly over the top of the exhaust manifold.

If your carb is leaking at 3 PSI, then you need to replace the needle valve and/or seat. 

And I disagree that higher RPM's require higher fuel pressure.  The correct electric pump will provide all the fuel VOLUME required of our single-carb systems while maintaining the correct 2.5-3 PSI pressure appropriate for the float and valve.
Phil Auldridge
Austin, TX
1940 60S as well as MGA, Stingray, '39 Ford Coupe, BMW 3.0 CS, '59 Jaguar, '51 Hudson Hornet, '64 and '70 Mercedes roadsters, and Nash-Healey LeMans Coupe
[img]http://www.auldridge.org/images/hdricon.jpg[/img]