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
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
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
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
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.
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.
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,
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 ,
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 ,
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
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.
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.
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
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
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
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.
TJ ,
That is the best 26.00 I will ever spend . The diagram is a great tool as well .
Thanks,
Bill
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.
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
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.
Quote from: gary griffin on June 24, 2012, 11:16:05 PM
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
that will do it nicely
the stag v8 does sound nice,but expensive and problematic
i have a buddy in atlanta area with a 49 or 50 tr 2000 roadster,cool cars
Quote from: TJ Hopland on June 24, 2012, 09:50:32 PM
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.
ford also used the inertia switch with a ball bearing in it to shut down the pump in case of a crash
i have on wired into my mini from an old ford tempo
just have to remember it is there if you jolt the car as it may trip the switch and need to be reset
I have to agree with Phil here. My father put an electric fuel pump on his 1938 Cadillac to solve vapor lock problems. It was turned on and off with the ignition and it did not give any problems in the approximate 200,000 miles he drove the car after putting in the pump. I am planning on putting an electric pump on my 68 ELDO for starting after sitting for a long time. I just need to find one that does not over power the float valve.
There seems to be some misunderstanding of how a mechanical fuel pump works.
When the cam bumps the pump lever it causes the diaphragm to pull fuel into the chamber of the pump through a check valve. When the lever is off the cam the spring in the pump presses against the diaphragm creating a nearly constant pressure that is dependant on the spring strength and diaphragm size. This pressure is only interrupted briefly each time the cam comes around to bump the pump lever. Of course the pressure is matched to the carb to prevent flooding. The carburetor is what regulates the flow of fuel; first with the float valve which fills the bowl. The depth of the fuel in the float valve then provides the pressure needed for the rest of the carb systems like the Venturi(s).
In Bill’s case the only place that explosion could have taken place is in the crankcase. Any explosion in the intake manifold would not have any effect on the oil filler cap or the valve covers. Even with the intake valves open the explosion would only go into the cylinder where explosions happen hundreds of times a minute in a normally operating engine.
The next question is what ignited the fuel vapors in the crankcase? Liquid gasoline will not burn (it’s too rich) so only vapors burned. Contrary to popular belief it requires a very high temperature to ignite gasoline vapors. The MSDS says it takes a temperature greater than 530 degrees F (280 degrees C). That requires an electric spark or a flame. That would mean Bill has a bit of blow by as well as fuel in the crankcase. That brings up the possibility that the fuel got into the crankcase by going past the rings.
MSDS at:
http://www.mcohio.org/services/risk/docs/MSDS_for_Gasoline.pdf (http://www.mcohio.org/services/risk/docs/MSDS_for_Gasoline.pdf)
Hello,
I have a question on Pressure . The stock 57 Cadillac mechanical fuel pump should deliver 5 1/4 to 6 1/2 lbs of pressure per square inch . Was the same pump used on both single and Dual carb set ups . i would think it does not matter because pressure is pressure.
Thanks Bill
Hello Glen ,
Your input is greatly appreciated . you raised the question about fuel getting into the crankcase by passing thought the rings . leaked thru the needle valve into the piston and through to the rings and mixed with the oil i can understand that .( How did the spark get into the crankcase ?) however i drove this car without any problems the day before for a straight 20 mile drive . pulled into the garage and shut down the car . aprox. 18 hours later Pow an explosion . I have two 1406 edelbrok carbs on my car . the one that sits next to the fire wall is much more used and to be honest looks it could use a good cleaning . the carb did back fire a couple if time on the shop that had the car for a few months before i drove the car home on Saturday . at this point i am really nervous about this happening again . after i changed the oil and replaced the valve covers with a spare set that i had off another 57 Cadillac engine i was reluctant to start the car again . however the car started right up , no oil leaks , ran smooth . went around the block and backed the car in the garage with the front end towards the door . New oil , new oil filter , installing a new rebuilt mecanical fuel pump from Gould and purchased a new edelbrook 1406 carb . i should be ready to fire the car up by the end of the weak . What are the chances of this happening again . I must of started my 57 Cadillacs 1000 times in the 3 years i never want to have something like this happen again . i am going to look for a spare set of valve covers just in case . The bad thing is there is no warning. It is like a car bomb going off .
Bill
I have heard of this type of thing before when gas gets into the crankcase. I don't know how the mixture gets ignited, but it can, and in the case obviously did.
Electric fuel pumps should always be wired through the ignition circuit so that when the key is on, the circuit is hot, and should still have an inline toggle switch to turn it off.
I don't have an electric pump on any of my 60 or 76, but have thought of adding it to cut down on cranking when the car has been sitting for a week or more.
On my Packard, I used it for cold starts after sitting a while, and only once in 100 degree heat for vapor lock.
Hope you get it all fixed!
Brian
Having an electric fuel pump to charge the carbuerator with fuel after sitting a long time and to overcome vapor lock is a orudent thing o do.
The mechanical fuel pump is approximatly 1 foot higher than the gas in the tank and when going up a steep grade even higher above the tank. When the fuel pump is drawing a vacuum of say 24 inches it decreases the evaporating point of gas and this along with higher temperatures causes rapid evaporation and subsequentially only fuel vapor is reaching the pump.
Electric fuel pumps are useually installed lower than the tank and they are pushing the gas rather than drawing it by reducing pressure in the fuel line therefore they are much less prone to vapor lock AKA percolation of the gas.
I know many cars today use electric pumps only with a great deal of reliability and many conversions to electric only work reliably for many years.
I am a pilot (recreational onle since 1974) and have a preferance for keeping things as designed whenever possible. We don't hear of these random problems with mechanical fuel pumps (only vapor lock, slow starting after sitting extended periods of time and occasional failure) and many have devised complex and elborate fuel systems that are working just fine but they are still the sole fuel delivery system on their vehicles. I prefer the redundancy of a good mechnical fuel pump as designed by professional engineers with an electric back up and primer system on a manual switch that I have control over. To each his own !!
Good News ,
Machanical Fuel pump installed , ( use electric only for priming ) new plugs , wires , cap , rotor . Oil change . Car starts right up , no leaks . runs smooth . I consider myself very lucky . Thanks everyone for all your help , and have a great 4th of July .
Bill
Electric fuel pumps are not a problem normally but with an engineered design, but just putting one on a car because it is easier than rebuilding a original engineered fuel system can be problematic. There are a lot of different systems out there but getting the right one installed takes some knowledge.
How many PSI is required by your system? If a pump is installed providing higher pressure how will your system handle it? A PRV (Pressure Reducing Valve) set to your delivery pressure is always a good idea. 2 0r 3 PSI would probably serve most Cadillacs.
How many GPH (gallons per hour) would your car require at maximum load? I dont know for sure but probably 15 GPH would be the most a Cadillac would use? A 5 GPM pump can deliver 300 GPH.
How will you keep from delivering fuel to the carbuerator when the engine is not running? A oil pressure switch is often used for that.
How can you prevent fuel delivery when the car is parked and you forget to turn off the switch if it only controlled by a manual switch? Wire it to the ignition switch so it cant operate unless the engine is powered up. (I would do this in addition to the oil pressure switch)
How can it by used for priming a car not operated regularily? A push button switch in addition to the oil pressure swich and the manual (If Installed) switch for priming.
Most installations have a pump with too much capacity and too much pressure and are wired to run without proper regard for the necessary safetys.
I will do a little research and determine which is the most reliable pump in the pressure range and GPH range for my car before I install a pump and it will be wired with the safeties I mentioned here
Possible a little over kill here but better safe than sorry.
Hello Gary,
i like your way of thinking , The engineers that designed these systems knew what they were doing and i agree i like things stock Almost 100%. The stock fuel pump always worked fine for me in my 57 Cadillac Seville that i had for 5 years . The problem i had with the mechanical system was more in my mind . I always wanted the option of a back up pump just in case of Vapor lock or just a mechanical breakdown in the pump itself . Back in the 50's or 60's when your car broke down on the side of the road it was just another car broke down . I can not imagine leaving my car on the side of any road today , and i am not a big fan of the tow truck . I purchased my Biarritz 10/ 30 / 11 and it only had the electric pump . ( should of changed it the next day ). My car was in a shop for 5 months January thouugh June . Out of my control . An excellent Mechanic that i respect very much called it the body shop blues , Only starting every other day or twice a week for just a moment to move the car 10 feet then back again . Although i did have the electric pump hooked up to an on / off switch ,I believe the car was left on maybe a handful of times with the ignition switch on and the pump running . causing a backfiring condition Gas in the oil and who knows what else . Although i had the pull /push switch tagged FUEL PUMP on / off . they probably just disconnected the battery every time the moved the car and left the switch on all the time . I also installed a solenoid made by the painless company that cuts battery power off with a pull /pull switch . The good news is that my car is OK now . Running only on the mechanical pump with two seperate line comming off the fuel tank . one electric pump for priming only . controlled by a switch .
Keep it stock when you can , And thank you for taking the time to write to me i appreaciate very much .
Bill