I just read in some 356 network they do have the same cranking up fuel issue as many of us have. One found a simple cheap device:
a ballon pump as used for small boat motors - for less than $ 15
Could be fitted between tank outlet and boot fuel line. They reported no fuel starvation up to tested 100 miles an hour - and no silli cranking battery flat and starter sick.
I will try within the next weeks and report!
Some also used a small electric fuel pump in line. Just for priming, then switched off and went on with the original mechanical pump, fuel beeing sucked through the electric pump. Again no problem.
A can of starting fluid is a couple dollars, if this is only a problem with its sitting for a week or more I would give it shot of starting fluid to get it running and let the fuel pump prime the carbs. But thats just me. I went with the electric fuel pump in the 1700 cc twin cam as it runs with a shortened jackshaft and the option of running a mechanical fuel pump has been eliminated.
As a trial I have blocked the Dellorto air āportsā on the top of the carbs several times with some very thin pieces of a particular sort of foam, backed up with some very thin spring metal, when I park the car. I believe this makes quite a difference when not using the car for a week or two. Over several months however I couldnāt notice any difference, and presume the fuel still manages to evaporate over longer periods. And perhaps the fuel line empties somehow as well.
Gordon
As neilsjuke already pointed out, the prolonged cranking needed to prime a mechanical pump also has the very worthwhile benefit of pumping oil up through the engine prior to it firing up. If itās been standing idle long enough for the carbs to empty through evaporation, itās certainly been standing long enough for all oil to have drained from the top end, leaving dry metal-to-metal contact for a few seconds after starting
Winter time cold-cranking is eased and the load on the battery, starter motor etc lessened by initially operating the starter motor with the throttle wide open, waiting till thereās a first sign of ignition then taking your foot off the accelerator pedal, giving it two or three pumps, then operating the starter with the throttle closed. Leastways, thatās what I do.
I donāt agree with your assumptions, Cranking an engine with out fuel adds little other than wear and tear on that poor old design of a starter the Joseph Lucas made million?s of. If you pulled the spark plugs and performed this its not quite as bad but still not of much value. With a running engine, oil pressure comes up in a second or less, if not there are other issues present. When you hear the commercials that 50% of all wear happens in the first 15 seconds, that happens regardless of whether it running or cranking on the starter. That is unless you have some form of pre-pressurized oil system. A couple of my friends use to say that the twin cam would need a valve job and water pump at 40k miles and not necessarily because the water pump was bad but because you were 90% of the way of doing the job. At 80k miles repeat this again with the bottom end looked after, first crank grind, and maybe first overbore. At 120K repeat valve job and water pump, at 160k miles top and bottom repeat. Ed Loveday drove his Elan quarter million miles before he died not long ago, the car is being restored by a new owner and will start its second life soon.
Starters were never designed for continuos cranking, 10 or 15 seconds is more than likely the safe cranking time. You donāt have to believe a word I write or do any of it. I used to have the biggest battery I could buy positioned in-between the rear strut towers and it was still a crapshoot whether it would start or not when it was sub-freezing. I finally learned. An Electric fuel pump, regulator, and most important an accident cut out switch will do the job. Maybe even that Joseph P. Lucas starter will get the job done. But the Japanese derived nippen-denso starters is just the thing that works great. The battery draw is minimal that a battery that is half of the weight will start when the stock setup wonāt. If you consider starting fluid ?cheating? then I?ll be gone while you are still trying to get fuel in the float bowls. Elan in neutral, Key on, bonnet up, pull the trunk tubing back give it a small sprits of starting fluid and hit the manual button on the solenoid. Another sprits or two to keep it running, when its running on fuel your off. With an Elan that is used every day you can probably get away without any of the above (except the 40k, 80k, top end, bottom end dance).
Just to be a bit ornery/split hairs, I think: āā¦ itās certainly been standing long enough for all oil to have drained from the top end, leaving dry metal-to-metal contact for a few seconds after startingā is not quite right. Firstly modern oils coat everything with a very good film, even if most of the oil has drained off, and secondly there are plenty of pools of oil left in the head - the cams, for example, immediately hit oil on the first turn. Still I guess there may be a spot somewhere or other that gains from āchurningā.
Gordon
By the way - I like the colour Anna - light blue (non standard?) I guess.
And also - you can go way more than 40K miles on modern oils before any work is needed.
itās Ice Blue metallic over Cirrus White. I was thinking of using it more or less as my daily car from april to october. So maybe I should go the electrical fuel pump (or electrical priming?) way . I would agree to what Gary says - getting up oil pressure as fast as possible.
I fitted a Facet 2.5/3.0 psi pump to feed the mechanical pump which has eliminated the cranking prime time, and she sure does start quicker. I intend to remove the mechanical pump at some convenient time.
I can?t believe the point that long cranking primes the oil as being a major benefit ? I?ve viewed my car to see that the oil gauge shows 45 psi from 2 seconds on the starter. To my mind it?s of no issue if a car is used reasonably regularly with modern oils.
If an engine is not started for some considerable time ? then long cranking may be of some benefit.
Lots of old salts seem to favor doing stuff like disconnecting the main coil lead on startup until oil pressure comes up, as though this is a magic panacea for engine wear elimination. Logic says the opposite, but canards die hard. Against:
Modern oil film strength, probably good for sitting a year
Higher RPM of the fast start building guts-saving pressure faster
Ease of use
ā¦ We have, at best, some notion that bearing surfaces undergo measurably less stress when the engine is cranking than when it is running. Anybody got some real data to suggest this might possibly be true? Iām pretty dubious.
The place this is most likely to be true is on the crank throws, where the pounding of a firing cylinder imparts a shear load that isnāt present when the engine is coasting under starter power. But how many of you, regardless of starting method, find that the reason you need to tear down your engines is low oil pressure indicating bottom end issues?
Must admit, I thought thatās what this whole thread was about as itās the only time that a healthy, well set-up twink needs any cranking, ie to get some petrol into the carbs. Otherwise itās one turn and off you go.
I fitted the Facet pump as a test prior to eventually removing the mechanical pump. I did this simply to see if it was of any real benefit in priming as I was only using the car every 3 to 4 weeks by which time the feed line had emptied back into the tank to some degree, and it took about 10 seconds of cranking to fill the carbs. It has reduced the cranking time, but whether it?s really worth it, I?m not sure.
If you use the car regularly the carbs should stay reasonably full and starting should only take a couple of seconds cranking.
To answer your question ? I don?t think the electric pump will send fuel past the mechanical pump ? it will only prime the pump. If you don?t start the engine for some time the only benefit is the time it takes for the mechanical pump to be primed.
Your original point regarding the bulb primer for outboard motors - this will do exactly what the Facet pump is doing for me.
Now regarding the oil pressure issue ? IMHO I don?t think this is worth any consideration at all. What I should have said in my last message was: ?If an engine is not started for some considerable time ? then long cranking may be of some benefit ? but I doubt it.?
I have a Facet type electric pump fitted on the bulkhead before the mechanical pump. My float chambers were emptying over one week (itās a weekend car), and I have a spring toggle switch so I can prime, using the electric pump for a few seconds prior to cranking, and then the electric pump goes off, and the mechanical takes over.
The valves in the mechanical pump are arranged for one-way flow, so yes the electrically pumped fuel does flow freely through the mechanical pump, up to the needle valve.
If planning to use an electric pump permanently, I suggest a fairly low pressure one (2-3 lbs), otherwise youāll force fuel past the needle valve and your float level will be too high
Matthew
. I would agree to what Gary says - getting up oil pressure as fast as possible.
