General Question About Pre-Oilers

[myoldboat2]

Over in the "no engine compression" thread, havasuboatman wrote, "If the motor sat for a year, you will want to pull the distributor, fashion a tool and spin the oil pump using a drill. That will pump oil throughout all of the oil passageway and bearings before you do anymore damage to them."

I have a question related to that, but not specifically about what havasuboatman was talking about in that thread. I don't know anything about pre-oilers. Do any of them work by spinning the engine oil pump, or all they all bolt-on units with hoses? It just seems that if spinning the engine oil pump can help by pre-oiling, why don't most configurations allow for that with a small electric motor of some sort? Or is pre-oiling just not very important for an engine that is used regularly?

 

[JustJason]

Re: General Question About Pre-Oilers

They all work by spinning the engines oil pump.

It is the engines oil pump that turns the distributors rotor.
So you remove the entire distributor assembley. Put in the oil primer pump, and spin it with a drill.
Engines do not have it because of the expense of building it into the overall design.

 

[jerryjerry05]

Re: General Question About Pre-Oilers

If you use it often it won't be needed.J

 

[havasuboatman]

Re: General Question About Pre-Oilers

If you use it often it won't be needed.J

Exactly. If your motor is used regularly, There is the need to pre oil the engine, though it wouldn't hurt. After all, most of the wear on an engines moving parts happens during start-up.

And just so there is no misunderstanding, it's the distributor that drives oil pump.

 

[Fordiesel69]

Re: General Question About Pre-Oilers

There will still be an oil film on the bearings, just not enough to support a load (cold start). So a way to cheat would be to pull the spark plugs and crank it for 15 seconds to get oil pressure. Or crank as long as you need to get oil pressure using 15 sec intervals as to not overheat the starter. Then put the plugs back in and fire it up.

 

[JustJason]

Re: General Question About Pre-Oilers

And just so there is no misunderstanding, it's the distributor that drives oil pump.

Doh... I guess my finger bone wasn't attached to my brain bone

camshaft turns the distro, distro turns the oil pump

 

[Fishermark]

Re: General Question About Pre-Oilers

I don't know anything about pre-oilers. Do any of them work by spinning the engine oil pump, or all they all bolt-on units with hoses?

When the other posters say that they all work by spinning the oil pump - they are referring to using the tool that replaces the distributor which you spin with a drill.

Another type of pre-oiler is mounted permanently and involves hoses, etc. It is used to help prevent dry starts. Whether it is necessary or not is another issue ... just know that there are other types of pre-oiling systems. If you google it, you will see many permanently installed types.

 

[Knightgang]

Re: General Question About Pre-Oilers

Doh... I guess my finger bone wasn't attached to my brain bone

camshaft turns the distro, distro turns the oil pump

Beat me to it...........

 

[jtybt]

Re: General Question About Pre-Oilers

That reminds me. I made up a pre oiler but never hooked it up. It's a real simple system.

I have a drain hose from the bottom of the pan to change oil. All I have to do is hook up my pump(water-puppy type pump with oil resistant impeller) to the drain hose. From the pump, it goes to a separate oil filter and to an anti-siphon valve(same kind as for the fuel tank) and from there I connect it directly to the oil port right above the oil filter mount(for small block chevys).

 

[Maclin]

Re: General Question About Pre-Oilers

Oil filters are an important part of the equation, they should be built with anti flowback design, not all are. That is why it is important to use OEM spec filters.

 

[jtybt]

Re: General Question About Pre-Oilers

Yup! in my design, to prevent oil flow back TO the oil pump.

...and I forgot to mention, this is also an oil changing system.

 

[WizeOne]

Re: General Question About Pre-Oilers

It is said that the majority of engine wear occurs within the first few seconds of fire up. This is even the case with engines that are used regularly. It is even more so true with engines that get such periodic use as boat motors.

I have eyeballed pre-oilers for some time now. When I can shake loose a few extra bucks I will put one on my boat and my seldom fired Mustang.

They are simple enough in principal. With a turn of the key, they release accumulated oil, under pressure, to lubricate the far reaches of your engine: just as if you had started the motor but with no parts moving to accomplish that. You will actually see the oil pressure guage rise or your idiot lite go out.

 

[myoldboat2]

Re: General Question About Pre-Oilers

Very interesting discussion. Thanks for all the input. I suppose a thousand pre-oiler designs have been patented, but you'd think that a really clean, simple design that could be designed into the engine would be worth millions. Or maybe they want engines to wear out...

 

[Maclin]

Re: General Question About Pre-Oilers

Not everything that gets lubed is in the oil pressure circuit as some things just get slung-then-wiped oil, and (hydraulic) lifters themselves may not be in the correct position intheir bores to get pressure. To truly pre-oil an engine for the very first fire up the (hydraulic) lifters should have been "plunged" several times before installing, and the engine needs to be rotated at least one full turn while the oil system is pressurized. Most damage ocurs in the very first startup of an engine so these extreme measures do not need to be taken for every occasional start.

Bearings are very good at holding slipperiness until well worn, other engine materials chosen also help keep it from killing itself after a hibernation. Preoilers are a good idea but in a rel life market where most engines outlast the electrical around them and even the vehicle in many respects they have little return value.