Oil Pressure at Start Up

[larryinnewyork]

Oil Pressure / Engine Wear at Start Up:

A person (not myself) buys a 1967 Chevy Pickup Truck.
Engine size is unknown but was probably rebuilt some what over the years.
* This vehicle will sit for 3-4 days without being driven.

This person wants to install an Engine Kill Switch.
Purpose: So he can crank the engine to build oil pressure 'before' the engine starts.
Then, turn off Kill Switch and start engine with (surposidly) better oil flow.

Question: Generally speaking, would this help prevent any engine wear.

Thanks for any responses.

This person refuses to own / repair the newer vehicles driven today.

 

[Chris142]

no.its not spinning fast enough to build oil pressure.better to just start it. plus if its a v8 the oil filter sits threads up so drain back is not an issue

 

[SwampSurvivor]

Seems like with the amount of cranking you have to do to get a carbureted car to start after sitting for more than 5 minutes, it would be enough to pre-lube itself without doing the kill switch thing.

Sorry, had to

I have no input as to whether or not it would prevent wear.

When my parents had a 2008 Wrangler, we would hold the pedal to the floor and crank for 10 or 15 seconds. Otherwise it would knock like crazy on cold mornings.

 

[Shannow]

Go back in BITOG history, and this was a great idea. Some Engine management systems stopped fuel/spark at WOT to help clear a flood, which was another tool to build pressure before letting a spark in.

Cranking revs are low, and oil pumps pump slowly.

IMO better to have a clean start, and not move off until you later put on your seatbelt.

 

[Astro14]

I don't think the kill switch will accomplish what he is looking to do - you will build oil pressure (albeit slowly) if you crank with no spark, but in a carbureted engine, as a 1967 truck would have, you will be pulling fuel/air into the engine from the choked carb...and that excess fuel from cranking with no spark will be washing the oil off the cylinder walls, increasing wear... 3 or 4 days isn't bad, just start it and be done.

 

[SwampSurvivor]

Originally Posted By: Shannow
Go back in BITOG history, and this was a great idea. Some Engine management systems stopped fuel/spark at WOT to help clear a flood, which was another tool to build pressure before letting a spark in.

Cranking revs are low, and oil pumps pump slowly.

IMO better to have a clean start, and not move off until you later put on your seatbelt.


Someone on here made mention that maybe that's the reason Fords race up to 2500 RPM when they start - to get the oil flowing.

Every Ford in my family for the last 15 years (except the 2013 Escape) races to 2500RPM when you start it cold. When the exhaust fell off the F350, I'm pretty sure it woke a few permanent residents of the cemetery up. Definitely woke the neighbors up. Open exhaust and idling at 2500 RPM!

 

[SteveSRT8]

If you ever install a cam one of the first things you learn is cranking is bad.

You can wear parts very well at extremely low engine speeds. Plus the oil pump doesn't pump much either, and will take longer to prime and pressurize the engine.

Far better to start it and run it at high idle. This is exactly what G team engineers from GM said is the reason our new fleet trucks start up at such high rpms even in warmer weather in Florida....

 

[SwampSurvivor]

Originally Posted By: SteveSRT8
If you ever install a cam one of the first things you learn is cranking is bad.

You can wear parts very well at extremely low engine speeds. Plus the oil pump doesn't pump much either, and will take longer to prime and pressurize the engine.

Far better to start it and run it at high idle. This is exactly what G team engineers from GM said is the reason our new fleet trucks start up at such high rpms even in warmer weather in Florida....


Aren't you supposed to break in a cam by running the engine at a higher speed anyway?

 

[HangFire]

Tell him if he really wants to cut down on start-up engine wear, he can install a pre-oiler and use an engine warmer to bring his oil up to temp before starting. Also switch from 10w-30 to 0w-30. There is no debating the technical benefits of any or all of these technologies, only the cost/benefit tradeoff.

 

[440Magnum]

Originally Posted By: larryinnewyork
Oil Pressure / Engine Wear at Start Up:

A person (not myself) buys a 1967 Chevy Pickup Truck.
Engine size is unknown but was probably rebuilt some what over the years.
* This vehicle will sit for 3-4 days without being driven.

This person wants to install an Engine Kill Switch.
Purpose: So he can crank the engine to build oil pressure 'before' the engine starts.
Then, turn off Kill Switch and start engine with (surposidly) better oil flow.

Question: Generally speaking, would this help prevent any engine wear.






MUCH WORSE. The slow grinding of a flat lifter cam at low RPM just "squeegees" the oil off the lobes while you're cranking. Way better to start-and-go.

If he's so uptight about startup wear, the best thing to do is install an engine pre-oiler. I don't know what's available now, but there have been manual-pump types and types that pressurize when the engine is running and let you release a slug of pressurized oil into the engine before cranking. Either way, that's better than dry-grinding the engine with the starter for 30 seconds.

 

[jrustles]

Originally Posted By: Astro14
if you crank with no spark, but in a carbureted engine, as a 1967 truck would have, you will be pulling fuel/air into the engine from the choked carb...and that excess fuel from cranking with no spark will be washing the oil off the cylinder walls, increasing wear... 3 or 4 days isn't bad, just start it and be done.


This.



My car does not prime the fuel pump until the key is turned to "Start". This causes one or two extra rotations in a start up, the oil light NEVER stays on for more than maybe a tenth of a second at the longest. Also, the RPM jumps to about 2500 and settles down quickly after, but that might be for the cat's sake.

With cool oil, the cranking alone is enough to turn off the oil light- and even if you just crank-n-stop, it may take 2-3 seconds for the gallery pressure to drop below the activation point of the OP switch, and turn the oil light on again.

A tribofilm (like MoS2 ) would make start up wear a non issue

 

[supton]

Dumb question: when he goes to start it, does it start right up (after the obligatory pump or two on the accelerator pedal)? If not, then I wonder if the Quadrajet needs a rebuild. Dim dark recesses of my mind says they can get somewhat leaky (some welsh? welch? expansion plug of some sort, that thing in particular). If the bowl doesn't hold fuel long enough and/or it's a hard starter, then I'd think fixing those issues first would be wisest. New battery, new cables (get the most voltage to the starter, don't scrimp and use undersized cables), new plugs and ignition stuff, carb in good tune--those things ought to minimize wear.

Of course, he could do all that and find out that the PO wiped out the engine anyhow. Or maybe not, some engines just give up the ghost early. Although even I'm a bit hesistant to say it's a bad engine after "only" 45 years of service.

 

[larryinnewyork]

OK.
I was just curious as to what everybody thought.

It sounds like most of you say "the sooner the engine starts, the sooner he'll have full oil pressure", but "a pre-oiler may help".

It's a family member, so I will just keep my mouth shut.

I myself believe in keeping vehicles 'stock' and doing plenty of PM

Thanks everyone.

 

[Ducman]

Originally Posted By: larryinnewyork
Oil Pressure / Engine Wear at Start Up:

A person (not myself) buys a 1967 Chevy Pickup Truck.
Engine size is unknown but was probably rebuilt some what over the years.
* This vehicle will sit for 3-4 days without being driven.

This person wants to install an Engine Kill Switch.
Purpose: So he can crank the engine to build oil pressure 'before' the engine starts.
Then, turn off Kill Switch and start engine with (surposidly) better oil flow.

Question: Generally speaking, would this help prevent any engine wear.

Thanks for any responses.

This person refuses to own / repair the newer vehicles driven today.






Your question is.
Would this help prevent any engine wear?

With the emphasis on the "any" part of you question.

The answer is.
It will probably prevent "some" engine wear, but not enough to ever measure in your entire lifetime.

It really depends upon a great many factors.
The biggest advantage the kill switch will have is in the event the engine is sitting for an extended period of time between start ups, with the icing on the cake being the eventual cold start occurring in very cold weather/ambient temps.
I don't think sitting for 3-4 weeks would be a problem, let alone 3-4 days between start ups.

The vast bulk of the "start-up" wear that occurs is in the actual warm up phase of the engine, and after the engine has fired into life, but before it reaches full operating temp.

In terms of engine wear reduction for a vehicle that's driven on a regular basis.
There is a two pronged approach which is likely to be the most beneficial.
You will be much better off, paying attention to the oil quality/formulation, and to also consider the engine manufacturers recommendations in terms of oil grade.
Also to consider a reasonable warm up period before driving off, and go easy on the engine until it's actually up to full operating temp.

Ford did a study on engine wear a very, very long time ago.
Basically the study was somewhat limited in scope, but it was fairly conclusive in only one regard.
The study revealed that there was a measurable amount of increased engine wear, when an engine has a coolant temp which was
There's absolutely nothing more that's conclusive to be drawn from that study.
As far as I know, there's no further information available on the matter.

I think short trips are murder on an engine and the oil.
Anything below a distance of 10 miles/16 kms is deemed to be severe service. And for good reason.
It's more important to bring an engine up to temp before driving it harder than normal, and to keep it at operating temp as much as practicable.
It's the reason why taxi's and heavy trucks go so long in service before wearing out their internal components.

The quality of the engine oils available to us today are outstanding compared to way back when Ford did their study.

 

[crazyoildude]

just crank the engine you dont need a kill switch with a carb

 

[Scott_Tucker]

Originally Posted By: supton
Dumb question: when he goes to start it, does it start right up (after the obligatory pump or two on the accelerator pedal)? If not, then I wonder if the Quadrajet needs a rebuild. Dim dark recesses of my mind says they can get somewhat leaky (some welsh? welch? expansion plug of some sort, that thing in particular). If the bowl doesn't hold fuel long enough and/or it's a hard starter, then I'd think fixing those issues first would be wisest. New battery, new cables (get the most voltage to the starter, don't scrimp and use undersized cables), new plugs and ignition stuff, carb in good tune--those things ought to minimize wear.

Of course, he could do all that and find out that the PO wiped out the engine anyhow. Or maybe not, some engines just give up the ghost early. Although even I'm a bit hesistant to say it's a bad engine after "only" 45 years of service.


Yes, there are plugs on the bottom of the body that can leak. They generally can be sealed with epoxy.

 

[another Todd]

He will spend more money replacing batteries than what he saves in engine wear. Just install a pre-oiler, they are made specifically to supply oil pressure before starting the engine.