Question: 1984 standard vs. high volume oil pump install w/standard oil pan

[djsroknrol]

I just got started today on my list of things I want to do right away. One of those top items is changing out the oil pump. I was told by the local NAPA man that there are 2 pumps I could get; the standard replacement or the high volume pump that delivers roughly 25% more.

He also told me that because of the increase in volume, I'd have to add another quart in after I install it because I have a standard pan. I thought the statement was weird, but thinking about it, I could see his point...the pump could pump the pan dry with the increase in volume.

The thing that bothers me about it is being overfull at startup...is it a something to be concerned about? Has anyone had any experiences with these pumps?

Bob

 

[ex-x-fire]

Your engine should had a high volume pump from the factory.

 

[boomdriver]

I just got started today on my list of things I want to do right away. One of those top items is changing out the oil pump. I was told by the local NAPA man that there are 2 pumps I could get; the standard replacement or the high volume pump that delivers roughly 25% more.

He also told me that because of the increase in volume, I'd have to add another quart in after I install it because I have a standard pan. I thought the statement was weird, but thinking about it, I could see his point...the pump could pump the pan dry with the increase in volume.

The thing that bothers me about it is being overfull at startup...is it a something to be concerned about? Has anyone had any experiences with these pumps?

Bob

i"ve been doing the research on this because that is also on my "list of things to do"...
The main reason for more flow is to keep up with normal wear in bearings and maintain pressure and flow up top. There are a couple things that can go along with this project....but the simple answer to being 1 qt overfilled is "no problem"....its only for 1 second at start up. After that the oil should be dispersed throughout the engine.


When the pan is off, according to the books it is possible to replace the main bearings in-frame. Bearing Caps can be removed, plasti-guaged and appropiate bearings re-installed.They are cheap.
As long as there is no galled bearing surface from a spun bearing this can be done to add life to the crank assembly and help keep pressure. I want to speak to someone thats done this in a C4 before I attempt it myself.
Doing the bearings helps prevent the loss of oil to the top end,.

Next is a larger pan. They are available but be certain the mfg knows its for a vette so they make it with ground clearence and frame braces in mind.

Last,. an outside oil cooler to help remove/manage heat and this also adds between 1/2 to 1qt of extra oil. This might be enough to keep the stock pan. Some folks go with a remote filter if they can find a place to mount and access easily for changing.

The biggest downside to extra oil in the stock pan is having oil standing against main seals,or the pan gasket (if deep enough) and/or oil slinging, where the crank picks up the oil and throws it up into the cylinders where the rings have to wipe off more than they were designed for. This may result in some oil burning. The PCV system also sucks up more fine oil mist from all the action in the sump.

The BEST thing about a hi-vol pump is that you can now add an oil accumalator and never ever have a dry start again. With the accumalator the hi-vol pump can easily re-charge it without starving the motor during warm-up. Where to mount it will be the challenge.

If you do a web search you can find lots of oil pump types/styles for this engine. Just search Chevy L98 oil pump or LT1 or whatever you have...the name brand options are out there.

Good luck with this,....its a worth while project.

 

[Hib Halverson]

Unless it's a highly modified, high-rpm, near-race or race engine, no small-block V8 in an 84 needs a high-volume oil pump. In stock or near stock engines, all they do is decrease power output and heat up the oil.

There might be an advantage in higher oil pressure and you can do that simply by pulling out the existing pump and changing the pressure relief valve spring to GM PN 33848911 which give approximately 70 psi hot oil pressure provided the engine is in good condition. Consult the factory service manual on oil pump removal and changing the spring.

You also can gain some oiling system performance is you go from a 5W30 to a 10W30 oil.

For a street-driven, stock or near-stock engine, do not, under any circumstances (including foolish parts guys at NAPA telling you to do so) purposely overfill the engine oil level. There are some cases, mainly race track duty cycles, where you might want to overfill but they are unusual.

 

[TedC]

Unless it's a highly modified, high-rpm, near-race or race engine, no small-block V8 in an 84 needs a high-volume oil pump. In stock or near stock engines, all they do is decrease power output and heat up the oil.

There might be an advantage in higher oil pressure and you can do that simply by pulling out the existing pump and changing the pressure relief valve spring to GM PN 33848911 which give approximately 70 psi hot oil pressure provided the engine is in good condition. Consult the factory service manual on oil pump removal and changing the spring.

You also can gain some oiling system performance is you go from a 5W30 to a 10W30 oil.

For a street-driven, stock or near-stock engine, do not, under any circumstances (including foolish parts guys at NAPA telling you to do so) purposely overfill the engine oil level. There are some cases, mainly race track duty cycles, where you might want to overfill but they are unusual.

I agree. You are adding extra stress on the SBC's distributor driven oil pump system. I helped a friend rebuild a 360 Mopar and we installed a HV oil pump with a larger oil pan and windage tray. HV pump was a big mistake. At higher RPMs we were pulling oil out faster than it could drain back in. We corrected this by installing a stock rated oil pump.

 

[djsroknrol]

That's what I thought....I'm not having problems with it, but I just want to head off any problems in the near future by changing it along with a few other things....

So a replacement standard pump it is....thanks folks

 

[John Mekisich]

Oiling System Performance

Hib, Can you expand on what the advantages would be in going from a 5W 30 to a 10 W30 for this application.

Unless it's a highly modified, high-rpm, near-race or race engine, no small-block V8 in an 84 needs a high-volume oil pump. In stock or near stock engines, all they do is decrease power output and heat up the oil.

There might be an advantage in higher oil pressure and you can do that simply by pulling out the existing pump and changing the pressure relief valve spring to GM PN 33848911 which give approximately 70 psi hot oil pressure provided the engine is in good condition. Consult the factory service manual on oil pump removal and changing the spring.

You also can gain some oiling system performance is you go from a 5W30 to a 10W30 oil.

For a street-driven, stock or near-stock engine, do not, under any circumstances (including foolish parts guys at NAPA telling you to do so) purposely overfill the engine oil level. There are some cases, mainly race track duty cycles, where you might want to overfill but they are unusual.

 

[Hib Halverson]

Hib, Can you expand on what the advantages would be in going from a 5W 30 to a 10 W30 for this application.

For decades GM has recommended 5W30 mainly for exhaust emissions and fuel mileage reasons. A 10W30 is better for long term durability...especially since the person making the OP in this thread lives in Lake Havasu AZ where it's really hot.

Most FSMs say that 10W30 is also, ok.

I have no engines on 5W30. That's one of the first changes I make with a new engine.

Now...if I lived in Alaska or other places that are really cold in the winter and not that hot in the summer, then, maybe, the 5W30 is a good choice.

In fact, if the OPer, is using a petro base 5W30, I'm going to guess he/she will see a slight increase in hot oil pressure just because of that.

Hope that helps.

 

[djsroknrol]

For the record, I'm running Castrol GTX high mileage 10-30

 

[John Mekisich]

Oiling System Performance

Hib, that is good information. I rely on my local Amsoil reps suggestions and he advises 0W 30 Amsoil for my 96 LT4, Volvo and Subaru turbos here in the SF Bay Area. Have never had any issues but I am all for long term durability.That being said I will take your advice and switch over to 10W 30 Amsoil at my next change interval on all cars. I use the Amsoil oil filters as well. Any input on those?

For decades GM has recommended 5W30 mainly for exhaust emissions and fuel mileage reasons. A 10W30 is better for long term durability...especially since the person making the OP in this thread lives in Lake Havasu AZ where it's really hot.

Most FSMs say that 10W30 is also, ok.

I have no engines on 5W30. That's one of the first changes I make with a new engine.

Now...if I lived in Alaska or other places that are really cold in the winter and not that hot in the summer, then, maybe, the 5W30 is a good choice.

In fact, if the OPer, is using a petro base 5W30, I'm going to guess he/she will see a slight increase in hot oil pressure just because of that.

Hope that helps.

 

[Hib Halverson]

Hib, that is good information. I rely on my local Amsoil reps suggestions and he advises 0W 30 Amsoil for my 96 LT4, Volvo and Subaru turbos here in the SF Bay Area. Have never had any issues but I am all for long term durability.That being said I will take your advice and switch over to 10W 30 Amsoil at my next change interval on all cars. I use the Amsoil oil filters as well. Any input on those?

I have no input on Amsoil engine oil or oil filters other than I do not use either product nor would I consider using them.

Ask your Amsoil rep why he suggests a 0W30 for the LT4 in your 96. I'd be interested to hear the reasons.

 

[Hib Halverson]

For the record, I'm running Castrol GTX high mileage 10-30

That's an API SM oil which is right on the low limit of enough ZDP for best durability of a flat-tappet valve train. If the engine is stock, you're ok. If the engine is modified with a more radical camshaft and aftermarket, higher-tension valve springs, there are better oil choices.

 

[John Mekisich]

Oiling System Performance

Hib,

That being said, what is your brand/type preference for oil and filters?

I have no input on Amsoil engine oil or oil filters other than I do not use either product nor would I consider using them.

Ask your Amsoil rep why he suggests a 0W30 for the LT4 in your 96. I'd be interested to hear the reasons.

 

[Marv02]

If you want to use a oil with Zinc for flat tapppet engines this what I use.

Vavloline VR1 Racing Oil it $6.00 to $7.00 a Qt but like they say pay the man now or pay him a lot more latter if you burn the motor up.


I using Napa Gold filter oil filter.

 

[aklim]

Question for Hib or anyone here. We have an oil cooler bypass. Instead of having the oil filter come straight onto the engine, we have that bypass that cools the oil.

Besides passing oil thru it, does it do anything to the pressure?

Reason I ask is that I have a 91 that has had this oil problem. Pressure is good until you hit it hard. Could it be oil starvation? We have changed from a larger Miloden pan to a stock pan but no joy. Changed to a Melling HV oil pump but still no joy. Thicker oil helps. It holds pressure longer.

Mobil 1 15W50 oil with Delco stock filter.

 

[boomdriver]

Question for Hib or anyone here. We have an oil cooler bypass. Instead of having the oil filter come straight onto the engine, we have that bypass that cools the oil.

Besides passing oil thru it, does it do anything to the pressure?

Reason I ask is that I have a 91 that has had this oil problem. Pressure is good until you hit it hard. Could it be oil starvation? We have changed from a larger Miloden pan to a stock pan but no joy. Changed to a Melling HV oil pump but still no joy. Thicker oil helps. It holds pressure longer.

Mobil 1 15W50 oil with Delco stock filter.

I'd have to wonder about the gauge after doing all that...I know that the digital gauge can be unstable....it can vary greatly when all things seem the same.

There IS a filter bypass valve in the filter adaptor. A relief valve of sorts, to prevent pressure from blowing up the filter when oil is cold, or the filter element is dirty or when there is simply too much oil to go thru the filter. The bypass lets the oil go around. I do not know if there is a dump port that allows some to go back to the sump.

Its accessed by removing the cooler block and then the filter adaptor. Whatever excess pressure there is will be sent straight around the filter if/when the filter bypass opens. From what I have been reading, the bypass is open much of the time. Not all oil gets filtered all the time. So, only a portion of the oil thats pumped actually makes it thru the filter. How that can effect the pressure is a little strange..Pressure can be absorbed by the filter and when bypassing the flow, there is more pressure direct to the gauge sending unit. The dump/relief valve just a little spring/flap do-dad that opens a port to the discharge side when the pressure gets too high. I can see the spring getting soft with age or use.

As a matter of fact, I just bought a sandwich adaptor for an external oil cooler and it has a relief valve in it so the pressure or flow will not exceed what the cooler and lines can handle. This one is very loose so the port is always partially open. That limits flow thru the cooler lines.

When I was trying to figure what was going on with my inconsistant oil pressure, I pulled the sending unit off the "tree" behind the head and fired the motor....stone cold with at least some oil being dumped to bypass, it still immediately gushed oil out the small 1/4" fitting....
I also run 15/50 in summer because the 10/40 and 5/30 is so thin that it does not get any stable pressure when its hot.


The only true way to know what the pressure actually is, would be to install a mechanical gauge and observe it through the normal driving conditions and see just what/when & how much the pressure changed.

Hope this helped some..I know I was loosin it over the oil pressure after spending a fortune on everything else......

 

[aklim]

I'd have to wonder about the gauge after doing all that...I know that the digital gauge can be unstable....it can vary greatly when all things seem the same.

The bypass lets the oil go around. I do not know if there is a dump port that allows some to go back to the sump.

Its accessed by removing the cooler block and then the filter adaptor. Whatever excess pressure there is will be sent straight around the filter if/when the filter bypass opens. From what I have been reading, the bypass is open much of the time. Not all oil gets filtered all the time. So, only a portion of the oil thats pumped actually makes it thru the filter.

How that can effect the pressure is a little strange..Pressure can be absorbed by the filter and when bypassing the flow, there is more pressure direct to the gauge sending unit. The dump/relief valve just a little spring/flap do-dad that opens a port to the discharge side when the pressure gets too high. I can see the spring getting soft with age or use.

I also run 15/50 in summer because the 10/40 and 5/30 is so thin that it does not get any stable pressure when its hot.

The only true way to know what the pressure actually is, would be to install a mechanical gauge and observe it through the normal driving conditions and see just what/when & how much the pressure changed.

Hope this helped some..I know I was loosin it over the oil pressure after spending a fortune on everything else......

I have a 91 so it isn't digital.

I hope there is since the pressure is good all around until you hit it at WOT then it drops. If there is something that leads back to the sump, it might explain why I am having that issue since I have changed from a deep sump pan to a stock pan and have the exact same issue.

So, to access it, I take off the "bolt", then the cooler and 2 bolts that hold the adaptor down to the block? That "bolt" is what the filter screws on to and in turn screws to the adapter? What are the replacement parts to that?

Anyone have a pic of that? I can't find it in the FSM.

I do have stable pressure though. Just drops when you WOT the motor under load. Never tried without a load.

True but I can't figure out what could make it drop. Thicker oil helps though so I don't think it is the gauge.

Does give me some ideas.

 

[G Winter]

Any electric gauge can vary with change in voltage. Does your volt meter also drop when you go to wide open throttle. Maybe you have brushes in the alt that are not staying seated. Mechanical gauge is the only way to get a true reading.

Glenn

 

[boomdriver]

I have a 91 so it isn't digital.

I hope there is since the pressure is good all around until you hit it at WOT then it drops. If there is something that leads back to the sump, it might explain why I am having that issue since I have changed from a deep sump pan to a stock pan and have the exact same issue.

So, to access it, I take off the "bolt", then the cooler and 2 bolts that hold the adaptor down to the block? That "bolt" is what the filter screws on to and in turn screws to the adapter? What are the replacement parts to that?

Anyone have a pic of that? I can't find it in the FSM.

I do have stable pressure though. Just drops when you WOT the motor under load. Never tried without a load.

True but I can't figure out what could make it drop. Thicker oil helps though so I don't think it is the gauge.

Does give me some ideas.

yep,
I think each section or adaptor has its own bypass port/valve. so pressure gets sent around the filter, and flow gets diverted from any block with the bypass port. We can't say exactly how much actually gets up there to the sending unit. 10% ? 25% ? who knows...
My next move will be a mechanical gauge so I can see whats moving.

 

[Hib Halverson]

Hib,

That being said, what is your brand/type preference for oil and filters?

I use Red Line synthetic 10W30 in all my engines except for the Big-Block in my 71 in which I use Red Line 10W40. To mitigate the cost a bit, I use extended drain intervals on all engines but I change filters every 3000-5000 miles. On engines in cars that see more than 10,000 annually, I change oil at 18,000-22,000 miles. On the others, I change the oil about every 24 months. I use the Analysts Inc. as my spectrographic oil analysis lab and for over a decade my oil change intervals and filter change intervals have worked quite well.

As for filters, what I use on most of my engines is no longer available. For a short period in the early 00s, ACDelco had an ultra-premium filter line called "Ultraguard Gold" which were made for ACD by Champion Filter (not to be confused with Champion Spark Plug). I bought a large quantity of the PNs I use which are UPF44, UPF52 and UPF1218. I'm still using that supply. On my LT5, because ACD never made a UPF filter for that engine, I use the Mobil 1 M1-207

If I had to buy oil filters now, I'd probably buy WIX oil filters or the standard AC oil filters except for the LT5 where I'd still use the Mobil 1 filter.