Those of you running the high volume oil pump.

[callmeebryan]

I had a question for those of you running the high volume oil pump on your 109's....

Is it absolutely necessary to enlarge the 4 main bearing holes, or are you guys having luck without doing that? I was reading GM high tech and they had an article that mentioned doing this.

Reason i ask is because i need to replace my oil pump and want to go with the high volume one for a little better oil pressure.

 

[turbofabricator]

If your bearing clearances are correct, then a high volume oil pump is a BAD idea. A high volume oil pump takes ALOT more power to turn and puts alot more load on the cam sensor. DO NOT use one, in my opinion. As bad as the oiling system is, it works great. Take time to modify the stock oiling system and keep clearances tight, your engine will run great with a standard oil pump. I like to keep the oil pump thrust at .001" or less. IT take a fair abmount of time to get an oil pump blue printed. I spend probably 3-4 hours setting up a timing cover on every engine. So, keep your oil feed holes stock and keep main and rod bearing clearances tight (.0017"-.0019"" and keep a standard volume pump with a tight thrust clearance (.001 or less) and the engine will run great.
On my twin turbo car I use a "medium" volume pump. I machined the pump and the high volume cover down .187". I went with this to feed the added oil needed with two turbos. Other wise I would have run a stock timing cover. Is that "over the top"?

 

[cpac]

TURBOFAB....what oil pressure do you like to see at high rpm

 

[turbofabricator]

Anything more than 70 psi is a waste. So, 60-70 psi is all you need. 10 psi per thousand RPM is the usual standard for most engines.

 

[callmeebryan]

Anything more than 70 psi is a waste. So, 60-70 psi is all you need. 10 psi per thousand RPM is the usual standard for most engines.

Well thats the thing. I have read at gnttype.org that a good general rule of thumb for the stock pump is 1psi per 100rpm, and i am right in that guideline. I idle at around 10-12psi (850rpms) and wot im around 55-60 (shift at ~5600)... i am just so used to cars that idle at around 30-40psi and wot are in the 60's.

I have noticed that after i do a couple passes at the track, the oil pressure at idle will decrease a bit, never below 5psi but usually around 8psi. At WOT the oil pressure will be in the 40's after a couple of runs.

Is the oil pressure that i am seeing anything to worry about? Do i even need to think about getting a new pump? Looking for some honest advice

 

[wbrophy]

That "hot" oil pressure is low in my book, 5/8 psi and 40's at WOT; I would try going to a thicker oil first before getting into the engine.

Example= 15/40 wt. at present, than I would try a 20/50 wt. oil (synthetic may stand up to heat better), etc. and see if that helps.

 

[callmeebryan]

That "hot" oil pressure is low in my book, 5/8 psi and 40's at WOT; I would try going to a thicker oil first before getting into the engine.

Example= 15/40 wt. at present, than I would try a 20/50 wt. oil (synthetic may stand up to heat better), etc. and see if that helps.

Using Rotella-T 15w-40.... does rotella come in a 20/50?

 

[Steve V]

You need tighter clearence inside that engine. I have 30-40 hot and 60-70 @ WOT with 5w-20! Clearences are stock,so is the pump.

 

[wbrophy]

Using Rotella-T 15w-40.... does rotella come in a 20/50?

I know Rotella makes a 15/40 synthetic because that is what I have been using "lately" but I would try another big brand 20/50 in synthetic, it may do the trick. Mobil has a V-twin motorcycle oil and you know V-twins run hot that has all the good stuff for example but I don't know it's wt. range but any national brand should do. Hell if you look around there is even thicker muilti-grade stuff.

 

[wbrophy]

You need tighter clearence inside that engine. I have 30-40 hot and 60-70 @ WOT with 5w-20! Clearences are stock,so is the pump.

My engines have all had that amount or higher of oil pressure with that weight of oil at WOT "but" five pounds or so lower when hot at idle with the stock pump. I think most people don't believe it.

PS: I even do the mod./internal oil leak so the thrust surface of the main thrust bearing gets oiled.

 

[callmeebryan]

You need tighter clearence inside that engine. I have 30-40 hot and 60-70 @ WOT with 5w-20! Clearences are stock,so is the pump.

Motor was "supposedly" just built less than 1000 miles ago. The guy told me it had only about 500miles on it when i bought the car. I figured the break in period wasnt totally done yet, so i have been changing the oil every 3 weeks since i have got the car.

Granted, the car was very poorly tuned (it literally wanted to stall), however the guy told me that the FAST B2B was installed and tuned by jack cotton. I find it hard to beleive that jack would let a car go with a poor tune like that. Compression on all cylinders looks fine.

It was built by Northeastern Turbo (in MA i beleive). The oil pressure has been like this ever since i bought the car.

Dont want to have to rebuild it :frown:

 

[wbrophy]

A gentleman I know bought a $8,000 dollar stroked 109 short block from a big name place that does its own machine work and has a very good reputation on the Buick web sites.
We had to go to 20/50 wt. to get the pressure up to were it should be. Oh and the car runs like a bat out of hell.

I should know because mine put down a foot brake 10.1 with the boost at 21 1/2 psi on unleaded & alky at the track with a slipping 2004R.:biggrin:

 

[turbofabricator]

You might also want to verify that your gauge is correct. Temporarily install another high quality gauge, like an Autometer. The 20w-50 oil will help also. The machine shop probably built the engine to Chevy specs, not Buick specs. This happens all the time. It will be OK, though. You can also fix the problem with a piece of duct tape over the gauge face, then draw in 70 psi with a Sharpie pen........There....Fixed! :biggrin:

 

[cpac]

Check The Spring In The Pump First , The Weekest Spring Will Only Give You 50 Psi And The Yellow Spring Should Give You 60 Psi And The Other 7opsi ,,,this Numbers Depend On Viscosity Of Oil And Temp.........the Other Springs Are Black And And Red ,but I Dont Remember Which Is Which.........turbofab Will .....some Of The Builders Like Looser Clearences On Raceing Engines ,,to Each His Own

 

[callmeebryan]

You might also want to verify that your gauge is correct. Temporarily install another high quality gauge, like an Autometer. The 20w-50 oil will help also. The machine shop probably built the engine to Chevy specs, not Buick specs. This happens all the time. It will be OK, though. You can also fix the problem with a piece of duct tape over the gauge face, then draw in 70 psi with a Sharpie pen........There....Fixed! :biggrin:

tried 3 different gauges... 1 electrical and 2 mechanical. All read the same.

 

[wbrophy]

tried 3 different gauges... 1 electrical and 2 mechanical. All read the same.

Whatever you decide to do, please let everyone know your results so unlike a lot of other threads this one will have some sort of result.

 

[Lee Thompson]

simple solution

Install a booster plate--pick up 5 on the low side and 10 on the high side.
High oil pressure cold and steadly dropping as oil get hot is a classic example of too much bearing clearance.

 

[Chuck Leeper]

"I figured the break in period wasnt totally done yet, so i have been changing the oil every 3 weeks since i have got the car."

Save your $$. The engine was as "broken in" as it was going to be, at about the first 100 mi of driving.

 

[Blazer406]

.......A high volume oil pump takes ALOT more power to turn and puts alot more load on the cam sensor.

I respectfully disagree... and here is why....

As I understand it.... an oil pump has a spring inside it that regulates pressure..... and once that pressure is obtained.... any additional flow is bypassed around the gears and returned to the pan....A given engine with the clearances in the oiling system "require" a certain volume of flow to create the pressure you see on the gauge..... this volume required to show say... 40 psi... is the same whether you use a std volume pump or a high volume pump.... doesn't matter... both will give you 40 PSI provided you can meet that "required" volume to give 40 psi with either pump. If your clearances are reasonable... the high volume pump (although not required) IMHO... because most of its volume it's pumping is being bypassed back to the pan.... isn't draining that much more horsepower than the std volume pump would be.

I would agree if the clearances are great enough that the std pump can't "keep-up" anymore... the pressure will fall off (hence low oil pressure).... but the high volume will continue to maintain oil pressure longer. It is at this point that I agree it is consuming more HP than the std volume..... but the engine is still surviving with increased clearnaces.... where the std volume has dropped oil pressure enough and engine damage is inevitable if you don't fix it...

So... IMHO... if clearances are reasonable... the HP difference between the std volume and high volume are only marginally different. It is only when clearance increases to the point that the std volume can't keep up that the loads incurred by the cam sensor are significantly different....

All this assumes the "loose" motor with the high volume pump has oil in the pan to suck...

Did any of this make sense?

 

[wbrophy]

Install a booster plate--pick up 5 on the low side and 10 on the high side.
High oil pressure cold and steadly dropping as oil get hot is a classic example of too much bearing clearance.

If the oil does not work than :biggrin: "Ditto" on Lee Thompson's suggestion and they also make a high volume pump and plate setup. Both can be installed without taking the front cover off and in the car. I have used the booster plate in the past due to not wanting to take the time to get all the grooves out of the aluminum cover plate and I think the high volume pump gears with required plate is still sold.