80 lb oil guage question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**402Bowtie** · 01-29-2016, 05:38 PM

I know the 80 lb guages were only offered on C40 and bigger trucks, so what kind of engines are people running that require the 80 lb guage? Why do some people seek out the 80lb guage over the stock 60 lb? I assume there are many engines today that require more than 60lb oil pressure?

I have a mostly stock 402 BBC I plan to run and am wondering if I should use an 80 lb guage....

Thanks for any info!

**Dieselwrencher** · 01-29-2016, 06:02 PM

Any engine with a high volume oil pump and cold weather can max out a 60psi gauge. So that may be one reason why people are upgrading to them. These 5.9s I typically use can make 90-100psi not plugged in, below 20*. Bye bye 60psi gauge. Haha

**LockDoc** · 01-29-2016, 06:53 PM

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I have 3 trucks that max out the 60# gauges. Especially when first started. They all have new engines in them. I have one tach dash that has a vacuum gauge and an 80# oil pressure gauge but I need to restore it.

LockDoc

davepl · 01-29-2016, 07:36 PM

The problem with people stuffing all of these high-volume and high-pressure pumps into engines that don't need them, besides the parasitic horsepower loss, is that it trips the pressure valve and bypasses the oil filter.

Particularly during starting and warming you'd like a clean flow of oil, but this is precisely when the extra pump capacity, combined with viscous cold oil, conspire to completely bypass the filter.

You only need something like 7psi to float the bearings and a few psi per thousand RPM, and more isn't better.

That all said, my bone-stock 2007 LS7 would peg 100psi when cold. I was afraid it'd explode the filter (which is in part why they have a bypass, I guess). So if you're running a late model LS engine you might be stuck with high pressures when cold.

**70STOVEBOLT** · 01-29-2016, 10:07 PM

I have a mostly stock 402 (mild cam and Edelbrock 750 carb). I put in new bearings and a new stock type Clevite oil pump and it buries the 60 psi oil pressure gauge until it is warm. That is with the stock spring in the pump. It will also bury it at around 3500 rpm after it is warmed up. I don't think you need an 80 psi gauge but if you want one then get one. I have one but it has some rust on the face so I am not going to use it.

01-29-2016, 05:38 PM	#1
402Bowtie Registered User Join Date: Sep 2003 Location: Wichita, KS Posts: 3,735	80 lb oil guage question I know the 80 lb guages were only offered on C40 and bigger trucks, so what kind of engines are people running that require the 80 lb guage? Why do some people seek out the 80lb guage over the stock 60 lb? I assume there are many engines today that require more than 60lb oil pressure? I have a mostly stock 402 BBC I plan to run and am wondering if I should use an 80 lb guage.... Thanks for any info!

01-29-2016, 06:02 PM	#2
Dieselwrencher 6>8 Plugless........ Join Date: Sep 2007 Location: Prairie City, Ia Posts: 17,142	Re: 80 lb oil guage question Any engine with a high volume oil pump and cold weather can max out a 60psi gauge. So that may be one reason why people are upgrading to them. These 5.9s I typically use can make 90-100psi not plugged in, below 20. Bye bye 60psi gauge. Haha __________________ Ryan 1972* Chevy Longhorn K30 Cheyenne Super, 359 Inline 6 cylinder, Auto Trans, Tilt, Diesel Tach/Vach, Buckets, Rare Rear 4-link and air ride option Build Thread 1972 GMC Sierra Grande Longhorn 4x4 1972 Chevy Cheyenne Super K20 Long Step side tilt, tach, tow hooks, AC, 350 4 speed 1972 C10 Suburban Custom Deluxe 1969 Chevy milk truck 1971 Camaro RS 5.3 BTR STG3 Cam Super T10 1940 Ford 354 Hemi 46RH Ford 9" on air ride huge project *Tired of spark plugs? Check this out.*

01-29-2016, 06:53 PM	#3
LockDoc The Older Generation Join Date: Aug 2006 Location: Montezuma, Iowa Posts: 25,771	Re: 80 lb oil guage question - I have 3 trucks that max out the 60# gauges. Especially when first started. They all have new engines in them. I have one tach dash that has a vacuum gauge and an 80# oil pressure gauge but I need to restore it. LockDoc __________________ Leon Locksmith, Specializing In Antique Trucks, Automobiles, & Motorcycles (My Dually Pickup Project Thread) http://67-72chevytrucks.com/vboard/s...d.php?t=829820 -

01-29-2016, 07:36 PM	#4
davepl Registered User Join Date: Aug 2006 Location: Redmond, WA Posts: 6,332	Re: 80 lb oil guage question The problem with people stuffing all of these high-volume and high-pressure pumps into engines that don't need them, besides the parasitic horsepower loss, is that it trips the pressure valve and bypasses the oil filter. Particularly during starting and warming you'd like a clean flow of oil, but this is precisely when the extra pump capacity, combined with viscous cold oil, conspire to completely bypass the filter. You only need something like 7psi to float the bearings and a few psi per thousand RPM, and more isn't better. That all said, my bone-stock 2007 LS7 would peg 100psi when cold. I was afraid it'd explode the filter (which is in part why they have a bypass, I guess). So if you're running a late model LS engine you might be stuck with high pressures when cold. __________________ 1970 GMC Sierra Grande Custom Camper - Built, not Bought 1969 Pontiac 2+2 427/390 4-speed Coupe 1969 Pontiac 2+2 427/390 4-speed Convertible

01-29-2016, 10:07 PM	#5
70STOVEBOLT Senior Member Join Date: Jun 2005 Location: Winona Lake, IN Posts: 6,414	Re: 80 lb oil guage question I have a mostly stock 402 (mild cam and Edelbrock 750 carb). I put in new bearings and a new stock type Clevite oil pump and it buries the 60 psi oil pressure gauge until it is warm. That is with the stock spring in the pump. It will also bury it at around 3500 rpm after it is warmed up. I don't think you need an 80 psi gauge but if you want one then get one. I have one but it has some rust on the face so I am not going to use it. __________________ 70 C/10 SWB 402/TH400/3.73 "The Needy Beast" 200,000 Mile Club Disc Brake Club Owner installed options: Front Sway Bar Power Steering Power Brakes Cigar Lighter Courtesy Lights Deluxe Side Markers Wiper Delay Sliding Rear Window Power Windows Power Locks Sniper EFI 2015 Silverado 1500 LS 4.3/6L80/3.23 lowered 2" front & rear



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