vegasredz062

I have been doing some research and found that a cam swap leads to low oil pressure at idle.

Can any shop verify they are running into this issue ? What oil pressure numbers are you seeing at idle ?

Looking to get a blower done with a stealth cam and worried about low oil pressure.

vegasredz062

Anyone? Cams = Low oil pressure on C7s . This is not good news for people that want bigger builds.

ChucksZ06

That would only be a problem if a camshaft not designed for the engine were installed. Your question or statement is too general for anyone to answer.

Theta

Even the giant (read: 50%+) fuel lobe cams don't seem to have idle problems, so I can't imagine a small blower cam having any issues.

VR and LMR have done a ton of that work already, so they would be the ones to ask.

travisnd

The oil pump is a gerotor driven off of the crank. Many who are used to C5/C6s don't read up that the LT1 uses a variable pressure pump. It has lower pressure at idle to reduce parasitic loss and pumping excess oil and then has a higher pressure stage at higher RPMS as needed.

Mike@NewEra

When we did our NEP custom vvt cam in my C7 it did not effect the oil pressure at all.

NICK YOSKIN

maybe if you are a caveman when your sticking the "stick" into to hole!



beat up a cam bearings can kill oil PSI

glass slipper

The C5/C6 oil pump is a gerotor pump, the C7 has a vane pump. The C7 scavenge pump is a gerotor pump. While it's true the LT1 oil system is a variable pressure design depending on load AND rpm, the pump is a variable displacement pump...not a variable pressure pump. The variable displacement is why they went from a gerotor pump to a vane pump...you can't vary the displacement of a gerotor pump.

In terms of horsepower, it takes PSI*GPM*.0007 horsepower to drive a positive displacement pump. (GPM is gallons per minute.) You get the maximum reduction in HP when you reduce GPM along with a reduction in PSI. A gerotor pump would have to have a separate pressure control that would bleed off a sufficient amount of oil to reduce the pressure but in the end, you would still have a higher GPM at that pressure than if you just reduce the displacement/GPM output to achieve the same reduced pressure AND reap the benefits of even less parasitic drag.

If you'd like to follow your own advice and read up on the LT1 oil system, here's a nice link for you:
http://www.corvette-web-central.com/LT1oilpump.html

You'll note the vane pump displacement is infinitely adjustable, that's how they can achieve the oil pressure vs engine speed/load over the whole range. There are not two stages as you stated and as you can see, it also varies based on load, not just RPM.

This is old technology that has been around for several decades...all modern (computer controlled) automatic transmissions have this exact same setup, an infinitely variable displacement vane type oil pump which varies output pressure and displacement based on demand. That's one reason modern automatics can approach the MPG efficiency of manual transmissions on the highway. The average person will get better MPG with an automatic in the city because they'll come nowhere close to shifting at the optimum point in a manual while a computer controlled automatic will hit it dead on every time.

ChucksZ06

I believe the above statement to be incorrect.

vegasredz062

2 shops are running into this as we speak..The other shops are not talking about it. This is a real issue and borders on dangerous oil pressure.

I would like to hear from

VR
LMR
ECS
and who ever else has done cams. what Oil pressure are they seeing at idle after car is full warmed up.

kp

Thanks for the link, I did notice the oil pressure sender was in front of the engine now. Wondering if the slightly reduced base circle or higher lift that most aftermarket cams have can be causing some issues with the lifter and oil galley. Article says that Gen 5 engine gauge measurements are 50-75kPa less (7-10psi) than LS engines to start with from moving the sender.

Mike@NewEra

My C7 is about 22 psi oil pressure at idle once fully up to temperature, which is the same as it was stock fyi. It's possible that it is install error. Is the low oil pressure happening immediately after the cam swap, or a few hundred miles after?

vegasredz062

lll Ask Him monday. Yeah mine is 22 also at idle stock.

He told me his was 15 at idle.

Andy@A&ACorvette

VVT cams under .525 lift don't affect oil pressure if retaining the stock lifters and related hardware.
Changing the lifters to LS7 style lifters in order to run high lift cams does affect oil pressure.
I haven't really delved into what and why but it is absolutely true.
I put the stock cam back in mine but did not pull the heads to go back with the stock lifters and related hardware. My oil pressure is still low.

RussM05

Ditto. Mine is 100 % stock. Using 5w30 Mobile 1. Cruise it at 32 psi. Seems normal.

Only thing I can think of that would cause low oil pressure with an after market cam would be the journals are smaller than stock.

vegasredz062

Thanks Andy! any other shops want to chime in? ECS? VR?

I think IF we are going to run over 650 we need answers. I really want 700whp due to the fuel by cam deal.. I don't want to be a guinea pig..

0Ron@Vengeance Racing

With proper installation there should not be an issue with oil pressure... There are too many variables (retaining DOD/Deleting DOD/VVT etc)to pin point someones specific issue, but any reputable shop should know the proper steps for each install.

FWIW, our C7 idles in the mid 30s and jumps to 50/60 under load... We have installed aftermarket camshafts in five C7s with no issue to date.

vegasredz062

Thats good to hear!! Ill call A&A and see if they got it squared away.

TheBiz

What is everyone doing with oil gallys in the block and DOD Delete?

0East Tx Muscle Cars

You have to put a "dowel" or a plug into it so the oil doesnt come out of them.

We will be doing a piston/head/cam/ swap in a couple weeks on our C7 and a bigger supercharger and ill let you know what the OP changes to with those changes.