Spoke to the machine shop who spoke with johnson about the issues. Machine shop said a combination of the johnson lifter plunger depth/oiling location can cause lower idle oil pressure and they said johnson did agree??? The machine shop had mentioned the lifters as a possible issue and I have read about lower oil pressure with the 2110r lifters but wasn't expecting that low.

As a note, the motor had very good oil pressure before issues with the cam. Cam bearings were replaced, all others reused, cam bearings were checked and all in spec.

Anyhow, the machine shop swapped out the lifters for LS7 style lifters, going to prelube and send it back to the shop for installation.

I do seem to run across conflicting information between lifters and oil pumps...

Thought high volume and johnson 2110r's were the way to go... I do have to go with the local shops that indicate they don't normally use high volume pumps and/or the short travel lifters. We will see when this is all back together but so far, not having good results with high volume/short travel lifters.

 

The other unknown is the cam bearings that were replaced. Can you confirm a cam bearing didn't move like this guy?
Got a cam bearing issue - LS1TECH - Camaro and Firebird Forum Discussion

I have the same lifters and while the idle pressure is around 20-25 after a severe beating, it doesn't get much lower than that even after hot lapping it at the road course for 30-40 minutes on a 90 degree day. Mains and rods all around .0024/.0025. This is with a Melling 10295.

 

Cam bearings were checked and no issues. Motor probably only has ran less than a couple hours. Should know by the end of next week what the "new" oil pressure is. I have to rely on the machine shop's expertise as well as the shop doing the work. I had initially installed the motor and noticed the low oil pressure after warming up, the shop recommended by the machine shop was actually the same one that tuned the car and does a lot of LS work. When I first got the car (head/cam/headers already installed) the car ran very rich and prior dyno was on the low side at 430 rwhp for the mods, after the tune it was at 485 rwhp and no more rich stink in the garage. The cam gave up a few months after that and had quite a few small pits on a couple lobes... chirped quite a bit!

I wanted to get the most reliable cam/lifter setup to minimize the issues that the motor had and also a cam with a very similar profile so I went with a cam motion LS3 stage 3 high lift cam and the 2110r lifters... guess I'll be going with the LS7 lifters and hopefully everything works out. At least the cam seems good with the prior tune but will probably need some small tweaks once the motor is broken in.

I'm just glad I didn't try replacing the oil pump and pickup O ring since I would have been totally bummed after doing that work with no improvement!

 

One thing no one ever checks is lifter diameter of the body. If it's off a .001 on all of them, that's a huge leak and I have seen a variance in some lifter bodies, even $1500 sets.

 

Forgive me if i missed it but you didn't verify the actual oil pressure with a mechanical gauge before going further? The factory oil pressure sensors DO become faulty and give low readings.. I know because i bought another ls1 daily driver recently and it was showing low oil pressure warning on the dash... i replaced the sensor .. problem fixed.

 

Oil pressure was verified with a mechanical gauge and there are also two different electrical oil pressure gauges, the stock valley cover (read through the OBD2 port) and another in the oil cooler block off plate (HSV gauge pod). I'll check the johnson lifters when I get the car back and I'll see if maybe I can send them back to be checked and then sell them as they are basically brand new with less than a couple of hours run time.

 

Those crank journal clearances seem wide for a street aluminum LS, more typical of an iron block LS. The AL block grows more with heat so factory spec clearances are about 0.001" LESS than the shop measured. LS3 Spec: 0.0008-0.0021 in

 

Nobody runs the low end of GM spec or wants to on purpose even on aluminum, lowest I'd want is 0.015" if I had to. He is right in line with an aluminum block at 0.018-0.021" and should have decent pressure with a stock volume pump even with elevated oil temps.

 

Spoke with the shop today, oil pressure is now ~45-47 psi warm idle. They haven't driven it yet do to rainy weather and no hood but it appears the johnson lifters were the cause of the low oil pressure.

 

So did they change to a different lifter? Did they tell you what they did?

 

Yes, I'd like to know also...

 

The machine shop said they put in LS7 lifters... They had several sets on the shelf they showed me when they asked me to bring in my old lifters... I'll get the details on what exact lifter they used. The machine shop said the racing lifters are meant more for high RPM use and motors they are designed for don't spend much time idling. After the repair shop replaced the oil pump, I believe he said the idle oil pressure went up about ~8 psi which would be in the 16-20 psi range with the johnson lifters. That was with the 15-50w break in oil... someone on here mentioned their oil pressure was low on a fresh rebuild with break in oil and returned to normal ranges when the oil was changed. I didn't really pursue that as the machine shop wasn't satisfied with the warm idle oil pressure readings and didn't feel there would be any difference in oil pressure after an oil change.

I'll get more info when I pick the car up later in the week... Letting the shop run it through the paces and check the rest of the car out. Besides the motor, the trans was rebuilt by tick with a new MGW shifter and a new monster twin disc clutch/TOB and the trans/clutch also needs to go through a break in period. I had only driven it around the block a few times, maybe into 3rd gear but all seemed good with the trans and clutch.

 

mic the lifter bodies also

 

It seems that the lifters weren't the issue after all as when the repair shop test drove the car, the oil pressure started to drop at idle.

It did take longer though... The car was idling for ~15 minutes while the mechanic was dealing with someone in his office, when he got to the test drive he said the oil pressure started dropping as he was going around the block. The machine shop owner will be stopping by the shop to see what's going on.

The mechanic wants to pull the cam and check the cam bearings... They did say there is no sign of any metal or debris in the oil or filter.

Will update again once a hear what they are planning...

 

The issue turned out to be the cam bearings. Shop used clevite bearings and it turned out they were a little "loose" with the new cam motion LS3 cam. Replaced the cam bearings with dura-bond and oil pressure is now 75 psi cold and 45 psi when warmed up with the johnson 2110r lifters. Shop indicated that they had one customer who picked up their block (new cam bearings) who had a comp cam that was extremely tight while the cams he had in the shop fit just fine. It appears there may be some variations with different cam bearing/cam combinations which should be looked at more closely.

 

Glad it all got worked out. I want to note as to what you said regarding cam bearing clearance and different bearing manf.. In other non-LS builds, it's common to see a wide variance in cam bearing/cam journal clearances and you have to make each scenario work. Most of the time, in my non-LS builds the cam is too big and bearings too small so I have to hand fit the whole thing. The core shift, too, in the older stuff and alum blocks is something to consider too The fact that most slap these together and run fine is testament to the design.

 

I appreciate you documenting this process, as I've had a build with similar behavior. I had my LS3 rebuilt in 2019 (~28K miles on engine) by a local shop that has since closed. I used Johnson axle-oiling lifters, CamMotion cam, new cam bearings (I think Clevite), IR barbell, Katech ported OEM oil pump, standard main/rod clearances using Redline 5W30. I've got my dash OEM oil pressure gauge connected to OEM location behind the manifold, and a digital psi gauge connected near oil filter. Oil pressure generally upper 40s low 50s cold, generally mid-to-upper teens hot idle, or low teens after abuse. I know I requested the shop to measure lifter bore clearances, but I don't think they did, and your comment about the cam bearing clearance also is new concern. Unsure if that oil pressure issue has caused side effects, but I don't plan to use this block again. I'm glad you got yours sorted!

 

Seems to be the same issue I had. I just changed the oil from the break in oil (br 15-50) to Castrol 10-40w conventional. Startup cold idle pressure is ~75psi and drops to ~ 30psi when hot. Jumps up to around ~ 65psi when revved a little. I believe the johnson lifters will cause ~ 10psi drop in idle pressure. Have you thought about trying a 10-40w oil and see if you get any improvement?

I would guess your issues are with the cam bearings... I also have a cam motion cam and the shop did note some variance in the cam journal size and I thought they said they used different size bearings on a couple of the journals (I can check with them)... maybe cam motion has some issues?

 

I've read the same about 10-15psi drop, even advertised on some reseller pages. I never found a straight response on whether that drop needed to be bandaid by other changes. Of course, assuming proper clearances.

 

What I have found for the minimum oil pressure is about 10psi @ 1k rpms, I think the low oil pressure warning is lower (around 5-7psi). The hot oil pressure in my stock GMC 4.8l is ~30-35 psi according to the dash gauge and goes up to ~50-60 psi off idle. Dropping 10psi with johnson lifters shouldn't be an issue although the shop that did the repairs prefers to use a high pressure pump with the COPO relief spring and that is what is in there now.