Finished up my h/c install tonight.

Primed the system and said a prayer...and the car fired up instantly like a dream.

No leaks from the head gaskets (thank god)but the oil pressure was somewhat iffy. About 45 psi cold and when it got hot...to about 210-215 on the temp gauge before the fans kicked in the pressure would drop to about 21-22 psi. I am running 5w30 castrol gtx.

Is this normal? Idle at 900 rpm, thin oil, and 210 degree temps...would this cause the pressure to drop to 21-22 psi?
Any stab of the throttle to 2000 rpm or more and the pressure would instantly go up to 40 psi. No knocking or ticking...everything seemed great besides the somewhat lower oil pressure at high temps and idle. I am running a thunder racing ported ls6 pump...which cost me 5 psi anyways last year.
One more thing also...is that I used some real sticky assembly lube for the cam install...could this be blocking off some of the oiling holes in the cam bearings? or possibly hindering the flow of my pump?

Do you guys think I have a pinched o-ring? I made damn sure I put the thing in perfectly. I re-used my o-ring...but it was new last year when I did a cam only swap. It still looked like new.

I really dont want to take this bitch apart again...I am sick of working on the damn thing

thanks for the input.

Troy

 

I regularly see oil pressure drop 15 - 20 psi when it reaches full operating temp. However I start at 60+ cold idle and wind up with 43 hot idle. Id be a little concerned with ~20 psi hot idle. What was your pressure like before?

 

Take the oil pump pick up out and put on a NEW o-ring. Just because it looks good doesn't mean it is good. They are $5 so I don't see why you want to risk a few hours worth of labor for $5.

 

Before it would drop to about 30 psi on really hot days when idling and at a stop light. 25 if I used 5w30.
So I lost almost 5 psi warm.

The car has always been about 45-50 cold start with 5w30 and 50-55 with 10w30 cold start. The ported ls6 pump cost me about 5psi....it was 60 cold start when I first got the car.
I used some 5w30 because that is all I had laying around and wanted to get rid of it...and I knew I was going to change the oil very soon after the install so I used it.

What I think I am going to do is start the car up a couple more times over the next few days...then change the oil out to some 10w30 and see what happens.

The car has almost no valvetrain noise and sounds real good...so I know it is getting good oil. It is actually quieter than when I was cam only before...I think because I tightened up the preload a little bit using a .040 gasket and also the new lifters.

Some people have reported that break in lube could drop oil pressure...is this possible?
I put it all over the cam and also on all the tips of the pushrods and rocker arms to protect on start up...thats what the bottle said it was good for. I used mel-lube (melling) it is red.

hmmm...if the lower pressure persists after the oil change I should probably get a new o-ring. Unless this is acceptable.
Im not sure...this is borderline

One more thing...I ditched my pcv and switched to a metco breather on the passenger side and put a small breather on the drivers side valve cover. Could this drop oil pressure by letting out more crancase pressure than before?

 

Well something is wrong from the get go if you lost oil pressure with a ported oil pump.

 

Many people have reported losing about 5psi when switching to a ported ls6...I thought this was common.

What about the breather...would this effect oil pressure? (mentioned in my last post)

 

If the car doesnt have erractic oil pressure and alot of ticking going on you are probably fine. I certainly wouldnt pull it back apart for no reason. I pinched my O-ring the first time I installed the pickup and I had no doubts what was wrong when I fired it up, very erratic oil pressure, lots of ticking. The car should start out with higher oil pressure when cold and then lose some when it warms up. Mine gets down to 28 psi hot idle when the temps get high in hot Texas weather, and thats with the stock Ls6 pump and a good o-ring. Cold idle is around 38-40 psi..... As long as you see a nice increase to 45-50psi when the motor revs I think you are fine.

 

Hmm, Well I have breathers on both covers and a ported oil pump (tsp). I gained pressure. I am about 65psi cold start and 40-45 psi hot idle. My oil pressure never drops below 40psi.

 

What kind of oil are you using and what kind of oil/coolant temps? Also how hot is it outside where you live? What I have observed on my vette is that when coolant temps approach 210 - 215 degrees the oil temp is 230-240 That thins things out alot.

 

After I swapped out my cam my oil pressure dropped about 5-8 psi once it was fully warmed up. On cold starts though its about 55-60 psi. Before the swap my oil psi would sit at about 40. I also put in a new oil pump (stock) and new oil pump ring.

 

Was using mobil1 5w30. It's about 90* outside, I live in Florida . My temps never get up to 210. The most I see is ~180*

 

Ah ha! There you go, I use Mobil 1 10w-30(most of the time), have used 5w-30 before. They both behave the same...When coolant temps get high as they often do in traffic with a C5 ...the oil thins considerably. My F-bod rarely got over 190 as well.... If anything Ultra Z should be concerned with why he is getting 215* coolant temps with an F-bod in Michigan.

BTW post up your dyno results when you get them Ultra, that combo is very similar to mine but I dont have the competition valve job or cometics....

 

It got to 210-215 because it was the first time I started the car after the swap and the cooling system had some air in it.
I started the car today and the temps never reached 200. I am going to have them lower the fan turn on temp a little when I get it tuned...this seems to be a popular mod after a h/c swap.

Anyways I have an update.

Started it 3 times today and it was 45psi cold and 38-40psi @ full operating temp every time. 60 psi @ 4000 rpm. these numbers will both go up about 5psi when switching to 10w30...it always has before on my car.

So I think ill be ok...what do you guys think?

I am guessing the assembly lube on the first start up could have hung up the pressure spring in the oil pump or did something to cause the slightly lower pressure. Because it was fine today and I dont see how it could be anything else....except maybe my sending unit is playing tricks on me.
So for the most part I am a happy camper

I am installing the clutch next week and then I am off to get a dyno tune at exotic performance plus...I am going to schedule the appointment as soon as I get the clutch installed and make sure everything is ok with that.

I should have my numbers up the first of june. I think they should be real good since I set up the compression @ 11:1 static and my dcr is about 8.6.I have all the bolt ons except for an electric water pump...and the fast 90/90 is too expensive for me right now.
Hopefully it goes well.
EPP has a mustang dyno...so I guess we will see. I am going to take it to a local dyno jet at pauls high performance afterwards to compare. They dont do GM but I am sure they will let me make a dyno pull...even though he is hardcore ford. I would like to see the difference between the dynos. And of coarse it is nice to see higher numbers

 

You are absolutely fine. It was the 215* coolant temps causing your oil to thin and drop your oil pressure. Even then you are fine.....