Oil restrictors hydraulic roller cams??

[nsxxtreme]

I have read so much info for and against oil restrictors.
It's made my head spin.

Currently I have a melling M55HV oil pump. With a Moroso 7 qt oil pan. Moroso oil pickup. Lunati roller lifters and a full roller assembly. I have good oil pressure up to about 4000 rpms. I get to about 80 psi once I near 5k rpms oil pressure drops to about 70 psi. The dropping oil pressure is what concerns me. Seems to me it should be able to easily maintain 80 psi at 5k rpms.

My clearences on my mains and rod bearings is .002 on both. One thing that did piss me off is the rod end play is .020 which eagle says is acceptable but shows over in my book. They swear I need oil restrictors. Everything else I have read says not to use them because the valve springs use the oil to keep them cool.

Any engine builders on here that can comment one way or another?

 

[cybrfire]

Springs do need oil to keep them cool. No doubt about that.

70-80 psi at 5000 rpms, nothing wrong with that in my experience.

 

[nsxxtreme]

Springs do need oil to keep them cool. No doubt about that.

70-80 psi at 5000 rpms, nothing wrong with that in my experience.

If the oil pressure was solid I don't think I'd have a problem with it either. The fact that I have a drop in pressure is what is concerning to me.

I'm starting to wonder if it's a Windage issue since this is a 383 with a longer stroke.
The Moroso oil pan has a Windage tray, trap doors and an oil scraper. I'm wondering if I need additional oil scrapers?

I'm not a Chevy expert it would seem to me you wouldn't want your pressure to drop it should always be increasing until it hits the relief spring in the oil pump which is set at 80 psi.

 

[sweetk30]

others have said good setup is key to oil needs. but you do not need a high volume pump thay are known to suck a pan dry at higher rpm's from what i have read / been told.

so with this info your setup would lead me to belive the oil being sucked out and not returning fast to the pan and way to much all over the engine.

also good rule of thumb 10 psi per 1k rpm.

 

[63chevyll]

Sounds to me your pressure relief valve is opening and doing its job.
And imo with a SB chevy, a HV pump is unless on a mild build unless additional oil is needed. Or running crazy race clearances

 

[nsxxtreme]

I've also heard the for and against high volume oil pumps as well. Enough to also make your head spin. I don't believe my pan is being sucked dry. I also kinda believe that's somewhat of a myth. High volume oil pump is going to get to a higher oil pressure quicker. As soon as it hits the 80 psi relief spring it's going to cycle back into the oil pan just like a low volume high pressure pump would. The only difference is a HV pump would be able to supply larger oil clearences and still maintain oil pressure. I think this sucking a pan dry stuff comes from a small oil pan with incorrect oil pickup to oil pan clearences.

Some back history I had a low volume high pressure pump. Same issue as now.

 

[nsxxtreme]

Sounds to me your pressure relief valve is opening and doing its job.
And imo with a SB chevy, a HV pump is unless on a mild build unless additional oil is needed. Or running crazy race clearances

Is that what you get when it hits the spring? I'm running 10w-40 in it right now. And I got on it on the way home on the highway and it goes up to the max psi oil pressure and then begins to drop. I think I saw it get to about 65psi scares the crap out of me.

 

[cybrfire]

I'd try throwing in an extra quart after its full.

 

[4X4HIGH]

others have said good setup is key to oil needs. but you do not need a high volume pump thay are known to suck a pan dry at higher rpm's from what i have read / been told.

so with this info your setup would lead me to belive the oil being sucked out and not returning fast to the pan and way to much all over the engine.

also good rule of thumb 10 psi per 1k rpm.

This is exactly correct. Also a HV oil pump robs Horsepower. Another thing, you should NEVER use oil restrictors in an engine with hydraulic lifters ever.

 

[ChrisPerry]

Maybe you don't have enough clearance between the oil pickup and the pan. Saw a Nova with a dented oil pan doing that once, took the pan off and straightened it out and it was all good.

 

[63chevyll]

Is that what you get when it hits the spring? I'm running 10w-40 in it right now. And I got on it on the way home on the highway and it goes up to the max psi oil pressure and then begins to drop. I think I saw it get to about 65psi scares the crap out of me.

Yeah, I've noticed bigger drops in psi readings when valve/ spring opens.

Don't worry.
I used to care about oil pressure until I started racing. Not saying what I've learned is the information you need to tell mom about
We run classes that require stock pans. circle track and fig 8. 3 different engines, zero baffleing, and 5-6 quarts.

We would hit 20 psi or less in the turns (4500-5000rpm) oil sloshing around and who knows what else is going on in there. Got concerned for one night, then it happened every race. Or shall I say, I started noticing it. Anyways, I quit caring when the engine never blew and we started winning races.

4 hard seasons later, same engine came apart and ZERO abnormal bearing wear. Engine only came apart because the block froze one winter

So like stated above, sounds good to me.

And besides, where were you planning on restricting it. The SB chevy has the best oiling passages out there

 

[nsxxtreme]

This is exactly correct. Also a HV oil pump robs Horsepower. Another thing, you should NEVER use oil restrictors in an engine with hydraulic lifters ever.

I don't want to turn this into a HV vs Standard volume thread tons of threads on the net already that argue that. A high volume pump is going to move as much oil as required to hit a maximum pressure of the relief spring at which point the excess oil will be cycled back to the pan. A low volume high pressure pump will do exactly the same thing. The only difference is I would expect the HV pump to hit the relief spring sooner and consume more power. The small amount of HP loss I'm not concerned with. The other problem I have seen with HV pumps they pump up the hydraulic lifters sooner and can cause idle issues. I have not experienced that though.

From everything I have read I agree with you on the oil restrictors. Yet eagle rods swears they are required. From what I have read roller lifters already have oil restrictors built in.

 

[nsxxtreme]

I'd try throwing in an extra quart after its full.

Tried a 1/2 quart. Was gonna try switching to a thicker oil maybe 20w-50

 

[nsxxtreme]

Maybe you don't have enough clearance between the oil pickup and the pan. Saw a Nova with a dented oil pan doing that once, took the pan off and straightened it out and it was all good.

The pickup I have is made specifically for this pan and for a HV pump it is bolted to the bottom of the oil pump. There is no adjustment possible with this setup.

 

[ryoken]

your freakin over nothing... that's WAY more oil pressure than you need... anything over 60 is excessive...

my new HV pump in my 454 runs 55 to 75... but my reasons for running a HV pump where different than most...

 

[diesel4me]

I've seen engines that were run at high RPM's with bearings that had grooves cut into them at the oil holes,that ran out to the edges of the inserts,from excessive oil pressure before,and they tossed a rod or spun the bearing...I'd say anything over stock specs is fine,too much isn't always "better"...

 

[nsxxtreme]

Yeah, I've noticed bigger drops in psi readings when valve/ spring opens.

Thanks for the info I never knew that, it still scares the crap out of me.

To give a complete back ground this is the second time I have built this motor. The first time I had a standard volume high pressure pump. It eventually took out my bottom end. I had this same exact issue. Mains and rods were oil starved. That one with the standard volume pump oil pressure would drop to 40 psi. Which is what made me go for the HV pump this time around. This is only an issue above 4k rpms.

Eagle is really sloppy with the connecting rod end play. On that motor I had between .020 minimum and .024 maximum (most were .024). Which I dont think helps keep the oil where it belongs. Every book I have read says that is out of spec yet eagle claims its normal.

A new block and new bottom end and I still have the exact same issue. Except oil pressure is at least higher then before. I'm kinda wondering if the oil is getting stuck swirling around the crankshaft. I know the stroke has increased, what I dont know is how much additional windage that creates.

 

[Fordum]

What type oil are you running? In a couple of vehicles that were getting pressure drops at speed or higher temp, were improved by running synthetic.

Not exactly a high performance engine, but my old 8N tractor used to run at less than 5 lbs when hot, the same weight in Amsoil it never drops below 20.

I have noticed similar gains in other engines. Especially with heat, but I see gains in RPM too.
Just don't start off a new engine on it. It can cause break-in problems.
Although I hear that Amsoil has a special break-in oil now with high zinc, but never used it.

 

[y5mgisi]

Im just confused. "oh no my oil pressure drops all the way to 65 psi at times!" ? I consider anything over 30psi to be good oil pressure. You had other issues if you toasted your rods/mains with 40 psi. There are 200k mile motors around here(on the site) that have never seen 40psi in their lives.

 

[nsxxtreme]

What type oil are you running? In a couple of vehicles that were getting pressure drops at speed or higher temp, were improved by running synthetic.

Not exactly a high performance engine, but my old 8N tractor used to run at less than 5 lbs when hot, the same weight in Amsoil it never drops below 20.

I have noticed similar gains in other engines. Especially with heat, but I see gains in RPM too.
Just don't start off a new engine on it. It can cause break-in problems.
Although I hear that Amsoil has a special break-in oil now with high zinc, but never used it.

I've always liked castrol GTX oil so its what I've always ran. In the prior build I was running 10w-30 synthetic. Since this is a roller motor I don't believe the zinc additive is required. I think that is a flat tappet thing.

I don't mind trying Amsoil I've heard good things about them. Amsoil does have a zinc additive that you can add to your oil for breakin.