I had the pan and rear cover off to repair the damage to my pan after landing from a wheel stand.

I noticed the barbell was popped out. So up against the rear cover as it can only go so far.

Had this thing apart several times, but haven’t seen that before.

Two changes since last time apart. Melling 10296 pump with the high pressure spring and the Sac City barbell.

So I’m thinking simply a lot of oil pressure? Maybe too much. It’s 80+ going down track. Maybe more. I don’t have time to look at it. Gauge is to low to see easily.

Cant be helping the passage alignment with it not seated.

Anyone else ever see this?
The barbell fits nice and tight.

Thinking while it’s out, I might put the std pressure spring in.

Ron

 

I can see where the higher pumped volume under 80psi could possibly push the barbell out. If you figure the area of the barbell exposed to 80 psi to be a bit less than 1 sq. inch, it is conceivable for that pressure to shove it out.
Too much extra volume could overwhelm the bypass passage capacity and raise the pressure above the normal bypass pressure.

 

Thanks Gary,

It’s a Moroso pan so no bypass. The filter has one though.

I’m sure I’m not the only guy running this pump combo.

 

There is a bypass in the pump itself. You did mention the higher-pressure spring. That's the bypass I meant.

 

ah. Got it

 

Or you could put a shim between the barbell and the rear cover to hold the barbell in place.

 

Was thinking the same. The barbell has a threaded 1/4x20 hole in it. Set screw would work

 

[QUOTE=RonSSNova;20416391]Was thinking the same. The barbell has a threaded 1/4x20 hole in it. Set screw would

I also have the 10296 pump. I'm running piston squirters in my LS7, so that's why the 10296 is in there. Just my .02 Ron, but I'm running the standard pressure spring. I honestly think you don't need that much pressure, but then I also remember you're doing a lot of 1/4 mile racing, IIRC, so maybe you do. Bet you're thankful for that thread in the barbell, eh!!

 

That would work Ron. I’d use some red loctite on the screw to keep it from turning under vibration. I’d bet $10 that mines the same. I see over 100 psi at cold start if I so much as touch the throttle. For what it’s worth, SacCity puts a taper in the back of the newer barbells for this purpose. As you know, the o-ring is far enough inboard that it won’t leak, even pushed back against the cover.

 

Thanks. I truly need another trip to the HW store. 😊
Looks like 1/4” long will do the trick.
Interesting they changed the design. I wonder if it works?

 

Yep. Too much oil pressure is just a waste of hp. Mine was at 80 with that pump. I'm using a LLSR this year so I'm trying .001 looser main bearings. There's always 20W/50W If I need it.

 

If your going to use axle-oiling lifters…which you need with the type of springs it takes to handle the solid roller setup…and/or a big oil cooler setup with that LLSR, you’ll want the extra pressure/volume. I’m 75 at cold start with Gibbs 30W oil.

 

I have axle oil lifters along with .0027 main clearance in an alum block.
Internet wisdom says the main clearance alone will cause low oil pressure when it gets hot.
So you are standing there with the 10296 pump and two optional springs…..you have a 50/50 chance of getting it “correct”. Forget the COPO spring.

Anyway, if higher pressure costs a few hp, no big deal.
hot idle is 42. Goes to 80 with rpm.
10W30 Schaffer’s oil

Here is how this ended up:




1/4” set screw. 56 cents.

 

With the lighter spring, you should keep your hot idle pressure as that won't crack the pump relief valve.
It might cap the high-end pressure at a lower number, but I don't know what the cracking pressure is.
Melling might have that answer.

 

Well done Ron. Next time mine is apart, I’m doing the same thing.

 

You do know the OEM ones don't sit flush with the block from the factory???

 

Interesting. The Sac one is flush

 

I don't ever recall them saying to make it flush or that it specifically had to be flush.

https://ls1tech.com/forums/generatio...check-out.html

​​​​​​​https://www.saccitycorvette.com/Billet-BarBell.html

 

@saccitycorvette Christian, Perhaps you have some input on this topic?

 

75# of oil pressure at idle? Wouldn't that be 135 psi at 6000 rpm? That sounds awful high unless I'm misinterpreting something.