racer7088

If you have the lower pressure or normal pressure spring in the Melling HV it can't pump really anymore oil the top then a reg volume pump can. If the relief valve is keeping pressure to 55 psi at 5000 rpm on both there will ne no difference to the volume of oil to the top of the engine between the different pumps.

The HV pump can make more oil pressure at lower rpms since it has more displacement though and can move more oil through the rod bearings etc if they are opened up to the point where the normal pump couldn't keep up certainly and you should have more low rpm oil pressure.

The top end is oiled through the pushrods and the same oil pressure will pump the same oil up there requardless of what pump is doing it if they are all set to the same pressure at that rpm. We use the HV pumps on several engines and some turn 8000 rpm and they have never had problems.

On endurance engines with the LS1 oiling setup though you will foam the oil at continuous high rpm but that's way more than driving around at 4000 for a while. It probably had tight bearings or ran out of oil etc. if I had to guess or something else wrong.

koolrayz

iTrader: (26)

I always use the smith restricted port push rods to help provide oiling priority to the lower end.

Full-Force

iTrader: (11)

I drove my car 50 miles with a 4400 stall and 4.10's. It was running 4000 rpms and higher down the highway. Would you believe the sucker still got 20mpg? I have the stock 99 pump. That was 2 years ago. I guess Im lucky.

Jeff@TotalPerformanceEng

iTrader: (6)

100%

4000rpms for extended periods is more than fine. Sounds to me the clearences weren't correct in the first place. There are MANY MANY guys who endurance race their cars for 20+ minutes at a time at 4K plus rpms without issue, with stock pumps, melling pumps, and ported/shimmed pumps.

Hopefully you went to a different builder the 2nd time around.

John02SS

iTrader: (47)

Exactly! The restricted tip keeps it from pumping so much oil to the top of the motor. I run a smith restricted push rod also for this very reason.

MAC4264

How much oil was drained from the engine when you realized it was hurt? You put 6qts in did you get back 6qts or something somewhat close? Hydraulic lifters have enough restriction in them to not have to resrtict them more. When bottom end clearances are to great the top end will starve, main and rod bearings act as a restriction for the top end as well. Personal experience, drove a GTO (oil sensor broke) for 7 miles with lifter tapping and had 5 psi at 1700 when checked with a gauge. Fluidamper vibrated front cover off oil pump, motor never has shown any sign of bearing in oil or filter. 11.3 is still pretty stout to be broke. I know when one rod or 1 main goes out you can see 50 to a 100 horsepower with in back to back dyno pulls of 1 of them going out. 3rd pull would be 75+ for sure and you better stop right there or it gets even more expensive.

fastGBcamaro

iTrader: (10)

I agree 100% with everything you guys have said. I could hve been slightly low on oil, and should have checked it before leaving to the track, it never had a problem burning oil so I just took it for granted. Lesson learned. As far as the bearing clearances, they were tighter than my builder would have normally went with, but I brought him an issue of GM high performance that had an article on building a LSx stroker, and the company doing it was a very reputable shop in the LS comunity, so my builder went with the specs that were given in the article. This time around he built the engine with the bearing clearances that he builds all of his race motors to. I am very confident that the car is going to run very strong. I will keep everyone informed with the results. I am suprised the car still went 11.3 on a badly hurt motor, I figured it was down almost 100hp, just like MAC4264 metioned. So I am really excited to see how it will do running at 100%.

BigDaddyBry

iTrader: (15)

Here's a simple question: did you check your oil level after arriving at the track, before you made your passes?

Just curious.

99blancoSS

iTrader: (115)

So your saying the builder hosed it and you used him again?!??!! Read an article for his bearing clearances and now you feel confident he is doing it right?!!!?!?



Please people, call me and dont waste your money on incompetant builders. I'm sorry but that is the lamest excuse I have ever heard for a builder to screw up clearances. You either know what your doing or you don't. We dont let the customer tell us what clearances to use. Thats why they came to us in the first place. Expertise in building an engine.

twin74s

iTrader: (10)

Pressure and volume are totally different. so your saying as long as its 55psi regulated that no matter what pump is on it its pumping the same amout?

See5

iTrader: (53)

I suspect those high volume Melling pumps are aimed at the DOD motors like the 6.2 in the Escalade. They have open ended oil spray bars and oil hungry variable lifters.

racer7088

The HV pump has more displacement so it can make more pressure at the same or lower rpm or run more clearance at the same pressure. Peak pressure is controlled by the pressure relief valve and spring though and not the pump size itself.

If you have the same oil pressure with both normal and HV pumps there is no more oil flowing with the HV pump except through it's internal bypass.

Neither pumps are flowing all out almost ever and if you block the pressure relief valves in them especially with cold or thick oil the pressure will go over 200-500 psi and the filter will blow right off the engine.

The basic sizing of the oil pump's gears is there in regular and HV pumps to make the oil pressure sufficient when the engine is not turning the oil pump very fast at low rpm and the oil is hot, but at higher rpms the relief valve keeps the pressure from going too high.

If you have 55 psi total oil pressure with both pumps at say 5000 rpm then no more oil will "go to the top" through the lifters and pushrods. The lifters don't know what pump is making the pressure.

This is why I don't run the high pressure spring since I don't need anymore oil going to the top end.

HTMtrSprt

A standard volume and pressure pump is more than adequate for virtually ALL LS1's. Proper clearancing though, is very important to the longevity of the engine (and when in doubt, go with more). The likely cause of your problem however is a hard launching car with a stock oil pan. The factory pickup location on these pans is the FRONT of the sump.... hardly the right place to be when all the oil runs to the back on a hard launch. Either you overfill the pan OR, you do what we do with a hard launching car..... modify the pan and pickup to get oil from the BACK of the sump. I build a lot of NHRA stock elim. motors and I do this to every one of them. Since I've never had an oiling related failure on one of these motors ( shifting at 7500 and trapping at 8000), I would have to say it works.

Jimmy P

iTrader: (177)

I am no expert, but sounds like the tolerances weren't right, and has nothing to do with the Melling pump. If that was the case, then everyone that has a Melling high volume pump and took their 3-speed car on the highway would need a rebuild each time?

fox16

iTrader: (-2)

a 5 min pull damn bro that must have been along road cause it takes me about 11 seconds to get to 120ish so if u do the math u would be hauling sum ***

Black01M6SS

iTrader: (3)

My guess is the road is about 12 miles long. Do the math and see if that comes close.

socmguy

iTrader: (18)

I think you're right. Though the drive may not have put the nail in the coffin. That last trip down the strip was enough to fry that bottom end.

fastGBcamaro

iTrader: (10)

Just got everything fixed and fired the car up on Thursday. I put about 30 miles on the rebuilt engine and am just about to go change the oil. The car runs great, but havent quite beat on it yet. I plan on putting the 3.73 gears in this weekend. I can't wait to get it to the track and see how it will do.

edcmat-l1

iTrader: (10)

Mains are oiled before rods. If it ran low on oil, or "pumped the pan dry" it should have spun more rod bearings than mains.
My guess is the mains were too tight, and after it got good and hot, they tightened up even further.

StevieZ

iTrader: (3)

I'm glad someone said this!