yes I'm sure your convinced its the oil pump!



yes I'm sure your convinced its the oil pump!

Postby grumpyvette » March 23rd, 2015, 9:14 am

one of my neighbors kids is rebuilding a fairly mild 396 BBC, and after he got it assembled and installed in the car (a 1971 chevelle) he started it up after priming the engine with a priming tool that he used to verify that he was getting oil to all the rockers, and after cold setting the valves , and hes got 35 -40 psi of oil pressure at idle with 10w40 oil in the oil pan.
Now I got called over to trouble shoot, as his issue is that as long as the cars engine runs between about 900rpm where it idles and about 1500rpm his oil pressure stays at that 35 -40 psi range, and oil flows from every rocker, it looks like its well set up, yet if he blips the throttle the oil pressure rapidly FALLS as the RPMS increase past 2000rpm!
now he started talking about a new oil pump, and the bearing clearances and several other things like perhaps the oil pump pick-up weld to the oil pump had failed,And one of his friends kept telling him, that old MYTH,that it was the high volume performance oil pump ,sucking the oil pan dry! but after questioning him a bit I was rather convinced I knew what the issue and its cause was as I'd seen similar problems in the past.
the K frame or cross member on a chevelle of that generation fits rather closely under the block,and rather far back restricting the stock oil pan voluum, as does the suspension, and he installed the stock 4-5 quart oil pan,to get clearance, with the melling m77hv oil pump.
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http://www.ecklerschevelle.com/chevelle ... -1977.html
after quite a bit of discussion I convinced him to unbolt the exhaust and motor mounts ,pull the distributor, starter etc,and hook up the engine crane too lift the engine about 4" higher so we could remove the oil pan without removing the engine totally from the car, and found what I thought we would find, the oil pump pick-up was sitting about 1/16"=to-1/8"th inch off the oil pan floor, severely restricting oil flow into the oil pump.
I proved that with a strip of modeling clay and a quick test fit,so now hes looking for a 6-7 quart oil pan with a slightly deeper sump that will work with his existing oil pump and cars frame,suspension etc.

melling oil pumps wrote:That is what a high volume pump will do. Now lets consider what it will not do.

1. it will not replace a rebuild in a worn out engine. It may increase pressure but the engine is still worn out.
2. It will not pump the pan dry. Both solid and hydraulic lifters have metering valves to limit flow of the oil to the top of the engine. If a pan is pumped dry it is because the holes that drain oil back to the pan are very restricted or plugged. If the high volume pump is also high pressure, there will also be a slight increase in flow to the top.
3. it will not wear out the distributor gears. The load on the gear is directly related to the resistance to flow. Oil pressure is the measure or resistance to flow. The 427 fe side oiler uses a pump with the relief valve set at 125 psi and it uses a standard distributor gear. Distributor gear failures are usually caused by a worn gear on a new cam gear and/or worn bearings allowing misalignment.


if any of you guys happen to know who makes that oil pan, for a 1971 BBC and its part number please post the info, yes I could custom weld up an oil pan, but I know he would rather just buy one
IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!!
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Re: yes I'm sure your convinced its the oil pump!

Postby 87vette81big » March 23rd, 2015, 9:28 am

I don't know off hand Grumpy.
If Pontiac I could answer right now.
Your the BBC Expert.
I thought most passenger car BBC oil pans were similar.
The Corvettes with BBC had a different extra 1 quart oil pan sump volume.
Along with 1970-71 LS-6 & LS-5 454 SS CHEVELLES.
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Re: yes I'm sure your convinced its the oil pump!

Postby 87vette81big » March 23rd, 2015, 9:30 am

Weld one up Grumpy.
$100-200 extra for You.
:mrgreen:
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Re: yes I'm sure your convinced its the oil pump!

Postby 87vette81big » March 23rd, 2015, 10:10 am

Milodon #30710 , $140.95 Summit Racing.
5- quart sump like SS 454 Chevelles had stock.
Shows baffled.
I like Milodon pans Grumpy.
Know you prefer Canton. Road race style.
Where I am at its mostly straight line action.
Drag or Top end runs.

Nice affordable Milodon oil pan. Beats china crap.

Better of course made but will cost $$$ &$.
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Re: yes I'm sure your convinced its the oil pump!

Postby grumpyvette » March 23rd, 2015, 11:42 am

http://www.summitracing.com/parts/sum-g ... e/7-4l-454
SUMMIT RACING LIST'S THIS (Oil Pan, Steel, Gold Zinc, 7 qt., Chevy, Big Block)
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I will point out that the bargain priced oil pans tend to be fabricated from much thinner steel, and have fewer features , but thats not always a bad place to start from if your custom fabricating a wet sump oil pan...keep in mind the stock 4-5 quart oil pan was never designed , to be ideal for an engine spinning over about 5500rpm, and it would be smart to measure the sumps ground clearance on your stock oil pan then calculate where a deeper pan would sit before ordering a significantly deeper design
read thru these threads, theres a lot of related info you might use

viewtopic.php?f=54&t=65

viewtopic.php?f=80&t=10516&p=44501&hilit=speed+bumps#p44501

viewtopic.php?f=54&t=1800

viewtopic.php?f=54&t=64

viewtopic.php?f=54&t=52

viewtopic.php?f=54&t=2187

viewtopic.php?f=54&t=120

65chevelle300 wrote:I'll take the Milodon pan any day, they are around 255$ for the 7 qt. version, part # 30950

It's highly advised to use the specific Milodon pick up which is a press fit that also bolts on, part # 18301

Milodon makes good oil pumps as well.



THIS 7 QUART MOROSO OIL PAN GOT GOOD REVIEWS
http://www.summitracing.com/parts/mor-20451

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IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!!
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Re: yes I'm sure your convinced its the oil pump!

Postby mathd » March 23rd, 2015, 11:45 am

7 quart canton oil pan for chevelle 71 454:
http://www.summitracing.com/int/search/ ... 4294706121

8 quart milodon:
http://www.summitracing.com/int/parts/m ... l/chevelle

8 quart moroso(if he dont want to spend 400$ for an oil pan..:
http://www.summitracing.com/int/parts/m ... l/chevelle
Mathieu
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Re: yes I'm sure your convinced its the oil pump!

Postby 87vette81big » March 23rd, 2015, 11:58 am

5 Inches of Ground Clearance ?
Dictates what pan to use.
Rpm peak range ?
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Re: yes I'm sure your convinced its the oil pump!

Postby 87vette81big » March 23rd, 2015, 12:01 pm

Been old in the past best wet sump oil pans for BBC Are 10-12 quart capacity marine oil pans.
Sure won't fit 1970-71 Chevelle.
Maybe C3 Corvette if stock ride height.
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Re: yes I'm sure your convinced its the oil pump!

Postby grumpyvette » March 23rd, 2015, 12:03 pm

thank you gentlemen
I'll pass on the info,and let him decide on the course too take,
and price he wants to pay, while pointing out the rather obvious benefits and options and clearance issues
IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!!
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Re: yes I'm sure your convinced its the oil pump!

Postby mathd » March 23rd, 2015, 3:59 pm

I dont know for the chevelle ground clearance, but with my camaro and 7 quart, the bellhousing and headers are lower that the oil pan. So if something hit the ground, its not going to be the oil pan, if it do hit the oil pan then i have alot more to worry about then just the oil pan loll.
yeah its not a BBC so i dont really know..
But at 400$ for the oil pan if they did not take care of that... On my link some of them show smaller pan depth, so he can measure and select what fit correctly before ordering.
Maby he can go to a 6 quart, to me 5 quart is a little on the low side.
Mathieu
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Re: yes I'm sure your convinced its the oil pump!

Postby 87vette81big » March 23rd, 2015, 6:10 pm

I like the idea of 9-11 quarts in the pan sump.
For a Pontiac V8 it don't exist new.
1963 SD421 Swiss Cheese Catalina had stock 11 quart pans.
Ultra rare today oil pan.
Homemade Ammo can Poncho oil pan 10-11 quart sump pan still on my mind.
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