redbaron442455

hello olds gurus,

I am helping my father get his 70 cutlass convertible going again (350 4bl) and due to my busy work schedule and my fathers impatience, he took his 350 to a local engine re-builder that his car buddies recommended, I made him a laundry list of things to do to the engine, two of them being open up the oil drain holes in the heads and use oil restricted push rods along with a high volume oil pump, so i got the call the motor is back home, and i was told the original push rods were "fine" and they couldn't open up the drain holes because its "too close to water" but they did put in the high volume pump.

what do you think my chances are of the oil pan getting sucked dry? should I put a standard oil pump instead of the high volume?
it has the stock oil pan, mild cam, #6 heads with big block valves, 9.5 CR and will be entirely street driven but im sure he will like to show off more often then necessary haha

any input is appreciated,

joe_padavano

First, how will the car be used? If this is anything other than a drag car, the stock oiling system is fine. Olds built tens of millions of these 350 motors. They did not have a massive oiling failure problem.
Second, you will NEVER suck the oil pan dry. That is yet another urban myth about Oldsmobiles that won't die. (Hint, the motors in Supremes aren't offset, either).
Third, find a shop that has a clue. Smoothing and opening the drainback holes is both common and a smart thing to do. They are not "too close to water", the shop just didn't want to do the work. Same with the pushrods, though again, with a stock or nearly stock motor, this probably isn't a big concern.
Fourth, don't believe everything you read on the web. Most people have no clue about Olds motors.

Good luck with the car. With the motor that far apart, I hope you replaced the stock timing set with the nylon cam gear.

redbaron442455

thank you for your input,
please correct me if I am wrong but my understanding was the stock oiling system is fine, but when you put a high volume pump your pushing more oil thru the system, and the oil drains in the heads cant drain fast enough, so that's why the drains should be opened up and or restrict oil to the rockers with restricted push rods, doing this prevents the valve covers from filling up with oil, which I have seen happen, mostly in boats, but something i would correct anyway. Also other advantages would be to reduce the drop in oil pressure at hot idle, allows larger bearing clearances, and the use of a lighter weight oil that's all that seems to be on the auto parts shelf nowadays,

the car will not be raced, mostly cruised around to car shows, occasionally burn rubber to show off, just wanting to build a solid long lasting motor.

OLDSter Ralph

1. The thing that would be nice would be replacing the nylon cam gear, assuming that hasn't been done.
2. Your Dad's buddies may know a good rebuilder.
3. The high volume oil pump probably won't scavenge the oil pan completely dry.
3. Your Dad is just driving the car with a motor that has survived "kids", and its NOT a boat.
..........Just my two cents worth

cutlassefi

BillK

This is another very big misconception that I hate seeing. That is only true if the High Volume pump is also a higher pressure pump. You can only pump a certain amount of oil (or any other liquid) through a hole at a certain pressure. If the oil pressure is the same then a high volume pump will not pump a drop more oil through the engine if all of the clearances etc are the same. It is pressure that pushes the oil through the engine, not volume.

Like Joe said, Oldsmobile built millions of these engines and they ran just fine for many many miles. No need to reinvent the wheel.

Inline

I chose bigger oilpan just for the sake of having more oil to dilute between changes, and in theory keeping it better between those.

76olds

I agree with inline, get a bigger oil pan for piece of mind if you feel the need and do oil changes before the viscosity gets too high.

Eric

joe_padavano

And again, for a nearly stock engine, a larger pan is yet another unnecessary expense. Literally TENS OF MILLIONS of Olds 350s were made, and they lived just fine with the stock pan. If you are worried about the oil between changes, you are not changing the oil often enough. Hey, but at least the larger pan will reduce ground clearance and force you to pay for a mini starter. Geeze, this is a nearly stock 350. Don't make unnecessary "improvements" that inflict collateral damage.

Inline

Yes, those wonderful V8's from dinosaur age maybe lasted 100k before total rebuild, same time Europeans made twice the miles. What a great design and victory of craftmanship. They aint so great that they cant be improved. Weird thing that same age european 2 liters had same oil volume than these big V8's. Weird..

joe_padavano

Wow, seriously? Five quarts appears to be the "standard" for most displacements, whether a four cylinder or a V8. Frankly, most newer engines have gone to LESS oil in the pan, primarily to reduce windage losses in the name of efficiency. I'll note that an old racer's trick is to use a 6 qt pan and only put five quarts in it for exactly this reason. I'm not aware of a lot of 1960s vintage Euro motors that go 200K miles without major work. On the other hand, the cast iron pushrod 454 in my Chevy truck has 285K miles on it with no engine work whatsoever. I only replaced the timing chain at 150K as a preventative measure. The rest of the engine is untouched.

And again, I'll restate what you've conveniently missed from my prior posts. For the OP's car that is a near stock 350 in a lightly used Cutlass, there is no need to make these mods. The risk of collateral damage by throwing together unmatched parts is far greater than the potential benefit. Nowhere does it say that the engines can't be improved. What it says is that 1) for the OP's intended use, mods are an unnecessary expense, and 2) mods need to be carefully selected and matched to the application and to each other to achieve benefits. The questions being asked are of the "I read on the interwebs..." type.

BillK

I just did the 307 out of my Wifes Riviera last year. It had 220K miles on it and if the plastic timing gear had not given up it would still be running. The bearings and crankshaft looked good enough to put right back in the way they were if I had wanted to. The cylinder bores had less than .001" wear on them. I bored it anyway because I could Switched it over to a hydraulic roller and I expect it will outlive me. The "old" school engines lasted every bit as long as some of the new ones if they were cared for. No they were not as efficient or small but they would last.

coppercutlass

I ran a 350 with a totally "stock" oiling system and big block pan spun it past 6300 rpm regularly at the track and usually drove well above 3300 RPM. Car ran 12.20's and it was heavily abused before it got sold and went on to live life in another drag car.

redbaron442455

Sorry for the misunderstanding, my question was will I run into problems because the motor was built mostly stock WITH a high volume oil pump, I am concerned that I will run into problems because it has a high volume pump and not the other modifications to accommodate it.

joe_padavano

You have nothing to be concerned about. Run the motor. You'll be fine.

JohnnyBs68S

So, just so I understand, is the only advantage of a "high-volume" oil pump that it will better maintain oil pressure after XXX,000 miles (or when idling) as the bearing clearances increase due to wear compare to a "standard volume" oil pump?

Inline

In short and crude, normal vs high-volume oil pumps difference, given same set oil pressure, is that high-volume simply delivers more oil per revolution of pump-gears. In theory, it reaches set-pressure faster, like in idle it have slight advantage on idling oil-pressure. Reality might not be so different. And if your engine gets really worn, or has really loose clearances, it will keep it on set pressure farther than normal pump due to added volume per revolution of oil-pump. Plus slight parasitic pumping loss vs normal volume pump, again due to added volume you just pump through by-pass back to oilpan.

I dont take any part for suggesting for either one.

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elB

The only time I've ever had actual experience with these engines "sucking the pan dry" is on a circle track race car that goes round and round at 3000-4000RPMs constantly as the pickup can get uncovered if the pan isn't baffled and runs low on oil. Unless your engine is built for this purpose, there's no real reason to use the high voltage oil pump or worry about it and it's one of those hot rodder rumors that hasn't gone away. Personally I'd be more worried that the engine has oil starvation issues from lack of regular checking of the oil level...