Big Block Chevy Engine No Oil Pressure and Other Questions
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Here are some answers to common questions about Chevy Big Block engines, mainly about oil and oil pressure. Here are the questions:
‘I’ve a big block chevy engine no oil pressure. What is wrong?’
‘What weight of oil to use in a big block engine?’
‘Is the Camaro big block oil pan stock OK for track work?’
Are dry oil sumps for chevy big blocks worth having?
Question: ‘I’ve a big block chevy engine no oil pressure. What is wrong?‘
Well, if your engine seems to have no oil pressure,the first thing to do is NOT to run it, except for testing, because you could damage the engine seriously. Then, make sure there is oil in the sump, and that the drain plug has not come off. If the drain plug is intact, and the dipstick shows some oil is present, then you need to look elsewhere.
First, you want to check whether the gauge and sender are working. However, if your engine makes a clattering sound, which it did not used to make, then don’t bother, you have no oil pressure.
Senders are reliable and cheap, so get a new one or borrow one you know is working from a friend, connect it up and see what happens. You don’t have to worry about engine oil pouring out, so long as you do it with the engine not running. If that doesn’t work, you need to get the gauge checked. Or, you can fit a new gauge.
If you still have no oil pressure, then the chances are that your main or big end bearings are worn, and the clearance is so great that the oil just spurts out. If this is the case, the engine will clatter, especially on the over-run. That is a sign that the engine needs a bottom end overhaul – quite an expensive job, as the crankpins and main bearings need regrinding, and you need oversize bearings. It might be cheaper and better to get new parts for your Chevy big block engine.
Question: ‘What weight of oil to use in a big block engine?‘
Big block engines are pretty reliable so the answer to ‘What weight of oil to use in a big block engine?’ is any good quality oil depending on the temperature where you live. For example, you want thinner oil in Alaska because it gets so cold in winter than ion California. In northern States of the USA, you want thinner oil, such as 10W30 in winter, and thicker oil, such as 15W40 in summer. In States like California, 15W40 should be fine all the time. However, if you have a really old engine, and it uses some oil, I would recommend 20W50 except in very cold winters.
Question: ‘Is the Camaro big block oil pan stock OK for track work?’
The Camaor big block oil pan stock version is not intended for racing, but is generally fine for most fast road work, including sustained use on twisty roads. However, if you are going racing I would not recommend the Camaro big block oil pan stock version.
These days, the tires produce so much cornering power that the oil can surge away from the pick-up, and that can result in a damaged engine. You can get an oil pan intended for high-speed cornering and drag racing, without the expense of a dry sump.
Or you can modify an existing steel oil pan – but you need to be careful you do not distort it, so it is best to braze it. To improve the sump, you add some baffles around the pick-up, to keep the oil there. However, you also need to leave space for the oil to come back from the rest of the sump under the baffles.
Question: ‘Are dry oil sumps for chevy big blocks worth having?‘
Whether dry oil sumps for chevy big blocks are worth having depends on the use. For road use, they are not. For racing or drag racing they are. The easiest way to do it is to add a reservoir which can hold about 6-8 pints of oil with an electric pump inside.
The pump is then taken through a flexible high-pressure tube to the side of the oil pan, where it delivers the oil to a a rigid pipe fitted in the sump, which ends right by the pick-up. An extra pump is used to pump surplus oil from the well of the sump to the reservoir. You will also want an oil cooler in the system. You also need to baffle the pick-up well.
This is the easiest way to use dry oil sumps for chevy big blocks.
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Posted on: Sunday, March 8, 2009 at 6:40 am 
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Can anyone tell me why the early mk1v big blocks had a groove machined in the back journal of the camshaft?
October 26th, 2009 at 6:09 amHi Ben,
Grooves in journals are usually there to allow the oil to get right around the journal. It will be connected with lubrication for sure.
October 27th, 2009 at 2:20 am