Used car buyers receive protection under some laws. These rules act as a safeguard from purchasing cars with specific problems.
The most common issues covered by these laws include a bent frame, damaged transmission, or cracked engine block.
You might also have a project vehicle that you’re working on that requires a new block for some reason.
If you are sold a defective vehicle, you can often take the dealer to court to get your money back plus any damages suffered. It might be an option to use SBC #3970010 to fix the problem and come out ahead.
You can also use the block for different upgrades or repairs with project cars.
SBC #3970010: Is This a Good Block?
The #3970010 casting block is the most common four-inch bore block ever made. It comes from a 350 and likely has a forged steel crank, but the heads are terrible for performance improvements. The design uses 1.72-inch intake valves, measuring out to around 8.2:1 when appropriately installed.
About seven million engine blocks with the #3970010 stamp were created in the 1970s. Some of them were made in Mexico, with the labeling in raised letters next to the casting number so that there is no confusion about its creation.
Many people get the number on the block confused with the serial number. This information provides data about the production date and application of the block.
You’ll see three information pieces when you look at the back of the block.
- In the 3970010 number, the “010” portion indicates the product is made with a high-nickel, low-ear iron alloy.
- You’ll see a heads number for additional reference.
- On the pad are the production date and intended application. If you see a V before the number, it indicates the product was made in Flint, MI.
In the late 1960s, General Motors decided that the 3970010 and other codes for their tracking system weren’t working as intended. They decided to abandon the concept, but they didn’t get rid of the numbers.
You can’t go by what the indicators say in the “70” portion of the blocks. Anything with that figure or higher could have varying metallurgy.
When you get past the casting number, an example of what you might see is a sequence like V0225CDJ. In that situation, the V stands for Flint. The first number, “02,” represents the month, while “25” is the day it was made. The final three letters represent the year. CJD would equal 1971.
What Is an Engine Block?
The engine block contains the cylinders and other significant components of the bottom part of the motor. When this component functions correctly, it lets the pistons move up and down inside the cylinders.
That activity starts turning the crankshaft, which is responsible for creating movement from the wheels.
An engine block is designed to last for the lifetime of the vehicle. Unfortunately, something can go wrong and cause cracks to start forming in this part.
◼️ How to Know If Your Engine Block is Good
Most engine blocks crack because of contaminants that made their way into the metal during the manufacturing process. If you encounter this situation, you’ll see leaks come from that opening, including oil or coolant.
You can see antifreeze mixing with oil in that situation or the reverse, creating an odor that produces smoke from the exhaust.
Other signs and symptoms of a possible cracked engine block include the following indicators.
- Low engine compression ratings are causing reduced performance.
- Visible smoke is coming from the engine.
- Ongoing overheating problems occur because of leaking antifreeze.
- Frozen coolant is in the radiator.
- More smoke comes from the exhaust than normal.
The good news is that some cracked engine blocks can get repaired. When that option isn’t a possibility, you’ll need to acquire a replacement.
That option can come from a rebuilt, new, or salvage engine. When you have SBC #3970010 available, you have a decent replacement that can work in numerous vehicle types.
◼️ What Causes an Engine Block to Crack?
Although several issues can cause engine blocks to crack, the primary problem involves having too much heat in the area. That means a coolant problem exists, whether it is from a leak, evaporation, freezing, or other malfunctions.
The overhead parts of the engine start expanding while the colder areas won’t move. That results in uneven expansion and contraction that leads to cracking from the stress.
Another problem that can cause cracks to form in the engine block is the failure of the water pump. Since it stops fluids from flowing through the system as designed, severe overheating problems can result.
Casting failures during the injection molding process are also known to create cracking problems in some situations. When thinner points exist in the metal,
With SBC #3970010, you’ll have an excellent reputation of success to rely upon if you invest in that part.
How to Source an Engine Block When You Need It
Production builders want engine cores that match specific vehicle applications. In most cases, they desire the tinware because the valve covers, oil pan, and time cover are typically make and model specific to the year.
That fact changes how core suppliers stock their inventory.
The days of the large production runs with the 350 small blocks and SBC #3970010 are long over. Let’s face it – the 350 Chevy hasn’t been in production since the 1970s. When you look for an original engine that hasn’t been rebuilt at least once (and probably twice), the task can feel impossible.
That doesn’t mean there isn’t demand out there for a Chevy V8, but it isn’t at the same scale it was two or three decades ago.
Some Midwestern core suppliers aren’t even stocking the 350 blocks because of this issue, and the same problem exists for other automakers. SBC #3970010 was a prevalent part because of its versatility in its era, but we’re in a new time.
When scrap iron prices were high a few years ago, many people scrapped their engines instead of salvaging them. That’s why there is a shortage of rebuildable cores and functional engine blocks.
On top of that issue, the late model engines were given thin-wall castings, which causes them to wear out faster than their older counterparts. You might find two or three at the average scrapyard that is worth fixing.
The lifter bores tend to go bad with the new engine blocks, along with the mains and the cams.
There Can Be 50 Engine Variations Each Year
When the 3970010 blocks were getting produced, you only had to source about fifty different engines. There was a lot of interchange between the makes and models, making it convenient for repairs and restoration.
Today’s engine blocks tell a different story. There are easily 50 different engine variations released each year. It’s an entirely new dynamic for the core suppliers who try to stay current with their inventories.
It is now crucial to take digital images of everything as a supplier, identifying engine numbers based on VIN or vehicle application. Even inventory digitalization is needed to ensure fast communication and service implementation. With the cost of freight what it is today, it’s too expensive to ship the wrong parts and take a return.
Even if your vehicle is only 4-6 years old, it can be almost impossible to source engine parts. Some of them are still covered by the OEM powertrain warranty, which helps drivers manage their expenses. Late-model engines also last longer with fuel injection used instead of dilution, which means an accident that totaled the vehicle is about the only chance one has to get the parts they need.
Tools Needed to Complete an Engine Rebuild
If you want to build engines correctly, you must have the correct tools. Whether that means you need to work with SBC #3970010 or another part, you’ll want these items available in your shop or garage.
1. Piston Ring Squaring Tool
This tool lets you accurately measure the ring end gap. Before it was available, builders would use inverted pistons to set the rings in the bore before measuring down from the block deck to the ring for squaring. With this investment, you’ll get a device that pushes the ring a half-inch down consistently.
2. Crank Sockets
When working with engines, you’ll find that it doesn’t take long to be during it over with the camshaft. A simple socket is sometimes the easiest way to get the job done, especially if it accepts a half-inch breaker bar or ratchet. Most high-performance engines use this resource today.
3. Engine Brushes
An old saying says that cleanliness is next to godliness. You don’t need to be religious to understand the benefits of keeping everything clean when working on an engine block. When you have a complete set available, you can clean out the oil galleries and other tough spots to reach.
4. Harmonic Damper Installer
When you need to install a harmonic damper, the work can be one of the biggest headaches of the entire engine building process. The part must get pressed into place with an installation tool. It screws into the threaded nose of the crank that gently squeezes it onto the snout without worrying about damaging either item.
5. Degree Wheel
You must degree a camshaft and check the valvetrain clearances when working on an engine. Three things are crucial to consider when shopping for this part: its size, adjustability, and visibility. The best designs offer a two-piece bushing arrangement that lets you adjust without moving the device.
6. Dial Bore Gauge
Every engine builder should have this tool. It’s not as expensive as you might think it is, and the item makes it easy to determine the size, taper, or straightness of your bores and bearings. Even the economy models are accurate to within 0.0005 inches. You won’t ever want to use a snap gauge after getting this tool!
Is SBC #3970010 a Good Engine Block?
The truth is that parts aren’t made today in the same way they were 40 years ago. Although we have high-performance solutions now, the time and cost to replace an engine block are enormous.
That’s why it makes sense to have an older vehicle – or at least one that lets you use an older block!
If I could choose one engine block out of them all, SBC #3970010 would be at or near the top of the list. It is a fantastic part if you need it to take care of your needs.
