Crate Engine vs Rebuilt: Is Rebuilding an Engine Worth It?

When I started writing this article, my intention was to compare buying and installing a crate engine versus rebuilding our existing engine. See, we’ve been on a little adventure the last few months. My husband George’s little ’31 5-window Ford coupe’s engine was in its final days. It was blowing smoke from the lake pipe headers, we couldn’t keep the carburetor tuned, the air cleaner was always filled with oil, and we did some rough math on the mileage it held with just our family builds over the last twenty years. Our little engine was worn out and signaling an SOS.

We’re not high-end builders who are going to tear it up at the drag strip. And without an Engine Masters tv show budget and no clear need to prove anything on a dyno, we started thinking about either rebuilding our little worn-out small block Chevy 350 or replacing it with a ready-to-install crate engine. So, crate engine vs rebuild.

Spoiler alert: We rebuilt our engine.

During the 2008 Power Tour and a torrential downpour, unbeknownst to us water got into a cylinder through the air cleaner and carburetor and we hydro-locked it the next morning. Within a week, we had replaced an egg-shaped #6 piston and a bent rod and we were back to cruising the streets. Just a year later, I bought and installed a crate engine in my coupe, and my original engine sat in the shop for a few years.

It was then installed into my brother's 1965 Chevy truck. Eventually, he swapped in a 5.3 Vortec LS engine from a 1999 Chevy Silverado truck with a 6-speed manual transmission from a 2010 Chevy Camaro SS. This was the first of many LS swaps he’s completed.

Next, it was installed in my husband’s 1931 Model A Ford Coupe. George was on a budget and an even tighter timeline. And it worked great for three years. He drove it to our wedding and honeymoon, to Texas for rally races, out to Colorado for the Hot Rod Hill Climb, to our beloved Vintage Torque Fest in Dubuque, Iowa, and on numerous trips to Kansas City. He’s been everywhere and the little engine was mostly reliable.

But during the summer of 2022, the engine seemed bogged down. And we couldn’t keep a clean air cleaner. Blow by oil wreaked havoc. And our carb wouldn’t stay tuned. And it all made us wonder if it was time for a change. But what sort of change? Would it be better to rebuild or replace the engine?

Crate engines are often the more affordable option over a purpose-built engine, even though the initial sticker price might make you think otherwise. Some still think a rebuild is cheaper than a crate engine. But is it? That’s what we’re here to find out.

BluePrint Engines is a trusted source for high-performance crate motors. With their many “levels of dress” we could choose as complete of a crate motor as we wanted. A short block is a sub-assembly that includes the block, crankshaft, connecting rods, and pistons with piston rings. A long block also includes the heads, camshaft, and valve gear. Long blocks may also include the balancer, timing cover, oil pan and valve covers, depending on the configuration. You can learn more in this article about What’s in a BluePrint Crate Engine.

There are tons of crate engines to choose from. We offer a huge selection of crate engines. The crate we narrowed down to was the BluePrint BP38318CT1 S/B Chevy 383 Longblock Crate Engine (Speedway Motors part number 227-BP38318CT1). With it we’d get 436 horsepower and 443 ft. lbs. of torque, all for $5,199. A nice upgrade from our tired small block Chevy 350. This specific crate engine would come already dyno tested with documentation. For a Model A coupe that weighs under 2,700 pounds, it would have more than enough get up and go to keep a smile under George’s sa-weet mustache.

Since it was in stock, we could order it, then roll up to the Speedway Motors retail store and they’d help us load a literal wooden crate into the back of our truck. It would be installed as fast as our hot little hands could work. Plus, this specific BluePrint crate engine would have a 30 month or 50,000 mile limited warranty. The warranty requires that you properly break-in your new crate engine, so if you choose this route, make sure you do so, or you could void your warranty.

I learned how to properly break-in a new crate engine during our Bucket Beauties T-Bucket build.

The Speedway Motors Museum of American Speed displays a Flathead Ford V-8 85 block in its original factory crate. It can be found on the 2nd floor in the Flathead Gallery between the Model A/B collection and the Flathead displays. The use of crate engines took off after World War II, just like much of the automotive aftermarket. Advances in manufacturing allowed for more consistency within the mass production of parts and assemblies. Before that, items like engines were mostly hand-built or hand-fitted.

In our case, refreshing an engine could be made more complicated than a crate replacement. If we rebuilt the engine, we decided we’d want a bigger cam. And we’d have to look at the heads to make sure they were okay. If we had to replace everything but the block, at what point is it still the same engine? Our sentimental foolish minds were reeling. Either way, in our best “well, this is happening moment,” we took the old engine out of the coupe.

The thing I didn’t realize was all that would be involved in a rebuild. We learned a ton during this project and my goal now is to tell you every little thing so you can be prepared for your engine rebuild. I kept a list.

We described to Joe what we thought we needed, but also wanted his help to make good decisions regarding the rebuild. We wanted a 383 from this worn-out 350. We thought it was a 4-bolt main (you can tell by the four bolts on the center three caps… four bolts hold on one cap.) We’d like to supply the parts and I wanted to paint it at some point.

When George was removing the pistons, one of the rings fell off in his hands. This confirmed our suspicions with all the oil blow-by in the air cleaner. Blow-by is caused by bad rings. The engine is building compression and the compression isn’t holding in the cylinder like it should. That compression is going past the rings and pistons and into the oil pan. It needs to get out somewhere and it’s a straight shot into the air cleaner from the breather of the PCV valve. Joe would help us sort out any other issues we might find.

He’d put the short block together for us so he could handle the clearances. Later, he decided to help us determine the push rod lengths as well.

#6 was already honed a ton more than the other cylinders and showed some wear. It had worn differently than the rest of the cylinders. This harkens back to my hydro-lock adventures in 2008 when I hurt a piston and bent the rod.

The assembly we chose was Speedway Motors' forged 383 stroker rotating assembly with flat top pistons. It includes forged aluminum pistons, I-Beam rods, a forged steel crankshaft and the main and rod bearings.

Joe encouraged us to buy flat top pistons. They have more compression than the dished version. He described for us the smog engines back in the day… they moved from flat top pistons to dished style to save money and gas but had no power. He also mentioned that we would need to run good gas with this flat top style, or the engine might ping a bit.

He also wanted us to get forged I-beam rods because they’d be more like a stock rod. They’re strong enough for a street car. The H-beam rods are for the guys going racing. An engine builder must grind more out of the block to make the H-beam rods clear.

As for the crank, he thought a forged steel crankshaft was the best. They’re expensive, but cast cranks tend to be softer.

This set has just been balanced by the machine shop at Speedway Motors. You can see a number at the top of the piston. He will mount the pistons into our engine during his rebuild process. More info on this Speedway Motors labor option is below.

When buying a rotating assembly such as this from Speedway Motors, you have the option of having our experts in the machine shop balance the rotating assembly before it ships to you. Simply add the machine shop labor to your order and they’ll handle the rest. The balancing is done with a state of the art “Hines” balancer by an expert engine machinist.

With this service, the machine shop balances the crank to the specific pistons and rods found in the reciprocating assembly we ordered. The manufacturer balanced the rods and pistons to a generic crank spec during production. Joe explained that manufacturing these days is precise enough that they’re all the same size to within a gram or so. But, having the Speedway Motors machine shop internally balance our assembly with our specific crank, and by using the true weights, makes the whole assembly run smoother. If we had brought him an assembly that wasn’t balanced, he would have had to send it out to get it done. He has found that some kits say they are balanced, but they’re not actually balanced to the crankshaft, only that the rods are all the same weight, and all the pistons are all the same weight. He warned to carefully read the descriptions when it comes to pre-balanced parts.

Joe suggested we get new head bolts, just because the engine has been in so many cars before us. We don’t know how often they’ve been off and every time you torque them, they stretch a little bit. So, it would be best to use new ones in our build, especially since we’re doing all this work to it. We chose Speedway Motors' small block Chevy cylinder head bolt set.

We needed a full gasket set, and the Fel-Pro small block Chevy performance gasket set was the perfect option. Joe will need the 2-part rear main seal from this set. The rest of the gasket set will be used at home when George puts together the top half of his rebuilt engine.

For a rebuild like this project, we should buy roller cams (or roller lifters) referred to as retrofit. The rollers must be linked together in pairs. Some newer SBC blocks come with roller cams, so they already have a system with clips and bolt-on items to keep the lifters in place. This older engine doesn’t have such provisions, so they created retrofit rollers to help. We found what we needed in Comp Cams' Extreme Energy hydraulic roller cam kit which includes a roller camshaft, link-bar roller lifters, and a new timing chain set. He mentioned that flat tappet cams don’t last like they used to, and roller tappets were the way to go.

Engines from this era have heads with very thin castings. It’s common to see issues and be required to replace them. Especially if the engine was prone to overheating, seeing temperatures from 280 to 300 degrees. We were the fifth car to use this engine, so we have no idea if the engine had overheated in its previous life. Joe wouldn’t know what we were in for until he had the heads off and cleaned.

If we needed to buy new heads, we might’ve chosen an aluminum version, like the Edelbrock 5089 E-Street SBC Aluminum Cylinder Heads which are lightweight and modern. But luckily for us, the original cast heads were in decent shape. I’m glad, I think. I struggled with the idea of having to replace the heads; for one, the cost. A good set of aluminum heads for an SBC 383 would be around $1,975. But also, if we replaced the heads, the rotating assembly, and the cam, then all we have left is the original block; then do we still have the same engine? Were we being sentimental saps?

Anyhoo, Joe cleaned them up, ground the valves and seats and resurfaced them. He was pleased with what he called “vintage” heads. He figured we’d have 9:1 compression.

Joe thought we should update our springs and retainers. We want a stock spring diameter and a retainer that will handle a max lift of .550-inch. We chose a single spring with damper and 7-degree retainers for the project. They look like a stock spring, they’re a little bit bigger on the outside, but they’re a lot stronger.

Also called keepers, we need to replace the valve locks. If we have hardened retainers, we should also have hardened (or heat treated) keepers. Joe pointed us to these heat treated valve locks to match our new retainers.

When we install a roller cam, the roller lifters are longer, so you need a shorter pushrod. You must have the heads on to determine the push rod lengths. Joe figured out what we needed and supplied the push rods for us.

Joe will replace all the core plugs during his rebuild. And he plans to tap the little oil pressure plug holes to allow use of screw-in plugs. Some race cars run super high oil pressure and the oil gallery plugs can pop out, so he taps them during a rebuild to prevent this.

Joe suggested we get a high-volume/high-pressure oil pump with a steel driveshaft and sleeve. He asked George to grab his old oil pump with the pickup tube and bring it in. Joe will take the pickup tube from the old pump and install it on the new oil pump and check installed height with our oil pan.

We replaced the carburetor with an Edelbrock 1913 AVS2 Series with electric choke. It cost us $475. Not really something we planned on, but it happened. And we had the pesky starter rebuilt by a local shop for around $90. Hopefully, I won’t need to hot wire the coupe anymore. I won’t include these two costs in our final total. Plus, we replaced the old spark plugs with eight shiny new AC Delco R44T Conventional Spark plugs.

Our rebuild, which consisted of turning our SBC 350 into a 383, cost us $6,544. A cost difference of $1,345. If we had needed to replace the heads, we would have added another $1,975 to the tally, for a total of $8,520. That would have been more expensive than a crate by $3,320. Being able to use our old heads saved us quite a bit of money.

I honestly didn’t keep track of costs during the entire project. I just knew there was always a part or parts to pick up from the Speedway Motors retail store that needed to be run over to Joe’s shop. At an age where our time is truly valuable, the crate option would have saved us time. But we also wouldn’t have learned as much about the engine. I’m weird but I find value in that.

Our good friend and neighbor Dave helped us time the engine. The old small block Chevy 350 was maybe making 260 to 270 horsepower. Dave shook his head and smiled at George. “Do you know what you did? You’re not going to be ready for it when you first start it.”

Mercy me, it sounded great. And the smile under that mustache. It was all worthwhile.