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Ultimate Guide to Building a Reliable 425 Horsepower Rock-Crawling Engine

Mighty Mouse chevy 383 stroker engine buildMighty Mouse, Part 5 of 5

“On this build, I did make one mistake, and I was extremely lucky…”

It’s a wrap – our final installment of our 5-part tech article outlining what it will take for you to build your own engine. Part 1 covered our build plans, engine prep and machining. Part 2 showed you how to build the long block. Part 3 detailed the top end engine build, and Part 4 showed you our results from an engine dyno and a chassis dyno. You might call this segment “The Verdict”, where we will talk to the results of our ambitious project.

Building an engine on your own can be accomplished and there is a tremendous amount of pride to be had when doing so. You’ll need some specialized tools to do the job, but most can be rented at an auto-parts store. It will also take a lot of research to source all of the right parts and ensure they are matched. To simplify this task, you can call a company like Holley directly and have them help you select all of the right parts to suit your needs.

In the end, it will be more expensive to build your own engine, and a lot more work than purchasing a crate motor, but you will not have that same level of pride, excitement and gratification of building an engine yourself, with all of the parts that you want.

Be prepared to set aside a week or more to accomplish this. The engine build itself goes rather quickly, but if you need special parts, tools or need to visit the machine shop, it will add a few days to your build time.

Engine Components, Cost & Findings

GMPP Crate Engine 383 strokerGMPP Engine Block and Serpentine System
The GMPP 383 Stroker Block (Part # 88962516) required very little machining. In fact, these performance blocks don’t require any at all for your garden variety engine build. Our machine shop (Schmidt’s Automotive) took very little out of our block. We do recommend that a block be true-decked and honed at least. We had our block true-decked, honed, hot tanked, magnafluxed and had the cylinder walls checked for consistent thickness. We also had Schmidt’s Automotive install our cam bearings. The GMPP stoker block will cost about $1,250 at time of publishing. As noted in Part 4, if you run a double-roller timing chain, you will need to relief-grind the face of the block to clear it.

The GMPP Serpentine Accessory Drive System (part # Part # 12497697) is the same drive system that comes on the early 1990’s GMC and Chevy trucks. It’s incredibly functional and parts are readily available, but it isn’t exactly a head-turner – think; function over form. The instructions that come with the set are considerably lacking and appear to be a photocopy of a photocopy (maybe several times over), which means the pictures are nearly indiscernible and portions of the text were missing. The kit itself is of very high quality, but we recommend that you find someone with a similar year truck and look at it and take lots of pictures. Pay close attention to the bolts they use on the truck, as the instructions in this area are quite limited. This kit will set you back about $750 at time of publishing.


Holley fuel injection heads distributorHolley Fuel Injection System, Aluminum Heads and Billet Distributor
The Holley billet distributor (part # Part#: 890-101) is, for all intents and purposes, a standard late-model GM HEI distributor with a billet body and some refinements and improvements made to it. This is a bullet-proof setup that delivers a very hot spark, very reliably and will cost about $360 at time of publishing.

The Holley Aluminum 202 heads (Part #: 300-552-1) are made from high-quality aluminum and feature 20 degree valve angles. The intake runner volume is 184 cc’s and the combustion chamber volume is 68 cc’s. The intake valve measures 2.02” and the exhaust measures 1.60” – all standard fair for a Chevy small block hot-rod motor. The Holley heads are very well constructed and come pre-assembled. They will cost about $1,300 at time of publishing.

The Holley Stealth Ram Fuel Injection System (Part #: 91504201) is a fairly complex, infinitely tunable multi-point fuel injection system that works well for a variety of engines with a variety of configurations and power outputs. However, initial setup and fine tuning requires a laptop and at least a few days of work. You will also need to know a lot about closed and open-loop fuel injection (it’s far more complex than most people realize). While the software system is very detailed and the instructions are too, there are literally hundreds, if not thousands, of variables that can be adjusted. We struggled for several days and got our engine running OK at best. We ultimately took it to a professional to set it up properly. In the end, the Holley Stealth Ram fuel injection functions flawlessly and turns a LOT of heads when I open the hood of the Land Cruiser. The Holley Stealth Ram fuel injection system costs about $2,420 at time of publishing.


Lunati rotating assembly camLunati Rotating Assembly
The Lunati Chevy SB 383 Stroker Rotating Assembly (Part # EA015-383-3) is, well, top shelf. While there are certainly other quality engine parts builders out there, many professional racers and engine builders rely on Lunati for the finest components with the highest levels of quality – we do too. The rotating assembly kit (crank, cam, lifters, rockers, etc.) is a fully balanced set and provides the perfect levels of engine efficiency, horsepower, torque and reliability. The kit builds an engine with approximately 11.1:1 compression, a bore and stroke of 4.030” and 3.750” respectively with a rod length of 5.7”. If you demand the very best, look no further than Lunati for your engine components. This kit will set you back about $2, 360.00 at time of publishing.

Lunati Voodoo Cam Kit
The Lunati Cam Kit (part # 60102LK) comes with a Lunati Voodoo cam and lifter set. This kit is a mid-level performance street cam with excellent drivability good for 400+ horsepower and up to 5,800 RPM’s. It works well with stock type exhaust manifolds and dual plane intake with mild 4 bbl carb, or center dump exhaust with fuel injection. This is an awesome 4X4 performance cam. Advertised Duration (Int/Exh): 262/268, Duration @ .050 (Int/Exh): 219/227, Gross Valve Lift (Int/Exh): .468/.489 and LSA/ICL: 112/108. This kit will set you back about $200.00 at time of publishing.

PSC Power Steering Kit with Remote Reservoir
The PSC kit comes with a high-performance pump and external reservoir. PSC is known for their high-quality, high-performance steering components and we have used them for years. This kit is a must for vehicles running a hydraulic assist or full hydraulic steering setup. It will provide years of trouble-free service in your 4-wheel drive and will cost you about $300 at time of publishing.


Chevy 383 stroker buildAs with any engine build or major project, there are miscellaneous costs. Including our trip to the machine shop, we racked up another $550 in tool rentals / purchases, gasket kits, assembly lube and various other parts, bolts and goodies.

Total Cost: $9,500
After doing some research, a comparably built crate engine will cost you roughly the same amount of money. It is certainly more expensive than your garden variety 400 HP crate engine, but they will not have the same top-shelf components within. Our engine has the finest, highest quality components on the market and is built to handle anything that we can throw at it. A crate engine would have been an easier task, but I was looking forward to a winter-time project to sink my teeth into. And, I was able to spend some quality time with my wife and my son, teaching them how engines work and how to assemble them – a priceless experience for certain.


Engine Highlights:

  • GM Performance Parts 383 Stroker Block, 1-piece rear main seal, 4-bolt main – part # 88962516
  • GM Performance Parts Serpentine Accessory Drive System w/out A/C – part # 12497697
  • Lunati fully balanced rotating assembly
  • Lunati “SledghammerSledgehammer” Forged steel stroker crank
  • Lunati “Voodoo” cam, roller rockers, push rods, double-roller timing chain and lifter set
  • Holley Stealth Ram multi-port fuel injection system – Part #: 91603211
  • Holley aluminum 2.02 heads – Part #: 300-552-1
  • Holley billet aluminum high-performance distributor
  • Pro-Tru aluminum flat-top pistons
  • High Performance engine bearings
  • MSD Ignition 8.5 mm super-conductor plug wires

Mighty Mouse chevy 383 stroker engine buildEngine Statistics:

  • Compression: 10.2:1 (acceptable for pump gas, recommend high-octane)
  • Horsepower @ Crank: 433 HP
  • Torque @ Crank: 476 lb/ft
  • Horsepower @ Wheels: 311 HP
  • Torque @ Wheels: 336 lb/ft


Lessons Learned

Cloyes double-roller timing chainAs with any large project, I always try and adhere to a rule I call the “5 P’s”. Proper Planning Prevents Poor Performance – and this rule has served me well for most of my life. I’ve built my share of engines over the last 20 years, engines whose power ranged from a scant 185 horsepower to just over 500 horsepower, and knock on wood, I’ve never had a fatal mistake or a catastrophic failure. Sure, there have been more than a few fireballs belching from the carburetor from time to time due to crossed sparkplug wires.

On this build, I did make one mistake, and I was extremely lucky. I installed a Cloyes double-roller timing chain onto our GM Performance Parts 383 stroker block. All went well during the first firing and the engine ran smooth. Upon my first oil change, I noticed metal shavings in my oil – a lot more than is usually present after a motor breaks in – not good. The engine was destined for an unscheduled removal and teardown. After a few days of disassembly, the culprit revealed itself – The GMPP stroker block does not have the clearance for a double-roller timing gear, and it needs to be clearance-ground prior to installation. I tore down the entire engine and took it back to the machine shop for inspection – The crank, cam and all other components were perfectly fine. I paid the extra money for a new timing chain set and a thorough cleaning and honing though.


Special Thanks

ATK Performance Engines
Mighty Mouse chevy 383 stroker engine buildThe engine building experts at ATK really came through for us in a big way. Over my career, I’ve met dozens (if not dozens of dozens) of engine builders, but the good folks at ATK are top-shelf. Their facilities are amazing, their staff super-knowledgeable and their work product is amazing. For us, the experts at ATK did some needed engine work for us, tuned the entire Holley computer system and ran our engine on the dyno. ATK also has a division that sells crate engines so be sure to give them a call.

The Horsepower House
The folks at the horsepower house really know their stuff. Their chassis dyno was used extensively not only to help us tune our Holley fuel injection system with “on-the-road” tweaks, but they also helped diagnose and dial in a few items for us too.

Steve Schmidt’s
Whether you are in need of engine machine shop work, or having an expert build a 1,000+ horsepower engine, Steve Schmidt is the guy to know. Their state-of-the-art facilities offer everything from machining to flow-testing and dyno testing. 

About Rick Webster

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