10 Things You Should Know About Threaded Fasteners
December 13, 2011 in
Even if you’re an expert, it’s always a good idea to review the basics. Here, the essentials of selecting and installing threaded fasteners are covered.
Do you know how to measure bolts? Are stainless steel fasteners the best choice for your build? What lubricants should you use with your nuts and bolts?
Some of us builders know these answers as surely as we know our own names, while others are still learning fastener basics. Regardless of your level of expertise, this fastener primer will provide you with some practical information you can use in your shop today.
1. Bolt Diameter
Bolt (or stud) diameter commonly refers to the “nominal” thread diameter. For instance, a 3⁄8-inch bolt shank should measure 3⁄8 inches (0.3750 inches) in diameter. Remember, bolt diameter refers to the thread or shank diameter, and this size has nothing to do with the size of the wrench required to service the bolt or nut. If you hear someone refer to major and minor diameters, here’s the explanation: major diameter refers to the diameter of the thread crest (the largest outside diameter of the thread) and minor diameter refers to the diameter of the root (the deepest part of the thread).
2. Bolt Length
For most styles of bolts/screws, the published length of a bolt refers to the length of the shank/threads from the underside of the bolt head to the tip of the shank. This applies to styles such as hex-head bolts, 12-point bolts, socket-head cap screws and button-head screws. However, a flat-top screw (flat on the top and chamfered under the head) is always measured at its overall length.
Tags: Fasteners, Mike Mavrigian, Tech Tips
HRR Tech Editor Mike Mavrigian Shares Progress on Retro LS Build
December 7, 2011 in
The latest installment in Precision Engine's LS 5.3L "retro build" covers installation of the hydraulic roller lifters, cylinder heads, pushrods and rocker arms, completing the valvetrain.
HRR Tech Editor Mike Mavrigian recently posted the fourth part in his series on a retro LS engine build. In this installment, which can be read on the Precision Engine website, Mavrigian details the installation of the Chevy-orange engine’s cylinder heads and rocker arms.
“While there’s nothing to complain about with the original casting number 862 aluminum heads, making them flow much better was a simple task,” Mavrigian wrote. “Total Engine Airflow, well-known for their development of LS cylinder heads, already had a CNC program for reworking the intake and exhaust ports to elevate intake runner volume from the original 200cc to 220 cc; and exhaust ports from the original 70cc to 78cc. ”
Tags: LS Engines, Mike Mavrigian, Precision Engine
HRR Tech Editor Mike Mavrigian Continues Work on Retro LS Engine Build
September 27, 2011 in
HRR Tech Editor Mike Mavrigian has completed another step in his Retro LS Engine build. As he wrote in a past update, his goal with this engine build is to create an LS engine that produces around 400 horsepower and has a retro appearance, and do it all on a tight budget.
“Basically, we’re taking a 5.3L (cid) LS engine, and overboring to a final 327 cid, making a new 327 Chevy that takes advantage of current technology, while stepping back in time to achieve a decidedly old-school appearance,” Mavrigian wrote.
In his first step, Mavrigian worked on the engine block. (You can read about the upgrades he made to the block here.) For his next step, Mavrigian showed how to upgrade the rocker arm trunions to ensure they would be durable enough for use in a performance vehicle.
“In the process of building any LS engine, if you plan to use OE rocker arms (whether reusing originals or using new OE rockers), you should be aware of the critical need to perform an upgrade to the rocker arms,” Mavrigian said. “Specifically, the OE trunions and trunion bearings should be replaced with an aftermarket upgrade kit.”
Tags: Birchwood Automotive Group, Engine Builders, Engines, LS Engines, Mike Mavrigian, Precision Engine
HRR Tech Editor Mike Mavrigian Begins Work on Pontiac 455 Engine Build
August 30, 2011 in
Mike Mavrigian, tech editor for Hotrod & Restoration, recently began his latest engine build—a bored and stroked Pontiac 455 engine at his Creston, Ohio-based shop, Birchwood Automotive Group.
“The direction of this build is to start with an OEM Pontiac 455 block, bore and stroke to 501 CID, and build an approximately 600-horsepower street performer,” Mavrigian wrote on his Precision Engine website. “The target audience [is] the street/strip muscle car and/or street rodder application.”
Tags: Birchwood Automotive Group, Engine Builders, Engines, Mike Mavrigian, Precision Engine
HRR Tech Editor Mike Mavrigian Begins Affordable Retro LS Engine Build
August 3, 2011 in
HRR Tech Editor Mike Mavrigian has started a new engine build that will be documented in detail on HRR’s sister site, PrecisionEngineTech.com.
Mavrigian will be building a carbureted 327-cid LS engine that features custom touches reminiscent of an early 1960s small-block Chevy. He’ll be doing the engine build on a strict budget.
“The goal of this build is to create an LS engine that produces around 400 horsepower, on a tight budget, and with a decidedly ‘retro’ appearance,” Mavrigian said on PrecisionEngineTech.com. “Basically, we’re taking a 5.3L (cid) LS engine, and overboring to a final 327 cid, making a new 327 Chevy that takes advantage of current technology, while stepping back in time to achieve a decidedly old-school appearance.”
Instead of running fuel injection, Mavrigian will be using a four-barrel carburetor.
“The block is painted good ‘ol Chevy orange, with a few additional appearance touches that take you back to the old classic glory days of the small-block Chevy,” he said on the site.
Tags: Engine Building, Engines, LS Engines, Mike Mavrigian, Precision Engine
Editor’s Corner: Reviewing Snap-on’s New Tech Angle Wrench
May 23, 2011 in
HRR Tech Editor Mike Mavrigian recently put Snap-on Tools’ new Tech Angle Wrench to the test. The wrench includes a protective case and is available in several versions, including ¼- 3/8- and ½-inch drives. The digital torque wrench is capable of operating in several modes, including ft./lbs., in./lbs., Nm and angle of rotation. Below is his review of Snap-on’s Test Angle Wrench Model No. ATECH3FR250A, which features a ½-inch drive. To read his complete review and see photos, click here.
Anyone who has serviced engines (or even certain driveline and chassis components) from the early 1990s until the present is aware that many OEM threaded fastener tightening requirements call for a combination of torque-plus-angle specifications as opposed to a torque-only spec. The common applications for this procedure include cylinder head fasteners, main cap fasteners and connecting rod bolts.
Tags: Editors Corner, Engine Building, Engines, Mike Mavrigian, New Products, Shop Tools & Equipment, Snap-on, Tool Reviews
How to Select the Correct Radiator
May 23, 2011 in
This downflow radiator from Saldana has horizontal tanks and tubes running vertically.
Controlling a liquid-cooled engine’s operating temperature is critical to both an engine’s longevity and its ability to perform. The radiator is aptly named, since it allows heated engine coolant to circulate to this external component and “radiate” heat to the atmosphere. A radiator is simply a heat-transfer device.
Without it (if the water pumped was plumbed in a “closed loop,” simply moving coolant within the captive block and heads), there would be no means by which the elevated coolant temperature could release, other than migrating through the block and head material.
The engine would operate in a savage cycle, with liquid coolant quickly becoming hotter until something had to give. The engine will begin to knock/ping as the combination of excess heat and combustion pressure exceeds the limit of the fuel’s octane. Continued detonation beats up rod bearings and can eventually burn holes through the piston domes.
Tags: Cylinder Heads, Mike Mavrigian, Oil, Radiators & Fans, Tech Tips
HRR Tech Editor Mike Mavrigian Announces Next Engine Build Project
January 18, 2011 in
Last November, Mike Mavrigian, HRR’s tech editor, asked Hotrod & Restoration readers, in addition to his Precision Engine readers, to offer suggestions as to what type of engine he should build next. The response he received was overwhelming, with readers and Facebook fans suggesting everything from Ford Y-blocks to Buick Nailheads to 347 Ford strokers.
“It was actually somewhat surprising (and good news as well) that interest in older, classic engine platforms remains strong,” Mavrigian wrote in a recent blog post on http://www.precisionenginetech.com/.
Due to the many requests for a nostalgia engine build project, Mavrigian has decided to build a “vintage” Pontiac 455, which he said is one of the current nostalgia-favorites for both street rodders and drag racers.
Tags: Custom Engines, Engine Builders, Engines, Mike Mavrigian, Nostalgia Engines, Precision Engine, Project Builds
Editor’s Corner: Choosing the Right Alternator for a Ford Flathead Engine
December 21, 2010 in
HRR Tech Editor Mike Mavrigian has been detailing the build of a Flathead since summer on his Precision Engine website. We’ve been keeping up with the build, and have updated readers when Mavrigian completes another part of the engine. (To read the entire build series, click here.
In this installment, Mavrigian explains his process for choosing an alternator and belt drive for his Flathead project. Due to size limitations, Mavrigian had to choose which alternator he used very carefully.
Tags: Alternators, Birchwood Automotive Group, Engine Building, Ford Flatheads, Mike Mavrigian, Precision Engine, Starters & Alternators
Editor’s Corner: Help Me Choose What Engine to Build Next!
November 18, 2010 in
By Mike Mavrigian
Now that the Flathead build is nearing the end, I need to decide what the next project should involve. That’s where I could use your help. If you have any suggestions regarding what the next engine project build should be, I urge you to contact me with your ideas.
The projects that I’ve executed have all been extremely well-received by our readers and the readers of the Precision Engine website. (To read the entire Ford Flathead build series click here.)
I’m thinking of a high-horsepower Ford 4.6 modular build, a nutty big-block Caddy build, among other thoughts. Your suggestions would be more than welcome.
Tags: Editors Corner, Engine Building, Engines, Ford Flatheads, Mike Mavrigian, Precision Engine