What makes great engine builders great engine builders? Sometimes it’s inborn talent. Most of the time it is decades of raw experience and the lessons learned from both success and failure. Great engine builders apply what they’ve learned over a lifetime practicing their craft.
The best, seasoned engine builders employ techniques that work time and time again, which is what makes them some of the best around. We’re going to share some of their protocols with you in hopes you can apply it to your engine-building regimen.
Gregg Jacobson of PHD Speedcenter, an experienced engine and race car builder in Southern California, stresses that being a successful engine builder is not only about experience, but always being willing to think outside the box. Do you want to be just an engine assembler or do you want to be an engine architect and builder? That’s what this article is about.
Absorb what you’re about to read and see how you can apply some of these engine-building tips to your project. CHP
Gregg Jacobson of PHD Speedcenter in Bakersfield, California, suggests checking all corner bores for true top center—not just one bore. It is always good to check all eight bores to ascertain consistency, time permitting. Most builders check just one bore. Gregg suggests checking at least four.
We don’t give enough thought to freeze plugs, also known as “Welsh” plugs. Gregg Jacobson suggests using brass or stainless steel freeze plugs for corrosion protection. Never use steel. Use the wider freeze plug shown here along with Permatex’s The Right Stuff sealer around the perimeter for better sealing.
The lifter bores should be honed during the machining process for greater oil control and stability, Gregg tells us. A good crosshatch pattern holds oil around the lifter.
Blueprint a new oil pump by checking clearances. You also want to check the relief valve and spring for freedom of movement. End clearances can be checked with a thickness gauge and a straightedge. They can also be checked with a depth micrometer. Use an ARP pump shaft and pack the pump cavity with engine assembly lube for a good startup.
Unless you’re performing a concours restoration it is preferable to go with cylinder head studs, such as these from ARP, instead of bolts for better clamping force, especially if you’re running a lot of compression or with boost.
Ryan Peart of JGM Performance Engineering stresses always degreeing the camshaft, whether it came from a buddy or from a manufacturer. Cam degreeing ascertains cam specifications you can keep in your notes and it eliminates any doubt. Most of the time a manufacturer’s cam card and what you learn cam degreeing are close. There will always be some variation between the card and your camshaft.
Although this is an old saw, enthusiasts and engine builders tend to miss this one. Every engine build should include hardened exhaust valve seats and stainless valves for use with today’s harsh unleaded fuels, which have been commonplace since the 1980s.
Checking all clearances is a must for any engine build. Here, we’re checking crankshaft endplay. Clearancing must include connecting rod side clearances; main and rod bearing clearances; camshaft endplay; crankshaft counterweight to piston, block, and oil pump clearance. It is so easy to miss the more obscure clearances, such as piston-to-counterweight at bottom-dead-center.
JGM’s Ryan Peart suggests priming the oiling system when you’re ready to fire. With an oil pan full of 30-weight break-in oil, it’s a good idea to spin the pump and get the galleys and moving parts oiled up for a wet startup. This saves new bearings and other moving parts.
Burbank Speed & Machine, in the heart of Burbank, California, strongly suggests checking ring endgaps even if you have pre-gapped piston rings. Trust ... but verify.
Whether you’re reconditioning existing rods or have a new set, Gregg Jacobson suggests fitting them with ARP bolts for durability.
Save an engine block by sleeving excessively worn cylinder bores. You can sleeve one or sleeve them all. If you have a numbers-matching block, vehicle collectability and resale value are critical so have the block sleeved by a qualified machine shop such as Burbank Speed & Machine. The cost is typically $100-$150 per bore, as of press time.
Mast Motorsports in east Texas stresses using a tack rag in your wipedown of parts. Most rebuilders use shop towels, which can leave lint all over critical moving parts. If you take a tack rag coated with automatic transmission fluid and do a cylinder wall wipedown, you’ll be amazed at how much dirt and debris winds up on the tack rag because automatic transmission fluid is a detergent. It is an excellent non-aqueous cleaner.
Check the oil pan to oil pickup clearance before installing the oil pan. If the pan clears the pump pickup without the gasket, it is certain it will clear with the gasket installed. Measure the pump and pickup as shown, then measure the pan depth.
Because Mast Motorsports builds so many engines each year, it has engine building down to a science. Each block is deburred and destressed as shown to eliminate high spots that can cause stress cracking. Cooling and oil passages are deburred to improve flow and reduce turbulence.
It is surprising how many machine shops don’t use torque plates during the cylinder honing process. A torque plate, when properly mounted and torqued, simulates cylinder head installation to get the cylinder bores dimensionally where they will be with the cylinder heads installed. This gets you a true hone and a bore where it should be with the cylinder head installed and torqued for optimum ring seating.
Too many of us are guilty of using too much sealer to where it compresses out for a sloppy appearance. Be conservative with the use of sealer. All you need between the gaskets and engine is a thin film. Here at the intake manifold block rails, you need only a thin bead depending upon the gap between the manifold and block. As the sealer cures, it expands and closes up the gap.
Stud the main caps for added strength. Studded main caps offer greater clamping power. This LS with four main studs is bulletproof.
There’s a lot of debate about valve adjustment with hydraulic lifters. The rule of thumb with hydraulic lifters is turning the adjustment down snug with the lifter at the heel of the lobe, then 1/8-1/4-turn for racers or 1/2-turn for the street. Then tighten the polylock. Mark each rocker arm with a felt-tip marker as they are adjusted. Do a quick run-through and check the adjustment again.
An alternative to hardened exhaust valve seats is stainless steel valves on vintage Chevy small-blocks and big-blocks. Get a multiangle valve job and drop the stainless valves into place. This eliminates the high cost of the installation of hardened valve seats.
Photos: Jim Smart