Q.
I’ve been redoing my 1941 Chevy pickup for the last 20 years. I have a completely fresh 283 with flat tappet TrickFlow heads and I’m getting ready to fire it. I put it together about 10 years ago and I’m very concerned about wrecking anything during startup. What precautions should I take?
Jeff Wilks
Old Saybrook, CT
A.
While starting a new engine after 10 years isn’t the ideal scenario, it happens a great deal and it can be done without causing any damage—but there are some precautions to take.
We’re going to assume that the engine isn’t equipped with dual (dampers are OK) or extremely high-pressure valvesprings. If so the cam should be broken in with single springs. The other assumption is the engine (particularly the cam and lifters) was assembled with an appropriate assembly lube. If there is any doubt, pull the intake manifold, rocker covers, push rods, and lifters, then coat them and the cam lobes with something like AMSOIL INC.’s assembly lube.
The major concerns when breaking in a new engine is protecting the cam, lifters, and valvetrain along with helping the rings seat against the cylinder walls by allowing “controlled wear” to take place. In simple terms the trick here with conventional honing techniques is to use a lubricant that will be slippery enough to protect the cam and lifters but not so slick that the rings won’t seat properly; that’s why synthetic oil is not normally recommended for break-in. Now, before anyone points out that many new car engines come with synthetic oil that’s because the factory uses a procedure called plateau honing, which allows the rings to seat rapidly.
At one time the additive ZDDP (Zinc Dialkyl Dithiophosphate) was used in engine oil to prevent wear. However, due to emission concerns, the amount of ZDDP in the oil required to meet manufacturer’s warranty requirements has been reduced. That’s not a big deal for engines equipped with roller lifters, but flat tappets and cams are particular vulnerable to excessive wear if the wrong oil is used, particularly during the break-in period. Fortunately there are a number of oils, such as AMSOIL INC.’s break-in oil, that have been formulated expressly to protect those parts on startup and the first few hundred miles. Be aware there are oil additives that contain ZDDP, however additives that are not expressly intended for break-in and can inhibit ring seating at the expense of protecting the cam and lifters.
After filling the engine with break-in oil use a primer to spin the oil pump—you can make one out of an old distributor with the gear removed or buy one for the purpose. Remove the rocker covers and attach an oil pressure gauge to the engine, then spin the primer clockwise with an electric drill until oil pressure builds and oil appears in the rocker arms (you’ll also feel the resistance increase on the drill motor). It’s a good idea to turn the engine over slowly by hand with a breaker bar two revolutions or more during this process.
Once the engine is primed, fill the carburetor either with an electric fuel pump or through the float bowl vent(s) and set the timing so the engine will fire immediately—avoid cranking for a prolonged period. Once the engine fires bring the rpm up to 2,000-2,500; this is necessary to throw enough oil off the crank to lubricate the cam and lifters, their only source of lubrication. Check the timing at this speed and it should be in the 32- to 34-degree range and then run the engine for 20-30 minutes (your cam manufacturer may have specific recommendations). Vary the speed of the engine, keeping it between 2,000 and 3,000 rpm, and it’s always a good idea to put a box fan in front of the radiator to help keep the engine cool, as you don’t want it to overheat.
After the initial break-in period we always change the oil and filter and refill with more break-in oil. Some balk at this because of the expense but we think it’s a small price to pay to get rid of the break-in lube and any other contaminants that might have accumulated during assembly. AMSOIL INC. recommends a maximum of 1,000 miles on break-in oil—we usually suggest 500 miles. At that point it’s safe to go with the engine oil of your choice, however, you should consider a product that’s made especially for flat tappet cams, such as AMSOIL INC.’s Z-Rod.
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