Ask Andy!

Clients questions, Tips, and a lot of information...

Got a question?


Can you tell me what weight oil to used to break in a rebuilt 1600cc engine? Also, should the oil be detergent or non-detergent? Thanks

Hi Charles,

This is a very common question that gets asked frequently. There are many opinions on this subject and the answers will vary depending on who you ask. For the sake of everyone that will read this post, I’d like to start from the beginning and talk about the assembly of the motor first.

Before starting the engine build, it is a must to have a clean work environment. From there, make sure that all of the engine components are cleaned before each part is assembled. In California, the EPA places many limitations on the cleaning products that we access to buy. Certain solvents and other cleaners are almost impossible to purchase. Most shops that use to have solvent cleaning tanks are now just soapy water! If you must use soap and water to pre-clean the engine components, blow them dry with compressed air and then have a space heater ready to heat the parts to make sure each one is completely dry. This will eliminate any rust and corrosion from forming.

When you start the assembly process you will want to apply a coat of pre-lube to the wear surfaces, such as the bearing surfaces and crank journals. Years ago an old engine builder shared one of his tricks with me and I have passed it on many times in the over the decades since. His advise was to use a good quality 30wt oil and STP oil additive. This is the only time that I recommend using STP. STP is very sticky and slippery, and adding STP to the 30wt oil makes it extra tacky helping it to cling to the parts. I have built a motor that was stored for a year and then I pulled it apart. The bearings were still lubed and ready to go! I was sold! Mix equal parts of oil and STP and apply it liberally to the bearing surfaces and crank journals.

For pistons and rings, I use automatic transmission fluid (ATF). ATF is a lubricant with detergent packages required in automatic transmission. Using ATF on the rings during the assembly will help the rings seat quickly and keep them lubricated during initial break-in. ATF also burns off cleanly and doesn’t gum up in the rings!

Lastly, I’ll address the specific pre-lube for the camshaft and lifters. To me, this is the most important part for the longevity of the motor! In an Air Cooled VW motor the cam lobes and lifters make metal-to-metal contact under a constant load provided by the valve springs. Assembly-lube, break in procedure and oil choice will dictate the life of your motor. So. Cal. Imports also owns Engle Racing Cams and we have a lot of knowledge when it comes to this topic. It is important to use a specific camshaft break-in lube here (not just regular oil or grease). We suggest the Red Line assembly-lube. We believe in this product so much, we give it away with every Engle camshaft that we sell. It costs us $600.00 for every 5 gallons of Red Line assembly-lube that we buy, but we bear this expense because we want our customers to the best possible results when installing an Engle camshaft. So. Cal. Imports does offer Red Line assembly-lube in small .75 oz packets (part #80326) and 4 oz containers (part #80312) at very affordable prices!

Use the Red Line assembly-lube on the camshaft lobes and on the sides and face of the lifters. This product is oil soluble, so it will dissolve and mix with the engine oil during the break-in period.

OK, so now that the motor is assembled with all the correct pre-lubricants, I would like to talk about which oils to use. For break in purpose, it’s not as important to what weight oil you use, but rather what is in the oil.  In the past eight or so years, most all of the major oil companies have done some major changes to the oil that we can readily purchase commercially. With all of the major automotive manufactures switching to roller camshafts and lifters, the need for chemical wear inhibitor packages that guarded against metal to metal rubbing have been since removed from typical automotive oil. The chemical that has been removed oil is mainly the zinc additive. The zinc additive was found to be plugging up the newer catalytic converters (a very expensive part to replace!). The problem is with the change in the oil is that all of the engines that ran flat tappet camshafts still needed to have that zinc additive for proper lubrication and wear performance. This change was largely unannounced to general public leaving us to fend for ourselves! All of us that grew up with Pennzoil, Castrol, Valvoline and many other big brand name oils, just know that these oils are no longer suitable to run by themselves in our Air Cooled VW engines!! Whichever oil you do chose make sure that it is a high detergent oil. So what are we to do?  We have two options:

1) Find an oil that has the Zinc lube package still in the oil.  So. Cal. Imports offers the Kendall GT 1 Liquid Titanium 20/50 oil with zinc (part #000651). This is now my #1 choice for all my cars with flat tappet camshafts!

– or –

2) Purchase an oil additive that you can use with your favorite oil to add back in the zinc that the manufacture has removed. Once again we go back to the Red Line Oil company. So. Cal. Imports offers an oil additive that does the trick, (part #81403). This bottle will add the correct zinc to 12 quarts of oil. With a stock VW 1600 only requiring 3 quarts of oil, this bottle will cover 4 oil changes!  This ends up being a great bargain for the added safety that you get.

Now we are ready for the initial starting of the engine. The most important item here is to not allow the motor to idle for the first 15 minutes of run time. When you run a motor with a flat tappet camshaft, the lifters must spin or turn in the lifter bores.  When a camshaft is ground, there is a taper to the lobe and the lifter face is not flat, it has a small special shaped dome to it. The combination of the two parts cause the lifter to spin in the lifter bore. In essence, by doing this, the camshaft is not truly rubbing against the lifter, the lifter is really turning against the lobe of the camshaft.  In keeping the engine running at 1500-2000 RPM’s for the first 15 minutes you are starting the correct wear pattern that will “teach” the lifter to spin! Failure to do this will cause premature camshaft lobe wear and shorten the life of your engine.

I do the break in with three steps, so as not to overheat the motor and/or miss potential problems. With the engine ready to run, I will start the motor and IMMEDIATELY bring the engine RPM’s up to 1500-2000. I do not over rev or “rap” the motor. Consistency is the key! If I see any oil or fuel leaks, or if I hear any unusual noises, I will shut the motor off, not allowing it to idle. I do this first step for 5 minutes. After the shut off, I will allow the motor to cool down. With the motor cooled down I will recheck of the motor, restart and repeat the exact procedure again. At the end of this 5 minute session, I shut off the motor, once again not allowing the motor to idle. After the second cool down, I fire up the motor for the last 5 minute break-in run, still keeping it 1500-2000 RPM. At the end of this time of the  final break-in period, I bring the RPM’s down to an idle. Do a final setting of the ignition timing. Lastly, I allow the engine to completely cool down to the ambient temperature, then readjust the valves and change the oil. Don’t forget to add back in the zinc additive if your oil doesn’t already have it!

I know this was a long reply but I trust that you will see the value in what has been stated.

Thanks  Andy



Need help?

discover our excellent