Engine Break In Guide and Opinions

I�ve done a lot or research across this forum plus others on break-in in preparation of breaking in my engine for my 3.8L rebuild thread (about to start it up again any day now). Without finding a definitive guide for our engines, unless you accept the RND guide, I hope to not only learn from you all, but to provide a source of info for others as they face the same process for their engines. Let�s start this post with explaining that I�m going to take the position that engines need to be broken in hard. I don�t want to debate the soft, factory recommended, low rpm, long oil change interval method. I�m looking for some opinions from people that are in the �break-it-in like you�re gonna drive it� approach. I�ve read multiple non-Porsche specific articles on break in, all leaning toward a harder, faster, heavy load approach. I�ve also read LN Engineering�s article on engine break-in and the two supporting articles they reference: http://www.mototuneusa.com/break_in_secrets.htm http://www.aircooled.net/gnrlsite/re...s/engnbrkn.htm I�ve also come across the break-in manual for RND Engines (a collaboration between FSI and LNE). Finally, I listened to a podcast with Jake that touched on break-in. I�ve found some similar info, but a few conflicts and I�m a bit conflicted. What is consistent and agreed upon: 1. Rebuilt engines should be fitted with the following new items: knock sensors, O2 sensors, MAF, AOS and oil fill tubes, oil and coolant fill caps, Genuine Porsche AOS and water pump. The engine must be smoke tested to ensure there are no vacuum leaks that can cause rich operation and damage the engine during break-in. Cooling system should also be vacuum bled. 2. Proper engine oil system priming and break-in is critical. Do not turn over an M96 engine to build oil pressure � excessive cranking will cause rod bearing failure as the oil system will not prime at starter speeds. To prime the engine, start and immediately turn off the engine. Repeat start/stop until the gauge shows at least 2 bar of oil pressure. Once primed, break-in can commence. 3. It is critical to verify fuel trims and AFR as overly rich mixtures during break-in will result in engine damage or failure. 4. Use intermediate oil after using break-in oil. Don�t use full synthetic until after 5,000 miles. 5. You must heat cycle the engine a number of times letting it heat up completely with thermostat open and letting it cool completely to ambient temperature. Where things start to conflict: 1. Initial run time - When not using a dyno to break in, run engine for: a. 10 minutes at 3,000 rpm (from a note I found from C. Navarro) b. 15 minutes at 2,000 rpm (RND engines guide) c. 20 minutes varying between 2,000-3,000 rpm (MAPerformance) d. 20 minutes at 3,000 rpm and then run up to redline to seat rings (Lake Speed Jr.) e. 20 minutes at 2,500 rpm (another interview with Lake Speed Jr.) f. 30 minutes at 1,500 rpm (per the RND instructions) 2. First oil and filter change - Change the oil and filter: a. after that initial run period of 20 � 30 minutes b. or leave it in and change it the first time at around 100 miles and after the first street run. 3. Break In Oil � a. Use break-in oil for i. Up to 500 miles ii. Up to 1,000 miles iii. Up to 1,500 miles 4. First drive � a. RND Engines method: i. Drive the car at a normal pace and avoid heavy acceleration for the first one hour of run time. Pretend the engine hasn�t been replaced- this is a key to success ii. To �seat the rings� of an engine with Nickies� cylinders slowly accelerate in second gear up to 6,000 RPM and then abruptly remove your foot from the throttle and allow the engine to �brake� completely back to idle speed while remaining in second gear. Ensure the engine is at operating temperature (coolant and oil!) before doing this. Repeat 5X. iii. Long sustained downhill grades are great for engine break in. These allow the engine to be placed into gear to �engine brake� the vehicle, again forcing the rings to seat. When descending a long grade (at least 4%isrequired) keep engine RPM at 4,000 and allow the engine to �brake� the vehicle. This is by far the BEST way to catalyze engine break in, from a ring seal perspective. b. MotoMan method (per LNE reference) i. Load the engine by opening the throttle hard in 2nd, 3rd and 4th gear. ii. The best method is to alternate between short bursts of hard acceleration and deceleration. You don't have to go over 65 mph / 104 kph to properly load the rings. iii. For the first 200 miles or so, get out into the country where you can vary the speed more and run it through the gears. c. MAPerformance method: i. Drive no less than 30 miles first time. Head off to a low traffic area, where you can do long pulls at low load followed by engine braking back down to idle. Repeat no more than 50 miles and avoid open throttle and full boost scenarios. ii. After the initial break in period, you'll change your oil and then repeat the process until you've hit the 500 mile mark. After this, your engine will be fully broke-in. d. Jake Raby Rennvision interview: (Note: this is what he does for HIS builds) i. Drives a 106 mile loop up and down a mountain, through flat section with turns, then back up and down the mountain. Drives up hills at a couple gears higher than optimal (�instead of 3rd gear, I�m in 5th with the pedal down�) for low rpm/high load to seal rings. When going down, he�s engine breaking by being in a gear lower than normal. �May accelerate up to 6,000 rpm and then put into next lower gear and hold it there for a few miles until the car slows itself down.� ii. Then he loads in a �break-in� tune into the computer that limits throttle response and RPM to 5,200 for the first 1,500 miles but tells the customer they can drive it as hard as they wish. So � what are your thoughts on Initial Run Time, First Oil and Filter Change, length of Break In Oil, and First Drive approaches?

First post here but just wanted to say thank you for such a comprehensive run-down, and with all the links too. Incredibly useful. I just purchased a 2000 a few months ago but am likely going to have the engine rebuilt within the next 6 months and am anxious about the break-in process. Eager to see how people weigh in and also to hear your reports, Jengah, about how you choose to break-in.

Certainly a topic that will elicit many opinions. The data needed to determine the difference between methods will require keen teardown inspections on hundreds of engines at both initial break-in and after accelerated life testing. I've rebuilt only 3 engines in 30 years. I have no data to share but look forward to the discussion. Maybe the best data to collect is: How did you break-in your engine, How many miles have you run since break-in, and Have you had any engine issues since break-in. From this list, maybe something will shake out.

This seems like an interesting thread. I'm getting my heads back from Hoffman today. Doing the research for when I get to the point of break in. Lots of variations on a theme on this topic. I'm also surprised not more comments on this thread. It seems like to started off so well.

Personally I stick to the motoman routine. The method of x0 minutes at x000 rpm sounds to me like the method to break-in new flat tappet cams. If your rebuild reuses the cams and tappets then I would go straight to the loading of the rings by following motoman's routine as idling irrespective of rpm to safely break-in cams requires so little throttle that the rings won't be pressed against the bore and thus won't seat. Keeping revs up during motoman's routine will keep loading of cam lobe nose low enough too. This is my look at it and based on the (little) experience of breaking-in 3 engines using motoman's method and mineral oil of factory specced viscosity. Replace with the same after 30 miles and again after 100 or so incl filter. Synthetic after that. Only one engine had new (schrick) cams (and they've run in nicely) so ymmv. However I think that most of the responses here will be just that and the professionals have each already stated their recommendation. Thanks for putting them all together in your initial post.

i posted a similar thread (snarky humor warning) https://rennlist.com/forums/997-foru...-it-wrong.html Ended up doing Joe Gibbs break in oil for 500 miles, mix of synth and dino for a thousand miles, then full synth Joe Gibbs. That was a few years back and the car has been great ever since.

For oil, ask your machinist. LN specifies the following: Driven Break-in oil should only be used up to 400-500 initial miles but can be changed out earlier. The switch would then be to a HR5 Conventional oil for the next 3000-5000 miles upon which you can swap to the DT40.

I did my first oil change at 100 miles, second is going to be at 1500. The oil wasn't black but it was not fresh anymore... First fill was a dino oil, first change is dino, then on to synthetic I did a 30-40 minute drive every day, not going over 5200. First day hilly country roads, Second day same. 3rd day a 40 min cruise on a state highway over a mountain range and back. I was basically just following FSI 's instructions, and a loose imitation Jakes description of their "test runs" The car got better every day.. Cheers.