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Engine break in - any conclusive evidence?
So...
I've been reading up on engine break in and was wondering if anyone had some evidence. It seems that everyone has theories but not many dyno results, teardowns, or before/after compression numbers to confirm those theories. From the FAQ thread: Method #1 (from Mazda manual) - First 600 miles: Drive at varying speeds road and engine speeds; avoid full throttle, rapid acceleration or kick-down of transmission. Do not use special “break-in” oils. Method #2 (from Racing Beat) - For the first 1000 miles (1609km) do not accelerate under full throttle, and do not exceed 4000 RPM. - For miles 1000-2000 (3218km), expand the RPM upwards - but do not accelerate at full throttle. - Over 2000 miles (3218km), full throttle and high RPM is acceptable. Method #3 (Mazda manual + Japanese Rotary Mechanic’s Procedure) - 0-600 miles (965.4km) Follow the Manual, but keep it under 4000 RPM - 600-800 miles (1287.2km) Open it up a bit, vary accelerations and speed RPM < 5000 - 800-1000 miles Drive the car, enjoy it but still keep RPM < 6000 - 1000-1250 miles (2011km) Drive it as it's power curve intended it to be RPM < 7000 - 1250-1500 miles (2413.5km) Test the car frequently from RPM 6000-9000 in every gear Method #4: The engine should first be run at idle for 30-45 minutes. During this time, be sure to check for leaks and keep an eye on the gauges. Ideally, for the first 100 miles (depending on use of new or used bearings), avoid operating the engine above 5000 rpm or under heavy load. From 100-200 miles, gradually increase rpm, but never allow the engine to approach red line. Beyond 200 miles we recommend only short bursts of power approaching red line for 100 miles. At this point, change the break-in engine oil. The engine break-in period is now complete. Method #5: http://www.mazdaspeeddevelopment.com...g/techtips.pdf, p22. On road after warm up with new bearings: RPM MILES 5000 60 6000 60 7000 60 8000 60 8500 60 On road after warm up with old bearings: RPM MILES 6000 25 7000 25 8000 25 8500 25 Method #6: Here's how to properly break in a new engine. The very first time it is started let it warm up to normal opperating temperatures. You don't want to floor it immediately after it starts up as some oil has flowed off of the bearings and you need time for it to recirculate. Once at warm up temperature, drive hard! take it up through the gears at full throttle several times. Drive the engine hard for about the first 20 miles. Then change the oil and the filter. Yes after only 20 miles. The hard break in on the seals (not the bearings) has left some metal shavings in the system that need to be removed. Only mineral based oils should be used during breakin. Drive the rest of the first 500 miles as you normally would the car. At 500 miles change the oil and filter again. At this point you can switch to synthetics if you want to. I run them in my rotaries. I don't care what the manual says. Results say more than words in a book. Over half of your break in was done in the first 20 miles and the other half was done in the next 500 or so miles. That's it. No need to baby the car around. You'll most likely make less power in the long run this way. This is a very different way of thinking but it works. my break in procedure--i do install my own engines 1- regular 10/40 dino oil first --prime the oil system before starting----start get the engine up to normal operating temps for about 20 minutes. turn it off and change the oil and filter. PUT A MAGNET SOMEWHERE IN THE OIL SYSTEM--on the filter--the oil pan drainage plug--it doesnt matter 2- after first oil change--drive the car normally varying loads and rpm ( no redlining but do go past 6 k)for 100 miles--change oil and filter again. still us dino oil. watch the engine and oil temps. Do not let the engine coolant get past 220F.Do not let the engine get to 210-215F on a regular basis. Do not let oil get pass 230F during this time. 3- drive for 1K miles 75% load, 75% rpm ( from redline) 4- Change the oil again--now use synthetic--you need a 40w oil or one that has the hths number of a 40 wgt such as redlines 5w/30. 5- dont let engine set and idle for "warm up" in the mornings--crank it-idle for just a few seconds--then drive in a normal manner. This style of break in has given me the best results. after 5K miles or so--you can redline it --full load it etc. use this info if you think it can help. Also, it makes sense to me to change the oil within the first 50 miles and a few more times before standard 3k intervals and using any synthetic. Thanks |
Everyone has their theories.
About the only (mostly) consistent thing seems to be to take it easy on the motor the first few hundred miles and don't use synthetic for the break in. Heck... a lot of race motors really get NO break in since they can't be driven on the street. I wouldn't really worry about it too much in general myself. But what do I know. |
A properly built race engine gets broken in on an engine dyno using the Mazdaspeed method or someting similar. That doesn't mean there are people who race who don't just throw it in and go. It just means they can't afford to do it right and/or are willing to foolishly take their chances. A pro builder verifies their work before sending it off for race use.
http://www.drummondengines.com/about.htm . |
I've read most of these and I still don't know what procedure to use on my reman engine... I'll be getting my car back next Monday.
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See method #5 above, a thousand miles is rather silly on a rotary engine
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Originally Posted by TeamRX8
(Post 4307072)
See method #5 above, a thousand miles is rather silly on a rotary engine
My real concern here - I have doubts the car will stay cool running 3rd gear at 7-8K RPM for 60 miles. Has anyone tried the Mazdaspeed method on the street? Also, any idea what load (throttle position) is used for this method? |
I agree that method does sound best, but it would also be quite hard to actually perform without a dyno, and cooling the car could be an issue.
I mean I suppose it could be done on a highway, and option two is for used bearings so it's not too bad since its only a 100 miles. But like cWatson, I'm wondering could you just get on a highway and leave it on cruise control going at 6k rpm for 25 miles? Aren't you supposed to vary the speed and throttle for a new engine or is it for new bearings? |
the run-it-hard method has been proven to make rings seat and seal better on piston engines but I haven't seen conclusive testing on rotaries
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In the thread that Rotarygod talks about the run it hard method, he lists several reasons why it would work for a rotary as well. It's his personal opinion, but then again he has years of experience of working on rotary engines and even provided info to the author that wrote a rotary engine book not too long ago. It would awesome if there was more data supporting rotary engine break in procedures.
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the problem with the different break-in methods is that different parts of the engines require different break in procedures.
example, running it hard may be beneficial to get the combustion seals to seat and seal better providing better compression and power but it may be detrimentral for the new thrust bearings and stationary gear surfaces, the oil pump assembly, chain and sproket, etc etc... |
Originally Posted by Emery_
(Post 4307164)
I agree that method does sound best, but it would also be quite hard to actually perform without a dyno, and cooling the car could be an issue.
I mean I suppose it could be done on a highway, and option two is for used bearings so it's not too bad since its only a 100 miles. But like cWatson, I'm wondering could you just get on a highway and leave it on cruise control going at 6k rpm for 25 miles? Aren't you supposed to vary the speed and throttle for a new engine or is it for new bearings? 5000 RPM for 60 miles means: quickly accelerate (50-75% load) through the gears until 5000 RPM @ reasonable speed limit. Then I'm doing 4000-5500 pulls using different throttle positions and some coasting as well. My idea is to do a give the engine a complete load/rpm picture. I'll be removing the cat for the 7000+ RPM range and changing the oil immediately after completing the break in. I'll do my best to get before compression numbers, but will definitely have numbers after the break in. |
All I know Im taking my brake in like a baby first steps slowly,, My mechanic has been braking in engines the slow way,, dont want to read witch one of the ones you have listed but, freaquent oil changes in the first 30 100 200 345 500 miles then slowly keep incresing rpms and less oil changes, He has been building rotories for years and has some street cars and mainly drag cars and he uses the same meathods , He rebuilt an rx8 engines years ago not sure how many miles on car but car is still running great with no issues at all.
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My last race engine I built we dropped it in on Tuesday, started it and loaded it on the trailer on Wednesday, was on the track at full throttle on Thursday. Engine made awesome compression and was fine until Mosport, and will soon know why it was removed from car when I do the teardown (within the next couple of days) and will report findings.
The Mazda break in method assumes new OEM apex seals and new OEM bearings. The bearings must more or less burnish themselves in and the OEM apex seals require some time to "seat" and develop full compression. Aftermarket seals, such as the GOOPY seals, the carbon matrix, and ceramic seals DO NOT follow this break in procedure. Ever. The single most consistent issues I have seen with Renny failures are side seals and O-ring failure, as well as a couple of cracked castings. I am coming to believe that if replacing side seals you should order the OEM ones specified on the rotor and install them WITHOUT "sizing" them. Unlike older rotaries (which absolutely negates all the "I have 30 years building rotaries" BS) the Renny side seals have exhaust gas flow over them, which causes them to expand/contract at different rates than any other side seal previously used. The side seal springs are also a factor, becoming overheated, weakening, and then failing almost predictably. |
^ Yep glad you mention side seals I ordered OEM and by #letter and your right about that but I don't comment to much here since I'm a noob or so called lol and my post count is not over a 1000 so I look like a rookie lol but yep this guy has some GOOD INFO ^ use it
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