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Ok, I'm at 320 miles on mine right now.
I don't think there is a black and white breakin.
I think you should go easy to hard slowly not easy for 500 then drop the hammer.
changed oil at 270 and it was black with lots of metal in it so, I know it is wearing in.
I have done a few short 1st n 2nd gear bursts so far.
Heat from unworn parts and a seal "tripping" from that friction is what I see as the danger.
If u have made it far enough to have good compression #'s and not blow it up on a hard run, I'd say it makes no difference in longevity of a motor.
Different people have different sentiments...... i think break-in is good to my rebuild motor. I understood what ErnieT said but i feel more comfortable after i did the break-in too her...... To me, i think rebuild motor alike new brake installed --- break-in..... anyway if you think breakin is comfort to you, go for it....... Once again, i will breakin my rebuild motor for 1500 - 2500 miles, because i feel more assurance on it
the RX-8 manual recommends 600 miles of variable rpm driving but never above 7000 rpm (keep in mind it redlines at 9000 and fuel cut at ~9500) and avoiding wot.
the model airplane OS .30 p-port wankel engine's recommended break in is repeated fuel-rich runs at wot with cool down periods in between.
I know both these engines are N/A so maybe it's different for turbocharged ones...
for my protege5 I did the hard break-in procedure with frequent oil changes (100, 300 and 1500 miles with mineral oil then normal 5000 miles as per the manual but using synthetic). I saw this in http://www.mototuneusa.com/break_in_secrets.htm there are like 6 parts to this and is recommended for new as well as rebuilt engines.
I know this info is for piston engines but I thing it applies to rotaries as well, we're breaking-in the seals and bearings the same as in piston engines
Location: Where there's only two seasons, hot and wet! I love Okinawa
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Originally posted by silver3rdgen Agree w/ Ernie.
Only real reason to break one in is if you replaced the bearings.....and thats if you didn't clearance them.
False. Bearings if new, whether they are clearanced or not have a dull silver color coating on the inside of them. When that coating is worn away, your bearings are then broken in. I had a motor blow up at about 500 km's because of a bent eccentric shaft that wore down the front stationary gear bearing. When we took the motor apart, (previous motor had new rotor bearings) the rotor bearings were NOT broken in after 500 km. From personal experience it normally takes 2000 km to break in all bearings. How do I know? OIL PRESSURE drops...
i don't think any of you can speak on this topic with authority, i talked to rick engman and he said that in reality, 1000miles is nothing....
he runs his motors for 10hrs on an engine dyno with varying/increasing throttle...then disassembles to check the bearings
he said sometimes you have to do it twice to get them fully broken in (and this is after he fully clearances them and then breaks them in on a lathe with a rubbing compound)
200-300miles for new apex/side/combustion seals, 500-1000miles for new bearings
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Originally posted by 93BlackFD 200-300miles for new apex/side/combustion seals, 500-1000miles for new bearings
is what he said, for street driving.....
1000 miles = 1600 km. I normally go to 2000 km to be safe...or the 4th oil change is when I know bearings are broken in. Guess me and Rich have come to the same conclusion.
Think of it this way, is breaking the motor in going to hurt anything?
Next point, run a rebuilt rotary hard(ie high rpm and wot) with new bearings, as Jspecracer7 said the bearing seating surface is new and "sticky", and you exponentially raise the risk of spinning said bearing. Your choice. I always recommend people to run at least 3000Miles on their rebuilt ported motors with minimal boost and no rpm above 5K. That's just me, I know the track record of our local rotary rebuilders and running new engines hard out of the box.
Art
hmmmmm, im not sure if its been covered all ready, but here goes my opinion, generally seals require some time before they actually seal(?) at their optimum level (someone help me out on the terminology :P) and usually that time will depend on the seal, mazda standard seals usually do it quicker then say the apex seals, which can take up to 1.5-2km to run at their utmost efficiency.
besides its not like rebuilding the damn thing is cheap, may as well take the precaution
Ok, the KDR motor popped after 18000 miles/18 months. I'm going on my 3rd motor. What's the consensus? 1000 miles? What's the minimum number of break-in miles to do a dyno tune??
Well, I just got my fresh one (new apex seals, side seals, and all coolant and oil seals.. No bearings, rotors or housings) on the road. It's been warmed to full operating temp for about 45 minutes to an hour.. After the second full warm up I held the RPMS at 3k for a few minutes.
Day one, about 10 miles on the motor: 12psi and 7800rpms. Judge ITO port and a TO4R. If it breaks, it breaks. I'm tired of waiting to drive it. I seriously think the super extended break in period is crazy on a rebuild.. Maybe a full reman its more reasonable. Seems to be holding just fine. I'll be sure to post if it falls apart..
Well, I just got my fresh one (new apex seals, side seals, and all coolant and oil seals.. No bearings, rotors or housings) on the road. It's been warmed to full operating temp for about 45 minutes to an hour.. After the second full warm up I held the RPMS at 3k for a few minutes.
Day one, about 10 miles on the motor: 12psi and 7800rpms. Judge ITO port and a TO4R. If it breaks, it breaks. I'm tired of waiting to drive it. I seriously think the super extended break in period is crazy on a rebuild.. Maybe a full reman its more reasonable. Seems to be holding just fine. I'll be sure to post if it falls apart..
Well, I'm thinking 300 to 500 miles should be plenty of break-in to do a dyno tune on a rebuild. My rebuild will have a new rotor, rotor housing, apex seals, rubber gaskets etc. I dunno. Depends on what my engine builder mandates, I guess. I've heard him say 1000 break-in miles.
I say go 1500 miles with variable throttle no boost. First oil change at 250 miles with dyno oil, second oil change at 500 miles with synthetic, 3rd oil change at 1000 miles and the final oil change at 1500 both with synthetic and then just run synthetic for the rest of the motor life. But that's how I do it, so its retty much however you feel you must break in your motor.
I just got my rebuilt from Rotorsports Racing in Kannapolis, NC. Their break-in instructions were no boost or RPM >4000 for 1000 miles. Change oil at 500. I spent too much for this job not to take their advice. BTW they had my car 8 weeks but I wanted them to do it right and did not need it for daily driver. I must admit it is difficult to not punch it.
FAST. That big port really opens the TO4R up fast. It still doesn't boost till like 3800RPM, but it's friggin instantaneous. BAM! Full boost. I'll have to get some video up soon...
I assume that, almost 20 years after the original post, there has been some new oil technology, many millions of additional rotary miles, new guys in the game, etc etc...
...
So what's the latest advice on breaking in a fully rebuilt motor?
My stock 1999 JDM 265hp 13brew blew late last year, and I had it rebuilt twice earlier this year (don't ask), including a new E-shaft and all bearings, and of course all seals and a street port to go with the EFR 7670.
The builder tuned it to fuel cut at 4,000rpm and very low boost, oil change at 1,000km, followed by a dyno tune after another 2,000km, with redline opened up to OEM after that. So all in all 2 oil changes in the first 3,000km, followed by normal driving.
He uses HKS rotary specific full synthetic oil.
I assume that, almost 20 years after the original post, there has been some new oil technology, many millions of additional rotary miles, new guys in the game, etc etc...
...
So what's the latest advice on breaking in a fully rebuilt motor?
Any thoughts or red flags??
Thanks!
The more things change, the more they remain the same.
I continue to abide by the most authoritative recommendations... Mazda Motorsports break-in standards
A proper and careful break-in period for a newly rebuilt engine is extremely important. The break-in procedures listed on the following page may seem excessive. However, an engine that has been broken in properly will see more power across the engine’s rpm range and longer service life than a comparable engine that has not. If using the old bearings, please note the difference in hours and mileage requirements for the break-in period. When breaking in any engine (race or stock), use a low ash content, mineral-based racing oil (20 w or 30 w). After the break-in period, change to a mineral or synthetic racing oil (30 w or 40 w).
Admittedly, the post break-in oil viscosity recommendations may be a little long in tooth, but the mineral oil specific aspect I think remain correct.
Finally, this isn't too far removed from the above advice from what I consider one of the three greatest 'merican rotary engine builders, Mr Engman.
Last edited by Carlos Iglesias; 11-21-21 at 11:08 AM.
03-24-04, 12:47 AM
