Old Slow Coach

Planning on running 26 lbs boost on a fresh, 3mm, race-ported 13 Brew. How many miles should one put on the motor before attempting to tune at this level of boost? Thanks!

OWHAT

i would say 1000 miles driven low in the revs with next to no boost, then slowly increase revs and boost over the next 1500miles,,

i would clock a 1000miles before tuning for this boost level

BLitzed33

Heat cycle it a couple times and just let her rip, I had no break in and she is still fine and I have about 5K of 25+ lbs boost hard driving. I changed the oil @500 miles using regular oil, then switched to Amsoil 20W50 series 2000 full synthetic oil, changed it again @1000 miles and have been great. I run amsoil premix as I do not have a oil metering pump anymore. Good luck

Old Slow Coach

I've heard that the more miles you can get on it, the longer it will last. I've even heard if you can be patient enough to put 3,000 miles on it, then you can beat the **** out of the motor for long time. However, there should be a concensus amongst the group about some minimum point of diminishing returns. I suspect that point is closer to 1,500 miles than it is to either 3,000 or "Heat cycle it a couple times" and RIP.

BLitzed33

It wont hurt anything to break it in for 1000 miles for sure, but as far as the motor lasting, I believe its all in how much power you want out of it, your driving habits, and the tuning...tuning is key along with the proper fuel and common sense, and maintenance. My motor has stood up to alot of abuse, to the point of it boost spiking to 35+ lbs one time, and detonating and blowing the ceramic out of one of my spark plugs because I lost fuel pressure due to a clogged fuel filter, and by a miracle, it is still running fine. On the first occasion, i was running C16 and water injection, and still had plenty of fuel. On the second occassion, I was still running C16, but lean.

cewrx7r1

iTrader: (2)

From the Mazda race manual.
The next page breaks it down to how many bearing were changed but the total mileage is the same about 400-500 miles.

Notice the comment about saying you can use synthetic oil!

Old Slow Coach

Good stuff... but not sure it exactly applys, but maybe it does. Just not sure what their definition of a "race motor" is. Does it mean race-ported exhaust ports with 3 mm seals running 26 lbs of boost? These things, I think, are factors that bear consideration. Oversized exhaust ports with heavier seals may not have been part of thier equation. Do you know? Does it take longer to attain protection against seal lifting -vs- seal warpage?

Old Slow Coach

Oh... Happy Thanksgiving, everyone!!!

No_Rotor_RX7

i'm with blizted33. unless you have brand new bearings then just let it idle for a good while and put it thru a few heat cycles and then tune it properly. just remember at those boost levels you either need c16 or a really good auxillary injection setup.

if you do have new bearings then run it for a couple hundred miles without any WOT bursts.

other than that tho always crank it up and heat cycle it using regular oil!!! never do a first start/ break-in on synthetic. after the first oil change tho you can swap in synthetic and you'll be good to go.

pp13bnos

iTrader: (1)

I'm one of the guys who likes a long break in period. What harm is it going to do having a long break in period? CJ

No_Rotor_RX7

there is no harm, just not always neccessary it all depends on what you're doing with the car. for some people it would take them a month to get 1000 miles or so on their car depending on the situation. some cars aren't really for the street. not everyone has access to an engine dyno. if it's no bother then throw the extra miles on there if it makes ya feel better, but we've seen time and time again that it just isn't needed.

we've built many engines and gone out and tuned them anywhere from 10 - 20psi or so (depending on the setup) with less than 50 miles on them and they run for years. if they blow, it's not due to break-in

but, everyone has their own beliefs on this. as said... what harm will it do to run it for a couple thousand miles or so? none. if thats what you want to do then go for it. just remember the oil changes! hahaha


honestly, you should do as recommended by your engine builder!!!!!!

Old Slow Coach

Thanks for all the replys, fellas! I think I'm going to add a few extra heat cycles and call it quits pretty soon. Motor currently has over 1,000, and I can tell you that the sound of the motor gradually changed at about 1,000 miles. Not positive I can attribute that sound to the seals setting up, but I think that's what was happening. The gradual change was similar to the sound change that occurs when a motor warms up after a cold start and things start to set-up. Anyone else ever observe this? Maybe, depending on lots of factors, this happens for some at as early as 400 miles, and could take up to 1,400 miles? Over the life of the motor, that difference becomes relatively close, so it seems possible that variation could exist. I've heard of batches of seals having metalurgical variations. Welll, hey, I think I hear the wife hollering at me.... time to go eat turkey!

BLitzed33

Yes the motor will start to seal up better as you get more miles on it. ErnieT's was the same as mine,...he laid down 643 whp. This new motor will be the same, heat cycled and on the dyno I am sure. Anyway, since you already have 1000 miles on it, you are by far fine to to do boost tuning. Let us know what numbers it puts down. Happy thanksgiving