So with GRM we've been through building the engine, and installing. I've done step 1, and step 2 should be done tomorrow.
My only question at this point is how do you properly break in a 100% fresh engine (bored block, new pistons / rings, etc etc) to ensure longevity and almost more importantly, power (ie: not hurt anything that will compromise your compression later on)?
if im not mistaken there are diffrent break ins depending on whether you are building a race or street engine. Some guys build race engines start them run em ten minutes then dump the oil and do it again and with higher revs for a couple hours and bam they take it to the track. With my rx7 i (street driven mostly) i ran it a while, dumped the oil and treated it like any other car breaking in no going into boost or over 4k and dumped the oil again in 1000 - 1500 and then again 1500 later. Then i started wailin on that motha.
It's a bit of a hybrid... occasionally street driven / essentially dedicated autocross Miata 1.6.
well since its not a full on race motor that you plan to rebuild in four races anyway i would just do a nice break in, prime the oil pressure start it up let it run 20-30 minutes maybe dump the oil (and inspect i know i did) and put new oil in and drive it chill for 1000 or so miles or more until you feel comfortable that you wont grenade it when you put the hammer down. Ive had buddies who dont hit it until they pass like 3-5000 break in miles. To each his own i guess. If im not mistaken though some people do use a special oil for the initial break in. Im not sure which im sure someone here knows about it i think some people use like a mineral oil with high zinc content and crazyness like that. I just used oil. I hope this helps.
I think that every engine builder has their own break-in process. So, ask 100 builders, get 100 answers. When I build a motor, what I do is use conventional oil, pull the plugs, squirt some break-free down the cylinders, crank it until I get oil pressure (this is easy if you are megasquirting it at the same time because you'll be cranking it a while anyway), then put the plugs back in, start it up, let it warm up, drive real easy for 100 miles, change oil, drive a little harder but still real easy to about 500 or so, change oil, start driving it normally. Some people start it up the first time then change the oil right then. New filters with each oil change. I start using full synthetic at either the 500 mile change or the next regularly scheduled change after that. I also retorque the head bolts after about 10 heat cycles. Just go one by one in the proper sequence, loosen up some, tighten to full tight, go to next one.
Fair enough. I appreciate the replies though. Having some general guidelines is better than me just going out and zinging it to revline a whole bunch of times and doing some burnouts :p
(ok, I wasn't planning to... but it'd be pretty funny)
Here's what we use at Flyin' Miata:
http://flyinmiata.com/tech/breakin.php
Beautiful, thanks Keith! If for whatever reason we need to let it sit a while at idle, would it make sense to bring the revs up some instead of just idling?
What's seating the rings is the change in cylinder pressure. Holding it at a higher engine speed doesn't really accomplish anything.
Yep, step 8 in the FM site is crucial! You gotta have the push / pull of the loaded cyl & coast down. Idling does nothing for ring seating & could be harmful - if its running rich / loading up you'll wash down the cylinder walls & the rings will never seat.
You will need to idle for a bit (set the timing, check for leaks, break in the cams if they are new), but get it on the road / dyno asap.
Also, dont put in synthetic oil for a good while. I've seen a few guys spend big bucks on pro motors / new builds and wind up taking a season for the rings to seat.
Rotella diesel oil is a good break in oil (it still has a little zinc in it I'm told), but I use Joe Gibbs break in oil.
Kendall
Yes for every post there will be a different opinion. Pushrod engines should be run at a high idle (1500-2000rpm) for twenty minutes to break in the cam, then proceed as outlined elsewhere. Otherwise you can wipe out a cam lobe. OHC engines don't have anywhere near the frictional loading on the cam so it's not necessary.
To load the cylinder walls, I put a couple friends in the car with me and drive it up a long hill repeatedly (not available in Florida). The hill and the weight give it the cylinder loading necessary for a good wear pattern without the high revs used by the Flyin' Miata guys. I'm not talking lugging the motor here but uphill at 2/3 throttle at 3000-3500 rpm with a bunch of weight will do the trick. I run back down the hill with the throttle closed to produce high vacuum. After 20 minutes of this, it's time to change the oil.
Vary the throttle and limit the revs for the first one thousand miles. I do that by avoiding long stretches of highway and going where I need to go via back roads instead. Change the oil and go thrash on your motor to your heart's content.
Good luck, Check all your vacuum connections again before starting the engine. Also, if you can't turn the oil pump with an electric drill (impossible on many cars), you can crank the motor with the coil disconnected and the oil pressure sender unscrewed to ascertain pressure and flow. When you see oil at the sender hole, you're good. This could be quite a bit of oil so be ready. Screw the sensor back in and go for the start.
We use Valvoline 30 wt dino oil for a break-in oil. I don't really think of 5500 as high rpm, but I guess it's all relative :) We don't recommend sustained high rpm for that step, simply bring the car up there then cut the throttle. Again, it's the change we're looking for.
Keith wrote: We use Valvoline 30 wt dino oil for a break-in oil. I don't really think of 5500 as high rpm, but I guess it's all relative :) We don't recommend sustained high rpm for that step, simply bring the car up there then cut the throttle. Again, it's the change we're looking for.
You're right. All my relatives think 5500 as a lot. 
You're right. 5500 isn't a lot on a Miata. The reason I use the hill is to create the large difference you're talking about without the revs. Why? Because the break-in requirements for the bearings are the exact opposite. Bearings like an easy break in to establish a pattern while the rings like to be whipped. There has to be a compromise.
My FIAT twincams had a 6500 rpm redline so I might run 4500 on those instead. There wasn't enough torque available at 3000 to run up anything of any size with weight in the car. Modify RPM based on torque curve.
An old friend back east was a light plane mechanic. They broke in new motors by loading the plane to maximum take-off weight, then climbing for about twenty minutes. Max RPM on an aircraft engine is relatively slow. I modified the procedure for land-based vehicles.
I'm surprised most people use straight 30-weight for initial start-up. I use 10w-30 for quick flow in the initial few seconds.
Jerry From LA wrote: The reason I use the hill is to create the large difference you're talking about without the revs.
It'll give you your high cylinder pressures, but not the low. You need that high vacuum.
Jerry From LA wrote: you can crank the motor with the coil disconnected and the oil pressure sender unscrewed to ascertain pressure and flow. When you see oil at the sender hole, you're good. This could be quite a bit of oil so be ready. Screw the sensor back in and go for the start.
That's what we did. Unhooked the coil and injector harnesses and cranked it until the oil gauge read that we had pressure, then plugged everything in to fire it up. She fired up pretty much right away on the 1st try and was running well, which makes me incredibly happy lol. As we were setting the timing we found a couple issues that are relatively easily corrected.
it started making a really loud (read: Bad) metal vibration noise. Turns out someone (coughme) forgot to tighten the timing belt tensioner pulley bolt. Big d'oh! Being my 1st built engine, I thought for sure it was tearing itself apart from the inside. Anyway, pulled the top 2 timing belt covers off and fixed that and checked the timing marks (made sure we were @ TDC on #1) and kept moving forwards.
Turns out the oil pumps mazda sells for the Miata are the same as the ones for the protege. Only difference is that the protege dip-stick goes in through the oil pump body. As the miata's is on the oil pan, it means that I've got a hole through my oil pump. Ok at idle sitting in the garage as it's not part of the pressurized assembly, but will make a big mess. Apparently the stock miata oil pump has a round plug that goes in that hole. The only thing is mazda doesn't tell you that.
I'm sourcing one tomorrow then getting started on breaking her in :)
Congrats on creating your first monster. Now you can go around like Boris Karloff screaming, "It's alive!" at the top of your lungs. I've been known to do it at the birth of an engine.
Regarding your dipstick hole problem, there's no way a first time builder would know that so don't be too hard on yourself. Hell, 99 percent of the people here didn't know until it happened to you. I bet Keith knew but he wasn't saying. Perhaps it's some bizarre Mazda right-of-passage ritual.
Keith, I neglected to mention I usually get on and off the throttle on the way to and from the hill for my high vacuum situations. There's also the downhill runs as well as the runout at the top of the hill before I turn around. I was just too lazy to describe it in great detail.
Jerry From LA wrote: Congrats on creating your first monster. Now you can go around like Boris Karloff screaming, "It's alive!" at the top of your lungs. I've been known to do it at the birth of an engine.
Naa, I was too happy to think about doing that. I just had a big stupid grin on my face 
Jerry From LA wrote: Regarding your dipstick hole problem, there's no way a first time builder would know that so don't be too hard on yourself. Hell, 99 percent of the people here didn't know until it happened to you. I bet Keith knew but he wasn't saying.
Honestly the only reason we even caught it before splashing oil all over the front of the engine is because my buddy Kevin (KCBHIW, has frequented the challenge with turbo'd mazdas for a couple years now) noticed it as we were giving the new engine a last once over on the stand before hooking it to the hoist. Apparently he's been there done that. What annoys me is the FSM makes no mention of it. With the amount of miatas out there, chances are Mazda will be selling a whole bunch of them. I actually have 2 new oil pumps, and they both have that. So, I'm going to give Mazda Motorsports a call on Monday and let them know they may want to check this, or at least give people a head's up about it. Let's see... new engine, test drive, dumps oil all over the place, oil pressure dips low... $1500 straight down the toilet (or more depending on what you're doing).
Yeah, that plug. It's a nice little surprise, isn't it? Only about $2, but you need it! We keep them on the shelf at FM, and if you'd bought your oil pump from us then we would have told you
The original Miata oil pump has the little plug in it, but the new ones that Mazda sells haven't had them for at least 7 years - that's when I discovered it. Theoretically you could transfer it over, but for $2 it's not worth the effort. The good thing is that it doesn't make a big mess, just throws enough oil to make you wonder what the heck you forgot. It certainly doesn't put your engine at risk. In terms of potential engine damage, it ranks up there with a badly installed front crank seal - which it kinda resembles when you see it, and will make you think bad things.
ah, fair enough. In any case I ended up getting one this morning and putting it in. You can almost do it by hand, but I had all my intake stuff already on and didn't feel like pulling it to do this again, so I just used a long extension to tap the plug in. Now to go put the extended front studs in and taker her out for a drive :D
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