I will soon have my 12A together and will need to break it in. It has a bridgeport and and header with 2 inch tubes into 3 inch exhaust pipe. Carbon apex seals lighten rotors and 48 mm weber and aluminum flywheel. What is the best way to break in this engine.

 

bridge port? i would keep it below 4k rpm for as long as you can.

 

The engine is bridgeported has a 48mm Weber, I took out 30 plus pounds of rotating mass. I have fabricated the intake manifold and header and exhaust pipe. The header has 2 inch tubes going into a 3 inch exhaust pipe and I fabricated a high flow muffler all out of stainless. I have modified the oiling system for high RPMs. I will have the engine together this winter and need to know what is the best way to break it in? What oil and how to run the engine before I go all out on the track. I will run the engine in my shop for an hour or so but then finish the break in on the track during practice rounds.

 

Wow this is very different from the way we break in Porsche Motors. Run it the way you plan to drive it, is my way of running in a type 4 motor or early 911 motor. Different animal right?

 

I have a 13b semi pp engine that I just broke in. I just used regular Castrol GTX and NGK spark plugs. I changed the oil and spark plugs after the 1st 1,000 miles, kept it under 5000 rpm the whole time. Then I did another oil change after 2500 miles, after that I would say my engine was broken in. That was pretty much it for me. I am at 5000 miles on my engine right now. I also have been using 1 oz per gallon of premix, I have no OMP.

 

It really depends on how the motor was built as to what kind of break-in it needs.

New bearings? Longer break-in as there are often high spots from pressing the bearing in that can seize if not worn down first.

Tight side seal clearance? Longer break-in as at higher EGT the seals can expand and bind if they are not worn in gradually first.

You can build a rotary, idle it for 20 minutes and then go race it if you build it to race clearances.

You can build a very tight engine for the street that may require a long break in, but will make more power at low rpm and last longer. If you race this engine even after it is broken in it will quickly loose the advantages of the tight build.

 

with the carbon seals i'd cruise it around for an hour on city streets, let it sit for an hour and do the oil change then drive it how you plan to drive it.

carbon seals don't really require a break in, the rotating bearings will break in within a hundred miles and being that it is n/a there is no reason to baby it for 1k miles like most turbo engines.

 

Hmmmm, I started up my 12a Bridge-port (n/a) worked through the basic tuning at home burning maybe a gallon of gas, took it to the track, pounded it with 150hp of nitrous and twisted it to 11,800 rpm's on the first pass! Have run it for 2 seasons now like that.... 700cfm Holley HP, 30" straight pipe exhaust, snowmobile clutch drive, idles at 4200 rpm's clutch engages at 5800 rpm's, my sand rail weighs 638# dry weight.

 

Old thread, but just for posterity and future reference this was the rotary engine procedure from Mazda Motorsports since from forever:

On road after warm up with new bearings:
MAX-RPM MILES
5000 60
6000 60
7000 60
8000 60
8500 60

On road after warm up with old bearings:
MAX-RPM MILES
6000 25
7000 25
8000 25
8500 25