Rotary Guru needed in New England

Calling all Northeast Rotorheads! I took my engine (NA S5) apart last fall expecting to have it rebuilt by now. I noticed during teardown both rotor housings had somewhat significant scratching (by my untrained standards) on the housings and am concerned that a rebuild may be a waste of time with the parts I have. I have left messages with the one outfit that used to be able to take care of rotaries in MA and called another place that advertises rotary stuff but they have not called back either. The engine was running great all season but during my last session on track it started overheating, not bad, but burping through the overflow tank. Does anyone one have any contacts in the Northeast for a person/shop that can look at my parts and see if they are worth doing anything with. Bonus if someone knows where to source a running S5 NA engine, I'm running out of time if I want to ready by April. TIA

Can you post decent photos of the scratches/flaking? Did you notice any wear/damage to the apex or corner seals that would correlate with the housing damage? If all else fails it should still be fairly easy to find S5 housings. I don't have any personal experience with the shop, but Goopy performance is in Haverstraw NY, a few of my friends have used them for new seals and gaskets. 

So here are some pics, first batch will be the front housing. When disassembling I found all the pieces intact. No seals missing and nothing extra bouncing around. Nothing catches a fingernail. This engine owes me nothing, it was rebuilt 9 seasons ago by a pro and has been abused ever since. I want to get 5 years or better out of my rebuild. If these parts are too tired I'd rather replace them now than after 20 hours of assembly. 

Rear housing

Front Housing

Rear Housing

Rotors

Based on these internet pics, would you spend the time to rebuild this engine? Why?? NA engine with durability as first criteria. Track use only.

I'd send the rotor housings to Goopy for resurfacing.  The grooving does not bother me, the warping at the leading spark plug causing the apex seal to lift (evidenced by the big carbon patch) does bother me.  Improve your cooling system, increase your oil premix, and run colder spark plugs.

In reply to Pete. (l33t FS) :

Agree. I run one ounce of premix per gallon of fuel. I guess if you're really beating on the car you could go a little heavier than that. The FC factory oil cooler is pretty good, but you could run an additional cooler and maybe look into an electric fan. When I went to an FC cooler and ditched the beehive style cooler on my FB I stopped having to take breaks at the track to cool the car.

I have a couple of FC factory coolers I am trying to sell to a worthy rotary build.

Let me know if you want one or want pics.  I will sell you one cheap. I am on the west coast BTW.

I mean coolant cooling, but every bit helps.

1oz/gallon of premix is fine if it is in addition to the MOP.  If you are relying on premix and are using the car more heavily, 2-3oz/gal is better, depending on usage cycles.  (Drag racing where you do more idling than WOT use, 2oz/gal is fine.)

The thing with premixing vs. the MOP is, the MOP applies the oil more or less directly to the rotor housing surface.  Premixing puts it in the fuel, where most of it goes into the engine and gets burnt without contacting any surfaces, so you need to use a lot more of it.

Thanks for the replies. I will reach out to Goopy's and see if they can help. I presently run just premix at 1 Oz/ gal and the OMP has been disconnected/removed. May have to bump premix up to 2 oz/gal.  NGK BUR9EQ plugs both leading and trailing. I typically do not have any overheating issues so I think my cooling system is OK,  I have a 3 row radiator, electric fan and the oil cooler is in good condition. 

Cool, so you've already taken care of a lot of that already.

Some warpage IS normal, unfortunately, so the most you can do is anything you can to mitigate.  You should see the warpage my old engine had, you could see all of the internal structure reverse printed on the chrome.

One other comment as it's hard to see on the photos - I'd also have a closer look at the apex seal grooves in the rotors. They mostly look OK, although I can't tell if one of them appears to have a slight "spread" on it at the corner or not.

Re Pete's cooling comment - even if they don't overheat, my understanding is that rotaries can be a bit prone to developing hot spots, so improving the cooling system might be a good thing.

In reply to BoxheadTim :

Mazda SAE papers showed 400F around the leading spark plugs at a certain coolant temperature and load.  You can bet that the coolant is boiling there.

The nice thing about 2mm seal engines is the apex slots rarely wallow out like the 3mm ones.  It is easy to get rotors with a nice .002-.0025" clearance.  Still something to check out of course, but the rotor housings don't have the chattering that you get when the apex seals flap around in the rotors.