Starting Rip Van Wankel

I recently bought a Formula SAE car (made a post about it last week). I brought it home Tuesday have been trying to decide what to do with it. It turns out, I'm too tall (6'-3", 185) to fit in it as is, so I'll either just sell it or lengthen the cockpit enough so the steering rack clears my shins.

The car has a Sachs Wankel that hasn't been started in 20+ years. I've never worked on a rotary, but I seem to recall there is something you're supposed to do or check prior to waking one up from a lengthy slumber.

Advice on starting?

Here are pictures: Formula SAE

Some people like to introduce ATF into the combustion chambers and let the engine sit for a little while to dissolve crud around the apex seals. Is that what you're referring to?

Is it supposed to run on premix or does it have some sort of oil metering setup? I would definitely start it on premix "just in case", but only after the usual stuff you'd do with a boinger engine as well. Like, clean out the fuel system, change the oil, crank it without a spark to build up oil pressure and all that jazz.

I'd pull plugs squirt two stoke oil in plug holes turn over by hand slowly if you feel pressure stop and rev direction re-lube and try again, this should help the apex seals get lube and wipe off any surface contaminates.

Id do 44Dwarfs method but with ATF and put it in the intake, exhaust port, and plug holes. Slow turns of the engine after that. If its stuck and wont rotate, put in the ATF and let it soak overnight. If the exhaust port is peripheral (straight shot into the rotor out of the side housing) you may be able to see enough of each apex seal as it passes to make sure its not broken and scrape out any accumulated goo in grove the seal rides in. If you get everything freed up you should get 3 evenly spaced good whumps per rotation out of the exhaust port when turning it over.

BTW, you're killing me-that wheelbase and width is pretty much perfect. Can you take a measurement from the steering wheel to the front axle and the same with the seatback?

Sachs Wankel....best FSAE ever!

I agree with the ATF treatment and rotate the engine to ensure you have compression on each face of the rotor.

Lube it up as described, but I'd use 2 stroke oil over ATF. Dissolves crap better (contains solvents) and is meant to be in there.

This thing almost certainly runs premix, not sure on ratio, maybe 32:1 to start?

32:1 is super oily. We run 100:1.

If you say Sachs wankel out loud it sounds really dirty.

Sweet car! You need a tshirt or bumper sticker that says "Sachs Wankels Drive Me Wild"!

Hey I have one of those. I've heard they tend to overheat in summer use. They don't have an oil system at all so they run the premix through the eshaft before it goes into the combustion chamber. I would take the carb off and fog it with some kind of oil to try to get some lube to the eshaft before you go crazy. They don't have a lot of power either (19hp IIRC). They don't weigh alot though.

I talked to the seller today and he said he replaced the apex seals right before parking it on the shag carpet in his rec. room in 1994. After checking the vitals, I connected a battery and pushed the start button. It spun so I turned on the ignition and fed it a shot of starting fluid. It actually fired and ran briefly. The sound that came out of the SuperTrapp sent my youngest son running in terror. I think it'll be fine once the old gas is cleaned out.

I also found a manual and it says 25:1 for the premix. Seems a bit much, but that's what it says.

When I was in FSAE in college they didn't let you run rotaries, always wanted to do a half 12a PP. ANYWAYS.

change the fluids, clean the spark plugs and try and cranking it.

I run 1oz of 2 stroke for every 1 gallon of gas.

Honestly give the carb a good clean and see how it does

I wish I had a Sachs Wankel to play with.

In reply to Apis Mellifera:

You still haven't said how much you're selling it for...

I'd need $1000 and that's what I've told people that have emailed, but after removing the fire extinguisher and getting in a different way, I can actually fit in the car. I think I'll get it running and go from there. I also bought a Honda CT 90 and CT 70 from him that I may fix and sell too. We'll see how the time works out though.

Remember this is from the days of crappy 2 stroke oil so they wanted it rich on oil. Yes todays oils are better but this is an odd animal too as the oil is a coolant for the apex seals. Parts for theses can be expensive and hard to find. If it were me I'd run a modern syn oil at 32:1 still very rich on the oil and jet the carb to suit. most things today run 40 or 50:1 some oils claim 100:1 but I'd never try it. Also try not to use starting fluid if at all possible as it will cut the oil film.

44Dwarf wrote: Yes todays oils are better but this is an odd animal too as the oil is a coolant for the apex seals.

The same argument applies to piston 2 strokes, more oil gives better piston-bore heat transfer and allows for leaner more powerful mixtures without melting a piston, better ring seal too. Some people still run in the 10-16:1 range in kart racing. Running light on the oil, at least as I understand it, is mostly an environmental thing on boats, and ease of use (e.g. it will idle all day with the idle set wrong and not foul a plug) on power equipment and recreational vehicles.

All the IT7 guys in the region run 100:1 and run engines for multiple seasons without need for rebuilds.

But again remember this engine has no eshaft oil system. You want to run a lot of oil because it has to lube a lot of motor. Comparisons to normal (mazda type) rotaries are not appropriate because there is no pumped oil system lubing the eshaft and side seals.

Also if anyone wants one of these motors I could be convinced to part with mine. It's currently not running but is all there with the CVT our of the Snowmobile it came from.

Needs more pictures... At least it's electric start so you don't have to yanky your wanky...

In reply to nocones:

My bad. My brain wasn't registering that key difference.

Apis Mellifera wrote: Here are pictures: Formula SAE

More than this?