Tugboat

I posted this Monday in the FWD thread, but haven't gotten any replies so I'm starting a new thread instead of trying to hijack that one:

I've been kicking around the idea of a rotary powered Fiero. I've been told one of my big problems would be having a CV joint too close to where the exhaust port is. Could the engine be tilted, with a different pan and pickup, or would there be other issues? If carbureted, I realize the intake would have to be changed too.

It's probably obvious, but I know next to nothing about rotary engines except the principle. What engine would be good for this swap? Where would be a good place to get one? What kind of vehicle did they come in? I think I'd like to start with a carbureted version. I have a couple trannys, an '84 4.10 4-speed, and an '85 3.35 5-speed. The 4 speed would be stronger.

Thanks for any thoughts or ideas.

re10

Find a local rotary shop or local enthuiast, ask for a completly munted housings / front cover etc and make up a dummy block (less internals etc), then use it to see if you are wasting your time or not.

Critoris

That's actually a great idea. You could also just try a trashed block to dummy up and fab off of, though I have no idea what front cover you'd want.

schwarzer ritter

its probably hard theres an article of a guy who put a 13b in a fiat x1/9 same basic idea on iluvmyrx7.com under ''other rotary '' articles

vmb

why would you want to go thru all the headache to fit a rotary in such a ugly car (my opinion)

MountainTurbo

Interesting concept. I've read about many V8 Fieros, some with a 32Valve DOHC Twin-Turbo Northstar engine (that HAS to be insane!), but never a rotary one. Could be a lot of fun, but probably a lot of work too!

Sojin

what kind of tranny like a rx7 or a fiero and dose i mount on the rotary engine because i need a MR or FF tranny for a project

Tugboat

Thanks for the replies. I think I have a line on a motor, but not sure of its origin or condition. Are they the same as far as bellhousing, exhaust location, etc?

Actually, the Chevy smallblocks are stronger than the Northstars, usually. There are a bunch of SC3800s too. I figure the light weight of the rotary would be an asset, not that a Fiero is light.

I was planning on using a Fiero tranny, I know I'll have to adapt the motor to it.

And this all may become academic as a friend just totaled his Bonneville so I've got a 3800 to play with.

Thanks

Tugboat

OK, so the 3800 aside, I found this on EBAY:
http://cgi.ebay.com/ebaymotors/ws/eB...category=33615
and I will become the new owner soon. Does anybody have any idea what version this might be, and what vehicle it might have come in? I have the idea that the seller has less than a clue. I'm hoping it hasn't spent too much time on a dyno.

Thanks

Darth Linux

it's an 81-85. came in a non GSL-SE RX-7

Tugboat

Thanks a bunch! That should help out.

Can the exhaust manifold be flipped over? It might provide enough clearance to the tri-pot (or whatever it's called) and axle. There appear to be holes under the exhaust port, what do these connect to? I've seen pictures of headers that don't seem to have any provisions for them.

I understand the exhaust system needs to be high grade material, does this mean stainless or some other alloy or just thicker?

Thanks again

Darth Linux

hmm. I've never tried flipping the manifold over but it may be possible. You'd have to see if the exhaust flange clears in the intake manifold.

Now, from that picture it looked like it had the log style exhaust manifold, making it 81-85 but if you are sure that it has two small holes, one on each housing, then that is a 74-80 engine. Those would have had the large "thermal reactor" manifold on them instead, and that would mean you definately could not just flip the stock manifold over. It wouldn't clear the intake and the air injection ports wouldn't line up. An aftermarket header blocks those air injection ports outright so you wouldn't have to worry about it.

What I've done is use an 84 exhaust manifold on an 80 engine by using 2 dimes and a bunch of JB Weld to plug those air ports.

You should count on using stainless steel for the exhaust due to the high heat of the exhaust. Regular steel will become distressed much earlier than compared to a piston engine, and it simoply won't last very long. Think of your exhaust ports as being blow torches and you'll get an idea of what kind of heat you are dealing with.

Tugboat

I don't know anything about this engine other than what the pics show and the man told me it's a 12-A. He said it was used at Ft. Meade in classes. It looks like it has dyno hookups, I hope they didn't flog it too hard. I take delivery tomorrow.

The two holes I'd seen in a picture somewhere and I thought also in a shop manual illustration. The manual showed the gasket having one of the holes, offset. The manual is for a turbo, I think '93.

If I can't get enough clearance by inverting the exhaust and maybe going to a header, what issues would be raised by tilting the engine, other than oil pan/ pickup and carburetor issues? Would the oil have any problem returning from the rotors? I'm not talking 90* here, maybe 20 or 30.

Thanks again.

Darth Linux

ok, regarding the holes, let us know if you have them or not when you take possession.

Regarding tilting, the oil and carb issues are pretty major ones - I don't think I'd tilt the engine anymore than it normally sits, which is back end low, until the carb base is level.

Tugboat

I can't really set the engine with the "back" end low, as it'll go sideways. I may have to tilt the carb/exhaust "side" of the motor upwards a bit but the eccentric shaft (I almost typed "crank" - OOPS) will be level, if that makes sense. I'll probably have to do something with the manifold in any case, maybe go to FI. If I can keep it level and not have to mess with the oil pan it would be a plus. Or would making it level cause the oil to be in the wrong place? I've looked around a bunch, but it's hard to tell these things in the pix, because that's not what they're focusing on.

I have kicked around the idea of using a VW tranny, the adapters are out there, but then I'd have to adapt axles and clutch/shift linkage and do more mounts. I also think my tranny is stronger. Know anything about Subaru trannies? J/K

Thanks and GL

Tugboat

Well I got the motor, shaft and all.

Pulled the exhaust manifold to see about holes under the ports and turning the manifold over, and WATER RAN OUT!! Yep, twin lakes. I Emailed the guy, I'm not sure if he'll do anything about it or not.

But there are no holes under the exhaust ports, just angled flats that could be drilled. The manifold hits the water pump inlet, and I think a header would too. Are there any different water pumps?

Thanks

Darth Linux

nope no different water pumps to my knowledge. Might be time for a custom header - people do it all the time putting turbos in RX-3s and such . . .

if you had water running out of the combustion chambers when you took the manifold off I'd say you are a candidate for the ATF or MMO treatment to get oil in all the right places and displace any remaining water before you try and fire that thing up . . . good luck!

Tugboat

Yeah, I need to get some ATF in it right away and see if I can get it turning over. The guy is going to work with me some, I think.

What price would you put on a 12-A that looks nice but has had water in it for an unknown time? Come to think of it, it's frozen right now! I've never seen this mentioned but that can't be good fot it!

Thanks muchly

Jeff20B

iTrader: (13)

Good luck igniting the ATF.

It might actually be a spun bearing.

Tugboat

Well, ATF has excellent anti-rust properties, which is what I need now. I'm a long way from igniting anything. Why would a bearing spin from water sitting in the rotors?

I pulled the plugs and got the motor warmed up enough (with a heater) to melt the ice and drain it out. Squirted some oil/ATF mix into the exhaust, and it turned over easily!! (Using the bolt in the eccentric shaft. I wouldn't have put much torque on it.) The noises from the exhaust and plug holes sound even, but at this cranking speed (ratchet) I'm not sure if that indicates anything.

I don't guess there's any way to tell if there was any damage from freezing, short of disassembly? What would it do, crack the rotor housings? Make dents in the end and center plates?

Thanks

Darth Linux

I paid Metallic_Rock $75 for an engine just like that . . .

runs ok so far . . .

Tugboat

Well, after working more oil around in it, (it's coming out BLACK) I think it has seal problems. It may have had some problems before it was set up. A stuck apex seal might free itself up, but that may not be the problem. Looks to me like it's teardown time. I didn't want to tear this one down. ;(

Thanks

Darth Linux

i wouldn't tear it down yet - at least fire it up ands see what happens. my 75 $ engine wasn't too appealing either before i got it running . . .

Tugboat

Problem is, I don't have a distributor, and the carb is screwed too. At least the secondaries are frozen, who knows what else from water sitting in it. If I do get a distributor, what are the chances? I'm a little afraid of damaging the rotor housings, if they're not already. If I had $75 in it, I'd go for it.

I need to find out how bad this thing is ASAP, that's why I'm thinking teardown. Rebuilding is supposed to be easy, and it'd give me peace of mind. I've looked through a shop manual and think I understand what to do. I've done boingers for years.

Thanks again.

Darth Linux

the problem with rebuilding is that most of the time it seems like you find your rotor housings are missing too much chrome to be able to reuse them, so then you have a $500 engine kit sitting around and an engine without housings. So you buy 2 new rotor housings, that's another $400 and all of the sudden your $500 used motor just cost you $1500 . . .

so I'm just suggesting you find a distributor, rebuild the carb (kits are $30 or so), work some ATF through the engine (turn the crank by hand). Do an exam on each apex seal with your finger through the exhaust port - kind of the prostate exam for your engine ), make sure each apex seal has some spring to it and is intact. then you can try and do a compression - one way is to hook up a starter to the engine (provided you have the flywheel on and the bellhousing from the tranny installed) - use the starter to turn the engine over at a real cranking speed and listen to the puffs. If they are all even then you should go ahead and attempt to get it running. If you can't hook up a starter then you can just try turning the eninge over by hand as fast as you can using a long handle on the front pully nut. Again listen for even puffs. If you have a lot of oil in the engine then you'll get a decent enough seal to tell. Normally centrifugal force increase the compression of the engine so if you try and compression test by hand the seals aren't being thrown out enough to seal good but if you have atf in there then you'll get a somewhat better seal - enough to listen anyway.

So do the finger inspection and listen to the puffs before you plunk down $500 - $1000 a rebuild kit and rotor housings. If it's totally screwed anyway then trying to start it shouldn't hurt it anymore - you'll already have to buy new housings etc. if it's shot as is.

hope that makes sense