RX7TR7

Hi everyone,
I just bought a Triumph Tr7 with an Rx7 engine in it. The car is being delivered by next week. Ive worked on and built v8s since I was 12, but I know nothing about rotary's. The guy I am buying it from said they bought it in a bulk lot of cars, and when they got it they tried putting a jump box on it and starting it. They said it cranks but will not start. It is carbureted so Im guessing its a 12A? Ive done a lot of Google searching and it seems the apex seals get dry and don't seal? But ATF will make them seal again. How often does that not work? I'm guessing APEX seals are the equivalent of piston rings? Do they ever just go bad and decide not to seal or is that usually not likely? Besides changing fluids and checking for Fuel and Spark what else should I go through before trying to start it? I want to be ready for when it gets here. Ive heard these a good strong long lasting motors, so I'm hoping I didn't buy a expensive core....

FührerTüner

iTrader: (5)

check compression.

Cookboy

iTrader: (10)

Apex seals wear or may fail, but odds are it's something simpler than that.

Pour a little marvel mystery oil down the carb, crank it a little. Spray some carb cleaner or starting fluid down and see if she fires up. Then go from there. Fuel filter 1st, remove fuel line and check for delivery. Check for spark. If you have fuel and spark, you may have a gummed up carb. If your carb is clean, you may have a compression issue.

A rotary TR7 is a pretty sweet thing to have, particularly if it's not a rust bucket.

FührerTüner

iTrader: (5)

I was thinking maybe a stuck side or apex seal.... from sitting.

Compression. Check this.

MosesX605

Yeah, I'd be surprised if it didn't start with a few ounces of MMO or Seafoam poured down the primaries. Even an engine with low compression should start that way.

RX7TR7

Cool how much do you pour in? Ive read about guys trying to unflood a rotary and it seems like a huge pain in the *** so trying to avoid that. Also I understand the value of a compression test, but if the seals were dry from sitting would I get any compression?

Cookboy

iTrader: (10)

A couple tablespoons (1 ounce) or so down each primary. Give the motor a spin. Then shoot some carb cleaner and fire that Baby up! With the rotary things are usually pretty simple.
The best thing you can do for one is to run it.

DivinDriver

iTrader: (15)

Be sure to post engine-bay pix when your car arrives; people here can help you ID your specific engine, then you can download all the manuals you'll need to get up to speed on rotaries.

If you've done V8 builds you'll find these simpler in concept but very different in details. A Wankel is a left-handed cross between a two-stroke & a turbine, but once you wrap your head around it it's a very logical design.

Welcome to the family!

RX7TR7

Thanks everyone for helping out. I'm pretty excited about this project. I've been reading everything I can about rotary's I think I'm starting to understand it. Here is the eBay Auction there is an engine bay shot in the pictures. The car actually looks pretty good http://pages.ebay.com/motors/link/?nav=item.view&id=301244155539&globalID=EBAY-MOTOR&alt=web

FührerTüner

iTrader: (5)

good deal!!!

RX7TR7

Thank you, Im glad someone agrees. Everyone else just thinks Im nuts haha. The only crappy part is 575 for shipping up to NJ. But hopefully it will all pay off once I get it running.

FührerTüner

iTrader: (5)

you could have probably picked it up yourself for cheaper

DivinDriver

iTrader: (15)

Not much close-up detail in the picture, but judging from the rat's nest and the location & shape of the air cleaner, I'd guess you have a 12A probably from 1981-83.

Definiitely not a 79 or 80 motor.

MosesX605

No beehive cooler, so its an '81 or '82 engine.

RX7TR7

Finally got the car yesterday. I popped a battery in it and cranked it. I could hear compression, so I poured a little gas down the carb and it ran for like half a second. I tried it again and flooded it. So the good news is it may actually run...

Now for the issues the carb linkage was jammed. I found a piece of T shaped linkage on the side of the carb close to the fire wall it was popping up and hitting a lever and jamming. I slid it out of its mount now the carb is unbound. BUt I dont know where it goes. Heres a few pictures to help.







Also here is a few engine bay pics so you guys could maybe tell me aproximately what year the engine is? I want to order some parts for it.

TheRX7Project

iTrader: (3)

Wow, $330 you STOLE that car. I paid $300 for a running 12a alone!

Cookboy

iTrader: (10)

There is a lot of useless stuff on that carb. You should strip the rats near, and strip the carb.
There are threads on each, and a google image search of "stripped Nikki Glazedham42" will reveal color coded diagram of what you want to delete. It oughta be rebuilt anyway, so there ya go!

MosesX605

Very cool. Definitely an '81 or '82 engine but most stuff interchanges across the '81-'85 range when it comes to the basics: plugs, wires, etc.

The part that was binding was the throttle return spring. Here's a picture of how it should be:



So far as flooding goes, these engines are fairly sensitive to flooding, so check out the deflooding procedure in the FAQ for an idea as to how to proceed. You'll probably need new plugs.

RX7TR7

I was considering doing the rats nest removal, but I wanted to get it running right first. That way I'm not wondering if I scrwed up something during that. As of now no fuel, maybe bad fuel pump not sure yet. Also the radiator is dry. So I have to find out why.

Cookboy

iTrader: (10)

Yes, cooling system is kinda critical.

RX7TR7

Ok good news, the radiator was only low. I refilled it with water and it seems to be not leaking.

You guys were right about the carb linkage fixed that now my throttle works very well.

Now the bad the fuel pump is dead. Its the original RX7 pump after some google searching its the original pump for 1979-1982. The cheapest I found it for is $100. Is there somewhere else to get it? I tried all the chain stores and they want to sell me the cheapo universal pumps and ive never had good luck with those.

Cookboy

iTrader: (10)

There are many answers to the fuel pump question. Some use a Mr. Gasket universal, there is at rockauto.com a Carter pump that many have used successfully, Redline has one that will fit.
A pressure regulator should accompany any of them, in my very humble estimation.

MosesX605

In my experience, the universal low-pressure pump will work just fine without a pressure regulator. They're not spectacularly durable, but they'll do in a pinch.

I had a universal on my race jalopy until I switched carburetors and it kept up just fine, even during a long straight at WOT. After I switched to the dual RE carb setup, I bought a Holley Blue pump and a pressure regulator. It's a bit loud, but will supply all the fuel you'd ever need and is pretty reliable.

Long Island Supercars

Before you go too crazy with aftermarket pumps, start with the basics. First make sure you have power at the pump with key on and a good solid ground. Look for a broken connector or even a fuse. If this gets the pump running replace the filter, who knows how long it's been sitting. You might have a good pump but someone didn't wire it correctly or they may have used cheap crimp connectors to tie into the factory harness that corrode instantly the first time it's driven in the rain (Common with "rats nest" cars). Solder everything you see that could cause an issue.

Carter P60504 Inline Fuel Pump Should match your 5/16" fuel line ($55 from summit)
Fuel filters are probably $5 for a new one plus clamps.

Nice looking car btw! that's a steal for less than $1000 total

RX7TR7

The fuel pump is definitely bad. I pulled the pump out and connected it straight to a battery and it did nothing. I even sprayed PB blaster in it and let it soak then tried again and it still was seized so its definitely done.

But then I tried getting a jug of fresh gas and an electric fuel pump and hooking that up straight to the Nikki then plugging the return line. I couldnt get any gas into the car so the needle and seat must be stuck. I tried tapping it with a hammer but it didnt free them up. Is Sterling still the best guy to go to for a rebuild?

Next problem the coils only get power when cranking but once I let go of the key I loose power. It looks like he swapped most of the RX7 harness over. Does the coil wire go to the computer or relays or anything in an RX7? Im going to tear into it probably over the next two days and see what I find. Im just hoping to have some kind of starting point. Also should they both have separate power feeds? Or could I just take the original Tr7 coil feed and just solder on 2 wires on for each coil?