Ok all, I'm new here, but I'd like your help. I've got an '87 Turbo motor and tranny out of an RX-7 that I'm swapping into a 60s MGB body. I'm running the motor N/A simply because I can't get the turbo to fit. The motor sits so far back that it's partially in the tranny tunnel. I had to fab my own header and part of the intake. We're gonna run it w/ a carb for now so the car will be driveable and sort out the fuel injection later(using a homemade intake manifold and a Holley carb we had sitting in the shop off of a vette). What I need to know is, what all can I eliminate/block off and still have the motor run properly? I know about the oil metering pump and using pre-mix. I went ahead and ordered the block off plate kit for the motor from k2 racing development. I know it includes the OMP and the ACV plates and a few others. This car does not need to pass emissions nor does it need to be inspected, just needs to run properly. Please advise as to what else can be eliminated in order to have a simple, properly running rotary. There is no AC or PS in the car. Thanks a bunch.

Ary

P.S. What fuel injection system would you guys recommend for later on? Try to get the stock Mazda computer to work? buy a stand alone unit($$ is a consideration)? or ....?? Thanks again

here's a pic for you guys

 

im not sure how the turbo motor running n/g is gonna perform... if im not wrong the compression is much lower.. so lower power out put is gonna suck..

im new to the rx7 thing.. but maybe sell the turbo engine and setup.. find you a n/a!

jaared

 

Don't do this! Please!

Sell that turbo motor to someone who needs it and buy a motor from a first gen. It'll make the same amount of power as a turbo without a turbo (maybe even more_, and has a carb and everything all there allerady. You're just ASKING for headaches and trouble by going this route. Turbos are low compression motors designed for, well, turbocharging. A first gen 12A will be happy with a carb, is WAY simple, has a distributor (how the hell are you going to control spark, anyways?), etc, etc, etc.

 

Yeah, you can probably find an NA engine for pretty cheap. I would do it that way though, just my opinion.

BTW, nice project! Rotary MGB...mmm....yummy...

 

hey i will swap if u want a N/A, lemme know!!

 

Before everyone starts screamin sell the turbo sell the turbo, I have a few reasons for buying the turbo setup, aside from the turbo. My uncle and I(my cohort in this adventure) like to tinker. We have owned the motor/tranny for about a year and a half now and have gone through many struggles to get it in there properly. Anyway, the reasons we wanted the turbo motor is one, for the tranny(bulletproof for anything we'd do w/ it), two because the motor can handle a supercharger if we decide to go that route, and three, it can handle a mild shot of nitrous if we go that route as well. I realize that the motor won't put out the power that it used to when it was turboed, however this car doesn't weigh a thing(about 2000lbs), and the stock motor put out something like 60hp in top condition, so if this motor only makes 100hp for a while, that'll be just fine. As for the carb, the problem is that my Uncle is moving in a month and a half and the car needs to be driveable to move it. This is an on-going project(the car was purchased back in dec 1997, so you can see it's taking a while). We don't plan to stick the carb on it and just leave it, it's strictly a temporary thing. Anyway, if you guys could help me out with my original question I'd appreciate it. I also appreciate your concern about the turbo motor going to waste, I'm new to the rotary world, but I've been involved with Jeeps for a long time and I can relate to what you guys are saying. Anyway, thanks in advance for any help.

Ary

P.S. Do I absolutely NEED an oil cooler to be driveable, or can I simply loop those two ports on the motor until I have time to install the cooler?? Also, anyone know where to get custom sized radiators?? Thanks again

 

Well, if you're running custom manifolds, you've taken care of most everything already. You're going to have to plug up the injector holes and the oil injector holes, then vent the filler tube into a catch can. There's really not much left without the stock manifolds.

 

Well, a portion of the stock intake is still there. The piece that has the ACV on it is still there, but that's it. Do you know if anyone sells plugs for the oil and fuel injector holes?? Thanks

Ary

 

An N/A tranny can take a pretty good beating, and an N/A engine handles a supercharger and nitrous just as well as a T2 motor.

 

Please don't argue with me, the motor is not coming out. At some point everything related to the turbo may be for sale though....but that's a ways off. Thanks for your help

 

im not trying to argue with you man, i was just telling you something. Im basically just agreeing with the others in saying your life would be alot easier with a 12A carbed motor, or a 13B NA. I doubt that you will enjoy the way that a turbo rotary with no turbo runs.

 

To answer the fellow's question, here...

You really don't need anything. You can block the ACV off. All the nipples on the LIM are vacuum sources, and don't lead anywhere in particular, so you can either use them or cap them. If this motor has EGR on the back of the LIM, you can block that off, too. Route the PCV line into a catchcan - it's near the oil filler neck, and comes off the center iron. The wierd thing on the "inside" of the LIM can come off, and the slot/hole thing it leaves can be filled with JB weld. Stick some bolts in the old oil injector holes. Block off the MOP pump and ditch it. The LIM has some coolant that goes through it, to feed the turbo. You'll need to reroute that back into the cooling system - it should feed into the cold side of the radiator. There's also a high-pressure oil line which feeds the turbo and return that leads into the oil pan, iirc - you'll have to deal with those.

For a fuel injection setup, I recommend a Microtech LT8 (obviously). We (BR7 Racing) sell a kit which replaces the upper intake manifold with a Weber DCOE 48mm TBI "side draft" setup. It's trick, and can be used if you want to go turbo later.

For now, if you want to keep the stock ECU to get the thing running, you'll need to keep the

throttle pos'n sensor
air temp sensor
water temp sensor on the back of the water pump (two prong)
AFM

... there's a bunch of them ... Check http://www.1300cc.org and look at the "pulling error codes" section - all of the "input code" devices need to be hooked up.

Any more questions? Ask 'em.

Brandon
BR7 Racing

 

you still didn't tell us how you were planning on getting spark...

 

If he keeps the stock ECU, he'll need to wire up the stock coils and keep the CAS. If not, a 12A dizzy will work (or a euro-spec 13B dizzy). If he goes aftermarket EFI, keep the CAS, too. The LTX8 would be an awesome choice - it comes with coils and all.

Brandon
BR7 Racing

 

to be quite honest, I don't know about spark. I'm kind of taking this project over from my Uncle 'cause he's in the process of buying a house and doesn't have time. He helps me and answers my questions, but he can't afford major wrenching time. I know that we have the stock distributor and two coils, I was assuming that's all we needed to get it running, maybe I'm wrong. I admit that I don't know my stuff when it comes to spark. My Jeep has a distributorless ignition, so I know next to nothing about distributors and coils that go with them. I'm here to learn and understand.

No7yet, thanks for your help, I'm sure I'll have more questions as I progress.

As for as the whole arguing thing, I'm sorry, I just felt like I was being ganged up on. We've spent countless hours getting this thing to fit, and the turbo just wasn't happening with out restructuring the entire passenger's footwell. Now if someone could point me in the direction of a low-profile aftermarket exhaust manifold that will allow the use of a turbo, it may work. I'll have to get some pics of how tight it is in there though. Thanks again for all your help guys. It's weird bein a newbie again.

Ary

P.S. Can you give me a ballpark on the LT8 system and also do you have a website?? Thanks
Edit: DOH, just saw your group buy website

 

If you can make it fit, I believe you can flip over a Racing Beat header to make it point forward, and modify it to add a turbo flange. It works on a 12A, anyway.

If you've got a dizzy and two coils, that's about all you'll need. Talk to the first-gen guys and see how it's all hooked up. You won't be able to keep the stock computer, tho - you'll need to get a fuel computer.

With the LTX8, all you'll need is a 13B Crank Angle Sensor (CAS) and some way of putting the injectors where they need to be (and of course tps, air and water temp sensors).

Brandon
BR7 Racing

 

I BELIEVE that header will create interference with the water pump and belt. I have an extra exhaust flange laying in the garage so I went out and matched it up to our custom header and I think you're right, the bolt holes line up, and the exhaust holes are only SLIGHTLY off, not enough to make a diff I don't think. BTW, what is that port in the stock exhaust manifold. There is no place for it on the headers that I can see. Another thing, what about the block off plate/flap(sorry, don't know the correct term) that is part of the stock exhaust manifold, can that be adapted to the headers, and if not, how does the turbo function properly without it??

Honestly I'd love to put the turbo in, I think it would be a lot better and a lot more fun(and it would get you guys off my back), but I know my Uncle has put a tremendous amount of effort into this and he knows his ****(he used to own/run/be a shop that converted any make or model car to natural gas and he graduated top of his class in mechanical engineering from University of MD).

Also, since my Uncle made up the custom manifold, I'm sure he could have made it point forward instead of just down and out. He literally spent months debating whether or not to ditch the turbo. The problem is that the MG engine bay is long and narrow and that the motor sits 1/3 in the tranny tunnel. This is great for weight distribution, but shitty for making stuff fit. I just ran out to see if there would be room and stupid me forgot that I pulled the motor out two days ago to massage the firewall a little more. Anyway, I'll check it out when I slip the motor back in tomorrow, and I'll try and get some pics. You guys can't believe how easy I made it to pull the motor in and out. 30 mins and it rolls out on the front suspension and a caster that bolts to the tranny X-member. Thanks for all your help guys.

and BTW, Brandon, I'm gonna talk to my Uncle(ironically his name is Mazda ) about the MT unit and see what he thinks, after all it's his dime. Thanks again

Ary

 

Having spent some time in a 1st Gen powered by a S4 13BT with the turbo and EFI replaced by an RX-4 carb set-up, I can assure you that these two opinions are completely wrong. The car was very fast and it weighed more than an MGB ever did. 13BT's are not "low-compression" motors, they are just lower compression than the NA's. And other than the lower compression, there's absolutely no disadvantage to using the Turbo block over the NA one. There's nothing particular about it that will cause "headaches and trouble". While the NA motor may've been the better choice to use, sometimes it's easier to just use what you've got than go out and find another engine.

Ary'01xj, to answer your earlier question, no you absolutely cannot run the engine without an oil cooler. Because there's no way to get coolant to the rotors and eccentric shaft, the oil cools this part of the engine instead. The oil cooler handles about 30% of the engine's total heat load.

 

In a car that small, hacking together a log-style manifold would be adequate. Be careful about heat issues, though - a turbo rotary runs very, very, very hot. The port in the stock manifold is for the EGR, iirc, and blocking it off doesn't effect anything. As for the flapper thing, well, I'm not quite sure what you're talking about. Also, ignore those guys about the low-compression engine. It's either an 8.5:1 or 9.0:1 static compression motor; and I'm sure you can tick of a HUGE list of N/A motors which ran the same compression (L88, 20R, 70s Ford 302, etc, etc).

As far as the MT goes, well, we're running a groupbuy right now (the last one ever). Now's the time to get one

 

NZConvertible, thanks

Brandon, log-style manifold means....(sorry, I'm pretty clueless with these car things ), and I've come to realize the heat issue. Any sort of heat wrap that could help alleviate this problem?? We're already pretty close to the fenderwell as it is.

The thing I'm talking about in the manifold is a flap of sorts at the exit flange of the manifold. It has what looks to be a linkage that controls it from the outside. I have no idea where it went or what it was connected to. I've never actually seen one of the motors assembled completely in a car, so a lot of things are just parts sitting on the floor that have no meaning to me. Thanks for all your help. I'll definately talk to the Unc about the group buy.(when does it end??)

Ary

 

Ohhhh, that's the twin-scroll setup. It closes one inlet to the turbo to change the attack angle of the gasses, which (theoretically) reduces spool time. Don't worry about it; you won't be replicating it.

By a log-style manifold, I mean basically a glorified tube laying parallel with the motor with two inlets from the exhaust ports, capped on one end, and with a turbo flange on the other. It's waaaaayyyyy suboptimal for flow, but it's great for limited-space applications - look at Miata setups for inspiration. Ceramic coating should help a good deal with heat, but you'll still need heat shielding.

GB ends June 9.

Brandon
BR7 Racing

P.S. I see you're "East coast"... anywhere near Tallahassee? We offer lots of services!

 

Nope, sorry(I don't know who's more sorry, you or me ), far cry from FL, I'm in MD right now, and normally reside in Virginia. Thanks for all your help, you'll definately get any business of mine purely because of customer service.

Ary

P.S. Where can I get these turbo flanges?? I haven't seen any on any of the sites like racing beat or others.

 

Nope, for an HT18-S (stock TII turbo) flange, it'll have to be a custom job. Nothing a plasma cutter in competent hands couldn't handle. I'd try to get the car running N/A first tho - less hassles. You can buy T04 flanges on the aftermarket tho... maybe you'll go for a 60-1? (fyi, that's an easy 400hp turbo)

Brandon
BR7 Racing

 

I think I'll pass on a 400hp turbo The car will have enough trouble handling 200hp. I have a question regarding the MT setup, can I run that without the turbo without any problems?? If so I may bypass setting the car up to run a carb and save myself the hassle. I'm really feeling my way through this, learning as I go(in case you hadn't noticed). I had set the objective at having the car running by Friday, but it's looking like that may not happen. I just have so many parts to track down b/w now and then. Also, does the MT setup come w/ any controller? is one necessary if a laptop is used(Uncle is a computer consultant and has about 5 laptops in a corner of his office)?? Thanks again

Ary

 

Yep, the LT8 will run a car N/A just fine. In fact, I'll be fitting an LT8 configured for a turbo onto an N/A this weekend. By the time the GB ends, an N/A-specific version will be available which has all of the load points down at or below atmospheric. If it's gotta be running before the GB ends (June 9 + 4 weeks for delivery), we also do retail sales - just let me know. The LT8 has the option of using 3 different tuning interfaces. Check some of my posts in the Microtech section of this forum for details on each. If there're any other parts you need help tracking down, or if you would like me to detail some setups we offer, just let me know and I can run through them for you.

Brandon
BR7 Racing