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My name is Ash and I live in little New Zealand. I own a MX5 that I am in the process of installing a 13B-REW engine in just for a bit of fun and experience, which once done will be seeing track time around 4 times a year and mainly street use since this is my work car.
So far I have the motor and started work on getting it ready to drop into the engine bay and I will be updating this thread as often as I can to ensure everything is documented so anyone else wanting to follow me has a good solid outline of what I have done.
I wanted a Nardi steering wheel so I found one local to me that was barely used which I was happy to buy seeing as I plan to keep the interior simple
And mounted my replica Bride seats since the old ones were torn and got these cheap
Stayed quiet for a few months till I got the hardtop painted and recieved my strut braces and oil cooler (in this picture you can see the JDM fogs I tracked down that were hard to find and still are I think)
Then I got tired of the Teins near the end of last year and bought some new BC coilovers
That brings me to the most recent activity at the start of this year which is this beautiful yet interesting (never worked on a rotor engine before just driven a few) 13B-REW engine sitting in my driveway. I am unhappy with the carburetor set up and will go EFI after the engine is in and I can confirm it is running perfect. Alot of tidying up to do but I will get there
I am very grateful to the people on RX7club for helping me, I asked alot of stupid repetitive questions but the guys on here have been fantastic so thank you very much and I hope to make the rotor guys happy with a nice clean fully functional 13B swapped MX5.
I have finally completed the AN-barb fittings on the oil cooler ports and will buy a blanking plate for the oil filter so I can remote mount it. Just incase anyone needs to know the fittings I used for the front and rear ports of the oil cooler on the 13B-REW, they were M18x1.5 not the M16x1.5 front cover and M18x1.5 rear cover fittings as I found online. I will post some pictures soon of those.
Bought the Gates power steering and air conditioning pump belt and only need to find out which lines go where on both pumps. There are low and high pressure outlets just unsure of which is which on each pump. I rebuilt the OMP feed line as well and found the OMP bolt and banjo are indeed 8mm and the bolt and banjo fitting on the housing/oil injector side to be 10mm
Block off blanks on the water neck may come in handy, I plan on running the heater core return coolant line to the side blank in an attempt to not do the factory way of using a "T" piece and connecting it to the lower radiator hose as I want that coolant to be as cool as possible.
And I managed to remove the AST nipple so will thread and block it which takes care of the silly AST missing problem and means I can run the cooling system the way the MX5 has it which is radiator has a pressure cap and overflow bottle works off the radiator
Nate91242 - I hope to document this as thoroughly as I can, I have made word documents with every piece of information I have found and measurements I have taken as well as a spreadsheet outlining costs so if you ever do decide to do it I hope I can provide all the answers you need since there is very little information out there at the moment.
Tinytyrant - Thank you for that, I am hoping to get it done right and make it reliable in the sense that all of my wiring and mounts will stand the test of time. Its been done before just never in a more documented and hopefully when I am done much more simpler way.
Got my low pressure in tank carburetor pump so I dont need any regulators in the bay to dial down the pressure of a high pressure pump (Ford Courier Carburetor pump if anyone needs to know)
I rebuilt the OMP oil line I broke as well so I am hoping upon start up I wont have any issues, if this works I will redo the other line and will fire sleeve both to protect from heat. I will be fire sleeving the rest of the wiring as well
Fittings are a 8mm banjo from the OMP through a 4mm Nylon line to a 10mm banjo on the oil injector side.
I have the Megasquirt ECU arrive and went over the wiring diagram, there are 3 main parts I need help with the other wires are fairly easy to instal and solder.
I bought a oil filter block off plate so I can use my remote mount filter with temperature sensor port and installed the oil cooler AN-barbed fittings on the outlet/inlet ports.
blocked off the AST hole after pulling out the nipple was a semi tight fit but hoping the thread tape will stop any leaks forming.
The motor is pretty much ready aside from wiring, the old engine comes out tomorrow and then the fun/headache begins. I am planning on wiring a low oil level and low coolant level LED alert since I dont have the factory RX7 cluster to warn me. I will use the stock sensors on the engine.
Started the tear down after work today. Really happy everything went smoothly and we reached the target of removing the gearbox for modification tomorrow and installing the new bellhousing. Goals for tomorrow are pull the engine and have the input shaft of the gearbox modified for the 13B.
Pretty tired after working 9 hours and then coming home to work another 3 on the car but its exciting to see it happen, dropping the gearbox was not hard it was just cleaning everything up and trying to reduce spillage from oil/gearbox oil so we worked slowly while stopping for lunch and a general clean up of removed parts/labeling of connectors. Also ordered my oil block off for the oil filter and just need to get the wiring sorted.
The car waiting for the heart transplant pre tear down.
I have my dad helping in terms of guidance for hard areas I am not sure on how to unbolt or reach but overall he is my hero. He and I did the gearbox and diff install on my Supra at home and will be doing this swap as well and I am very lucky to have him to help. Working from the Supra to the MX5 is a huge difference, the shear size of the car makes it so nice to work under where you are not reaching with many extensions to unbolt items and the clearance between the bellhousing and the tunnel was like a football field of room compared to the Supra. So I hope to have more updates tomorrow with a nice solid days work on the car and hope to have something to show at the end of all this
Old B6 engine is out and the 13B test fitted in. Found the areas of the subframe that need to be cut and flattened as well as found the front of the subframe needing to be cut a bit more to give more forward clearance on the oil pan area.
Removing the old engine was really simple and quick and now that the rotary is in the measurements can be made and then the cutting can be done. All thats left now is:
1. Grind down stock MX5 5 speed input shaft since its too long for the 13B
2. Cut subframe and weld flat plate to restore strength
3. Measure and make engine mounts
4. Wire in the engine, fill fluids and hope it starts
Not a very productive day, sort of disappointed in the way it turned out today. Started off great with cleaning the subframe from all the mess, got the AC bolts sorted and built my new power steering feed nipple to adapt the MX5 power steering to the RX7 power steering pump.
Then the sad news to me is: Took off the munted nut on the rear of the engine and removed the flywheel as its too big to fit inside the NA FC bellhousing, and my MX5 flywheel wont fit onto the 13B engine so I need to somehow track down the correct flywheel. I am thinking I need a NA FC flywheel and clutch? if someone knows or could please point me in the right direction that would be great.
Still need to cut the subframe (hope that happens tomorrow) then separate the stock MX5 bellhousing to mount the FC bellhousing and then need to make the mounts. I am behind schedule so I am not very happy but I will work harder to pick up the slack.
So far the engine sits nicely inside the engine bay and tucks up well. Few cuts on the subframe and I should be able to have it in, its just the gearbox/clutch thats a problem at the moment.
Cut the ear/box section from the firewall area that most people trim anyway so that gives me alot of room on the sides. Next is cutting the subframe to allow the oil pan to sit where I want it too and then its wait for the welder to come down and neaten everything up. So far I am making good progress as opposed to yesterday and should be back on track by the end of today. I will source a NA RX7 flywheel and clutch set up and then hope it fits my MX5 spline
Munter describes it. Your pilot bearing should probably be replaced. It wasn't installed deep enough and there is no pilot seal that I can see. That means no grease and high levels of wear.
The problem is new clutch kits no longer come with the seal and no instructions for how deep to install the pilot bearing. Then you get some munter thinking he needs to change out the old pilot bearing when they usually are fine. That's been my experience. Good luck. Cool project by the way. I might want to do a Miata at some point.
Thank you very much Jeff20B. New pilot bearing will be coming once I get the flywheel and clutch sorted. I would say if you ever want to do a MX5 project like this go with a V8 Flyin Miata subframe. Makes the dropping in part a piece of cake unlike mine.
The subframe at the moment is fairly easy to modify its just the front section that needs to be larger to accommodate the oil pan. Honestly using a V8 subframe will be best unless you are willing to cut the MX5 subframe like me. Once done I will have some pictures and a guide just sit tight for now.
Update is the oil pan was remove to allow the engine and bellhousing to sit deeper into the engine bay to see where I need to cut. I have marked out the subframe sections along the side its just the front area by the oil pan that needs attention now. Work has come to a stop while I wait for a flywheel, some how separate the bellhousing on the old gearbox and fix a power steering hard line my dad bent
Got the bellhousing off and will install the FC bellhousing tomorrow morning. Once that is done plan of attack is reassemble the gearbox with new bellhousing and PPF so that the car is once again in alignment drivetrain wise and then put the engine back. Measurements will be taken on the subframe one last time and I will cut the frame wider and lower the engine in, that should allow me to make my custom mount measurements and be done with the engine install area. I am pretty happy since this makes progress almost back on track (subframe should have been cut today )
(remove Clips, these hold the input shaft and bearing on the bellhousing)
I have some photos of the clearance and my proposed mounting/cutting:
You can find a short drain bolt to replace your long one. Any 12A or FD should have one. Only the FC and a few other models with center motor mounts required the long drain bolt. Looks like someone swapped yours. Doesn't surprise me seeing as your engine also has a carb for some reason.
I predict a short bolt will solve your clearance issue. Good luck!