Ash.B

For sure that is the plan with that drain bolt but for now I need to get the engine out and get the gearbox and drive train in. I am very disappointed with the carb setup but I have a plan to change it over to EFI once everything is running.

Ash.B

Update is the MX5 starter does not fit the FC bellhousing as I was lead to believe. So I have to hunt down a starter and flywheel/clutch set up . At this rate I will probably need a new slave and fork as well knowing my luck.

The input shaft gets sent to the engineer tomorrow since my dad said he doesnt want to try grinding it down at home which makes sense. So that means subframe only gets cut tomorrow and pushes the whole project backwards

Ash.B

Couldnt wait and sit around knowing nothing is getting done and starting the motor is getting pushed further away so I took the grinder and attacked the subframe

Came out well with the sides giving me more than enough clearance without having to cut alot of the metal out, the front is the only part left on the subframe needing a chop which will only be done once the gearbox is back with FC bellhousing and the motor is sitting in the correct place. So far with a quick feel around the front bar of the subframe will need to be cut roughly half of its width to give the oil pan clearance but I will confirm that tomorrow.

Still waiting for clutch/flywheel combo and starter motor

Ash.B

(marked outline)

(passenger side)
(drivers side)
(sitting lower)

carbroke7

wow nice!

Ash.B

Update time:

Input shaft is getting machined then transmission is getting put back together by the shop. Will be expensive but worth it getting it done right, so I guess thats a cost to factor in when doing this swap

Found a S1 (early 12A to early 13B) flywheel/clutch/fork and starter motor to work with the bellhousing and 13B engine I have.

RXSpeed16

iTrader: (41)

Sorry I'm late to the party, but this project is awesome!!!

Here's the modifications needed to make the miata input shaft fit. Usually they swap the miata internals into the FC case. So I don't know how your hybrid is going to fit.
http://www.mazdatrix.com/faq/miatainputshaft.htmp

The only stock NA flywheel that will be correctly weighted for an REW is an 89-91 non-turbo flywheel. Alternatively, you could also use an aftermarket NA flywheel with 89-91 rear counterweight.

12a starter would work, but the mounting is slightly different from NA 13b's (which are different from turbo 13b's). 13b starters are also stronger. Clutch and fork should work. Looks like you need to make some clearance for the slave on *your* passenger side firewall.

Keep up the great work!

Ash.B

Thank you RXSpeed16, I have the correct (I hope) flywheel and assortment coming up sometime this week to early next. The input shaft/gearbox should come back to me tomorrow with a very hefty price tag for some apparent reason (I will know more tomorrow) and then its notch the front subframe bar and fit the oil pan into the large cavity I have created

So far I have learnt that if you want the input shaft done it most likely will require the gearbox assembly that holds the input shaft to be stripped as most machine shops here in New Zealand wont do it with everything attached. The subframe width wise has alot of room to drop the motor into with very minimal cutting needed, and if you go 13B get the S1 flywheel set up with bits which is needed anyway rather than asking and waiting around, so there you go thats all the information you need when doing this swap

Oh you may also need to bash the front of the transmission tunnel but I will have more on that tomorrow when things get bolted in place

Stay tuned

krgoodwin

I did the same thing and it bolts together perfectly. I have heard some people say you shouldn't bolt a different bellhousing to the transmission as the internals are bored as a set. We shall see how it works.

So an S4 flywheel is not the correct weight for a S5 rotating assembly? I don't know what my flywheel is. Should I be worried?

If you bolted the transmission to the PPF the front cover will hit the steering rack before you clear for the slave cylinder. You can see the cut in this picture.

Ash.B

Ah right, I have already cut the box section to clear the slave, I will have to double check the front cover clearance as I thought you only had to modify the oil pan to clear the subframe or vice versa.

krgoodwin

Once you notch the firewall you only need to put a small notch in the oil pan to clear the steering rack mount.

What I meant is that the engine can not go low enough to clear the slave without cutting because the front cover extends too far forward and over/into the steering rack.

Ash.B

Ok so I have cut the ears along the rear of the fire wall to give alot of room around the bellhousing area, so I only need to slightly notch the oil pan to clear the front of the subframe?

Ash.B

Not a very happy day. Got the gearbox back and it fitted nice and snug. Motor however will not sit lower to line with gearbox due to subframe being in the way and it looks like a large amount of frame is in the way too

Ash.B

I was thinking maybe raising the car since its on coilovers may help with clearance?

krgoodwin

Raising the coils will not help your clearance issues. shimming the subframe (body lift) will help but I can't suggest it.

I fixed this issue with a V8Roadster tubular subframe.

Even with the new subframe the drive line is angled (engine high) more than I would like.

Only solution I have though of it to shorten the PPF and maybe more notching. This is a lot of work though. The 20mm the 12A would probably not be enough but might help.

You could also scrap the PPF and mount it like an FC. Again I can't suggest this.

P.S. you may have figured this out but I am food from Club Roadster.

RXSpeed16

iTrader: (41)

Cool! I see you used the V8 roadsters subframe, so you probably had some flexibility in mounting the engine. Did your shifter location end up being close to stock using this transmission?


If they are mismatched, yes. Just depends on how confident the right one is on there. They usually don't get mixed up unless it's an inexperienced hobbyist-type rebuild. My reasoning is a newbie won't have the extra parts laying around and a professional shop would know better. So it'd have to be someone in the middle.

FWIW, We had a 12a that had a mismatched front counterweight and flywheel. That engine destroyed a rear main bearing within 4 hard hours on track. I attributed it to the flywheel mismatch. Simply because the builder "thought" it had a later 12a front counterweight. Upon disassembly, it did not. We had a good relationship with the guy, it was just a mistake since he assembled it a while back.

krgoodwin

Yes, the bellhousing back is all Miata so it lines up perfectly. It is a little higher because of steering rack clearance issues.

The engine was built by a respectable shop with S4 N/A rotors. I can only assume the front counter weight it from the same set. The flywheel, I have no idea what it came off of. Are there part numbers on the flywheel? Damn, I really don't want to take that engine out again.

RXSpeed16

iTrader: (41)

You mean a miata trans and mounting fits into a miata?!??! Blasphemy!



Did the shop match the flywheel with the engine or did it come out of a parts bin? The identifying number is stamped on the engine side of the flywheel. Flywheels
You might be able to look through the inspection cover with a flashlight and mirror to read it.

krgoodwin

Flywheel came off a donor as the engine I bought was bolted to an autotragic transmission. I will have to see if I can see anything through the inspection hole.

Ash.B

Haha yup I figured it was you Food, thank you very much for all the help so far. I have the motor bolted to the transmission so that was a fair bit of work but now I see where I need to cut and it looks to me like the entire front of the subframe needs to be removed

I might give bashing the transmission tunnel a go but I need the bellhousing to sit higher or the motor to come down lower

Ash.B

Update time:

I have found the problem on the engine side of why its sitting high. The oil pick up tube is resting on the subframe and even a tubular frame would give me very marginal clearance since the motor sits pretty much square on the whole frame. I am unsure of how to change/modify the pick up any ideas?

Ash.B

This is how it sits

Carnifex

This is an awesome build.

Ash.B

Thank you very much. I know there are a few rotary MX5's around (most notably and my favorite is a silver MX5 with a 13B NA swapped into it) but I am hoping but the end of all this I will join in with those that have accomplished a clean and fully functional swap

http://philscarblog.files.wordpress.com/2009/09/re3.jpg

Carnifex

yeah i hope to see this soon. goodluck with the rest of the build