1991 Efini RX7 FD3S

[Chawkie]

Fair play. I'm feeling I've a massive problem ahead when I try to start piecing mine together after a couple of years !!


The engine mounts originally would have been one rubber bonded aluminium one and a steel one with a bolt on rubber mount. Later engines came with 2 steel ones. Most will swap to 2 steel mounts as it's not possible to get replacement aluminium ones or they're mad expensive or something.

I managed to pick up a set of pretty fresh series 8 mounts from Japan a few years back as part of the stockpile

[Smythy411]

it that’s another great update 👌🏽

Thanks lad ✌

What the actual fook. And I thought new cars where bad with the nest of electrical and piping.....

That is a serious amount of vacuum lines!

I'd say that stud breaking is a blessing in disguise. Better to be installing the engine and checking things over next weekend when you are well rested.
You got some amount of work done there.

That's assuming I get a full weekend at the car next time 😅 But I'm never well rested

I’d have lost my rag with the rats nest, kudos man!

I can't wait to get rid of it! I'm eying up ECUs already!

Christ that was some amount of work in a short time fair play to ya. Just on a suggestive note would a new water pump not be a good idea?

I had planned on changing it, but when ordering parts last year, I wanted to keep this engine refresh to just what it needed. Just in case it blows up on first start Bearing is good, there is no play in it, and it has a metal impeller, so not much to worry about right now. It's easy to access anyways in the engine bay, so if the engine goes fine after the rebuild, I'll think about changing it then

Fair play. I'm feeling I've a massive problem ahead when I try to start piecing mine together after a couple of years !!


The engine mounts originally would have been one rubber bonded aluminium one and a steel one with a bolt on rubber mount. Later engines came with 2 steel ones. Most will swap to 2 steel mounts as it's not possible to get replacement aluminium ones or they're mad expensive or something.

I managed to pick up a set of pretty fresh series 8 mounts from Japan a few years back as part of the stockpile

Thanks man! That is good to know about the engine mounts. I just assumed one had been changed out at some stage or something.

[dimitri]

So close, but I also reckon a quick stud change the next time you're out and you'll be fresh as a daisy for the engine install and fire up.

Just on the water pump pulley....a bigger pulley at the same belt speed will equal lower RPM of the water pump wont it? Maybe the intent is to avoid cavitation on high engine speed installs or such, or did the newer engine have a different pump style?

[Smythy411]

So close, but I also reckon a quick stud change the next time you're out and you'll be fresh as a daisy for the engine install and fire up.

Just on the water pump pulley....a bigger pulley at the same belt speed will equal lower RPM of the water pump wont it? Maybe the intent is to avoid cavitation on high engine speed installs or such, or did the newer engine have a different pump style?

Yep your absolutely right... My head was not working when I was looking at that pulley and doing the maths 🙃 Probably used more so for engines that are geeing a lot of high RPM driving to reduce the pump speed killing the bearing, and as you said, avoid cavitation....

Please ignore my moment of slowness.... I may fix the post accordingly

[dimitri]

No worries, I had to sketch out a few examples on post-its before I was sure enough to cautiously query it

[Smythy411]

Hope everyone is getting used of these fortnightly updates. Today's episode follows much the same trend as the last few.... lots of photos, lots hardship, and lots of botchery!

So I landed home Friday evening with some goodies for the engine. Some fresh sparkplugs for starters, which are not the easiest to find, and considerably dearer than any BMW or Toyota plugs I've bought before




A couple of fresh genuine Mazda oil filters on the menu too. One will be swapped in after I've ran the engine a small bit more, and the other after I've done my engine run-in mileage




So back to the broken exhaust stud from 2 weeks ago... When I got back to Cork after that last weekend, I went rummaging for my tap and die set. It's an old enough set and well used, so I made the conscious decision to go buy new taps and a few decent drill bits. I wanted to make sure I was well armed when I get back to the engine






Right its 6pm on Friday, so let's get drilling... ah great the drill battery is dead of course




Then perfect timing, a buddy called in looking for parts and to distract me for the rest of the evening 🙃

Ok Saturday morning, so let's get drilling. Start with a 5mm pilot hole




Then out to 8mm. Got it pretty well centred, just touching the housing threads on one side. An 8.2mm hole would have been the proper size to tap m10






The first couple threads could be picked out with a bit of prying before I needed to start using the tap




Ah lovely, this is gonna be easy....




An hour later I was less enthusiastic. When I started tapping the hole, the harder steel threads left from the stud was pushing the tap into the softer aluminium. Eventually the last bit of thread managed to work its way out with the tap, but the first couple threads were not in great condition afterwards. I had a 3 stage tap so could tap it right back into the back of the hole. Once the stud was screwed in the whole way, it was good and solid




I then cleaned up the threads on all the studs and bolts








Fiiiiiiiiiinaly I could bolt on the exhaust manifold, along with the heat shield and turbo control actuator (this controls the big turbo control flap here which is what controls the exhaust flow to each turbo... blocking off one turbo until higher in the rev range to allow the turbos work sequentially)




I was behind schedule, again, so decided not to take a break for the F1 quali

https://youtube.com/shorts/9vx_ZA8_2GQ


Time to bolt on the turbos. I'm using the 99 spec turbos from my spare engine as they are in better condition, and capable of much more power. They should still run fine on the standard series 6 ECU, but I will monitor over boost with a boost gauge just in case. If needs be, I can add a restrictor plate into the exhaust or run a boost controller






Then bolt on the turbo charge pipes. There is a slip joint in the middle to allow the pipes to be installed, and this is sealed with an o-ring. I noticed it was not very tight so thought I'd better check the o-ring








It was a long time since this could have been called rubber

https://youtube.com/shorts/BBT-RZ7EG44


Fresh new o-ring from a generic kit




One last blue vacuum hose to change out




Better




Rear intake pipe on




And front one




And that side of things was done for now






Better swap the sparkplugs now as it's a pain when in the car




One of the old plugs broke in half when I was removing it! Definitely due a change




Right so we are ready for lift off! In comes my 90hp engine crane






Time to squeeze up all the sump bolts and fit the engine mounts. The exhaust side engine mount has a stainless steel shield to protect it from the heat.






I had planned on giving the engine bay of the car a good scrubbing and power wash.... of course I completely forgot about this until I opened the bonnet to fit the engine It was getting late, so just spent an hour cleaning the oil and gunk off the subframe and a quick degreasing






Yes yes, I know it's dodgey just dangling the engine off the loader prong, and it could slide off the front if I make a wrong move.... but don't worry, this is not my first rodeo. I am clinical with this machine






Note that I am on my own in the shed doing this... hard get help on a Saturday night! So I was getting plenty exercise jumping up and down from the tractor every 4 seconds






And we're home!






Called it a night and retreated to the house. I got straight back at it on Sunday morning, starting the exhaust downpipe. And I immediately wished I'd bolted this onto the engine before it was in the car . It would have been worth the extra wiggling of the engine to get it in place. And I should have known this from the last time I had to fit it after the manual conversion! Such a tight space between the engine and chassis




After that heartache, I turned to some easy stuff, like plugging in the wiring loom and feeding it into the cabin. This is when I noticed something quite bad... the map sensor nozzle had broken off at some point!




Must have happened when lifting out the engine back in September




This could be a showstopper for trying to fire the car up... so I starting thinking of ways to "fix" it. After a rummage around the shed I had an idea and drilled out the nozzle hole to 5mm




Then add a short bit of Kunifer brake line




And a messy dollop of Wurth Bond and Seal




With that botch job left to cure, I turned back to the underside of the car. And dove into a job I was avoiding all morning. Fitting the gearbox... on my own... lying on my back... 2ft under the car. I fitted the air feed to the cat, which goes over the gearbox, and that's where the photos stop for a while




I'm still sore to this day after the many yoga positions I had to do to lift the box into place, and angle up the diff to get the prop and PPF in. It was however helped by the fact I'd mated the engine and box already, as they slotted together so cleanly this time! The exhaust followed, along with the many tunnel braces




It was time to take a well earned break for lunch and F1.




After the race I eased myself back into it again with another easy job. New sump plug washer... can't get much easier.




And then finished up the underside for now by fitting the starter and clutch slave cylinder. The ol' blue wire still running to my toggle switch to start the car since the manual conversion




With the underside done and the wiring all sorted, it was time to go back to the engine bay and start hooking up fuel lines and coolant hoses. The intake pipes were roughly thrown in too to get the engine to a point where I could give it a go at starting




Another handy thing about my starter switch is that I can turn over the engine and build some oil pressure with ease. Not that I needed to worry about that as I'd forgotten to plug in the ECU for the first start too . Got a little nervous when I heard no life from the fuel pump

ECU connected up I went again. I hooked the jump leads up to my old A4 for some good diesel cranking amps

Don't worry about the smoke, that's all the Vaseline burning off and escaping from the exhaust flange I hadn't tightened up. What was worrying, however, was the scraping noise coming from the engine 😑 After some mad panicking, thinking it was from the engine, and a couple more goes at firing it up trying to locate the noise, I found it was the clutch fork just touching the pressure plate. Being a pull type pressure plate, you have to push and click in the release bearing into pressure plate... I of course forgot this and just jammed my clutch slave in without thinking. I removed the slave cylinder, pushed in the bearing, and refitted cylinder properly. Let's go again.

The noise was now gone but it was hard to start and wouldn't run right... until I remembered the map sensor sitting over on the shelf drying. The sealant was set enough to connect the hose so I fitted it and plugged it in

Idle is too high at the minute, but I reckon that's down to me fiddling with the TPS. I had taken it off to check the plug wiring on it. But the car seems to be running smoothly and revving nicely. I topped up the coolant then until I realised it was pouting out the side of the engine. I'd forgotten to hook up the heater matrix hose, and with that sorted, I got the coolant system filled and bled

Well that was a big weight off my shoulders hearing the car run. This was after midnight on Sunday night in Clare, and I needed to be in work at 7am the next morning in Cork, so I left it at that for the night. I've only ran the car for maybe 60seconds so far, so I'm not out of the water yet. Will need to get it up to temp to make sure everything is good to go. But that being said, it definitely has more compression that what I started with so I'll take that as a win 😅

The good temporary bench has done me proud, and all that's left on it is a load of spare nuts and bolts I've forgotten to fit somewhere 👀




And another great thing to see is the car back sitting at it's old ride height






And so concludes another exhausting update on the car. Again, a good bit done to the car, but not as much as I was expecting/hoping. I will probably be home again on Paddy's day so I will get it running up to temp and maybe even drive it out of the shed! Stay tuned!

I'll leave ye with some more exhaust noise

[Aontroim]

Great work! You should rightly be proud of that!

[Smythy411]

Great work! You should rightly be proud of that!

Thanks Man ✌

[Bazg2]

Another top job, one has to doff their cap to your home spannering skills 🎩

[Shkinner]

Fair play to you - very impressive! I love reading these updates, so keep em coming!

[Deadly Dave]

Fantastic, well done.

[Smythy411]

Another top job, one has to doff their cap to your home spannering skills 🎩

Fair play to you - very impressive! I love reading these updates, so keep em coming!

Fantastic, well done.

Thanks boys! Appreciate the comments 👌

[R26B]

Well done, some great ingenuity there and determination to solve issues. Fair play for taking the time to take pics, they add a lot to the thread.

[Smythy411]

Well done, some great ingenuity there and determination to solve issues. Fair play for taking the time to take pics, they add a lot to the thread.

Thanks man! Should have another update coming later today or tomorrow

[Smythy411]

Right, this update should be a little shorter that the last few, as I had just 1 full day at the car this weekend. I got back to Clare last Thursday night around 9pm, and decided I might as well get an hour or two in the shed to get a head start. I opted to sacrifice my Paddy's day too finally get the car back driving

Eased into it with a nice simple job... fit the bonnet stay rod




Fired up the car and went about checking for vacuum and exhaust leaks. It was very loud, and as you could probably tell from my videos from the last update, there was definitely a big exhaust leak. I had assumed it was just the flange between the downpipe and the cat being very loose, but after further investigation, it seemed to be coming from much closer the turbos 🤔. The downpipe itself was on good and tight, so it had to be the flange between the turbos and exhaust manifold. The only problem now is that you can't access the bolts on this flange easily now with all the heat shields and the tight space in the car. I retreated to the house to think over my options for the following morning. There was only one thing for it, I had to go stripping down the charge pipes over the turbos

Removing rear inlet pipe was a battle in itself on Friday morning. The studs are too long on the turbo intake, and wouldn't allow the pipe to come off with lack of clearance to the bulkhead




I ended up having to use a hacksaw blade on the end of a vice grip to chop the end of studs off so the pipe could slide over. With that loose I could wiggle it out along with the charge pipe, and had the eventually I had a bit more access




I had to remove the rear turbo oil drain pipe too before trying to remove all the heat shields. But of course, with the proximity to the chassis, there was no way to actually remove the shield covering all the nuts I needed to access. So I had to use an assortment of prybars and spanners to squeeze in behind, moving the shield around as much as I could. Turns out every nut was loose on the studs holding the turbos to the exhaust manifold Not sure how I managed that, I am sure I remember squeezing them all down tight! A silly mistake, that really annoyed me!

Anyways after most of the day wasted, I had all the intake and charge pipes back on. I then went about properly fitting back everything in the engine bay I'd skipped passed the last weekend. I wanted to fit my Mishimoto fans and shroud that I got with the Mishimoto rad




I then realised that the mounting tabs were different so oddly it was not a direct fit. The wiring was also going to be a bigger job than I thought, as the new fans were single speed, whereas the standard fans were variable speed and controlled by a series of relays.... The standard fans are still pretty decent so I left them in for now and will look at doing the bracket mods on the shroud and getting a proper fan controller to replace the factory relays




Eventually I got it all back together and stood back to admire the complete engine bay... finally!




Time to fire it up again!

Much smoother, but still idling too high at just over 2k rpm. I spent a good bit of time messing with the idle screws to try get it right but couldn't get it to drop under 2k. Eventually I took off the TPS for a look and spotted it had not seated right when I fitted it back on. Refitted it and my idle was down to near 500rpm! Adjusted it back up up to around 7-800 everything seemed so much better!

Still a bit low there. I need to do some fine tuning to get the cold and hot idles perfect, but we are in the right ballpark!

There was only one thing left to do... fit the seat and make it move

Good thing the front lip is very flexible

Took the car for a couple quick spins over the road. First drive had a pretty bad boost leak, which was sorted with an adjustment to some hose clips. Eventually I'd 8km done and the car was starting to drive pretty well!








It was a bit hesitant to start boosting, and the idle still needs work, but I was just so happy to be back behind the wheel of the car. When the boost would kick in, the car was definitely plenty fast! I went to bed a happy man after a successful St. Patrick's day!


I had a couple hours spare Saturday morning then before I needed to head away again, so I go the sudsy water out!






The dogs were very curious about the noise












I took the car for a good 20-30km spin and it starting clearing it's throat and running a bit better. I was running out of time so I got it back to the shed and back onto the ramp to drop the oil. I let it drain away while I tidied up the shed.




I'd no time to refill the oil, so I left myself a quick note incase I forget the next time I'm home 😂




And that's where the long updates will probably end for a while. I'll hopefully bring the car back down to cork next month and try get some good mileage on it to make up for lost time. Hopefully it will be back running perfect again without much work. Think I'll get a smoke machine and test for vacuum leaks, and do a proper set-up of the TPS and idle. Until then, enjoy the photos!