Category: MX5

The new HG arrived and confirmed to be the right part, nice open oil galleries and water feeds at the Cylinder 1 end. This is important as I will be running a coolant reroute that switches the water outlet from the head to cylinder 4 rather than 1. Running the VVT gasket with a reroute negates the entire purpose of the reroute itself.

[img]http://images.plebeians.net/i.php?/upload/2019/08/07/20190807050942-0b37dbe8-xl.jpg[/img]

Popped the head on and then the ARP studs and torqued down the head. Still needs another torque check after some weather cycles. Then added a Boundary billet oil pump

[img]http://images.plebeians.net/_data/i/upload/2019/08/07/20190807050934-725fb1ed-xl.jpg[/img]

Replaced the oil seal that came with it for a genuine Mazda one. Lots of people reporting oil leaks with the Boundary seal.

Then add one new water pump and backing plates so we can get the timing gear installed.

[img]http://images.plebeians.net/_data/i/upload/2019/08/07/20190807050925-772e6bda-xl.jpg[/img]

Now the Mazda B6/BP engines have a pretty severe flaw in that the crank extends only about 5mm proud of the timing belt gear, with the ancillaries pulley left to hang in free air for most of its length:

[img]http://images.plebeians.net/_data/i/upload/2019/08/07/20190807050907-25d929ad-xl.jpg[/img]

This leads to the common issue of a wobbly ancillary pulley and then a flogged out keyway on the crank.
To combat this a guy in the US has started machining up these spacers for the crankshaft that replace the stock washer, and come with a longer key that is sandwiched in place:

[img]http://images.plebeians.net/_data/i/upload/2019/08/07/20190807050915-35237f01-xl.jpg[/img]

As can be seen here it eliminates the void in the ancillary pulley to the crankshaft

[img]http://images.plebeians.net/_data/i/upload/2019/08/07/20190807050845-4eaf6be8-xl.jpg[/img]

[img]http://images.plebeians.net/_data/i/upload/2019/08/07/20190807050858-efbe5425-xl.jpg[/img]

It is probably somewhat overkill, but its a reasonable solution to the problem that Mazda caused for the engine.

Now that the head is on I could start mocking up various components to check fitment and compatibility.
First up is this oil filter thermostat housing which may be a solution to the relocation issue i think I will have.

[img]http://images.plebeians.net/_data/i/upload/2019/08/07/20190807050826-fad5f185-xl.jpg[/img]

However the alternator sits just to the right there, and the intake manifold is exceedingly close on top. I suspect that this orientation will be the only one that works, and then the oil lines are pointing in the opposite direction. Will have to keep working on that one.

Next up I decided to get most of the engine mocked up and test fit, so out came the inlet manifold and fitted up, then the turbo manifold to clock the turbo:

[img]http://images.plebeians.net/_data/i/upload/2019/08/07/20190807050724-e5a6a957-xl.jpg[/img]

Once the turbo was clocked and in place it was time to start thinking about how everything fit up. First problem is the oil feed on the block.

[img]http://images.plebeians.net/_data/i/upload/2019/08/07/20190807050817-a554dae9-xl.jpg[/img]

Apparently it is a 1/8 BSPT not a 1/8 NPT, which means that the NPT fittings get about a thread in before fouling.

Next is to try and decide what sort of oil and water feed fittings to use. Mocked it up using the ones that came with the eBay turbo

[img]http://images.plebeians.net/_data/i/upload/2019/08/07/20190807050809-7a7857a4-xl.jpg[/img]

I think ill keep the banjo arrangement on the water drain, but the feed there ill switch to a stainless one.

Then fitted up the Kinugawa wastegate actuator to accomodate the turbo being clocked:

[img]http://images.plebeians.net/_data/i/upload/2019/08/07/20190807050800-8e193f9d-xl.jpg[/img]

Will just have to clock the cover, but I need to change the spring over anyway so that can be done later.

Added one coolant reroute

[img]http://images.plebeians.net/_data/i/upload/2019/08/07/20190807050751-4d8860ee-xl.jpg[/img]

Uses a spacer plate and a thermostat cover from some Kia, will work well. Need thermostat.

Also considering using this cast iron dump pipe to V-band adapter

[img]http://images.plebeians.net/_data/i/upload/2019/08/07/20190807050741-9fc486bd-xl.jpg[/img]

Looks like a half decently made piece of equipment.

So a few things to tidy up there, but its all pretty much sorted. Hope to have the engine screwed together by the weekend.

Plus the last piece of major hardware arrived for engine reassembly:

[img]http://images.plebeians.net/_data/i/upload/2019/08/07/20190807050837-0c636577-xl.jpg[/img]

Lightweight chromoly BP flywheel from Xtreme clutch. Cheaper than getting a stock BP flywheel and getting it resurfaced.

Well this took a back seat over the holidays with being away, and also with waiting on a new head gasket.

When i ordered a HG for this originally they sent a 01-05 VVT BP gasket, in the 94-00 gasket slip. I didnt notice until i went to put it on the engine and found that it blocks off half of the water galleries to the head:

[img]http://images.plebeians.net/i.php?/upload/2019/07/28/20190728230412-8e0b0bfc-xl.jpg[/img]

This is especially bad as Mazda changed the water gallery arrangement on the VVT heads as well which means that if you use this gasket with the BP4W head it blocks off almost all of the water going into the head… fail.

In the end it took almost 6 weeks to get a new HG in, courtesy of the supplier sending me VVT gaskets twice more and being away for holidays.

Anyway, in the interest of not letting the arachnids fornicate too much longer i started doing other things.

First on the agenda was to get rid of the insanely long fuel lines into the engine bay and their associated bulb flare ends. A couple of 6AN hardline adapters took care of that:

[img]http://images.plebeians.net/i.php?/upload/2019/07/28/20190728230407-56ceca3c-xl.jpg[/img]

Also, a label maker and heatshrink makes life a lot easier in the long run, especially as both feed and return are the same size. (Also see red ziptie).

Next was this pair of replacement swaybar mounts, given the stock ones are relatively notorious for cracking. Its probably overkill, but I had credit at a supplier to use up.

[img]http://images.plebeians.net/i.php?/upload/2019/07/28/20190728230353-795d2be5-xl.jpg[/img]

[img]http://images.plebeians.net/i.php?/upload/2019/07/28/20190728230345-7345afa3-xl.jpg[/img]

The new HG arrived today, along with some other parts, so it is time to get back into it.

So a mate came around today for me to weld up a suspension bracket on his Landcruiser, and while he was sorting out the suspension i was just pottering about in the garage. After cleaning up I turned to the car and decided to start getting it ready for the engine to be pulled, thinking it was going to be next weekend.

Nek minnit, engine ready to come out:

[img]http://images.plebeians.net/i.php?/upload/2019/06/15/20190615023921-1795ccd7-xl.jpg[/img]

But wait, no engine crane available. Never fear, high lift jack is here:

[img]http://images.plebeians.net/_data/i/upload/2019/06/15/20190615023811-3efebaf8-xl.jpg[/img]

Voila, one engine and subframe out under the bumper reinforcement:

[img]http://images.plebeians.net/i.php?/upload/2019/06/15/20190615023831-1af07fcf-xl.jpg[/img]

Old B6 engine out, ready for being torn down with my 5yo:

[img]http://images.plebeians.net/i.php?/upload/2019/06/15/20190615023907-a28c0d1a-xl.jpg[/img]

Nice empty engine bay with the NB8B subframe temporarily in place so that the car could be dropped down to level again:

[img]http://images.plebeians.net/i.php?/upload/2019/06/15/20190615023854-69847719-xl.jpg[/img]

Thats a few weeks ahead of schedule, so now its time to tidy up a few bits in the bay and start thinking about getting the BP back together to go in.

Got bored yesterday while waiting for parts to arrive, so instead of tidying the garage ahead of the engine swap, i welded in the reinforcement plates to the subframe:

Take one set of Spec Miata subframe gussets:

[img]http://images.plebeians.net/i.php?/upload/2019/06/06/20190606173241-fa14971d-xl.jpg[/img]

Line up:

[img]http://images.plebeians.net/i.php?/upload/2019/06/06/20190606173138-84db057c-xl.jpg[/img]

And weld:

[img]http://images.plebeians.net/_data/i/upload/2019/06/06/20190606173204-275c47d8-xl.jpg[/img]

Also, take this as a lesson of why not to build engines when doped up on Codral from a sinus infection. What is wrong here:

[img]http://images.plebeians.net/i.php?/upload/2019/06/06/20190606173259-7053dcaf-xl.jpg[/img]

So the MX5 is the first turbo install I have done where its not factory replacement or completely and entirely compromised by packaging, and i generally have a reasonable amount of time on my hands to get little things sorted (yay for no race schedule).

On all the previous cars (even the factory stuff) the water ports have been relatively horizontal, and I have followed suit for other turbo conversions.

However, reading this Garrett whitepaper (mirrored on GCG) [url]https://gcg.com.au/component/rsticketspro/view-article/18-water-cooled-turbos-they-need-water[/url]
they suggest a 20° clock with the inlet down and the outlet up. But also recommend an uphill pipe from the outlet to somewhere else in the engine to enable thermal siphoning after shutdown.

[img]http://gcg.com.au/images/water_p7.jpg[/img]

On the MX5 this is a problem, as the high pressure inlet sources for the turbo are all in the head, and higher than the turbo. Conversely, all the return locations are low in the block or the mixer.

Originally i was planning on just running the high pressure side out of the thermostat spacer at the back of the head, where the heater core comes out. Or as another guy down here has done, inline with the heater core:

[img]https://i.imgur.com/w2TPhkc.jpg[/img]

But that puts the inlet side at 20° elevated, rather than on a decline, and from this graph is more than somewhat undesirable:

[img]http://gcg.com.au/images/water_p8.jpg[/img]

How much am I overthinking this? Just put it in horizontal and leave it be?

Started working out a place for the intercooler and oil cooler, and I think it will end up with them stacked in front of the radiator. A little less than ideal, but nowhere else really works for packaging.

Used it as an opportunity to practice more on the TIG:

[img]http://images.plebeians.net/_data/i/upload/2019/05/25/20190525005709-fa133f9e-xl.jpg[/img]

Made up a long bracket to go between the upper AC mounting holes:

[img]http://images.plebeians.net/_data/i/upload/2019/05/25/20190525005735-bbdc22b3-xl.jpg[/img]

FG intercooler fits well in there now:

[img]http://images.plebeians.net/_data/i/upload/2019/05/25/20190525005727-68707ef2-xl.jpg[/img]

Although im still considering getting a shorter and wider core to mount in the air stream some more. Perhaps something like this at 500x230mm:

[img]https://i.ebayimg.com/images/g/vy0AAOSwFeNcw8Dj/s-l1600.jpg[/img]

Typical that just after I pick up the block i come down sick and am out of action for a week or so. Crawled out of bed today and was feeling a touch better, so started pottering around building the engine.

First up was doing all the calcs for the piston/rod/pin combos:

[img]http://images.plebeians.net/i.php?/upload/2019/05/23/20190523050531-3e3b1bd9-xl.jpg[/img]

Then file fit all the rings, which mercifully didnt need much more than a touch on the linisher.

Add one set of ACL race bearings:

[img]http://images.plebeians.net/_data/i/upload/2019/05/23/20190523050523-b9f234c1-xl.jpg[/img]

[img]http://images.plebeians.net/i.php?/upload/2019/05/23/20190523050514-b652dd86-xl.jpg[/img]

Add rings and spin them all around to different parts of the piston, and compress:

[img]http://images.plebeians.net/i.php?/upload/2019/05/23/20190523050504-3274377c-xl.jpg[/img]

Insert into block:

[img]http://images.plebeians.net/i.php?/upload/2019/05/23/20190523050359-8b808809-xl.jpg[/img]

Check bearing clearances with Plastigage… then find out that your plastigage has gone hard, and go buy ACL Flexigauge. Check bearing clearances with Flexigauge:

[img]http://images.plebeians.net/i.php?/upload/2019/05/23/20190523050409-f0e42e62-xl.jpg[/img]

Rinse and repeat 4 times while fielding calls from OS and small children, and you get this:

[img]http://images.plebeians.net/i.php?/upload/2019/05/23/20190523050431-d1a2741e-xl.jpg[/img]

[img]http://images.plebeians.net/_data/i/upload/2019/05/23/20190523050456-2a51c8a3-xl.jpg[/img]

Subsequently realise that you cant remember aligning the rings on piston 2, and so remove that to check… thankfully i had actually done it.

CSH time: When i was in high school a kid a couple of grades above got a Datto 1200 for his birthday and proceeded to do it up, so that he could drive it to the Year 12 formal. When it came down to the wire he started it up and it was spewing smoke out the exhaust. Nevertheless he drove it to school proudly.
What went wrong? Well he was a little bit OCD with the car, and so lined up all of the piston ring gaps on the pistons…. :knock:
Taught me that you shouldnt line up piston ring gaps, even before i had built an engine.

Anyway, now waiting for replacement valve springs to come for the head, and then I should be able to screw that together and start thinking about closing up the engine.

Well this just arrived today, guess im locked in on my ECU choice:

[img]http://images.plebeians.net/i.php?/upload/2019/05/09/20190509012347-1f6af7cc-xl.jpg[/img]

Now to decide how to wire it up. That adapter its using is for an NB but sold to me as an NA adapter 🙁

Also ducked out after work today and picked this guy up:

[img]http://images.plebeians.net/_data/i/upload/2019/05/16/20190516233732-304d7d04-xl.jpg[/img]

Torque plate bored and honed for the forgies, decked for MLS gasket. Cracking turnaround from Speedworks, only dropped it off on Wednesday.

While waiting for my silicon bronze TIG rods to arrive i started pulling down the BP head.

Exhaust valves look pretty hammered and carboned up, and I think its probably been running a touch lean:

[img]http://images.plebeians.net/_data/i/upload/2019/05/02/20190502165525-a409cff9-xl.jpg[/img]

All the valves came out easily with the help of this tool:

[img]http://images.plebeians.net/_data/i/upload/2019/05/02/20190502165535-20ae16df-xl.jpg[/img]

Seriously, if you are pulling valves out of heads, get one. Its a lifesaver.

Exhaust valves were pretty gunked up:

[img]http://images.plebeians.net/_data/i/upload/2019/05/02/20190502165545-0a793d70-xl.jpg[/img]

[img]http://images.plebeians.net/_data/i/upload/2019/05/02/20190502165554-3bff63a6-xl.jpg[/img]

With a few mins on the wire wheel they cleaned up fairly ok:

[img]http://images.plebeians.net/i.php?/upload/2019/05/02/20190502165610-cf5ef668-xl.jpg[/img]

Should be good enough to use for now, and i might see if i can source another head for some 1mm OS valves and heavier springs later on.

Need to lap them back into the head, but all my lapping compound has gone hard. So that will have to wait until i can get some more.

Had some sunny-ish weather, so i got out the pressure washer and gave the head and intake a good clean. Played tunes on the intake manifold in honour of MCM:

Started lapping the valves back into the head, decent finish for now, even if it not so shiny as the original:

[img]http://images.plebeians.net/i.php?/upload/2019/05/04/20190504013157-aff5d6aa-xl.jpg[/img]

First time ive lapped valves since building 4Ks, Kents and the Mini engine.

Also noticed some pitting on cylinders 1 & 2 from a touch of low detonation:

[img]http://images.plebeians.net/_data/i/upload/2019/05/04/20190504013229-19a40345-xl.jpg[/img]

and some scratch marks which suggests that this head may have been apart before:

[img]http://images.plebeians.net/i.php?/upload/2019/05/04/20190504013247-5793d750-xl.jpg[/img]

Perhaps from cleaning with a rotary brush or something.

Debating whether to give the combustion area a clean up with a ball polisher like so:

[img]http://i45.photobucket.com/albums/f100/justinbelshe/Dadzuki/DSC02335.jpg[/img]

Still unsure on how it will work for a complex combustion area rather than the simple bowl type that I’ve used it on in the past.

Also the intake on the BP has this massive expansion chamber in the intake:

[img]http://images.plebeians.net/_data/i/upload/2019/05/04/20190504013140-a4cdc3ea-xl.jpg[/img]

Its actuated by a vacuum lever off this cam:

[img]http://images.plebeians.net/_data/i/upload/2019/05/04/20190504013148-f29cd011-xl.jpg[/img]

Debating whether i delete it entirely. Looks like it only has one exposed end where the cam comes through, and i should just be able to remove the butterflies and pull the rod out. Then i can tap a thread in the casting and seal it up that way. Will decide another time i guess.

Had a bit of downtime yesterday in between brewing stages, so i pulled the NB steering rack and started pulling it down.

Firstly, looks like it has had some work done to it in the past, some nifty old school wire work:

[img]http://images.plebeians.net/i.php?/upload/2019/04/25/20190425053256-2ff2fd6d-xl.jpg[/img]

Pulled the pinion housing out:

[img]http://images.plebeians.net/i.php?/upload/2019/04/25/20190425053320-475afd76-xl.jpg[/img]

Then removed the pinion:

[img]http://images.plebeians.net/i.php?/upload/2019/04/25/20190425053341-8a7e259e-xl.jpg[/img]

Some people talk about this being a horrible job, but it just slipped out with a few taps of a soft face hammer.

Similarly the valve body slipped straight off:

[img]http://images.plebeians.net/i.php?/upload/2019/04/25/20190425053358-3d2d3fcc-xl.jpg[/img]

Now we can see where we need to weld:

[img]http://images.plebeians.net/i.php?/upload/2019/04/25/20190425053411-53968e3f-xl.jpg[/img]

This seems to be the newer design of rack, with the rectangular tang end, rather than the splined setup. I have some silicon bronze filler on order and toying with just silicon bronzing it up. But if not ill just put in some side stitches in the concave reliefs with ER70S6 and add some silver solder to braze the rest together.

Then as i was pulling the car back into the garage i found out another issue with the idiotic fail of an overflow bottle:

[img]http://images.plebeians.net/_data/i/upload/2019/04/25/20190425053430-f08623dd-xl.jpg[/img]

The side of it fouls on the popup headlight actuation arm, and broke the pivot cup.

[img]http://images.plebeians.net/_data/i/upload/2019/04/25/20190425053443-149e747b-xl.jpg[/img]

Apparently this is a fairly common wear and tear issue, and the solution is to clean it all up, and glue them back in place:

[img]http://images.plebeians.net/_data/i/upload/2019/04/25/20190425053455-3ab44d8d-xl.jpg[/img]

[img]http://images.plebeians.net/_data/i/upload/2019/04/25/20190425053455-3ab44d8d-xl.jpg[/img]

Will have to see how well it works, and how long it holds up for. Might just order a spare to keep around.

Nup, failed on first actuation:

[img]http://images.plebeians.net/i.php?/upload/2019/04/25/20190425231301-5f4f79ae-xl.jpg[/img]

This showed up in the post today though, makes it vaguely better:

[img]http://images.plebeians.net/i.php?/upload/2019/04/25/20190425231239-6c8cde38-xl.jpg[/img]

Took advantage of having some store credit at Supercheap, plus their Easter weekend 20% off special orders and a few other bonus deals.

Another month on, rolled the guards, got a wheel alignment for the rear, and started the logbooking process. Currently waiting for CAMS to get back to me on my cage certification so i can put that on the logbook application.

Had to snap a few photos for the logbook:

[img]http://images.plebeians.net/_data/i/upload/2019/04/23/20190423220912-f8f2c8b0-xl.jpg[/img]

[img]http://images.plebeians.net/upload/2019/04/23/20190423221415-247ab197.jpg[/img]

On the way home today i ducked past the waste transfer station to get a weight. Currently 1010kg with 3/4 tank of fuel, toolkit and spare tyre in the boot. 975kg without the stuff in the boot. Not bad given that it still has all the carpet and stuff in it, only ditched AC and door trims, plus added the frame rails and rear subframe reinforcements along with the NB diff.

Overall the NB diff and subframe make it feel a lot more planted in the rear, and it hooks up nicely now. The upgraded brake master makes the brakes feel very on point, and almost slightly touchy, but not to the point of locking up. Need to tweak front/rear bias though as it feels a little forward biased currently.

Next up is to start mocking up the IC for the turbo install so I can put in the oil cooler and thermostat ahead of time. Starting to get new quotes for the engine machine work, given the continued delays with the current shop.