1990 Toyota Supra Turbo (Manual)

If I paid that much for the car, I think I'd have cried...
Plus the money for parts that are half missing. Well, there are a few things that would be rather tempting... Glad I didn't buy the white auto one that was on e-bay not long ago though! It looked far far worse than yours does! Granted it was less than a 1/4 of the price.
Good luck when it comes to repair that properly.

Why didn't you take it back and ram it up his ?

Right - so, engine. Well, I got it back here after all the welding, and there were a few more bits and pieces I twiddled with, like the Camshaft position sensor, and a temporary patch on the coil pack connector. And it ran fine. Until March 30th, when I decided that after doing an interior valet and clearout and getting it looking shiny, I took it for a drive as the sun was going down.

However, on a hairpin bend, at about 50mph, the power steering went DEAD and nearly stuffed me into a tree. I figured it was the belt, as it has done it before. Immediately, I headed back home via the most direct route possible, but without power steering, you need forearms like popeye - it really is a heavy child born out of wedlock!

Of course, if problems weren't bad enough - halfway home, there was a dull thud and the engine cut out. It wouldn't start. So, I coasted to a stop, popped the bonnet. What greeted me, was the sight of the power steering belt wrapped around all the other engine bay belts, which was odd as it should have dropped onto the road. I pulled what I could out of the engine, but there was still a tight wedge wrapped around the water pump pulley. I *had* to get home. So, I tried starting it and it sounded ROUGH. I babied it - doing no more than 20mph. When I hit my courtyard, the engine just coughed and died. Gave up the ghost. Wouldn't restart.

Opened up the bonnet and a cloud of oily steam was released. Ohhhh lovely - blown head gasket. It's common on the 7M as the torque spec was given for an Asbestos gasket, but then asbestos gaskets were banned, and the gasket changed for a composite one. But the spec wasn't changed along with it. 56lb/ft is NOT enough torque on the bolts, so most have had at least one gasket go by now.

I gave up for the night, as it was too dark to do anything with. Following morning it started, sounding like it was running on three cylinders, engine management light showing 'er, hi, yeah, we need to have a word'

Managed to reverse it back into my hangar bay, and immediately started to strip down the engine. By 4pm, things looked like this:



Yes, that is the upper intake manifold on the floor!



So the plan was to use a stock OEM Toyota Gasket set for the rebuild, with ARP Head studs, remove the EGR system, and use the top end failure as an excuse to do a proper job all round.

Once I got the turbo off (an AWKWARD JOB) and spent 3 hours cleaning it, I found out that it was a Turbo Technics Stage 1 hybrid - the housing is a stock CT-26 thats been milled out to accept a modified CHRA. The compressor wheel in it looks almost identical to a Garrett T04B-S3 (70mm/48mm, 7 main fins, 7 sub) so it should be good for about 17psi or so, although i'd hit fuel cut at around 10psi until I get around to fitting a new AFPR, SAFC II/SAFC Neo, 550cc injectors and Lexus AFM.



More and more parts were stripped away, and finally came the job of removing the half-crispy wiring. Ew. That's all I can say. The plastic bit that goes across the upper timing cover just crumbled away in my hands. Some fuckwit had decided to rewire the knock sensors with DOORBELL WIRE. With SCOTCH TAPE. The wiring itself was half baked after 20 years of heat cycling. Time for that to go away to my mate Johnny in Bracknell, who is a wiring loom GOD. And he does them for FUN (a little mental!)



Before I tackled getting the head off, I started on cleaning up the rest of the parts i'd removed.

First up, the Fuel Rail:


Then the Upper & Lower Intake manifolds





Following day, it was time for the head to come off!





The face of it was pretty good, no nicks or dinks out of it, and a green scourer and petrol brought it up nice and shiny, and when measured with a straight edge & feeler gauge, there was no appreciable warping. I removed the EGR cooler whilst I was at it, and about a half kilo of oil & carbon buildup along with it!



I've cleaned the cylinder head about as much as I can physically manage without having it hot tanked. A pressure washer and dishsoap did wonders for removing a huge amount of built up, baked on oil deposits, and acetone on a toothbrush for the fiddly area's. However, there are areas of the head that still aren't clean, but I just can't get to it, and honestly can't be bothered to do. I know it's probably a bad thing to say, but there's only so much 'clean' you need, IMO. At least, on an almost stock, budget build.

The cams came out, as well as the buckets AND the shims. Upon measuring the clearances and the shims, it looks like i'm going to need some 3+mm shims, as most of the clearances I measured were 0.40 and even .45mm - way, way, WAYYYYYY out of spec!

My right arm became exhausted through scrubbing with toothbrush & scourers - cleaning the cams til they come up near MIRROR finish on the lobes puts masturbating into 3rd place for arm cramp!

All the valves were removed, cleaned along with the valve springs and seats, then ground back in with fine paste only. New valve stem oil seals were installed as well. After all of that, all that comes into my mind are the words: "I HATE COLLETS."

Cam caps are all torqued down to 20NM and the #1 caps have been sealed with FIPG (using Loctite Copper FIPG instead of the Toyota stuff thats...silly money). CPS has been loosely installed, but i'm pretty sure it's about as bang on as I can get by eye. Front cam gear plate has been installed after being painted at around 6am, and all the lifting hooks have been installed as well.

The fuel rail was then re-installed, but this time, with the set of 550cc RC Injectors, and to make sure I don't run pig rich, the Lexus AFM housing has had the Supra AFM electronics installed, and the accordion hose to turbo fitted (curse word of a job to do as you have to stretch the rubber over the larger opening).

End result? Have a look for yourself!



So - what about the gasket that came off? Well, here it is, next to a brand new one - note that Cylinders 1, 5 & 6 were all blown on the water jackets, and the gasket had all but disintegrated.



Next up? The block - but i'll leave that for after breakfast!

I decided to investigate the odd problem of the rough idle on first starting, which I figured would be related to the cold start injector. Turns out I was right. When I pulled the injector out - it was COVERED in oil & carbon in an almost centimeter thick layer - so no fuel was getting out at all, therefore causing the crappy idle. The biggest build up was on the aft side of it - that points straight to the EGR inlet on the manifold. Good thing i've ditched the EGR then!

The other thing I figured out, is that the full engine gasket kit *does* include a thermostat gasket - a bonus, because I was going to get another one for about $6 as the existing one was...how shall I say, baked? Yep, baked is a good word for it. Cracked, brittle, and about as useful as a rich tea biscuit at repelling water.

I also figured out the new and improved vacuum routing, as due to the EGR removal, I have a Vacuum Switching Valve that needs to be removed, and a load of vacuum piping that needs to be arranged properly, if i'm to avoid any vacuum leaks.

I considered cleaning the manifold even further, but honestly, as it's a stock rebuild, I don't see the point in spending hours with a toothbrush, scrubbing away like crazy - it's clean enough!

I was missing a few ancillary bits at this point, one of them being the bolt that holds the Power Steering Pump Bracket Stay in position on the block side of things. Technically I only needed a standard 14mm headed 10mmx1.25 bolt that's 16mm long, but the hardware store won't stock them in that size, as 1.25mm pitch is a little odd for a 10mm thread. Being anal, I decided i'd rather get the proper thing from Toyota, than bodge it. I've already had to use two 13mm headed 8mmx1.25 nuts that were used for holding the fan onto the water pump pulley, to hold the power steering bracket in place. I'm basically trying to make sure that the engine is built properly as can be. Hence why I used a proper Toyota gasket, ARP head studs and new fixings where possible.

The exhaust manifold finally went back on, after I replaced 4 of the 7 studs in the head.



The 3 that remained in there stayed very much in place, as I know just how soft the alloy is that the head is made up of, and really didn't want to get into the hassle of drilling/tapping the threads in the head or helicoiling things. I did however, run a die down each of the exhaust studs in the head to make sure they were clean of curse word, and used ARP assembly lube on each of the threads to ensure that they wouldn't sieze.

Bolting the turbocharger back up went pretty well for the most part, locating it is blasted fiddly though, not on the manifold or the elbow, but the oil feed and drain.

For those of you unfamiliar with the CT26 - the drain is a solid piece of metal, with a 90 degree bend in it, that locates on two studs on the block. Locating it is fiddly, but can I get in there to tighten the nuts? Probably, but I got a headache after an hour of working on it. I managed to get the nuts located though, thank feck! The ballache is going to be getting a torque wrench in there, probably via a series of adaptors, extensions and spatial geometry, testing just how far my arms, wrists & fingers can be contorted before breaking bones & tearing ligaments!

The oil feed was also being a sod. See, with the manifold heat shield on, the oil feed is about 1cm away from the hole, and of course I have to contend with two copper crush washers on either side of the bolt & banjo fitting. I held of on that headache for a little while longer!

The PS pump was finally reconnected to the fluid cooler though, thanks to the double sided copper crush washer I bought, and now only lacks the fluid reservoir - something that gets connected last I think.

Oh and of course, how could I forget the oil filter bracket, installed with new copper crush washers and a shiny new filter that's destined for a life of approximately 20 minutes!



The wiring harness was then connected up, with the exception of the thermostat housing (i need to bolt up the upper timing cover first), and i've discovered a potential worry, in that the green, single pin sensor on the thermostat housing, won't tally with the wiring harness.



See, previously, my harness had been missing the correct connector, and someone had used a spade terminal as a bodge. Not knowing that, Johnny, who redid my wiring harness, put a brand new, gold plated spade terminal in its place. No biggie I thought, until I realised it was bigger than the one he replaced, and voila, it will no longer fit in the connector. So, i'm going to have to sort that out, otherwise i'll get a thrown code. Everything else is plugged in, barring the stuff on the upper intake, even the knock sensors are plumbed in, and far better looking than the bell wire that was in there.

I also discovered that I had a load more Samco silicone hoses in a box, although, I had no idea what they were for, initially. Turns out that Samco went as far as to make the hoses to & from the throttle body in silicone, which is nice, as the ones that were there were starting to look a little tired, worn and threadbare around the connecting ends - which is a bit of a relief. I'll take the opportunity to plumb in the lower rad hose this time, but i'll still need a load of red silicone hose for the vacuum lines, and i'll need a longer section of silicone hose for the rear elbow on the head.

See on the '90 spec, the water pipe that runs around the block, connecting the thermostat housing/water pump, to the intake side of things, is made of crappy steel, that corrodes and has a 60' bend in the pipe that connects to the elbow via a hose. Of course, the pipework I had needed to be replaced, but I got it off a '92, by which point the pipe was made of stainless steel and has a 90' bend in the pipe that connects to the rear coolant elbow, meaning the silicone section of pipe that I had, would no longer fit. Grrrrr.

However, I had something of a revelation that has helped push my tinkering & improvising to a new level! Remember that section of pipe that I needed? Well, no more! Thanks to finding those Samco hoses, the short one that goes from the heater matrix to the VSV on the bulkhead was replaced, but thankfully, that short hose was the same internal diameter as the hose I needed.

Some trimming with a kitchen knife, and I have a 90' bend that *just* clears the cylinder head, and only barely rests against the rear lifting hook. There is a very slight kink/ovalling where the bend is, due to the angle of the hose not being exact, but, it's not going to impede flow at all. Wierdly however, in the EPC, the bypass hose listed, is the same part number from 05/1990 to 05/1993 (yes, the Supra WAS still made in '93, although in Japan only). I might just have to get a generic length of samco hose in red at a later date. In the meantime, this should hold.

The upper timing cover was bolted up, as was the thermostat housing, and I started to tie up all the loose ends, I was considering slinging the upper intake manifold & throttle body on, but it was gone 5am and I was starting to get lazy and tired, my thought was "curse word it, it's been 6 months, another 6 hours isn't going to hurt".

Realistically, once I get the turbocharger oil feed banjo bolt in, I can start plumbing curse word in with regards to the intercooler, but that'll be a ballache, no doubt taking me several hours to just do one single bolt. The light at the end of the tunnel is definitely starting to appear, and after the engine is back together, the interior should only take an hour or two to bolt back together, and voila, fingers crossed, the child born out of wedlock thing will start. I have a mental list of everything that needs to be done, what bolts are just hand tight and need torquing up, so i'm going to do a big push. New coolant, 4.7 litres of Generic 30 weight oil to run it through for 30 mins, another 4.7 litres of 5w30 and another filter for the first 500 miles, and then I can get a wix filter, and some 5w30 in there for the next 5000 miles, assuming I don't throw a bearing first....no, wait, I take that back, fate, don't curse me now!!!

*mumbles to self* think positive man, think positive...!

You'll also notice in the photo below, that the cam covers that were sat on there, have been substituted for the GTE ones, simply as I no longer have the funds for the IS300 coil packs, so the stock GTE ones will have to stay for a little while longer. I will admit though, that tarting up the GTE covers took about 2 hours for both, as opposed to 6 hours each for the N/A ones - mostly due to the lack of any embossed lettering! Some 3/4 coats of primer and 2/3 coats of proper 3E5 spraypaint from Toyota sorted them out rather nicely - even if they are meant to be temporary.



The following day, and thanks to my mate Dave, I managed to get the upper inlet manifold on, bolted up, all vacuum & water lines connected, TPS and ISCV plugged in and aside from the turbo oil feed, I was almost ready to go.



Of course, I would have needed 4 pairs of hands all about the size of a toddlers, with the strength of superman in order to sort that b'stard thing out!

I decided to be a bit flash with the cash though, and shelled out for a set of braided stainless oil & water lines, that were FLEXIBLE. When they arrived, everything looked fine except that there were two errors I discovered only AFTER I had fitted the adaptor plates to the turbocharger. Turns out i'd been sent the adaptor kit for the Toyota Landcruiser, and NOT the supra, so although the lines were the right length, and fitted the adaptors - the adaptors pointed the WRONG WAY for the oil feed, and the water feed/return. the company I bought them off offered an exchange, but only if I spent £100 on mailing them back to Japan (how do they get it to me for £15, but 'La Poste' wants to charge me nearly 10x that??). So, it was time to get creative with a blowtorch and a vice and adapt the adaptors.

Twisting/bending metal is something that honestly worries me - i've had way too many things just die from fatigue on me, so i'm considering replacing the plates as soon as possible, with something i've designed via CAD. The lines are fine though - so they're staying. I'll likely also switch from a Banjo bolt, for the oil feed, to an M12x1.25 to -4AN stud to eliminate any problems with flow.

However, that's pretty much where my build comes to halt, at least for the moment. The weather here has been just all kinds of wrong for working outside on cars - from the freezing temperatures, to the rain and the 9 inches of snow...it wasn't happening!

There are signs that the weather is getting more clement today though, being about 10/13*c here at the moment, and even blips of sunshine, but it's still a case of tools being firmly down for the next few weeks, and I need to get my mechanic-fu back before I do anything else!

So - thoughts/questions?

You must have the patience of a saint with all the issues you've had in such a short time. Big respect for keeping on it. Will be keeping a close eye on this car and keep my fingers crossed for you!

Enjoyable write-up cheers

Star of the show for me is the 3-en-un huile that keeps popping up in various snaps

I'm building my 7M up (in my dining room) and it's interesting to see someone else doing one, I'm curious why you didnt torque to 90lb/ft which the bit of paper in my ARP stud box told me to do? Have I gone too far?

Worried

Any pictures of the arches?

Ramirez - Pictures 7 to 12 on the first post are the rear arches

grayb - Cometic will take the hit - just a question of if the head can take it - and I hope you didnt get the head machined more than 5 thou!

The problem with skimming the heads is, if they're not PERFECTLY true when you do it, and if you do more than a 5 thou skim, you have to be VERY careful about the cams. Plastigage ALL the cam journals - if they're okay - you should be fine. Generally, the heads shouldn't need machining at all, the most i'd ever get done on any head, would be 2 thou - just to bring the face up nice and clean. Too many machinists treat the 7M like any other engine and just skim them without taking into account the specifications and tolerances. Do you have a copy of the TSRM?

5M's are good - but 5M head on 7M block = 6M

Although - you could just get another 7M head from somewhere - i'm sure my mate Ed has one knocking about somewhere!