4200 Turbo Supra

[Blckshdw]

Well, the duration of this project spans several message boards, lol! Also, everything was hosted with photobucket, so most of the pics are now lost. Anyway, my first and remaining build thread is back at trailvoy:

https://forums.trailvoy.com/showthread.php?t=51636&page=1

You know, this was one of the first threads I came across after I joined Trailvoy when searching to learn how to wire up an amp and subs for the first time. I remember thinking to myself "If this is the kinda stuff these guys do all the time, I'll NEVER fit in around here!" We can all see how that turned out...

For as much as I've learned between there and here, over the last 9 years, stuff like this is still so impressive to me. I have a lot more learning to do, before I'd be brave enough to try to tackle anything close to this.

 

[limequat]

One of my favorite all time quotes:

Good judgement comes from experience. Experience comes from bad judgement.

 

[cornchip]

I'm not a fan of external oil lines, but I can see how this would help starvation under the right circumstances. A good video about using an accumulator HERE by Moroso.

 

[limequat]

Just remembered bruhaba had a very similar failure mode after he turned up the boost on the Supercharger. I won't lie. I hit 20 psi more than once with the supra. I wonder if high boost causes enough cylinder pressure to squeeze out the oil film on the rod bearings. And if so, how would one prevent that? Higher pressure?

cornchip, thanks for the link on the accumulator!

 

[shovenose]

Just remembered bruhaba had a very similar failure mode after he turned up the boost on the Supercharger. I won't lie. I hit 20 psi more than once with the supra. I wonder if high boost causes enough cylinder pressure to squeeze out the oil film on the rod bearings. And if so, how would one prevent that? Higher pressure?

cornchip, thanks for the link on the accumulator!

I'd suspect an oil with higher film strength would be the difference. Something like Royal Purple HPS (not regular RP, that's not any better than other name brand synthetics) 10w-30, should hold up better.

 

[Reprise]

Good judgement comes from experience. Experience comes from bad judgement.

This is sig-worthy. Now if I only had room to add it!

Awesome to read about your efforts / progress with this build. And I vote +1 on the accumulator. I had debated adding one to an Exploder w/ the 4.0L 'Cologne', to deal with a timing chain issue. Would have eliminated the dry startup issue with it.

And it gives me the opportunity to say... I'll be sending an e-mail your way shortly to see what you can do with a 6.0L / 4L80e, PCM tune-wise (and arrange for a good time to send mine in, as I see you're busy with 'Project Supra' right now.)

 

[littleblazer]

I'd suspect an oil with higher film strength would be the difference. Something like Royal Purple HPS (not regular RP, that's not any better than other name brand synthetics) 10w-30, should hold up better.

I remember seeing a thread on bitog showing that particular royal purple having a ratherlow film strength.

 

[bruhaba]

Sorry to hear you spun a rod.

I spun #3. There was no evidence in the bearings of starvation further from the pressure source. my #6 rod looked brand new. I did get with Marc and had a discussion and bought his gallery fitting. I didn't end up using it, partly because I was lazy, partly because i convinced myself root cause was over revving....so I'll pass it on if you want it; i think i sent him 40 bucks shipped for it.

I'm about to fire my build up real soon. I ported the crap out of a new head, ported the crap out of the blower, put a new GM crank in it, custom forged venolia pistons CR 8.5:1, billet rods from K1 I found on ebay somehow for like 170 bucks, new mahle oil pump I shimmed, convert to ls2 throttle body...I can't remember what else but you get the idea. This is as far as I'm taking this. I'm going to blow on it as hard as my eaton m112 will blow, I made a crank hub for a lightning performance crank pulley...its a huge crank pulley.

I never saw any detonation evidence, piston, rings, plugs and cylinder walls looked amazing. it had 120k mi on it, 20 of which were supercharged. I beat the living piss out my stuff. I overrevved it to ~7200 going sideways on an on ramp with an engine not fully warmed up. 10 minutes later under all light load i heard ticking, 20 minutes later knocking; drove it home from there another 15 minutes and it was a box of rocks. Those stock rod caps were begging for mercy at ~7k rpm in a long stroke motor. I'm pretty confident it just squeezed in on the journal, the bearing bit and spun.

I still have to figure out why it overrevved when i was manually shifting it; it wouldn't throw the 1-2 shift even though i moved the lever. I had done that once before but not in a 1st gear sideways event so I probably caught the over rev sooner and let off.

 

[limequat]

Bruhaba, thanks for your input! What you say makes a lot of sense.
I had my rev limiter set at 7k for a period of -probably- a year or so. And I used every one of those rpms every time I drove it! I can't pin down my knock to a particular time, because the Cam phaser was broken in the same time period.
To those that mentioned it, the oil I used was Rotella T6. This is Good Shit, designed for diesel engines.

So lesson learned, rev limiter stays stock. That removes the need for cams regrinds.

Reprise, I'll be watching for your note!

 

[littleblazer]

Rotella is pretty good. I prefer the delvac for reasons I won't get into here but did you have a oil temp monitor? I wonder if it just got pushed too far. Maybe an oil analysis would show how the oil was if you still have it around...

 

[limequat]

^ I do have some oil in the pan. It's more of a sludge, actually with all the bearing dust in it.
I did not have an oil temp monitor.

 

[littleblazer]

I'd be curious, if the oil were to get too hot you could more easily pinch out the film. If you think it would be worth it to have it checked out, the results would show if it were still in spec and usable. These engines run warmer to begin with so maybe the turbo pushed the oil over the edge. Or a leak down issue contaminating it. There are tons of possibilities.

 

[damifino]

So, a new (professionally) welded aluminum oil pan is on the Supra. I welded up the up-pipe to manifold connection and put her all back together again. Been fighting laziness and a dead battery. I fired it up and it was running rough. Really lean. Trying to tune it last year with the hole in the up-pipe screwed things up. But the PCM is correcting, and it smooths out pretty nice after a couple of minutes. What the hell lets go for a drive!

The 4200 devoid of any torque management or torque converter is incredibly responsive. Add boost and it becomes tough to control ones self. So when I first eased her out onto the pavement it was less of a "easing" and more of a full throttle, fishtailing launch. And then: BANG! The power was gone. The engine got rough and didn't want to idle. I came to a light and tried to heal-toe to keep the revs up while still stopping, but it stalled. Turn the key, <click>. Damn.



A good Samaritan was kind enough to help me push it out of the road. He even offered to help diagnose the problem. When I popped the hood he couldn't get away fast enough. "Oh I used to know a little bit about the older ones." The Supra is now knocking on 30 years old. So the above picture is my wife saving my bacon.

Turns out the BANG! was top and intermediate boost pipes saying adieu. With no solid connection of intake pipes, the MAF was insistent that there was zero airflow and the PCM delivered fuel accordingly. In the end, I fudged the injector scalar just to get it started and limped back home.

Fast forward to this morning. The I/C pipes are cranked down 'bout as hard as I can manage, and there's about 30% more fuel in the tune at idle. Battery is charged. The engine rolls over twice, catches and settles into a smooth idle that only I6s can do. The PCM is hardly adjusting the mixture at all. So far so good. Up and down the driveway, no hiccups. She wants to run. We set out to the dirt roads around my house where I subject my neighbors to a series of 1st gear half throttle pulls: BrrrrrrrrrRRRRRR WHOOOOSHHH!
As I round the bend en route to my drive way, I can't take it anymore. I roll into the throttle at 3k rpm. The VVT turbo is instantly on the case. After about a second and a half -even though I haven't even hit WOT- the big GT37 is blowing 9 psi and the 275/45/17s are fighting for something to grab onto.
Oh my dear Mary mommy of Mohommad it is so... BANG! The steering goes stiff and the throttle is dead. I coast it into it's perenial parking spot and turn it off.
Until next time, Supra. You nasty tease.

limequat, I am thinking about a NA 4.2 swap into a 240Z. Would need to modify the oil pan for clearance (make it more shallow). What mods to pan did you make? I do not have a 4.2 to look at, just looking at the feasibility in regards to the architecture of the bottom end. Machining, fab work and welding are not of concern, we can handle all that. Thanks.

 

[limequat]

limequat, I am thinking about a NA 4.2 swap into a 240Z. Would need to modify the oil pan for clearance (make it more shallow). What mods to pan did you make? I do not have a 4.2 to look at, just looking at the feasibility in regards to the architecture of the bottom end. Machining, fab work and welding are not of concern, we can handle all that. Thanks.

Hi Damifino! the easiest thing to do is to buy a cast pan from emtechmotorsports.com. That's assuming you need a rear sump.
I went to a fabricator to modify a stock pan for me. We basically cut everything 2" down from the rail and made simple cube shaped rear sump. You will also have to modify your pickup to match by extending or shorting to get the pickup in the sump.
Consider that the oil pan has many features that you want to retain: A/C mounts, dipstick hole, transmission bellhousing flange, and baffling. Now is a good time to add an turbo oil drain provision. If you don't plan for boost, it's still good to have the option.

If I was starting over, I would shoot for at least 7 quarts of capacity, preferably more.
It is my belief that the oiling system for the 4.2 is already marginal for above-stock horsepower. You may want to consider an oil cooler and shimming the stock pump.

 

[limequat]

Ok, got my new-to-me SAAB engine going into my formerly chevy powered Toyota!

The engine comes from a 2009 9-7x and sounded great before it came out of the 9-7. Now the process to strip it down and transfer over the modifications necessary to get into the Supra. Looks decently clean:

That's my son trying to look cool while running down the coils, lol.