Project Thread Supercharged Supra

[cribbj]

Thanks PWD & Scott, well it keeps the hobby interesting to try new things doesn't it?

I have a dumb Q for those of you who have actually finished your engines, or have a completely assembled motor sitting where you can look at it?

There's a set of three tapped holes on the outboard side of each head, just below the valve covers. Are these holes used for anything? If not, I may use them to mount my wiring raceway. Ideally I'd like to put the raceways inside the Vee, but things are just too crowded in there.

Here's the holes I'm on about:

 

[JustenGT8]

Nothing crtical as i use them for something else on my engine.

I see you are ready to go turbo as well

 

[stevechumo]

Those 3 holes are for holding the wiring harness. On my SC4, the left side is for the harness from the starter to the battery, and the right side is for the harness to the alternator and the ground. I hear you, Justen. John is ready for the turbo as well.

 

[cribbj]

Thanks for the answers and I see that both of you spotted that -10 AN fitting on the upper pan.

Well, it's not an oil return for a turbo like you think, but is actually the pickup for my external prelube pump. With my working schedule, the car can sit for a month or two between starts, so I installed a prelube system on my 2JZ, and will do the same on the 1UZ.

Before starting, I prelube the 2JZ for 10-15 seconds - that's all it takes for the oil pressure light to go off, then I know I've got oil pressure and all the bearing journals are happy. I use a Mocal differential oil pump for this and it works a treat. Basically I put the external system in parallel with the engine's own oil pump, and isolate it with a nonreturn valve.

Here's the other side of that -10AN fitting; the screwed pipe isn't very pretty, but it's functional:

 

[JustenGT8]

That's a bit of a let down John ;-) Nice work though. I just turn the engine over on the starter until the pressure gauage twitches, then i fire up the ignition circuit to start.

 

[scotturnot]

Nice John! I to have alternate plans for those holes at least on the drivers side.

 

[cribbj]

That's a bit of a let down John

Well, it could easily be converted to a turbo oil return if I ever get bored with the SC's torque and decide I want some serious high end HP. ;-)

I just turn the engine over on the starter until the pressure gauage twitches, then i fire up the ignition circuit to start.

Yep, that's always been the classic and accepted way of lubing the motor before firing, and frankly, I've never understood or agreed with it. You're still spinning the crank and rods dry in their journals until the lube oil pump starts working. And if the lube oil pump is airlocked (as they are many times), then you really are spinning the motor dry.

With an external prelube system, none of the engine's reciprocating assembly has to turn to generate lube oil flow and pressure.

 

[JustenGT8]

Well, it could easily be converted to a turbo oil return if I ever get bored with the SC's torque and decide I want some serious high end HP. ;-)



Yep, that's always been the classic and accepted way of lubing the motor before firing, and frankly, I've never understood or agreed with it. You're still spinning the crank and rods dry in their journals until the lube oil pump starts working. And if the lube oil pump is airlocked (as they are many times), then you really are spinning the motor dry.

With an external prelube system, none of the engine's reciprocating assembly has to turn to generate lube oil flow and pressure.

as you say not the perfect solution but in it's defense there is no load on the bearings and there's always some form of oil film there...particularly on our modern motors with pretty tight clearances.....i've never had an engine 'wear out' as such so good enough for me. Simple, like me, too

 

[cribbj]

I've been doing some thinking about the engine's heavy power wiring, since I'll be relocating my battery to the hatch area.

I'm thinking to consolidate the heavy gauge stuff to a single connection point on the engine, and probably do this in the form of an insulated stud in a protective box on the lower left side. Then from this stud, I'll connect both the positive battery cable, coming in from the hatch, plus another cable which will feed the main fusebox.

Since the starter for the UZ engines is in the Vee, using it as a junction point isn't an option, and is a bad idea anyway. Ditto for stacking cables on the alternator and using it as a junction.

The engine will have a scratch built harness anyway, so I'm needing to figure out a clean way to get the batteries connected to the starter, then the alternator connected to the batteries, and the whole shebang connected to the fusebox. So I think the insulated stud in a box has merit.

Alternately, I could put a stud on the engine to join the alternator & starter, then use a bulkhead stud at the firewall where the cable will pass through. I actually like this better, however it increases the number of connections, which is not a good idea. Dodgy connections and overheating account for 80% of the problems in electrical systems.

Thoughts & comments (especially from Sideshow & Doc Tweak) are welcome.

Here are the schematics of what I'm thinking. Top one is the single stud on the engine. Bottom one is the double stud idea:

 

[mshawari1]

I would prefer the first idea of the single connection point. But as I know the fuse of the alternator is located in the main fuse box?

What is the gage of the cable in mm2 "1/0 welding cable"

​

 

[cribbj]

Yes, the first way has fewer connection points, so it's better. You're right, the alternator fuse is located in the fusebox, which is why I'll now need to protect it (the alternator) with a fuse between it and the stud. This won't be as tidy as having it in the fusebox. but it'll have to do.

1/0 AWG is a little larger than 50mm2. Typically I wouldn't run 50mm2 at more than 125-150 amperes, but the very fine stranded construction of welding cable lends itself to much higher currents for short periods.

In lieu of the single stud, I may try one of these if they're not too large:

Or one of these, which is a heavy duty (100-425a) ANL fuse holder:

Then I could configure the schematic like this, which is probably the best of all options:

 

[Cobber]

John,

I have the battery in the boot on the cobra and it's wired exactly the same as your last drawing. I used a marine style single stud under the tunnel just behind the firewall. It's easy enough to get to if I need to and just a single connection.

A friend works for a forklift company and they sponsored the battery cables for me . Don't know what it is rated to but it is fine strand and more than enough to drive an electric fork truck.

Must be getting close to dropping that engine in?

 

[cribbj]

Must be getting close to dropping that engine in?

Thanks Andy, I wish we were that close, but at the rate the 2nd motor is coming together, I probably ought to go ahead and drop the 1st one in and just run it until #2 is ready. We're hoping for great things out of #2, but it's taking way too long to get it together.

So I'm just cleaning up loose ends and trying to stay busy and motivated ;-)

BTW, did you put a large ampere circuit breaker or fuse at your battery? I'm trying to source something in 200 to 250 amperes, but am only finding Chinese junk.

 

[Cobber]

John,

I used a 150a manual re set circuit breaker and it was sponsored by the same forklift company. No idea where it's made, pretty hard to find things that are not made in China now.

Works fine and has not popped yet.

Try your local forklift company you never know they might want to sponsor you too

Same as this.

http://www.baxters.com.au/index.php?page=details&id=7231

 

[cribbj]

True about the Made in China situation, however the junk being sold direct by the Chinese is worse than poor quality; it's downright dangerous.

At least the Chinese stuff being sold by the big names has passed through "some" quality control.

If 150a is working for you, I may give it a try. Bussmann make a pretty rugged model called the Hi-Amp, but 150a is as high as they go. I was a bit concerned about popping it under starting conditions.

 

[stevechumo]

Thanks Andy, I wish we were that close, but at the rate the 2nd motor is coming together, I probably ought to go ahead and drop the 1st one in and just run it until #2 is ready. We're hoping for great things out of #2, but it's taking way too long to get it together.

So I'm just cleaning up loose ends and trying to stay busy and motivated ....

Do it, please. I believe the car's chassis already started to rust without being expose to the wind resistance.

 

[4000GT]

Here is what I did in my Supra...

 

[cribbj]

Looks very clean Andrew - is that the lefthand cavity in the boot where the foam is/was? Are those dual Odyssey batteries? Which ones are they, if you don't mind sharing?

At one time for my black Supra I ran a single Odyssey PC680 from the hatch. It was "just" OK as long as the car was garaged and the weather stayed fairly warm. Fortunately, that car always fired up immediately whenever I hit the starter. But a single Odyssey wouldn't work with an aftermarket EMS, particularly the AEM, which is not known for fast starting. A pair of them in parallel as you've done would be much better.

Thinking of going with a pair of the Braille batteries this time

Hehe, thanks for the support Steve. In fact, my blue car hasn't even been started for around 9 weeks.

 

[Cobber]

See if you can get someone to put a current tong on and see what the starting amps are for a 1uz.

Mine are on site and won't be going back for a couple of weeks.

 

[stevechumo]

A dual battery setup is good, but I read somewhere that connecting both batteries together without having another device to keep it balance isn't good. They'll drain the charge. I forgot what they call for that device.