Rebuild of the SC's 1UZ

[rdm20fan]

This is the motor I'm putting in my TT SC400.
The block is actually from a 92 (I think) LS400
Here are some pictures of what Chris and I have done so far.
These are some pictures of the block.

 

[rdm20fan]

These are some pics of the head.

 

[rdm20fan]

Just a couple extras

 

[Lextreme II]

Bob,

Very nice... beautiful forged pistons. You should get MLS gaskets and ARP Studs with it, then BOOST>>>>. at least 20 psi.

 

[sniper]

Ya you really REALLY should use a MLS headgasket, then you can go crasy with it

Whats the number on your block? I can tell you exactly what year and month it was made.

 

[rdm20fan]

Chrisman and I put a 20v 4A-GE together.
We went from N/A to Boost on it also, and went through a couple of head gaskets at low boost.
we ended up using a stock Toyota Head gasket, and pushed the 1.6L to 20 PSI, and never had a problem.
We also had trouble with after market rod bearings, and ended up changing back to toyota bearings.
I have done some research with head gaskets, and have not found a company who makes me feel comfortable.
For my application, I think Toyota Head gaskets, are what I want.

 

[Peewee]

Quick question dude.

Can you install the pistons from the bottom up?

I ask because I want to do headwork, and new pistons, but funds may not permit it to be done at the same time.

So I was going to do the heads, then a few months later get new pistons, but not if I have to remove the heads to put the pistons in.

 

[Red Supra]

That motor looks good boys! Don't forget those ARP LS1 Rod bolts. I think that the vvti 1uz has metal headgaskets stock.

 

[svpmx83]

Can you install the pistons from the bottom up?

The main journal webbing will not allow it

 

[Peewee]

Dammit, same as older Toyota blocks.
Ah well, its gonna be an uber build all at once then.

 

[Lextreme II]

Red,

The VVT-i have mls, but the water passages are different from the early 1uzfe and it might have a cooling issue.

 

[rdm20fan]

the new head gaskets I got from Lexus are different then the ones we took off.I did notice that the oil stains at the rear of the head were alot draker then the front of the head, and the new head gaskets seem to have the larger water passages toward the last cylinder. I'm hopin this is to run more coolant tward the rear.

Thanks for the info about the VVT head gasket Max.
I'll look into that for the AE86's motor.
Chris and I did not replace the rod bolts.
I think (Hope) we are going to be ok.

 

[Lextreme II]

Bob,

Please tell me you going to replace those used oem head bolts. The head bolts are not suppose to be re-use.

 

[rdm20fan]

Yes we are reusing the stock head bolts.
I checked with Lexus, and double checked in the 93 SC400 manual, and the bolt are not torque to yeild, and can be reused.

 

[Lextreme II]

If you going to spend that amount of money on the motor. U should at least get new oem bolts. What i heard from my mechanic and Toyota Tech stating that those bolts should not be re-use. They are stretchable bolts and should be replace when heads are taken out. FYI....

Chris, its that you? Torque the main stud with an extension bar?

 

[rdm20fan]

Chris, & I heard that too, or at least the internet says so,
We double checked with our local Lexus, & Toyota dealer. (largest in the US)
They both claim that they reuse the head bolts. and only replace them if one is broken
The SC manual claims they can be reused.
It's not a fact of the $ for a new set,
Chris & I have lots of faith in Toyota, and belive that this isn't a week point.
There are a lot of guys making alot more HP then me, on the stock parts.
I think we will be ok with the stock head bolts.

 

[Zuffen]

The head bolts do stretch and the workshop manual gives you the permisable strech before replacing.

The test is to mic the diameter of the bolt. If it is below the minimum it has stretched past it's safe point.

 

[rdm20fan]

the picture is me with the pipe, on the mains.

They call for (I think) 18 Ft lbs plus an additional 90 degrees. the pipe makes the 90 degrees very smooth.
I was posing for the picture, but somebody cut off my head.
We figured someone would catch it, and comment. thats why i posted it.

 

[jibby]

Hey guys looks like a fun project-

What type of forged pistons are you using in that 4.0 liter V8 motor? What other parts will you be changing out from stock? What is your hp goal with your twin turbo's. Did you bore the block out and to what size if you did? I am heading in that direction with my sc400, I am looking for a 1998 motor to build but they are hard to find. Those are the best motors from all the sc400's. Lexus did not sell to many in 1998, apparently I was told only 800 were sold, and I guess none are not many are at the junk yards. The search continues.

 

[rdm20fan]

we are using the Ross Group buy pistons. The block did need to be bored out. but it was a small amount.