1JZ-GTE valve job start reveals scored cylinder walls

[Dingoboy]

Hello all,

I haven't been around for a good while. My '92 1JZ has been in limited use, largely due to FL heat & no A/C. Sent it in to my mechanic for A/C repair & a valve job due to telltale blue smoke. Before beginning, he did compression & leak-down tests, & all cylinders were good. (I forget the numbers, though) When he pulled the cylinder head, he found the walls of #1 and #2 scored, and in his opinion, a bit too deeply for a simple hone to suffice. I'm going over tomorrow to have a look, but he thinks I'm going to need to bore it out & get new pistons, rings, etc.

I'm just wondering if I'm getting in way too deep, so I'm looking for ay advice from those in the know. I cannot justify having him put it all back together at this point without making the needed repairs. Any advice on how big to go, piston brands, etc.? It's been a long, long time since I had an engine worked on this deeply. (That was a full rebuild on a '90 7M-GTE 15+ years ago)

I'll add photos tomorrow, assuming I can get decent shots in the garage.

 

[Radial]

Probably a great opportunity to go 1,5JZ with N/A compression and low boost.
I've seen such great results with 1j head on 2J N/A bottom end, super magnificent spool times and great torque.

But, single turbo and standalone ECU is required, and I think you need some new rods to support the new power.

 

[Dingoboy]

Not entirely familiar with the 1.5JZ situation. And my mechanic, while a competent dude, is not intimately familiar with the 1JZ engines, although he did own a 2JZ Lexus of some sort a few years back. I looked and called a lot of shops hoping to find a 1JZ familiar mechanic in the Tampa area, but had no luck. Closest was Orlando, and that's a bit of a trek.

Right now, I'm trying to find out if the 2JZ pistons are 100% compatible to the 1JZ. I know the bore is the same, but I'm not sure about pin height, skirt, etc. Is this a direct swap? Probably going to order from JE or Wiseco, but neither of them list 1JZ parts, so I need to be sure before I order.

Also, anyone know if the 1JZ crank bearings are identical to a 2JZ?

I will try to find some info on the 1.5JZ setup... not sure I want to replace the crank & rods if they don't need it, as this is already going to require me to dip into my 401k savings.

 

[hvyman]

1jz crank bearings are same as 2jz.

Personally i dispise 1.5jz. 1jz head ports are tiny for a 3l. And gte bottom ends are more durable. Its more of a cheap fix than an upgrade.

 

[f00g00]

Driftmotion sells CP forged pistons modeled after the 1JZ pistons.

 

[Dingoboy]

Thanks for the feedback. I saw the CP pistons mentioned elsewhere & being sold by several online vendors.

There was a very knowledgeable fellow at JE who assured me that 2JZ pistons would work, but would result in slightly lower compression due to a difference in pin height. And I believe I read that the rings are slightly different between the two. So with CP actually stocking 1JZ pistons, I feel somewhat motivated to reward them for their efforts by buying their products. Spoke to a tech at Wiseco (I used their pistons on a 7MGTE rebuild 15 years ago) who said they would produce a proper 1JZGTE set for about $900, or $50 more than the CP pistons.

As long as I don't find any negative info on CP, I think I'll go that way. This car already had a boatload of Driftmotion parts in her over the last few years, so as long as their prices are in line with the competition, may as well support a forum vendor, eh?

But now I'm thinking that as long as I'm getting all of this work done, may as well do some other upgrades. Going to do some searching & reading before I start a new thread with the inevitable stupid questions about those choices...

Thanks!

 

[Dylan JZ]

Derrick @ Advanced Race Technology in Sarasota is the best JZ mechanic, let alone mechanic in general that I've ever met. The Tampa guys PALE in comparison to what he has been doing, especially as of late. He does not advertise at all, mostly because he's always really busy, but it's an option if you want something done right.

 

[Dingoboy]

Derrick @ Advanced Race Technology in Sarasota is the best JZ mechanic, let alone mechanic in general that I've ever met. The Tampa guys PALE in comparison to what he has been doing, especially as of late. He does not advertise at all, mostly because he's always really busy, but it's an option if you want something done right.

THIS is amazing news. Been looking high & low for a 1JZ mechanic near Tampa. My guy is not even a Toyota mechanic- I just trust him, and he has worked on 2JZ's. I'll have to contact Derrick about installing the engine mgmt & tuning, which my guy doesn't do. I has been thinking I might be headed to Titan motorsports in Orlando for that.

Thanks for the recommendation!

 

[Dylan JZ]

It's funny you mention EMS install/tune because while Derrick is a great mechanic, his passion and area where he excels most is in just that, tuning.

He makes a living essentially fixing bad tunes from two notable shops in Tampa (one known for Zs and the other known more for Supras), and he has occasionally (meaning very few times) improved upon tunes coming from a certain large shop in Orlando.

Something to keep in mind given that. I wish you the best regardless

 

[Dingoboy]

Sadly, with everything I'm doing the best I can do for now as far as tuning is an SAFC. :-(

Just dropped 5 grand on parts. Already paid nearly 2 in labor & machine costs.

And I still need my A/C fixed.

And I'll need a mid-pipe made after the engine goes back in with the new single turbo.

But I'm going to find Derrick & see what he can do for me. My guy probably won't want to get into the EBC & SAFC install, and he does not tune.

 

[Dingoboy]

Made a few revisions to the rebuild... AFC-NEO out. AEM Version 2 PnP ECU in. New wiring harness ordered from Tweak'd Performance.

Mechanic is taking his sweet time, but he is also giving me a break on labor because he's doing this in his spare time. I'm getting antsy, but only because that's my nature. The Supra is not my daily driver, so I will be patient. Want it done RIGHT.

Made a couple of calls to Derrick @ Advanced Race Tech in Sarasota about doing the tuning. No return calls. Will keep trying.

With any luck, the car should leave the mechanic's shop in running order, using the default 1JZ tune that Driftmotion supplies on the new ECU, but I want to make sure it gets a proper tune ASAP once it's back up & running.

 

[Dylan JZ]

Try his email: advancedracetechnology@yahoo.com; if you don't get a response I'll text him. He's usually just really busy, but that doesn't mean he doesn't want the business.

He tuned my DM AEMv2 and sorted some "issues" that basemap that's included has (quite a few).

 

[Dingoboy]

Yep, e-mailed, too. But will do that again as well. No rush until the mechanic gets things going back into the car. Right now, the block is supposed to be at the machine shop.

 

[Dingoboy]

Turns out the block is still in the car. I am assured it should come out this first full week of January. Again, for a break on labor, I DID tell him to do this in his spare time. He's been overloaded with work- a good problem to have. He is supposed to call me to confirm when the block is out. I want to go over & clean out the engine bay- get a couple of decades of grease & gunk out, then clean all of the parts laying in the back of his garage. Not enough cash left in my world to look into having anything prettified with powdercoating, etc., but I can clean. That only costs me elbow grease.

 

[Dingoboy]

So... not a damned thing has been done since my last update, except that my mechanic is now selling his shop & home to move out of state & care for a severely ill relative. Which is also the reason not a damned thing has gotten done. This being a side project, he has had no time to devote to it, since he's been closing up shop on Fridays to drive to TN for the weekends, after trying to cram 5 days of work into 4, etc., etc.

However, After about 5 weeks of consideration, Victor & the crew at Induction Performance in Thonotosassa have agreed to pick up where my mechanic left off, and expect to have me back in a running Supra by Summer. (They can't take it until Mid-February) Had I known of Induction Performance in the first place, I would likely have brought it to them when I thought I just needed a valve job. Their reputation seems solid & some Googling has revealed that these guys build some serious Supra's and GTR's. My little 400+ whp build ought to be child's play for them.

Bonus- they have the dyno & experience with the AEM ECU's, so I won't need to find a tuner after the build is done. SCORE!!!