Engine swap worth it?

[PnOyGhost]

I was also thinking about going to a 1jzgte engine rather than doing my 7mgte up. but i like the torque that the 7m puts out. also does the 1jz have a higher redline than the 7m does? i want an engine that will accelerate pretty fast. dont want to do a 2jz swap since ive been told there is too much wiring. so the choices are 7m or 1jz. i also looking to put a gt45 on the engine but i want as little lag as possible for spool up.

[azrael]

The wiring differences between the 2JZ and the 1JZ will be minimal. You are looking at an ass of a wiring job if you plan on putting ANYTHING in that engine bay that didn't come stock.

1jz redlines higher than the 7m. Significantly.

7m produces more torque.

2jz is the answer.

[PnOyGhost]

can i change the redline on the 7m with cams? or is there any other way?

[WeDgE]

can i change the redline on the 7m with cams? or is there any other way?

Only way to change redline on a 7M is with a aftermarket ECU or a standalone.

Keegan, AFAIK the torque rating of the 1JZ is actually more than the 7M.

[azrael]

Low end torque, more accurately. The 1JZ might make more torque, but it does it at a stupid RPM.

You can raise the rev limiter on the 7M with aftermarket electronics, sure, but redline and the limiter are there to ensure you don't do any horrific damage to your motor. The reason it redlines so "low" (says the guy with the 22R) is because it's an under square motor. The stroke is long, and thus as you rev it up, it needs to be more finely balanced (or more bomb-proof) to prevent it from blowing up.

Forged internals and an exceptional balancing job on everything that rotates would be a good start if you want to rev a 7M high.

I mean, you can remove the rev limiter if you want. It will rev high. Once.

[annoyingrob]

There is a lot more stress on the 7M rods due to the stroke. Piston acceleration is much higher, which is what's limiting how high you can rev. With some nice rods, and good wrist pins, you can safely rev the 7M higher. To make use of that power, cams, and some mild porting will work well.

Stock 7M redlines at 6250-6500rpm depending on year, and at that speed, you're likely to blow a hole in the block.

Stock 1JZ redlines at 7200rpm, however you can take it up to 8k (or even higher) on the stock bottom end if you stiffen up the valve springs

Stock 2JZ revs to 6500ish IIRC, however that too is stable up close to 8k too. (I rev mine to 7500)

As for wiring differences between the 1JZ and 2JZ, whoever told you there is "too much" wiring is on crack. The harnesses between the two motors are very similar. The ONLY thing the 2JZ has that the 1JZ doesn't is a few more VSVs for the sequential setup, and that is completely contained within the engine harness, so it's just a few more wires to extend, nothing to splice into the body. There's also the traction control on the 2JZ if your 1JZ didn't come with it, so there's a speed sensor for that. (3-4 wires)

If you're thinking about swapping a 1JZ, do yourself a favor, save up a few hundred more bucks, and go 2JZ. The 1JZ does have torque, just not off the line. You're going to gain a boat load more low-end with the 2JZ, and you're going to really want the extra displacement to spool that monster.

[Keros]

As I've come to understand, most people (it would seem) go 1JZ so that they can say they kicked people's ass with a 2.5L engine... which, honestly, when you're battling against big V8's, is a real kick in the balls for guys with 5.7-8L V8's. Long story short: for the fun of doing so much with so little.

The 2JZ is literally better in every way, but the 1JZ is unquestionably solid... except for Rob... his 1JZ hated him :p

The other reason is cost... the 1JZ is marginably cheaper than a 2JZ swap.

Honestly, if you're having trouble deciding, just buy a 7M someone else has built and put it in. The 7M isn't nearly as bad as many people make it out to be.

Doing a JZ swap is a big undertaking... dropping in a new 7M is alot easier and cheaper. The numbers people put down with built 7M's are nothing to scoff at.

[Supra_Newfie]

The 7M isn't nearly as bad as many people make it out to be.


Unless your name is Jim!

:)

Grant

[NecroCyde]

the horse was dead 5 years ago, put your damn sticks away already, lol

please dear sir do some comprehensive searching and reading on your own before asking questions. the good people here have answered questions just like yours a dozenfold.

im taking this poor horse body over to ravine before anybody wacks at it again.

[Keros]

the horse was dead 5 years ago, put your damn sticks away already, lol

please dear sir do some comprehensive searching and reading on your own before asking questions. the good people here have answered questions just like yours a dozenfold.

im taking this poor horse body over to ravine before anybody wacks at it again.

QFT

It's been talked about, argued about, debated, and flamed over so many times on so many forums in so many places... it's rediculous. So I'll cover most of the bases here, for your benefit, to make it easier:

The only real answer to the question of "is it worth it", is if it's worth it to you.

We're not the one paying for it, or driving the car, or installing the motor, doing the wiring, doing the rebuild, ect, ect.

A peice of junk 2JZ straight from Japan will be as, perhaps less, reliable than any particular 1JZ, 7M, ect. As has always been said, there's a reason why it's exported out of Japan: It's their junk and they don't want it.

What happened to Jim's 7M could well have happened to any freshly built engine. Contrary to popular belief, the 2JZ is not powered by voodoo magic, it is subject to the same rules as any other engine... and many, many 2JZ's have died for the same reasons other engines die.

7M's have a bad rep because of poor headgasket torque, and poor owners. Radiators don't last forever and assuming such is bad news on a 20-24 year old 'performance' car. Then owners are shocked when they do a standing burn out and blow the headgasket... could it be, that perhaps their car wasn't up to the task?

If the 7M was so bad, why is it that I've never heard a peep out of Ryan about how horrible his is? Why didn't his rings shit the sheets, or his headgasket pop, or his engine overheat? Could it be that the 7M really is a good engine when well built? Just like many other well built and well maintained engines out there really are?

Last count for Jim's build was... what, 3500 bucks to get to pre-blown rings stage? So, that's a 3500 dollar mistake. Would spending 3500 rebuilding a 2JZ have had any less potential to blow up in such a way? Probably about the same potential. I don't know if it was Jim putting the rings in wrong, a mistake in the break in period, or what it was that caused it... but I'm going to continue to doubt that it was one of those "meh, it's a 7M, what'd you expect?" causes.

The reasons to stay 7M:

-You already have the wiring for it
-Direct bolt in
-Most torque per horsepower ratio out of any import motor that I know of
-Low revving [wait? what? An advantage? Q: Why? A: Do you really want to have to rev to 6000rpm to get some power down? Probably not. The 7M delivers good solid torque and power low down in the RPM band compared to other motors of its displacement]


Reasons to swap to 1JZ

-Marginably cheaper than a 2JZ
-OEM MHG
-High horsepower per torque rating
-very high reving

Reasons to swap to 2JZ

-No more harder to wire than a 1JZ
-OEM MHG
-About even horsepower to torque ratio, literally the middleground between the 1JZ and the 7M
-high revving

As you can see, there is no free lunch... each has their own strengths and weaknesses. The only disadvantage that the 7M has is it's oiling system, which has proven time and again to be its only major flaw... but it can be solved with some dedication and money... like all things. This flaw really only shows up at +500rwhp on healthy and well maintained motors. But run your 7M low on oil and find out how fast it can spin a bearing, at any rwhp.

At the end of the day, if you go about importing a 7M-GTE, 1JZ-GTE, or a 2JZ-GTE from Japan, with plans to make 500rwhp; you WILL have to rebuild it anyway. No ifs, ands buts, or maybes. You'll have to rebuild it if you want it to stay together. Yes, I know joe schmoe's friend in florida did 590rwhp on his imported 2J last year, who gives a shit. Do you really want to find out if you got a good JDM import or a bad one, the hard way, by having it explode?

So in reality, Jim's 3400 dollar repair bill ain't lookin so bad when you consider you'll pay that AND the cost of the JZ series engine AND the cost of all the nits and bits to put it in AND the cost to wire it up.

As far as I can figure, a 2JZ, at the MINIMUM, would cost atleast $5000 (seriously, do the numbers, and that's not any 500hp either, that's on stock twins. Add in a big single upgrade with intercooler and exhaust manifold to start talking 500rwhp)... to get the engine, put new gaskets in it, and put it in the car. Would you trust a new set of gaskets to get 500rwhp in a 2JZ? You probably could... But consider that at 500rwhp @ 18% driveline loss, that's 590-600 crank horsepower, which is 200hp per liter. That's alot. 2JZ's are known to be stout, but at those levels, you would want it to be in tip top shape. Consider that a dodge viper makes something like 60hp/L and costs 100 grand.

So, you'll want to pretty much do everything to that 2JZ that you'd have otherwise done to the 7M to rebuild it... so, did you save a dime? No, not in the slightest.

Long story short, to make a big horsepower 2JZ from the ground up, that's going to last a while and treat you well, will probably cost 10000, to have a ball bearing turbo, and the works. To have a big hp 7M, you basically do the same things, so the bill, for all intents and purposes, is about the same.

The difference in the cost of the two is that the 2JZ you have to buy the engine, a bellhousing, an oilpan, and wire it. Everything else is about the same.

Bear in mind that there's a price premium on everything related to a 2JZ due to its popularity... which doesn't help you much.

Just remember that the 2JZ was intended to superceed the 7M, so it SHOULD be better. No one should stand to debate that it isn't better in alot of ways... but the 7M still has its place in the supra world.

The 7M's bad rap comes from the idiots who own them and don't maintain them. I don't just mean checking the oil and coolant. I mean headbolt retorques, replacing/cleaning the old tired rad, having the engine underplastics in place, replaced the old thermostat, thorough coolant system flush... easy stuff that is more time than money. The majority of BHG threads I see on SM usually start with "I did a burn out in my highschool parking lot, BHG on the way home :( " Gee, I fucking wonder why his headgasket blew. 99 times in 100 the weaklink in the MkIII is the owner. The flip side of the coin is that on these 20 year old cars, the line between reliable and catastrophic failure is very thin: You didn't know there was a problem until you're scraping up peices of the headgasket.

I will also comment that many people who do crazy things to a 7M wish they had used a different motor to begin with: LS series, JZ series, UZ series, are usually umung the wishlists of engine selection. Take that for what its worth... By crazy I mean revving it to 10000rpm and driving the balls off it every day.

Honestly, I'd use Ryan's motor as the best measuring stick of the 7M's potential. Just do what he did and it should outlive you. If you want a 2JZ, get one. I'm not going to tell you to go get one, or not get one. I'll sit around and type huge long rants like this just for something to do though, lol.

Judging by your other thread, it looks like you have the parts for a solid 7M build. Unless you're really gung-ho about having a JZ series motor, I'd stick to your guns and do your research, and make sure you do your 7M build right the first time.

Good luck.

[PnOyGhost]

alright thanks for the info man. that helped alot. i think im gonna go with my 7m build.

[Piggity]

Wow, very good points to consider with any supra swap!

[JimR]

I just read this whole thread now... after I noticed I was in it. :-)

All the reasons for why my engine blew up were related to tuning. None were related to how the engine was built, or that it was a 7M. I ran too low an octane fuel (90 instead of 94) with too high an afr ratio (11.5-11.8:1 instead of 11.0:1) and I was pushing the car as hard as it will ever be pushed.... at the racetrack going balls-to-the-walls for 20 mins at a time.

I can blow up any motor you give me! Here's how I do it:
- Put in low octane fuel
- Adjust the piggyback/standalone/etc to pull air and bring up the AFR's without proper timing control.
- Put in a proper MHG, and a head range colder spark plugs, so the pistons melt first.

Whether it's a 7M, 1J, 2J, or anything else makes no difference. Nothing can withstand severe detonation for long.

The $3500 I spent on my initial bottom-up rebuild was not wasted. I'm only spending about $1000 on "true re-work". Everything else like forged pistons and a new rad are extras.

Ok that's enough about my engine! lol :-) Good luck with your build, and make sure that the important shit is clean clean clean!

[azrael]

Jim, you should start a parts cleaning business.

[JimR]

Jim, you should start a parts cleaning business.

I don't think anyone would pay me enough! lol. But I sure could use my own sonic cleaner... man that would be sweet.

[Deranged]

wow i'm glad i read this thread! Keros , your advice master 2000!

[Funkycheeze]

As a side note, I did do all the right things with my motor, but it cost over 5000 in parts alone, not counting the turbo. So if you want to turn a 7m into a swiss watch, be prepared to lay down some green. Especially if, unlike me, you need to get others to do the work.