Blowing up the 1uz-fe

[jibbby]

Wayne great info....420Rwhp and running 8:20's is very impressive on a stock 2UZ...that may be a first...Too bad she gave way...

Let's see, now we have 420rwhp on 2UZ, tuned and failed, 400rwhp on a IUZ.. tuned and did not fail......Peewee mentuned 450rwhp and tuned to perfection..Ok I think we are getting a little closer to some solid facts...

I am now starting to think just maybe the 1UZ-FE motors at stock can probably handle somewhere in the 425rwhp range safetly but well tuned is a must from all the info I have compiled on all the forums...Would anyone disagree with this?

Also now that Wayne has spoken another weak part of the stock internals on the 1uz.. that should be concided as being weak is the cranks even though the two engine differ a bit...and not only the rods and pistons....Thanks again Wayne.....

 

[rytherwr]

I didn't mean to give the impression the crank of the 2uz was a problem. That is the one area that I am proud of....even with all the broken pieces flying around inside the block, the stock 2 bolt main caps and the crank remained unscathed with the exception of a little scarring on the counterweights. The crank is forged in the 2uz and I suspect it might also be forged in the 1uz....if so, it's a pretty hardy piece.

Wayne

 

[jibbby]

Ryther---Ok, so when your rods failed you think that may have caused the domino effect damage to the crank and block...It was your rods failing and not your crank and or pistons under the excessive power...Is that correct?

 

[rytherwr]

Correct....from what I can see, the rods failed (when you look at a 2uz rod, you will see why) and started a chain reaction that killed the rest of the engine. Again, crank is forged and nothing happened to it, save some scratches on the counterweights. 2 bolt mains held up as well.

Wayne

 

[Lextreme II]

Wayne,

The two bolt main is very strong already. Imagine the 4 bolt main you are doing for your project. WOW...WOW...

 

[jibbby]

Great posts, RDM. Here's the major issue I can see with the early 1uz rods. The shank of the bolt is .0050 less than 1/4 inch. That's not stout enough to handle big HP for long. The good news is that the threaded portion of is very nearly 3/8 inch, so a replacement ARP 2000 or L19 bolt will increase the overall performance of the early 1uz rod.

Eric

Cowboy, I heard the same thing mentioned else where before your posting...That shank bolt you mention connecting the rod infact is most likely the weakest part of the entire stock 1uz-fe's motors... That is the point were engine failure is most likely to occure....With that being said and with your experience what would be your best guess on what kind of power those 1/4 shank bolts can hold before breaking and sending the piston and rod flying in every direction and destroying the cylinder walls and block......That is probably a hard question to answer, maybe you can you give me comparisons of any sort...I think this will be my final focal point to these engines....Thanks fellas.....

 

[rytherwr]

David,

You are exactly right! After seeing what the two-bolt will take, I feel VERY comfortable with the bottom end, especially with the forged crank, larger main studs and L-19 rod bolts, and the H-beam forged rods under the Ross pistons. Plan on taking it to the edge....:veryhappy :veryhappy :veryhappy

 

[jibbby]

Hey Jibby, When my piston failed at 370, it was because of a lean condition. And the 370RWHP was maxing out the fuel system. Only 1 piston melted. the other 7 looked perfect.

The 1UZ rods are simular to the Supra 7M-GTE rods.
I have seen the stock 7M-GTE rods make 550RWHP & 30PSI. )quote


Apparently the 1uz-fe rods are fairly stout.. The raw heat created when the engine ran lean on you just melted the piston down and the rods were never compromised because of raw force and flex...

Doing a little Xuz-fe rod research here...

 

[JustenGT8]

Let's see, now we have 420rwhp on 2UZ, tuned and failed, 400rwhp on a IUZ.. tuned and did not fail......Peewee mentuned 450rwhp and tuned to perfection..Ok I think we are getting a little closer to some solid facts...

I am now starting to think just maybe the 1UZ-FE motors at stock can probably handle somewhere in the 425rwhp range safetly but well tuned is a must from all the info I have compiled on all the forums...Would anyone disagree with this?

I'm running over 500rwhp on stock internals Jibbby....not sure how long it's gonna last and reluctant to run at the track at that hp as thermal loads would get nasty quick but have run at the curcuit quite a few times with 430+rwhp no probs.

 

[cribbj]

Justen, what sort of cooling system are you running when you do circuit racing?

Circuit racing is so much more demanding of the cooling system, 'cause the engine is being asked to put out lots of power almost continuously, rather than quick blasts followed by fairly long cooling off periods, like we do on the street and strip.

Julian Edgar made the comparison between an automotive radiator and a heat sump or heat sink a few years ago, and he was right on the money with that.

I'd be curious to know about your radiator, fan(s), pump(s)? And what sort of temps you see?

 

[JustenGT8]

Hey cribbj,
I run twin thermos (12 inch from memory) on full time, a larger frontal area 40mm all alloy rad with dimpled core. Extensive ducting and shrouding to make sure all air goes thru the FMIC and rad. I also run WI as you know. Another little trick is redline water wetter...dropped my coolant temps approx 5 deg C.

Inlet temps stay at just over 30 deg C. Coolant temps never pass 90 deg C. Not sure what oil temp does but i suspect it does get a bit too hot so i only run full synth and do an oil change before each track day. I have a SERC oil cooler but have never got around to fitting....should pull my finger out

While i drive hard i also try and conserve the car so always warm up lap and build up to speed. On our local track only 5-6 hot laps then cool down and park for a while to shed heat soak.

I reckon 1 track km is worth 100 street km

 

[jibbby]

Justen - That's impressive that you have put out 500whp on a completely stock 1uz-fe motor... I am aware that the 1uz-fe motors are capable of making 500whp on a dyno with proper tuning as I posted that previous quote many moons ago.. However at 500whp you must be testing those stock pistons to fullest...

What's the torque rating that you made on that same motor if you don't mind me kindly asking? I've got my 1uz-fe up around 500 ft pounds of torque... Wondering if yours put out more? The high torque numbers is what really started breaking stuff on my car and not really the whp numbers...

 

[JustenGT8]

Jibbby,
Torque and power are directly related so if you have a plot of one you can calc the other.....power = torque x rpm/5250 ie at 5250rpm they are equal. You can't really get torque from a rolling road dyno as it's only measuring tractive effort. Having said that my rough back calcs show i'd have in the region of 680ftlbs at the flywheel so i'd smoke you mate

 

[jibbby]

This is rather an older thread, but there are some key points in this thread as to what the 1uz's can handle... It maybe worth a read for some of you new guys to the forum...This was my earlier effort to see the true stoutness of these motors..

Check it... From what I have seen in five years of toying with these motors and the forums the stock early model 92-94 1uz-fe motors can handle anywhere from 400-500whp with a good tune for a long period duration... I can personally vouge that these stock motors can handle a steady 500 ft pounds of torque for years and years...My guess is the stock 1uz...probably can handle even more... My motor still humms and I am still looking for ways to increase power.....

The stock Soarer/SC400/LS400 trannies are a different story.... Expect failure and untimely shifts around 400whp and or 500 torque..

Cheers people......:alcoholic:

 

[Fr_3_aK]

So long as you feel it's worth bumping this thread for new guys:

At what RPM are you making the 400-500 rwHP?

I know in Australia you can get the rev limiter changed to 7500 or 8000 RPM.
http://www.planetsoarer.com/ecu/ecu.htm

Just wondering if anyone has personally tested the "limit" in RPM terms. I ask because im keen to mod my SC400 to 455rwHP and 8000 RPM with stock internals. 1UZFE's seem cheap enough anyway to experiment.

 

[jibbby]

I make 300whp and slightly over 500 foot pounds of torque under the nitrous...


The torque numbers are a good indication that the 1uz-fe motor can handle 500whp from my personal experience.....

 

[Fr_3_aK]

Maybe i should rephrase the question:

With 400-500 rwHP @ 8000rpm how long would you expect the stock internals to last? This is assuming the tune is perfect and nothing else goes wrong etc etc

Anyone know?

 

[JustenGT8]

I make peak hp around 5500rpm (a little earlier actually but can't be bothered to dredge up the dyno sheet ).

rpm is what kills engines and while mine will rev to 7000rpm, there's no point and i rarely take it above 6500rpm. Get the right diff ratio and it's no issue

 

[LondonBenji]

I'm still pondering whether or not I could safely run a completely stock 1UZ (bar fueling and electronics) at 500bhp at the rear wheels and drive it like I do and on a track without busting it......

 

[jibbby]

I think you can run 500bhp...Just tune it right, don't go too lean or mess up the timing and you should have no problem... I have ran 500 torque for two years on stock internals, my 1uz still purs like new...That is nitrous blasts too... These motors are alot stouter then most people think...

Don't sweat it LondonBenji....