max76

Hi guys, Happy New Year at all!!!!!

I have a question for you.
In Italy said that the Lt5 engine from '90 to 94 isn't a good engine.That aftre 45000miles have big problem on valves and cammes...Now, someone of you have a stock lt5 with this problems?
It's true or false that the Lt5 is a delicate engine?
Thanks
Max

DRM500RUBYZR-1

False !!!

rhipsher

All LT5's are virtually indestructible. They were built for high RPM long distance racing. My 90 ZR-1 has 79,000 on it. And when I drag race it or road race it I beat the hell out of it. And the next day take the top off and go for a nice easy cruise with the wife. You will brake clutches and U-joints but not the engine. Even most of the Zo6 crowd will admit if they had to bet their life on which engine would run at top speed for 24 hours strait without having a melt down they would bet on the LT5.

LT5corsa

100% false!


I'm unsure how many Z's are in Italy, but I know of 30 Z's in Spain and each one of them say great things with TONS of miles!

ZRWON

Right you are!!! The ZR-1 Registry site has a list of of ZR-1 owners who have more then 100,000 miles on their ZR-1's with no motor rebuilds or 100,000+ miles since the rebuild. I'm sure that list of over 30 owners is only a small fraction of the ZR-1s exceeding 100K milles. My name is not on that list but the '90 LT5 in my BEAST2 was "kinda" rebuilt at 92K miles but not because it had problems and needed to be rebuilt. The late Doug Johnson, the owner, just wanted Jim VanDorn (Pirate Racing) to tweak it with his Automasters Street Skinner package increasing it to 391rw hsp; 1/4 mile times of 12:26 @ 119 mph; 1.96, 60 ft time "just because" like many other ZR-1 owners. Check my home page (in my signature) and the links on it for the full story about JVD, the Black Widow, Doug and my BEAST2.

bb62

Do you have an article with this assertion/information or is this just someone's opinion with whom you had a conversation?

The LT5 could very well be the MOST durable engine ever built for automotive applications. It was built by Mercury Marine which mostly builts marine application engines that are required to have added durability (much like aero applications).

Are you aware of the high speed records set in the early 1990s in Texas where stock LT5s (pulled straight off the assembly line) powered ZR-1s to world records for 24 hours/5000 mile events (and others) averaging around 175MPH over the distance.

Do you know of any ZR-1 owners in Italy?

94ZR1

False

Lotus had some developmental problems with it and those rumors persist to this day
The LT5 could go 450,000 miles if maintained properly
45,000 is just broken in
Any minor problems with these cars were addressed a long time ago
I would rather have an LT-5 than an LT-1 or an LT-4
70,000 on the 94 to the left and it is stronger than the day it was born and at 7000 rpm it sounds as good as a v-12 Ferrari

BTW there is a great book about these cars called "Heart of the Beast"
I have read it about 12 times and it will tell you everything you need to know

Now if you want to talk about durability lets talk about the Fiat 850 spider, the 124 Spider, the X-19 and the Alfa Spider I had
(Actually the Alfa was pretty reliable)

94ZR1

I bet they wouldnt

bb62

I'm sure that would cause a firestorm in the C6 (and C5) forums.

Goldcylon

False without a doubt

max76

Thank's for all the answers...i'm very happy to listen that my lt5 is longer durable!!!
This notice is born accidentally during a discussion for an lt5 sales.
A person said that at the technical meeting ncrs they have explain that the motors lt5 are delicate and that to 45000miles they have serious problems.
I have read the records of lt5 and i'm very happy for that!!!
So, now, after your answer i'm very happy to have a zr1 in my garage with only 18000miles!!
I don't know how many Zr1 there are in Italy, i only know that are few.
Bye

DRM500RUBYZR-1

IF that was a tech judge, perhaps he sat on his little flashlight or extend a mirror while it was positioned wrong, or maybe he sniffed a little too much original air from an original tire.
Forget those fears.
ENJOY your car!!!
You will not hurt it!

Marty
1FUNZR1

max76

Sure...i think the same things!!!
This car is for me a long dream..i was 15 years old(now i'm 32) when for the first time i see a corvette and i said: a day i'll buy it...
I have been so luky to find a Zr1 in perfect conditions and i love it, it's a dream of a life and i'm so happy to have realized it...
Thank you so much guys...

I ask you a things...what I can make in order to improve the cooling of the motor? To replace the thermostat?

FU

Hi Max,
A 160 thermostat WITH a reprogramed chip will help the cooling and performance. The LT5's uaually tend to run warm.

A good LT5 ZR1 site is http://www.zr1netregistry.com/forum/index.php
Come over and introduce yourself.

zr1fred

Quote:
This notice is born accidentally during a discussion for an lt5 sales.
A person said that at the technical meeting ncrs they have explain that the motors lt5 are delicate and that to 45000miles they have serious problems.

The guy who said that is full of (what's the Italian word for cow manure?) One of the dumber things I've heard lately, and lately I've heard quite a bunch of dumb things! The engine is probably the most reliable vette engine to date.

npritchard11

I just rolled 71k today and I've never had motor troubles. I burned out the primary and secondary fuel pumps by running the tank dry. The float got stuck and indicated half tank at nearly 300 miles on the trip odometer - my bad, should have noticed that but I wasn't driving it too much at the time. The heater core busted. The plastic/nylon gears in the headlamp motors gave out and had to be replaced. A few vacuum leaks here and there. BUT, never a problem with the motor itself. Most of the other stuff comes from the poor care the car had before I got it.

-Nate

FICINJECTORS

False False False. We have a guy on Lake Lanier in Ga that put a LT5 in his boat. I put injectors in this motor last winter. I can tell you that it was a stock 90 and he beats the pi$$ out of this all summer long. The lake is 30 miles long and we have run this thing on 93 octane, e85, c16.. The thing never quits and has jury rigged everthing. Actually its pretty neat. This thing is at WOT most of the time and has held it there for sometimes 30 min to 45 mins without letting off. He blew a few reg small blocks prior to this LT5 but the engine in my opinion is the Best engine ever put in a GM car.

93RubyZ

False! The LT-5 is what makes the ZR-1 special. GM couldn't afford the public relations disaster that would've happened if the car they intended to beat the world's best and was selling for as much as $100k in 1990 had a delicate engine. So they made sure it was very durable. The LT-5 is one of the best auto engines ever built.

As mentioned, go find a copy of Heart of the Beast. You'll love your ZR-1 even more.

willyszr1

i have 2 zr1s my 90 has 160k and i drag race it every other week it has run a best of 1.77 @ 120.54 mph . we did a leakdown test on it 4 days ago and the worst cylinder had 4% leak down . not too bad for an old gal

willyszr1

opps forgot my glasses again et best is 11.77 not the typo. sorry