ZR1 Problems?

Zektor · 03-05-03, 01:24 PM

Hi Guys,
Just how tough is the ZR1 engine. What are the most common things to go wrong with them etc.???

Cheers
Dazza

Justin_cv87 · 03-05-03, 01:33 PM

The ZR1 engine is the LT5, and i dont know from experence, but i heard that it could go 24 hours at high RPMs. why someone would want to drive for 24 hours at high RPM's is beyond me, but i would think an engine is pretty tough to do that!

JT ZR-Won · 03-05-03, 01:43 PM

Quote:

Originally posted by Justin_cv87
The ZR1 engine is the LT5, and i dont know from experence, but i heard that it could go 24 hours at high RPMs. why someone would want to drive for 24 hours at high RPM's is beyond me, but i would think an engine is pretty tough to do that!

That is true. It was originally tested at Wide Open Throttle for 24 hours with no leaks or problems before it was able to be officially in production.

The engine itself can take a beating. There aren't any "common" problems that go wrong that I know of. The usual things that might happen are common C4 things that happen on all the Vettes. I've heard many people refer to the LT5 as "bulletproof". I'm a firm believer because I've definately hammered on my LT5 more than once and it seems to want more.

Jay

Jeffvette · 03-05-03, 01:46 PM

Very tough.

Common problems, look at any other typical C4 and you'll find them.

I think the worse is the constant using of tires and the grin you will have on your face while driving.

JT ZR-Won · 03-05-03, 01:57 PM

Quote:

Originally posted by Jeffvette
...... and the grin you will have on your face while driving.

True. My cheeks are a little sore now that you mention it

Jay

carter200 · 03-05-03, 02:53 PM

[QUOTE My cheeks are a little sore now that you mention it[/quote]

Aaron71771 · 03-06-03, 07:33 PM

During development, the early LT5 had to survie 200hours alternating between max horsepower and max torque in 5 minute intervals. For 93-95 engines it was bumped to 400 hours. That's 16 days at max output !!! very impressive. The biggest problem with ZR-1's is they are too much fun to drive.

vettl83 · 03-09-03, 12:31 PM

I agree with Jeffvette, the biggest problem I have is the 3 or 4 to 1 tire replacement ratio of rears over fronts. 31,000 miles on the clock, only failure had to replace the antenna mast kit and front air deflector 29.00 and 60.00. 84 CF 91 ZR-1

ArtZR1991 · 03-09-03, 06:15 PM

quote:

but i heard that it could go 24 hours at high RPMs. why someone would want to drive for 24 hours at high RPM's is beyond me, but i would think an engine is pretty tough to do that!

Close quote

The LT5 was built from day one in the tradition of a very high speed endurance racer/grand tourer, much in the European context. As many probably know, it was introduced in Europe to the press and the public as a production car.

The endurance qualities of the engine are what enabled it to set the world endurance speed records in 1990. It held the records for about 12 years, and is still the only production car to ever hold the records. In the strict Corvette tradition of a "street fighter", it was a somewhat misunderstood engine, though it is quite fast. But as a high speed road car, it is fabulous, and I have followed it on several forums for many years, and the occurance of any internal or LT5 specific failures is incredibly rare. IMHO, the engine is really bullet proof.

Personally, and I have had a few cars in my day, it is the most enjoyable engine-car combination I have ever had. I mean this strictly from a driver's perspective.

In fact, I have become so convinced that I have developed several fixes for the C4 issues (road noise, body flex and noise, lack of chassis stiffness) that I will be finished with on my car this summer, which will (assuming they work), will extend the life of the car, and make it a really fine 2 seat touring car.

I am documenting my fixes thoroughly, so that do it yourselfers can apply them to their cars. Some of the (minor, very easy to do in an hour) hood related improvements have already been published, and at the other extreme, I will offer a kit that can be installed in two days (4 hours work spread over two days), that will completely eliminate top off chassis looseness, yet require no maintenance, and removal and re-installation when the top is removed and re-installed. So far, the design makes the car competitive with a C5 targa top car. The remaining issues involve the designing of a kit that has enough effectiveness, but is still easy to install by a typical Corvette owner.

Wow, I got off the subject... No, actually, though the improvements will work on any C4, the LT5 is such a wonderful engine that it started the thought processes about improving the car.

Sorry for the long comment, but the ZR1 and the C4 Corvette are wonderful performance bargins, and with some special, well engineered tweaks aimed specifically at their faults, you could have the world class performance bargin of all time. A modified ZR1 can sit in the very finest European and Japanese company, and make its owner proud.

Boy what a rant... But it's true.

Regards..

PS_ I hope to have all of my improvements documented, proven and published, by the end of the summer.

BiZ · 04-10-03, 08:09 PM

My Z has 104k miles on it. I have put the last 22k on it. I don't know what was replaced prior to my ownership. But in the last 22k miles I have replaced the water pump, power steering pump, battery, and secondary vacuum hoses. Pretty much things that just wear out.

One thing about the LT5 is that it will eat accessory equipment when run into the 7KRPM range frequently. Most of that stuff can't handle the high RPM for sustained periods of time.

phrogs · 04-12-03, 01:26 PM

The only problems I have head are, water pump, actually all the accesories are subject to problems due to there nature but I have only seen the water pumps, the motor itself the head gasket, lifters, injectors, then the vacum system.

but mechanicaly it is a unbelieveable engine
the big things Ive seen have been due to nitrous an exploded plenum on one guys car had an explosion in there!

but really I wouldnt worry about the engine.
I have been looking for a car with a motor that is destressed so I can build it up and I can find one!!

johnny

secondchance · 04-13-03, 10:42 AM

Quote:

Originally posted by Justin_cv87
The ZR1 engine is the LT5, and i dont know from experence, but i heard that it could go 24 hours at high RPMs. why someone would want to drive for 24 hours at high RPM's is beyond me, but i would think an engine is pretty tough to do that!

24 hr endurance was done by GM to prove that the LT-5 not only produce prodigious hp and torque but could do so for extended amount of time. Only way to achieve this endurance is through minimizing reciprocating mass (OHC set up) and quality control during the manufacturing. Note that not all DOHC motors are capable of 7000+ rpm.