65 fi

I have seen a few restomods where the LT5 ZR1 engine is being used. Seems like an interesting idea but weren't the LT5's considered problematic? What were the weak points? Are there cam options to bring the horsepower and torque up?

tjschraf

The LT5 is a very reliable engine, I recommend looking up zr1netregisry.net

lots of information on that.

Also, there are plenty of very knowledgeable guys on these motors.

jim lockwood

My memory is that the pre-production LT5 engines had some oiling issues.

The production engines, though, have a reputation for being bulletproof.

Jim

cv67

You will never ever have to touch the engine and can hammer on it the whole time. Former owner-they really are that durable. I took very good care of mine mechanically but worked it hard! Sold it with 142k to a buddy its close to 180k and still runs strong passes smog etc.

Weak spots are the original injectors-if the secondary system is working right you are good to go. They use thier own vacuum pump to operate.

Cams are a waste on a stock displacement LT5.
port the intake, injector housings, headers retune (look up Corey Henderson or Mark Haibeck for tunes). Easy 400+- rwhp that idles like a kitten and rips. Doing the heads can get you more...Leave the bottom end alone. Just happen to know someone who ports these

z06scentair

As stated these motors are very reliable. The LT5 has got to be the best looking motor ever put in a corvette. Hell I leave the hood up on my car majority of the time just so I can walk by and look at it.

As far as more HP and Torque are concerned.....I would consider it pretty close to the LS6 in the C5 Z06. It doesn't have the bottom end torque that LS motors have, but mid to top end power is AMAZING in stock form.

65 fi

Seems this may be an interesting option. Would increasing the displacement and going with more radical cams help the low end?

perry mitchell

Not a Corvette but one of the cars in my stable.
www.lateral-g.net/members/mitchell

65 fi

Wow! Beautiful job! Did you modify the engine?

dhutton

I have been contemplating the same thing for my 66 coupe but I am struggling with the cost versus resale value versus performance compared to an LS3. I am not sure it wins out in any of those, just uniqueness factor it comes out ahead.

Don

perry mitchell

Just the addition of the scratch built long tube headers. The stock horsepower rating was 405.

65 fi

My concerns as well. FYI, I have read and heard many positive comments about the LT5. There was some original concerns about the engines that have been clarified as early engine issues which were resolved before the production manufactured engines. I investigated using a R07 but cost and durability were enough to squash that idea. The other engine options I have considered are the LS3, 427 Z06 engine, and new LT1 engine. I like the idea of a high rev engine but am a little concerned about "old technology" and a cast aluminum block. Nelson racing has a billet block overhead cam engine but 55k.
The LT5 just looks so good and I suppose the LS engines are basic to the GM engines of the 1950s?

65 fi

Perry, given the opportunity, would you go with an used engine or unused crate engine?

perry mitchell

My LT5 motor came out of a wrecked ZR1 with less than 25,000 miles. I knew the original owner and how the car was treated up until the day he sold it. It was wrecked later that night. If I were to do it again, I would by a new crate LT5 motor since you can find them for 10 to 12K. They are the most beautiful and exotic motor Chevrolet, or anybody else for that matter, has ever produced.

Vette Daddy

My 91 stock bottom LT5 has approx 530 hp. We added cams. This thing is a monster. I've had Big Blocks, SB's. Nothing beats the feel and sound of an LT5, IMO.

Beautiful engines that will go beyond 200k miles and will still take abuse.

GreaseMonkey

The LT-5s are crazy nuts. They do not like to sit still while running, but love running when the temp is up. Honest to God, when mine is running right, and the outside temp is pushing 100 degrees, the beyatch is unbelievable. The actual tone of the engine changes to like "let me loose".

Sitting in traffic is another story. In 2002, my ZR-1 was a Celebrity pick at Corvettes at Carlisle. 95 degrees outside and we were car 76 out of 100. What a beyatch. Everything was hot; starter, air, everything. Not a fun time.

I know the engine in the actual ZR-1 has many computers attached/controlling things. Not sure if that just taking the enigine and brain for the engine eleviates that issue. I had a damn door switch go bad and the car thought someone was stealing it and went into shutdown mode

cv67

Maybe the RO7 is out of reach have you considered an SB2.2? Parts are reasonable big block like valve covers and HUGE power!
There are two different intakes youll want the shorter one not sure if hood clearance would still be an issue or not
Using a Dart block with the larger bore could really take advantage of the heads capabilities...add as much stroke as you can get in that puppy add a hyd roller cam. Drive anywhere and smoke just ab out anything in your path!

65 fi

Is it possible to use a LS computer and coil packs with the LT5? Can the computer be programmed to have all the injectors come on together?
This may be a question for the C4 section but there are some very knowledgeable people here.

z06scentair

There are a couple of people working on this setup now......but its not a done deal yet.

65 fi

I would love to know more. Are there any manufactures that would be worth getting in touch with?

cv67

Would google Corey Henderson or Mark Haibeck they will have the answers you need.

Remembe the LT5 has a second set of injectors the pc has to drive not sure the LSx computer would deal with that. Some guys say they use a FAST system but I know nothing about the intricasies of them personally.