Bad Timing

Bearly Flying

Bearly Flying

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Early this year I was having starter problems with My 91 ZR-1. I managed to get it out for the Meet and Greet in Ponoka in May. But shortly after that it got to the point I couldn't trust it to start.

Finally I decided to pull the starter to replace the solenoid contacts. For those of you that are not familiar with the LT5 DOHC engine in the ZR-1, the starter is located in the center of the Vee underneath all of the Air Intake Plenum.

010-3.jpg


I started tearing apart the engine on June 15th. Found the problem. (a $3.00 part)

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The ZR-1's had a few area's that could be improved upon, the intake ports were relatively small and the fuel injectors were designed before the world of ethanol fuels which would cause the mild steel pintels to rust and the cause the injector coil windings to degrade and short circuit.

Being as I already had all of that removed, I shipped Plenum and Injector Housings off to a ZR-1 Specialty Guy in Illinois to have them ported and Powder Coated. New injectors, gaskets and a S.S. bolt kit from Jerry's Gaskets.

The LT5 has a vacuum operated Secondary Throttle system that opens a set of butterfly valves in the secondary intake ports and activates the secondary fuel injectors. (16 fuel injectors in total) A common modification is to remove the secondary throttles and run all of the injectors full time. So I removed the secondary system and sent the chip out to be reprogrammed.

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All the parts and pieces showed up this summer, just in time for me to head off to work.

Finally got a bit of time off, the end of October, got busy reassembling the car.

Got everything buttoned up, looking pretty good,

IMGP3907_zps01a585f4.jpg


Fired it up, running sweet, no codes, leaks or problems.....

Opened the garage door to go for a test drive......

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It's going to be a LONG winter.... Son of a #$%@
 
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That is one sweet running engine.........to bad the weather shut US down....now WE both have something to look forward to this spring.
 
With any older, high mileage car, it pays to bite the bullet and have the starter rebuilt in the off season before it leaves you sitting. I did it with our old Chevelles and never had a problem. Those ZR1s were/are an amazing engine and could run around a high speed track all day like a race car. They have a sound all their own too. It looks like we'll have at least another week without any of that white stuff. I can wait. ;)
 
Honestly that is one cool looking motor. Too bad it could not have been a winter project but it is done now. Time get working on the snow blower.
 
Great post!...and quite a funny/sad ending. Ahhhh. Winter. Booooooo!

Glad the ZR is ready for a new season.....only 5 short moths away!.......I mean months!!!
 
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Lookin' real good Don -- well done. I would have loved to wait for a Z but this one came up and I jumped at it and glad I did.

Can't wait to hear how yours is running . I must say that's an odd place for a starter.:confused:

Roll on spring and a short winter.

Colin.
 
Colin; It is a very unique engine, it was designed by Lotus, built by Mercury Marine and was the most expensive engine GM ever had.

Shortly after it's release, a Team took a basic stock ZR-1, installed a roll cage, larger fuel tank and racing tires. Went out to Stockton Raceway in Texas, and set a bunch of Speed records. The Car AVERAGED 175 mph for 24 hrs. ( This record might have recently been broken, but there is some controversy on whether that Car was a stock production model.)

The first series of motors were rated at 375hp @ 7000 rpm. The second series had improvements mainly to the exhaust and a few tweaks to the intake system and were rated at 405 hp @ 7000 rpm.
There was a third series designed and a few test engines built that was supposed to go into the C-5 ZR-1 which was rated at 475 hp. Sadly the program was cancelled and the C-5 ZR-1 never came to be..

Some LT5's have been built up to the 600 to 700 hp range naturally aspirated, that's some serious horsepower.
 
The ZR1 made everyone take notice.......would love to ride in one once, let alone own one. As a 25 year old when they were released (and owning a Camaro), I payed close attention to all the hype. IMO, best looking forward engine GM ever made.....no tacky plastic covers to hide everything.
 
Uhmmmm, Thanks for the suggestion theboss, but I have a snowblower...

Gotta admit that has to be the first time I have seen that.
 
Bearly Flying said:
Colin; It is a very unique engine, it was designed by Lotus, built by Mercury Marine and was the most expensive engine GM ever had.

Shortly after it's release, a Team took a basic stock ZR-1, installed a roll cage, larger fuel tank and racing tires. Went out to Stockton Raceway in Texas, and set a bunch of Speed records. The Car AVERAGED 175 mph for 24 hrs. ( This record might have recently been broken, but there is some controversy on whether that Car was a stock production model.)

The first series of motors were rated at 375hp @ 7000 rpm. The second series had improvements mainly to the exhaust and a few tweaks to the intake system and were rated at 405 hp @ 7000 rpm.
There was a third series designed and a few test engines built that was supposed to go into the C-5 ZR-1 which was rated at 475 hp. Sadly the program was cancelled and the C-5 ZR-1 never came to be..

Some LT5's have been built up to the 600 to 700 hp range naturally aspirated, that's some serious horsepower.
Click to expand...

Thanks for the data on the LT-5, Don -- It's an engine I've read much about and admire a lot.........I can quite see that the almost $30k option was well worth it.
You've got quite a gem.

C.
 

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