Roscobbc
Moderator
The farmyard ZR1 has been featured by Jonny Smith's Late Brake Show - interesting, really hope they lubed-up the bores before towing in gear.......and what about the cams running dry......?
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"Barn Find" '91 C4 ZR1 on Ebay
- Thread starter Chevrolet
- Start date
Last triumph
Well-known user
Watching with interest, from the peanut gallery of regret.
Roscobbc
Moderator
Easy to regret not buying - but if that motor goes badly wrong it will potentially cost them bundles and more!
Corvetteville
CCCUK Member
Well done Autofunk
Looking forward to the next episode. Good luck, may the gods be with you!
Looking forward to the next episode. Good luck, may the gods be with you!
teamzr1
Supporting vendor
Having owned and raced starting with C3 and then early year C4s that were lucky to have 200 flywheel HP, BIG SMOG pigs
When the ZR-1 came out it was a must I own one as it was design to run at high speeds (with my tuning the ECM )
of 185 MPH non-stop in Open Road racing I did
At speeds really over 140 MPH the car got too much lift and could feel what they caused in handling at speeds
So I had two goals
1. generate more downforce
I did that with a custom front undertray
Vented lightweight clamshell hood
Custom-made side rails with more of a slant and tested in GM wind tunnel gained another 5 MPH
Fully functional and adjustable rear wing
2. Make the car lighter
The custom hood reduced front end weight
Used the rear hatch glass which weighed like 60 pounds s a mold and had a Plexiglass made to replace it
(though early high speed tests, it would flap like bird wings
Removed spare tire
Removed passenger seat was like 70 pounds
Then had Belstein make up new FX3 shocks to function well for all these changes
With all those changes,
that ZR-1 would haul ass very nicely and still drive like a cruiser on the street
With all those changes, this ZR-1 was a true racer yet ran very well on the streets
When the ZR-1 came out it was a must I own one as it was design to run at high speeds (with my tuning the ECM )
of 185 MPH non-stop in Open Road racing I did
At speeds really over 140 MPH the car got too much lift and could feel what they caused in handling at speeds
So I had two goals
1. generate more downforce
I did that with a custom front undertray
Vented lightweight clamshell hood
Custom-made side rails with more of a slant and tested in GM wind tunnel gained another 5 MPH
Fully functional and adjustable rear wing
2. Make the car lighter
The custom hood reduced front end weight
Used the rear hatch glass which weighed like 60 pounds s a mold and had a Plexiglass made to replace it
(though early high speed tests, it would flap like bird wings
Removed spare tire
Removed passenger seat was like 70 pounds
Then had Belstein make up new FX3 shocks to function well for all these changes
With all those changes,
that ZR-1 would haul ass very nicely and still drive like a cruiser on the streetWith all those changes, this ZR-1 was a true racer yet ran very well on the streets
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teamzr1
Supporting vendor
Here is a 1990 ZR-1 owner claims was stored for 17 years with only 40,000 miles on it for sale of $19,000
sfbay.craigslist.org
Looking at the photos, is spotless
1990 chevrolet corvette zr1 for sale by owner - San Jose, CA - craigslist
Hello I am selling my ZR-1 Corvette. I am the second owner. Very clean all original car, and in very good condition. Before I took possession of the car in 2021, it had been stored for 17 years....
Looking at the photos, is spotless
FelixP
Busy user
The dual mass on the ZF6 can make a knocking sound when it's tired also
Llewelyn
CCCUK Member
Hi guys! The engine isn’t knocking thank god!
I hope you’re all enjoying the content. Injectors going in on the next video
Clutch release bearing is noisy and the lifters were dry which is why it sounded thoroughly horrendous. Fingers crossed though so far we think the engine is okay.
Thanks for watching
I hope you’re all enjoying the content. Injectors going in on the next video
Clutch release bearing is noisy and the lifters were dry which is why it sounded thoroughly horrendous. Fingers crossed though so far we think the engine is okay.
Thanks for watching
teamzr1
Supporting vendor
Considering they have taken the intake manifold off/on like 3 times, they could have missed the very small, short vacuum hose that
goes to the MAP sensor at back/center of engine, near firewall
That small hose plugs into the MAP sensor and other end to the intake.
That hose is known to pop off real easy, and age of hose may prevent hose staying plugged in
There is a second MAP sensor that is used to kick in the secondaries / butterflies and other 8 fuel injectors and that vacuum hose also should be checked
Those 16 injectors due to age and then not used for many years they should have taken them off and cleaned and tested them and also made sure the O-rings are not sucking in air
Again a reason to have an OBD scanner and let the ECM tell them what is wrong, any DTCs tripped and what the engine feedback sensors are reporting
Never understood why people go through this when GM and SAE built in OBD DTCs and OBD scanning/recording functions, reporting to person doing the diagnostics what is wrong
Chevrolet
CCCUK Member
No, Thank you! I am full of admiration for you two young guys. Well done!Thanks for watching
As you might have seen on the CCCUK Facebook page, Tom Falconer said that (back in the day) "At least a dozens went through his hands…. Great to sell and warranty because of the bullet-proof DOHC engine."
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Corvetteville
CCCUK Member
Excellent stuff, doing a grand job.
CaptainK
CCCUK Member
Sure am thanks. And love the friendly banter during the work too. Impressed its all being done on a driveway too.
Llewelyn
CCCUK Member
Thanks guys!! Really glad you're enjoying being a fly on the wall while we tinker and try to resurrect this very interesting car.
Re Team ZR1 comments
Our take on the diags side of things is as follows
The car has been sat for 18 years - Therefore EVERYTHING must be renewed:
Fuel system - Pumps, strainers, lines (probably), filter, injectors
Air/vac - Air filter, most likely all or most of the lines and diaphragm actuators, electric vacuum pump, air reservoir if leaking etc
Spark - plugs, leads, ignition coils
Then engine - Fluids, filters, coolant flush, belts, thermostat, tensioners, rollers, water pump probably
Other - Alternator/charging circuit checked
etc etc
Until we're at this point (which we will be, so stay tuned for updates ) our opinion on trying to diagnose via OBD is that it is completely pointless because you won't get any meaningful data when it hasn't been running for ages. I've actually (off camera) pulled the codes and they are basically meaningless at this point in time. The car needs to be brought to a base level of functionality before any kind of informed diagnostics can be carried out.
Next episode we've got 16 shiny new injectors going in and hopefully that will make it run much more smoothly. Off camera by the way the fuel filter has already been changed but you'll see that on Sunday as well !
We could have taken the plenum off once and renewed everything in one go, but where's the fun in that!
I don't claim to be an expert mechanic or Corvette savant, I'm just an enthusiast with a bit of practical knowledge and I'm trying to do the majority of work myself (ourselves, we jointly own it). We're filming it so people can watch and join in our journey and we're always open to advice or guidance!
Re Team ZR1 comments
Our take on the diags side of things is as follows
The car has been sat for 18 years - Therefore EVERYTHING must be renewed:
Fuel system - Pumps, strainers, lines (probably), filter, injectors
Air/vac - Air filter, most likely all or most of the lines and diaphragm actuators, electric vacuum pump, air reservoir if leaking etc
Spark - plugs, leads, ignition coils
Then engine - Fluids, filters, coolant flush, belts, thermostat, tensioners, rollers, water pump probably
Other - Alternator/charging circuit checked
etc etc
Until we're at this point (which we will be, so stay tuned for updates
) our opinion on trying to diagnose via OBD is that it is completely pointless because you won't get any meaningful data when it hasn't been running for ages. I've actually (off camera) pulled the codes and they are basically meaningless at this point in time. The car needs to be brought to a base level of functionality before any kind of informed diagnostics can be carried out.Next episode we've got 16 shiny new injectors going in and hopefully that will make it run much more smoothly. Off camera by the way the fuel filter has already been changed but you'll see that on Sunday as well !
We could have taken the plenum off once and renewed everything in one go, but where's the fun in that!
I don't claim to be an expert mechanic or Corvette savant, I'm just an enthusiast with a bit of practical knowledge and I'm trying to do the majority of work myself (ourselves, we jointly own it). We're filming it so people can watch and join in our journey and we're always open to advice or guidance!
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Chevrolet
CCCUK Member
Like your "Can Do"/"Go for it" attitude with that car
Just to say, "back in the day" as Ross mentioned already mentioned on the Facebook page, the UKs #1 C4 ZR1 expert was Geoff Jeal. He worked on them/tuned them, and was a development engineer at Lotus on the ZR1.https://www.linkedin.com/in/geoff-jeal-9403494/details/experience/
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