Original L81 engine pic's..

[Peer81]

Cheat, cheat!??
I call it an upgrade! :gap

Greetings Peter

 

[VetteV8]

A "product enhancement"
Cor

 

[GerryLP]

You are welcomed, Peter!

That is quite a Vette following there. Is there a dealership at home that has been importing them and since when?

 

[Peer81]

Gerry Sorry I forgot to answer your question.
Very few Corvette's are export models and have been delivered from GM to a Dutch dealer. Most of them are bought in the States and shipped overhere. New models C6 I think also the C5 back then were sold by dealers but as this is a very small country it's not a car that sells very fast. Other things, when you import a Corvette directly to Holland you need to change the rear bumper so it can fit a big licenseplate, orange turnsignal lights etc etc. When you detour and import to Germany and make it road legal there no such thing is needed, then you drive to Holland and our goverment says "If it's oke in Germany than it's also oke overhere" so you have to keep the original bumper and taillights (only have to add a red fog light somewhere).

I fitted the 4 channel amplifier in the passenger compartment behind the seat, fits like it was ment to be
Its a second hand handmade Genesis amplifier, English brand.

To make a nice enclosure for the speakers wasn't that easy. I bought a set Focal 165 Kr2. The big speaker needs about 10 liters with a close enclosure, I don't have 10 liters but this it the make I could give but in the test run it sounds very nice and it sound like the bass is amplified by the rear compartment space. The cut out on top of the enclosure is for the screen so it can funtion without any problem. In front of the enclosure you see some grey waterproof carton. It's very dificult to fill the space between the speaker enclosure and the sides surrounding it, but with some extra foam it will be oke. The enclosures will also be carpet black and that will finish this interior.

Other things I did.
Rebuild the carb ones again with the proper epoxy, now need to redo the testing again, but that isn't a punishment really
Changed the u-joint bolts. I had 3 different types and I really like the socket head bolts to changed all of them into zink treated bolts.
Changed the thermostat from 195F to 180F, also changed the acc. fan switch from original 2 connector to a new 1 connector with lower temp to match the 180F thermostat.
My alternator one day choose to put 18v on the system insteat of the normal 14.4v. Smoke from under the centerconsole and dash. Nothing worked after that. Big story short, checked everything, no real problems only a fried alarm sensor and by that a shortage in the alarm system. Solved all that and now everything is back to normal.

Still need to let the painter do some small things I and he forgot.
Recharge the airco with R12.
Rebalance and line the wheels and suspension.
And most important.. drive drive drive!

Greetings Peter

 

[GerryLP]

Gerry Sorry I forgot to answer your question. ....Rebuild the carb ones again with the proper epoxy, now need to redo the testing again, but that isn't a punishment really Changed the u-joint bolts. I had 3 different types and I really like the socket head bolts to changed all of them into zink treated bolts.....And most important.. drive drive drive! Greetings Peter

Peter, it is "oke" About the carb...do you remember when I posted how well she was running (and she still ran rough after hot and shut off and restarted in relatively short time) giving 20 MPG? Well, After resealing the primary wells, she ran terrible. It may be a coincidence, but she began running as if a couple of sparkplugs were fouled (and I mean same day). For more than I tried, she would not tune right. After, spending close to 3 weekends, she was still running as if there was a mjor air leak. Out of desperation, I used WD-40 directly into the airhorn, and she smoothed out instantly and purring beautifully. After a while, she would roughn up again. It is acting as if perhaps in between the cover and body there were a crack. Mind you, not engine check light or codes. It is weird indeed. I may have to install the alternate carb until I find the problem with this one. GerryLP

 

[Yoda]

Gerry,

Could it possibly be the carb gasket spay the base of the carb and see what happens

You probably already have, and I'm just show how senile I am getting

Bud

 

[Peer81]

All I can remember is thinking, why do I buy al those gizmos and take everything apart for like 4 times and Gerry's runs just perfect the way it is! It's ashame she doesn't anymore.
Is your dwell meter also indicating a lean condition? THen covering the choke valve with your hand should have the same effect as adding WD40. Like Bud says a vacuum leak would be the most common problem but tracing it can be a time consuming thing. Normally what I do is connect a vacuum meter to the vacuum line that goes to the air cleaner so you don't have to plug it. Then disconnect all the vacuum lines at the carb one by one and either plug them or put your finger on them to hear and see if there is any difference. Then the carb base is always a good one, I experienced the carb "settled" some more or I didn't tighten the bolts in the first place.... but I could give them some extra to almost one extra turn each. And off course an invisible leak would be the EGR valve not fully closing anymore. I made a metal plate that fits over the EGR hole on the intake to check this but it wasn't the problem in my case. You can look if the throttle body is cracked around the throttle valve openings (sides) and if the throttle valves fully when assembled (view from underside). Well that should be about it I think.
Good luck with the hide and seak game.. :ugh

Greetings Peter

 

[GerryLP]

Gerry,Could it possibly be the carb gasket spay the base of the carb and see what happens You probably already have, and I'm just show how senile I am getting Bud

Sprayed two cans worth, Bud. All other areas are fine. Even placing my hand over the throttle horn does not help.

 

[GerryLP]

All I can remember is thinking, why do I buy al those gizmos and take everything apart for like 4 times and Gerry's runs just perfect the way it is! It's ashame she doesn't anymore.Is your dwell meter also indicating a lean condition? THen covering the choke valve with your hand should have the same effect as adding WD40. Like Bud says a vacuum leak would be the most common problem but tracing it can be a time consuming thing. Normally what I do is connect a vacuum meter to the vacuum line that goes to the air cleaner so you don't have to plug it. Then disconnect all the vacuum lines at the carb one by one and either plug them or put your finger on them to hear and see if there is any difference. Then the carb base is always a good one, I experienced the carb "settled" some more or I didn't tighten the bolts in the first place.... but I could give them some extra to almost one extra turn each. And off course an invisible leak would be the EGR valve not fully closing anymore. I made a metal plate that fits over the EGR hole on the intake to check this but it wasn't the problem in my case. You can look if the throttle body is cracked around the throttle valve openings (sides) and if the throttle valves fully when assembled (view from underside). Well that should be about it I think.Good luck with the hide and seak game.. :ughGreetings Peter

Peter,

Other than restarting her after a good heat soak, she ran fine. When I lifted the carb off the intake, I could tell where the primary wells were dripping because on the intake side on the spot directly below the primary wells was clean (no soot), but everywhere else, had a bit of soot or dirt. I remember thinking that it would be a bit of trying to fix something that I could live with, but didn't expect for her to be running so badly.

When she was running smoothly, I had applied some black RTV sealant on both sides of the base gasket. And so I did the same again, even though this makes you buy a new gasket everytime you remove the carb. But for the performance, I thought this a necessity. Over the previous 3 weekends I have tried several checks, and she still runs rough. I even looked at the pcv valve as a culprit, but it is not sticking. It could be that it is not sealing (crud between the seat and the valve), so I will replace it just the same. I will also do some house keeping like ohm'ing the sparkplug wires and checking the spark plugs.

Finally, I'll remove the valve covers and see if a pushed is off its rocker position (this would cause the miss), but this would be a long shot, since I do not rev her engine very high. I'll keep you all posted.

GerryLP:cool

 

[GerryLP]

Well, after adding all of the time for that other work, I decided to swap the carb straight. And guess what, she is back to running much better. The carb got rid of the problems. Took her for a 15 minute drive and runs much better, although not quite like when I drove her to that round about to Los Alamos. I'll have to tune her a bit more. GerryLP:cool I

 

[Peer81]

Good to hear you got her up and running.
The thing that pops my mind is, is the new airhorn gasket the same as the previous one? Could be the gasket is mismatched or misses some openings. But to be honest, if your missing or have partly closed vacuum openings the carb would be running ritcher not leaner.

Greetings Peter

 

[Peer81]

Had some time yesterday to play around with the vette.
First I wanted to know how many km I can drive with the fuel light on, as it wasn't on jet I had a paper and pen with me to write down the number and 5 liters fuel to add when the tank was fully empty. Thing is I became suspicious when the fuel gauge was reading past empty and still no light. Took the dashcompartment out and tought the fuel light, and there was the light.... hmmm, experiment failed. I put the 5 liters in the tank drove to the nearest station and put in an extra 73 liters. And if I remember correctly it's a 90liter tank but I never got more in then 80 with an empty tank. So next time when the light comes on, i drive to the nearest station, fill her up and then I also know how much is still in there.

Next thing, I connected the dwell meter (I always drive around with my dual AF ratio meter). As the AF meter was reading between 15 and 16:1 (14.7:1 being perfect) a little on the lean side. I was surpriced to see the dwell meter was idling around 35 degrees (slightly rich condition). The thing is, my wide band O2 sensor is sending a immitated narrow band signal to the ECM which the dwell meter picks up, so it's all from the same sensor. I'm thinking is the ECM really looking for a 14.7:1 mixture or a leaner but safe mixture like 16:1?

As I didn't form a good new seat for the accelerator pump discharge ball the car hessitates on acceleration, so that is what I'm going to look into next

I also setup the sound system, it as a stunning good sound if I ever get tired from the true duals :L

Greetings Peter

 

[Peer81]

Here another small update as the last one is over 4 months ago.
Small things done in the mean time.
Started with finishing the interior. The carpender finished the carpet, I'm very happy with it also because the space behind the door is properly finished.

On the German ebay I found a nice professional ultrasonic cleaner (Emag 50HC). But when I begone cleaning parts the thing stopped working, send it back to the factory. They repaired the thing, but when I had it back it broke down within a few minutes. As it is a second hand model I send it to somebody in the Netherlands to look at it (sending it to Germany is a 30 euro singel trip)

But when I had it it was working great.

My low fuel light (see other topic) was not working perfect and Cor knew a way to buy the correct transistors for me (Thanks Cor )
So off to work.

Changing them isn't a big problem if you have a soldergun and a steady hand

After changing it the problem I have now is that the 10 second delay between the signal wire and the light is gone, so the light is blinking when the fuel is around the low fuel level. I also found it weird that the low fuel light isn't lighting up at startup (as the other lights) so I put an extra condensor between the signal and ground wire so the light will burn for a few seconds till the condensator is full.

Next thing was the cruise control. I didn't open it when I had the change because I couldn't find a good service manual on the net (service manual is a little theoretical on this part) but a few months ago a found a manual made by Theo Law. He was willing to send me the manual by email which is great so I could start taking the thing apart. Ones open and when you understand how it works it isn't that difficult.

Cleaning is straight forward and not that difficult. As my cc was hunting the correct speed up and down I thought the problem was in the vacuumregulator. It turned out it wasn't. The magnatic disc is running on front and back in two small bushings. The rear bushing is fine but the other bushing is almost gone. You can see clearly the wear on the disc.

Problem is that the "axle" on the disc has a 0.97mm width but the bushing opening is 2.5mm wide! That also explains the wear on the disc. Lucky for me my uncle thinks he can make a new bushing with a 3mm width diameter and a 1mm opening.

And this week I took out the old dubble xenon project. Some years ago I bought a Alfa 159 headlight. Some bi-xenon projectors from a BMW E46 to combine it in some way into the corvette headlight. It isn't going to be a fixed headlight so I may run into some trouble when the assembly is in the down position but that is for later. Now I need to position the projectors in the headlight assembly just right. Needs to be level as the projector has a cut off shield, I still need to find a way to adjust the lights without shims but I have no idea how to do that. I also bought some bezels that will fill the space between the projector lens and the Alfa tube.
As the Alfa tubes aren't the same size the small one is on the inside and the bigger one on the outside. If it fits I still need to make my own shroud to finish around the Alfa tubes (as original). As the Alfa tubes are smaller als the original lights the assemblies will not go up as high as original but more horizontal.

And some detailed pictures how the bezels are in the Alfa tubes. The bezels were much wider then this but they didn't fit the tubes so I also cut them down. The tubes are also wider at the rear then on the front so the bezels will fit almost perfectly. Then again, with the xenon lights on I don't think you'll ever see the bezel but oke

Tomorrow I have more time to continue this project

That's it for now,

Greetings Peter

 

[GerryLP]

Thanks Peter for the update.

My Vette's CC is also acting up. I havenot had time to mess with, but what it does is not engage as designed. I had found an NOS turn signal lever on eBay, and I swapped out the original for
it, but still not engaging. The curious thing is that I can set it by pushing the button at the end
of the lever, and then press the brake pedal and after hit resume, and it will engage.

So that is why I have not invested the time to correct it, but if you figure a few troubleshooting
steps, then I am all ears, brotha.

GerryLP:cool

 

[VetteV8]

Gerry, what you describe is almost exactly what I have [as Peter already knows ]
Sometimes all works as designed, sometimes not; in that case my procedure to get it to work is as follows:
Try to set the speed with the 'set' button, nothing happens, then slide the 'resume' button and hey, there it accelerates back to the speed I pressed the setbutton in the first place!

Perhaps this should be made a separate topic, as we are now 'jacking' Peters topic somewhat.
But anything you find would be very interesting.
Cor

 

[alexdrastico]

Peer's work

Hi Peer i'm Sandro from Italy, precisely Sardinian island, i want to say that you're doing a great job on your Vette!!!! Thanks for all pic's that show us your details.

 

[Peer81]

Thanks Sandro, great to see somebody in Italy with a 81!

As for Cor's and Gerry's CC problem.
A small explination about the CC system. As the car is running the speedo cable turns a magnetic wheel inside the CC (it is connected to the speedo cable) opposite to the magnetic wheel is the brass wheel turning at the speed of the magnetic wheel. The brass wheel is not turning but fixed to a spring. So in conjunction with your speed the brass wheel is tilted some degrees.

From the engine is a vacuum line connected to the CC system. Inside the CC the vacuumline is connected to a tube which endes inside the CC. At the end of the tube are openings inside the tube (so the vacuumtube is connect to outside air. On the tube is a slider, this slider can expose more or less air openings to the vacuumtube (raising and lowering the Hg's vacuum inside the tube. I hope it is still clean up to this point. Now connecting the dots, the brass spring loaded wheel is placed inside the slider. So when the spring is turned on harder the slider slides to the "right" covering more of the vacuum ports so the vacuum inside the tube is higher.

But this is all happening when the CC system is inoperative. Now when you hit the CC botton the solenoid under the slider is activated and moves up, fixing the slider in place. This is how the CC system can maintain the same speed, as the CC system is moving up is it covering or uncovering another vacuumopening but I forgot what is is for...

The only thing that is missing in Mr Law's writeup is the resume botton as it wasn't present on pre 81 Corvette's.
As there are and vacuumlines going to the resume part and a electrical plug it should work as a vacuumcanister? I don't know and haven't looked into my service manual.


But now thinking logically. When the CC activate botton isn't working but the resume botton does and the car is speeding up or down to the preset speed. So this is telling me that the solenoid is working as the slider is fixed at the correct spot as the CC is (after hitting the resume botton) showing the correct speed. I think when you find out how the resume botton works you have the problem

Greetings Peter

 

[Tom Bryant]

It's too bad that you are having trouble with your ultrasonic cleaner. It looks like the perfect thing for cleaning those small parts.

Tom

 

[Peer81]

It should be perfect for cleaning small parts, I hope to get an answer this week if it can be fixed.

Greetings Peter

 

[c3sleeper]

Flwheel

Just on a curious note im restoring a 1981 also and was wondering what size of flywheel they have?