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Posts posted by davidjonh

  1. I just wanted to provide an update in case it might help others with similar issues. I want to thank both Dan Booth and Jim Turner for their help provided in identifying the parts and for future solutions. As it turns out I sent pictures to Dan and he indicated that the bracket and rotor I have are basically the original 1985 design. Dan indicated it was normal for the pads to sit above the rotor edge and that after approximately 30,000 miles this resulted in some Avantis pulling to the left or the right as the overhang of the worn pad would rub on the top of the rotor. To solve this he would taper the top edge of the pad so as the pad wears there is no overhang produced. He also indicated that if I could bend the bracket back to within about 0.010 to 0.020 inch I might be able to keep the brake from locking up. I did my best with what I had in my garage and bent the bracket back and tapered the top of the pads. So far the brake is not locking up and it seems my problem has been solved for now.

    Considering the extra weight in the front of my electric Avanti and the lack of compression to slow down an electric vehicle, a long term solution in my case is to install the Turner brake system with larger rotors and pads that contact more of the rotor surface area. As Jim and a lot of others have pointed out to me, the original design with the pad edge sitting above the rotor edge seems a little strange but again apparently it is normal.

    Thanks again to everyone for your help, especially Roland Vardon for pointing me in the right direction. I now have about 50 electric miles on the Avanti but now have another problem with the drive train as I snapped a one inch adapter shaft which was keeping the Corvette rear end from lifting under acceleration.

    Dave Heacock

  2. Thanks again. The original rotors and calipers, or what was on the Avanti when I got it, were in such bad shape I tossed them a number of years ago. The new calipers don't have any names on them and I am assuming they are just a replacement part. I found my original receipt and the number on it corresponded to what you can find on the net for an 85 Avanti.

    Your are absolutely correct, and I had never thought about it, the fronts are at 4 1/2 for a Ford. I remember that when I was redoing the rear brakes on the 84 Corvette rear end that the bolt pattern was different so I either needed to change the hub bolt pattern or the rim.

    Been talking to another great Avanti guy and looking more at the Turner kit and it seems that the turner kit has a double thickness in the center area where the bracket would be the most likely to bend or twist. Since a picture may help explain what I now have I'm going to try to include a few. From looking at the Turner brackets I'm wondering if I could use these brackets with the components I now have with my 15 inch rims. Otherwise, if things bend again I might try to re-enforce the center section of the bracket.







  3. Thanks for the response. I probably would have considered the Turner kit but when I was repairing these things probably three years ago I was unaware of most things about Avantis. I'm not sure what was originally on the car when I got it except I do know that the wheel rims are Ford with a Ford bolt pattern (actually a Lincoln Towncar rim). I'm thinking the bracket holding the caliper is original. While 11.5 inch rotors have been mentioned to me recently after this problem developed I'm also pretty sure the extra inch in diameter would not fit into the existing bracket--an 11 inch rotor might just fit but I have no idea if one is made for my application. I purchased the rotors from a place in Sacramento which deals almost completely in brakes and clutch components and thought they would know the size of the rotor for my application. However, I can't remember if I took the original rotors in, which might have been the wrong rotor, and asked to replace them.

    Is there a way to determine if these are the original Dunlop/Bendix designed brakes? Being an 85 I thought they were GM parts. I looked on the net for the number which was on the receipt for the caliper and it did seem to match a 1985 Avanti.

    Thanks again, Dave

  4. I have finally been able to drive my electric Avanti with a total mileage of about 30 miles so far. However, I just discovered that I had the front left brake hanging up. During my rebuilding of things I had replaced the rotors, calipers, pads and brake lines. After taking the brake components apart I discovered that the bracket to which the caliper is mounted was bent and slightly twisted. I can't be sure if I just didn't notice this when I was redoing everything or if this happened while I have been recently test driving the car. What does appear a little strange is that the pads on both sides sit about 1/4 inch above the top of the rotor. What I am now wondering is are the rotors the wrong size. They measure 10 1/2 inches. Thinking back a long time ago I seem to remember that the wear pattern on the old pads showed the pads wearing such that those pads must have also been just a little higher than the rotor. I would appreciate any comments.


  5. The question came up about the light weight of the Avanti fiberglass body. Several years ago I had my '87 Avanti weighed; adjusting for driver and fuel the dry weight was 3294 lbs. The heaviest dry weight listing that I could find for the '87 Monte Carlo SS that is used for the frame and chassis is 3239 lbs. So my Avanti weights 50 lbs. MORE than the steel bodied Monte Carlo. <_<

    The question I have is what is the Dry weight of a '63 Avanti to a similarly equipped '63 Lark?

    I'm not sure I can be of much help but as I have been building my electric Avanti I have tried to make some weight measurements. I was just about to have it weighed again a few weeks ago when an electrical issue placed things on hold.

    I have a 1985 coupe which I had weighed when I first got it. It had a 305 Chevy in it, less than 1/4 tank of gas and the measured weight was around 3457 pounds without the driver. This was done on a truck scale and I don't know how accurate they are.

    I took the body off the frame and after I had a rolling frame with a 250 pound motor and probably another 50 pounds for the transmission I had it weighed on the same scales again. At that point it weighed 1180 pounds but it had a 1984 Corvette rear end installed with a modified frame but it was basically the same X frame used by the first Avantis.

    I then put the body back on the frame and used individual wheel scales to get an estimated weight and it was now 2405 pounds. The body had all the glass in, doors on with hood and trunk lid. So I guess the difference between 1180 and 2405 might be the fiberglass body weight.

    As I said I'm not sure how much help that is.


  6. Thanks Gene, Wow sounds like you are going to have one really great Avanti. The pictures of the transmission being put in remind me of the day we took the engine and transmission out of mine. All I could think of was look at all the oil and grease and that transmission sure looks big. How much horsepower does the Cadillac V6 have--seems like a nice combination.

    I sure hope the inside of the tank is okay. I found the inline wire mesh filter on my bench--should I send it to you? I can probably put it in a small bubble pack.

    Look for another update in the next week on the electric Avanti. I'm building the battery box right now that is just forward of where your transmission is going in. Thinking of drilling out the three holes on each side where the engine mounts went and threading the holes for larger bolts so I can remove the box any time I need to rather than welding it to the frame.

    Best Regards, Dave

  7. "The car is on jack stands, the fender to wheel gap will be reduced when on the ground."

    Gene, I kind of like the five spoke rims you have in the picture with the fender showing. Who makes these and do they make them in a 15 inch rim? Something for my future to do list. How are things going on the Avanti--I just went back to the web site to drool over the stainless frame and suspension.


  8. Again according to John Hull's book "Three "factory" AVX automobiles were built. The coupe and T-top models were built on Pontiac Firebird chassis with the convertible built on a Chevrolet Camaro chassis." I don't have any idea what "factory" means. But the story here was really interesting and the pictures of the cars are really great--sure would love to have the money to buy one if they were still made. If these were made today as an electric vehicle with even a 100 mile range and quick recharge capacity, it sure seems they might sell very well.

  9. I have a 1985 Avanti that I am converting to an electric vehicle. I am almost ready to place the frame, with the new drive train, back under the body. In order to save weight and eliminate any unnecessary drain on the battery pack, I want to remove the current power steering and convert it back to a manual steering set-up. Since I will be able to balance the weight on the front and rear axles and since I have installed low rolling resistance tires I think the conversion back to manual steering will be acceptable from a driving standpoint. I have heard the steering box for a manual set-up is different than the power steering unit and I'm not even sure if I can get an older unit. Is it possible to keep the current linkage but remove the hoses, pump and cylinder?

    Any thoughts on what I might do?


  10. Gene, your name is on the tank. How do I get it to you? I remember reading something about how to clean it out but not sure where I read it. I would assume that it would need to be shipped by truck, maybe yellow freight or ???

    Getting back to the original issue about the rivets vs the adhesive for strength. Did you get an answer? I installed the fiberglass frame mounting piece today and some how things sort of got out of hand. I think it all turned out in the end okay but the adhesive set up a lot faster than when I did it the other day. I guess it was a lot warmer and I may have added too much hardener. I'm sort of wondering the same thing about the rivets but I plan to leave them anyway. Some how the passenger door actually works now and all I can figure is that the outer panels were sagging some and I had to put upward pressure on the outside bottom edge of the piece to get it to go back where the old one was, which was basically broken in half vertically.


  11. Yes I do have the gas tank and I would like to give it to a new home. I think I looked into shipping it before but can't exactly remember how to do it since it is a gas tank. I also have the original rear end I would like to give to a new home if anyone is interested.

    I was just trying to upload a picture but since the single upload size is 500k I have a problem since all my photos are slightly larger that that. Any idea as to how I can make them smaller in size? I'm using a Mac so that might be an issue.


  12. "The rivets in question are circled in red. Are these rivets a structural part of the fiberglass mount, or were they just used to secure the fiberglass mount to the body until the resin cured? In other words, can these rivets now be removed with out any loss in structural integrity?"

    Your progress with the stainless frame and the Avanti is starting to look great. I don't really have a direct answer for you but in preparation for repairing my 85 I needed to replace the passenger side dash reinforcement and hold down, sort of like the ones you show. I contacted Dan Booth at Nostalgic Motor Cars and he was able to send me a new fiberglass piece along with the panel adhesive used to secure it. From his description of how to replace the fiberglass section it sounded like it was important to make sure I used the correct adhesive and did the job correctly. I would think he would know the answer to your question if anyone does. Even though I got the piece and the adhesive some time ago, I am just now about to replace it.

    Last time I saw my frame, yesterday, it was in the air on a hoist, 90 degrees to the ground. I hope to have a rolling frame soon with the Corvette rear end installed.


  13. Can anyone recommend any good books, products etc. on fiberglass body repair?

    Jim Wood

    Jim, I know basically nothing about fiberglass but somewhere I read about the company Fibre Glast. I have talked to these people and they seemed very knowledgeable. I ordered some material but haven't had a chance to try it yet. You should find some good stuff on their web site www.fibreglast.com or you can talk to them at 800-330-6368. Hope this helps.


  14. Gene & Jim, these are some very interesting numbers that are very helpful. When I first weighted my 85 Avanti it weighted 3500 pounds with almost no gas in the tank and no bodies inside. My goal for the finished car is 4000 pounds or less. I was hoping I could remove maybe 1000 pounds and if so the car less engine, drive train, exhaust system, gas tank, coolant system and some other gas components would weigh 2500 pounds? So if the frame weighs 300-400 pounds, which doesn't seem unreasonable, then that heavy body with glass, doors, seats, dash, wheels and suspension weighs 2100?

    When I get the rolling frame together I will let everyone know what the weight is along with some pictures.

    Again, thanks for the information.


  15. Gene, The reason I am asking is that weight is my enemy when it comes to building my electric Avanti. My project has taken much longer than I had expected but solid progress has been made. I am within one week of finishing all the repair & repaint work I can do on the bare frame, the Corvette rear end is completed, the front end suspension should be completed within maybe 30 days, motor / transmission combination has been completed and I have the adaptors for mounting the Corvette rear end to the frame.

    Thinking ahead I need to keep the weight of the rolling frame and body combination to a minimum. I have weighted many components like the rear end, wheels, and front suspension but I have no way to weigh the frame or the body. Once I get the rolling frame I can take it to a local scale to have it weighed and then place the body on it and re-weigh it.

    A long range goal would be to replace the steel frame, if possible, with an aluminum frame if the weight reduction would be significant. Are you saying the aluminum I-beams you have could be used to replace the X-member in the steel frame and if so, any guess how much weight would be saved? My contact with Peter over a month ago indicated his existing frame may be toast so he may need to replace the complete frame if he converts his Avanti.

    Unfortunately I already have purchased stainless torque boxes and one side has been fitted. But again, long term, I might want to restore another Avanti and having another option would be great, especially the time savings issue.

    If you are interested I have some web pages which are slowly being added to:



  16. Gene, got back from our trip and have talked to Peter about his Avanti project. I guess his frame needs a lot of work. He was mentioning that maybe you have built aluminum frames for the Avanti? Weight is critical for my project but for right now I will be going with the original X frame until I get the car on the road. Depending on performance and of course money, I will make changes as I go.

    Read your article in the Avanti magazine and it was really great. Nice to see who I have been talking to as you have been very helpful. Great description of your project with some very interesting pictures. I have been wondering about the weight of the stainless frame vs the original and I see from the article that it is about 100 pounds less but much stronger. Peter was estimating that the original frame weighs about 900 pounds. Does that sound about right?


  17. I was able to get in touch with Peter who is interested in building an electric Avanti. We are currently on the road and internet access is hit or miss so when we get back we will be talking. Should be interesting.

    On the Corvette rear end I want to use coil overs rather than the fiber spring so I can pick the coils after I can figure the final weight of the vehicle. Since I have never done any of this before I'm sort of going by what others have talked about. The tie rods(?), I think we are talking about the same thing, can be modified so they attach from the bottom rather than over the top--again I haven't done this yet and and all my paper work is at home so I'm just trying to remember some of this.

    I have been thinking of cutting out the spare tire well and making a square hole so I can install batteries which can be placed lower than the bottom of the well but no lower than say where the exhaust was to begin with. This will help balance the weight front and rear and lower the center of gravity of the car.

    If I remember correctly the wheel to wheel mounting surface is about 65 or 66 inches? I have had the half shafts shortened but nothing is back together yet. I need to go back and see what we are talking about clearance of knuckles and cover mount? but I think I have looked into this and it should be okay.

    You have been lots of help. I'm thinking once I get the rolling frame I will place it under the body and slowly lower it to see where I need to make the cuts. Does that sound like a plan?


  18. This really looks nice and the completed car should be great. With my modification to my 85 by installing the Corvette rear end I have been wondering how much of a modification I need to make at the rear end. Did you have to make any other cuts in the rear within the passenger area or was the only cut necessary the removal of the spare tire well removal? By removing the spare tire well does this have any effect on the overall strength or stability of the body? Any pictures of the underside of the body attachment points?

    Looks great, Dave

  19. [quote 'grobb284'

    Enjoyed speaking with you on the phone yesterday. I hope you found some of the answers to your questions useful. Sent you an email today with more information on narrowing the Corvette independent rear suspension. Call again if you think it would be helpful.

    I did find our discussion on the phone very helpful and I sent a reply to your email last night. I picked up the rear end and parts today after getting them cleaned. I am now at the point where I need to decide how I will get this rear end modified and into the Avanti frame. I like the idea of having one source for modifying the rear end and possibily making the necessary components for mounting the rear end into the Avanti frame.

    Thanks, Dave

  20. quote grobb284'

    Would suggest drilling the hubs and rotors. Provides a factory style solution without "add-ons", and keeps the halfshafts and cambers bars longer. We can drill them for you if you wish.

    Grobb, thanks for the information, who would I contact to drill the rotors and hubs? I have found some new hubs at a slightly more reasonable price so I think I am going to buy the new hubs and have them drilled rather than taking a chance on using the old ones because I just don't know how good the bearings are.


  21. Well I started looking back at the information I have been gathering on the C4 Corvette rear ends and find that I have conflicting information about the width. I even found an article which indicated the earlier models, 84-87 measure 61-1/2 but other information says 62-1/2. So I decided to put the pieces back together as best I could, not exactly knowing what I was doing, and Grobb is correct, it measures 62-1/2 inches. So I guess you have to be careful about what you read in writing.

    I also talked to Flat Out Engineering and discovered that another Avanti owner was just sent one of their kits for a standard width of 57 inches, which I if used in my case with the current wheels and re-drilled hubs and rotors will put the wheels within 1/4 inch of what they originally were. So I am not the first in using their kit. Modifications will probably be needed for some of the kit components or the frame but this looks like a pretty good solution.

    The problem now is do I use wheel adaptors, aluminum or steel, or do I try to have the hubs and rotors redrilled to the new pattern? I have been calling around and it is hard to find anyone who will redrill the hubs and rotors and some people say use wheel adapters and others say no way. Anyone know how you clean up the aluminum components of the C4?

    Moving forward, often confused, Dave

  22. Yes the 84 Corvette rear end has sealed bearing assemblies and they are at 4-3/4 rather than the standard Ford 4.5 inches. My rims are something like 6 or 6.5 and are not really deep like some of the newer rims. From what I understand they are off a Lincoln Town car and somehow got on the Avanti.

    The frame on my 85 is the old Lark frame, again from what I can understand and looks in pictures just like the standard X frame from the earlier Avantis. I thought that 85 was the last year they used this frame. I understand the rake is in the body with the use of the spacers and as my Avanti sits level I can understand why there are lots of spacers in the front to raise the front back up to the level position and eliminate the rake. I have been told by Corvette shops that the 84-87 Corvette rear ends are 61.5 inches and the later ones are at 62.5 inches. I picked up the rear end when it was apart so I first need to get the wheels mounted and then put it back together and take some measurements. If it is actually 61.5 inches I would need to narrow it by about 1-3/4 inches per side which may cause some concern about the way the wheels contact the ground. Adding wheel adapters results in narrowing each side by an extra inch but also pushes the wheels out that same inch so it would seem that wheel contact with the ground would be about the same.

    I'm not sure what the "C4 cast brace" is unless it is the "wing" which really can't be narrowed without a lot of modifications. I have been working with Flat Out Engineering in Orange CA and while it is possible to narrow the Corvette rear end, you have to be careful of components hitting each other and how the wing and other components are mounted. Flat Out makes very nice kits for installing the Corvette rear ends but this is the first time they are thinking of working with the Avanti frame which is different than the older trucks and such. Again, I need to get the rear end back together first to make some measurements but before I do that I have to get the wheels on, sort of like a catch 22. It would seem that if you narrow the rear end slightly and then lower it in the center the wheels will sit flat but that is something I need to work out.

    The conversation here is really helpful and hopefully as things progress I can get this figured out. Flat Out suggested I place the Corvette rear end under the frame and make the half shafts level and then place the frame at the standard ride height to make the other measurements. Thus my quest for ride height position.

    Thanks all, Dave

  23. Tom, that link is really interesting and a great help. I started looking back at all my information and found some interesting things. First my measurements for all three wheels, through the centerline of each wheel were 27-1/4 inches to the wheel well which is pretty much what others are showing. The funny thing is that on the front right side it was 26-3/4 and maybe I now know why. The wing on the radiator bracket which supports the front of the body was broken completely off on the right side and the fiberglass mounting piece on the firewall was almost cracked all the way around it, again on the right side of the car. Maybe that is where the 1/2 inch lower figure came in for the right front of the car.

    I went out and measured the vertical distance from the top of the rear center frame support and the front leaf spring eye bolt hole (which in my case is the lower hole at the rear of the large bracket) and found it to be about 1 inch lower than the rear center frame support. If I assume I back calculated the distance from the ground to the top of the rear center frame support, the leaf spring eye bolt hole would be approximatey 9-3/4 above the ground. That is at least in the same general area as your dimension of 9-3/8. Of course my tires are 195/65 R15 and measure a little over 25 inches in diameter and the frame is not sitting level on the engine stands so I have to "adjust" my measurements. It looks like the X-member is about 4-5 inches off the ground from the link you gave me so I can see where mine will be once I get the frame off the engine stands.

    I plan to remove the rear leaf spring on the Corvette rear end and install Aldan shocks and coils so I should be able to adjust some heights later. I want to put the rake back in the car and with what I am doing I should be able to remove most of the spacers in the front. In order to use my current rims and my new tires I did some more checking today and it seems like I can either use wheel adapters for about $100 or have the hub and rotors redrilled for maybe $300-$400. Problem is, if I redrill the hub and find out later the bearings in these sealed units are bad, I would not only need to buy new hubs/bearings at $180 each but also have to have the hubs redrilled. Talk about one thing leads to another.

    Your results using the add-a-leaf are indeed interesting.

    Thanks, Dave

  24. Tom, thanks, you are probablyl correct that it is going to vary between cars and condition. My 85 has 15 inch tires so I'm sure that can make a difference. When I back calculated the height at the top of the center mounting bracket that is attached to the rear bar I came up with 10-3/4 inches but the body is up in the air about three feet on saw horses and is not level. I discovered that makes a difference when you are trying to measure from the wheel well. My system for lifting the body is a very slow process which I ony want to do one more time when I lower it down on the frame The problem is that I what to install the Corvette rear before I roll the frame back under the body because I know some modifications may be needed to the trunk area.

    From what I can remember and some pictures the rear leaf springs seemed to be mostly flat before I took the body off and the drive train out. I have some pictures of an 85 from an Ebay sale of a vehicle that was in like new condition and it looked like the springs were also flat.

    Thanks again. Dave

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