Bringing out the dead Options

[Jeff Hail]

Bringing Out The Dead.....or how to restore a rusty 914 and convert it to a street/track car when I have time after dealing with everyone elses stuff.

My background is collision and restoration (day job) of high end automobiles for 28 years in addition to race fabrication. I jumped the fence and left that industry to pursue pretty much the same thing except on the paperwork end which is really boring and thankless. (another day job)

I look at rust like a diamond in the rough. Rust is afraid of me because it know's it cannot live in my world. Metal becomes submissive because I have confidence in my metal working talents. I will add to this post as work progress's.

I hope my years of experience can help others as I add. I believe there is a right way to repair a car and wrong way. I metal finish because in the end its cleaner, lighter and stronger. I was taught old school techniques with new school technology. A great combination. I also believe in doing a job once correctly using the highest quality materials and proper tools. Many ways to skin a cat I say. If you hold it by the tail it can still bite!

Good advice to follow:
Take measurements of the door openings and targa bar to windshield header. Cross measure then do it again to confirm. Recheck your measurements against the factory figures. Make a couple of adjustable braces for each side that attach from the upper seat belt anchors to the door hinges. I recommend cross braces also right to left. These can be made from rod or tube and turnbuckles for cheap. Racer Chris has some really nice ones with rod ends. Support the car from below equally on both sides of the undercarriage and front and rear. I do not believe jack stands can hold the proper tolerances at 4 points. It takes a minimum of 6 and preferably 8. These are all easy to do and are essential to a square and level chassis. Not everyone can afford a Cellete bench or hourly frame time at a shop for these type of do it yourself repairs. Impovisation can be done correctly and for a lot less money. Make sure your floor or platform is level.

Keep in mind that tolerances for the 914 were 7-9mm from the factory so anything you can do to make it better is worth it. 7mm by today’s standards is huge. 9mm is a Grand Canyon. Anything you can do to tighten the tolerances will provide a better end product. Exterior panels were fit with the adjust and weld method and are only a skin.

My 914 had measurements all over the place on the front end and the rust issues were all in the rear that needed correction. Car was never in any collisions.
90% of the measurements were factory assembly tolerances. Porsche's aint perfect.

I made my own dedicated bench for 911's and 914's. By some stroke of luck I ended up with a 1 mm variance in height (datum) and 2mm in length and width is zero with my own fixtures. This has been substantiated with endless anal cross measuring and factory manuals. I used a steel front suspension cross member as a front body holding fixture. I went through 4 before I found an acceptable one. The first 3 were so far off factory tolerances (4-6 mm out of square) I rejected them before I found a good one.

My bench is not for pulling. It was designed for assembly and replacement of structural parts. It will support 3,000 pounds. $350 worth of steel and another $175 in industrial castors was worth it considering its use. A stripped 914 shell is a feather and easy to roll around. When you cut and replace structural parts recheck your measurements. Control points change when you remove, replace and weld in new parts. They are easily controlled with patience.

If it does not come out perfect do not lose sleep. Remember tolerance and variance was not perfect from the factory. If you have a control point locating hole that is 14 mm a dowel or pin of 9-10mm was used during birth. That is why suspension systems are adjustable for variance and wear. You will also find center indexing points on the front and rear of the body. Easy tools to use are plumb lines, tape measures and levels if you do not have access to high end measuring equipment. You can locate and make symmetrical measurements throughout repairs. If you have one side that is undamaged or not rusted use that side as a starting point for measurements. Use panel gaps as a visual indicator during repairs and welding.

3 important factors- height, length and width. If you are me then there are 4 (Z axis) and that one will make you lose sleep!

Some pics of the beggining: A back east 914 comes to California.

[Jeff Hail]

A valid PM was sent to me by Wes in reference to metal fatigue. On my previous post I may not have been clear but I will try to explain by example.

I referred to high stress/ high flex areas and double walls.

Where the inner long come's together with the rear frame rail it was double walled by the factory highlited in red.

If I were to just weld the inner long to the rear frame rail without the double wall it would be a very flexible joint and eventually fail. This would be compounded by suspension movement and engine weight and torque. This area is where the rear center section of the tub (torque box) ties into the rear structure of the vehicle. This area needs to be as strong or stronger than the factory designed it to be.
Everytime the suspension compresses this area is subjected to load. Everytime the vehicle is launched it is subject to load.

These parts are made of 18 guage sheetmetal which is not very thick. The area where the inner long ties into the rear frame rail is subject to high flex. The load of the rear section of the unibody is partially transfered to the long connection.
The long is a straight box and then kicks up into what is known as the Hell Hole. If rust of damage occurs at this area it will or has become fatigued with use. In a worse case scenario the car will sag. First because the supporting metal in this area has disappeared and second what metal left is supporting the weight of the car and suspension loads. It give's way. This is usually observed by a tight door gap in a very bad case of rust.

The example shown with the "paper template" would reflect the double wall at this connection. The purpose of the double wall is to spread the load at the joint into a larger area. This will reduce the load carried by the long/ rail connection at the seam/ weld area only. Because the rear rail is kicked up it acts as a lever pushing up each time the suspension compress's. The second wall controls the allowed flex in this area reducing fatigue that the long/ rail joint is subjected to.

An easy understanding would be a paper clip. A large paper clip is about 18 guage or so. If you straighten it out and then bend it back and forth it will break in two. Now take 10 paper clips and do the same thing all grouped in a bundle. It will be more difficult to bend 10 bundled and the bend area is now radiused into a larger area. If the paperclip is allowed to flex in a small area versus a larger area it will take less cycles to break. The same principle with sheetmetal applies except the long is comprised of a 3 sided box speading the load into a larger area into the wheelhouse and firewall connections.

Hope this helps